经腹联合经阴道彩超在评估凶险型前置胎盘合并胎盘植入中的应用价值

本文对经腹联合经阴道彩超在评估凶险型前置胎盘(PPP)合并胎盘植入中的应用价值进行了探讨。选取我院2017年6月~2019年6月PPP患者172例,所有患者均给予经腹彩超、经阴道彩超检查,以产后病理结果为对照,分析经腹彩超、经阴道彩超,以及二者联合,对PPP合并胎盘植入的评估价值。产后病理结果显示,172例PPP患者中,有合并胎盘植入患者120例(69.77%)、无合并胎盘植入患者52例(30.23%)。对PPP合并胎盘植入的敏感度、特异度、准确度进行评估,结果显示,经腹彩超其值分别为76.67%、73.08%、75.58%,经阴道彩超分别为83.33%、80.77%、82.56%,经腹联合经阴道彩超则分别为96.67%、96.15%、96.51%,二者联合明显高于经腹彩超、经阴道彩超,差异有统计学意义(P<0.05)。证实经腹、经阴道彩超是评估PPP合并胎盘植入的有效检查方法,且二者联合的评估价值更高,值得临床推广。     

经直肠超声联合前列腺特异抗原密度诊断前列腺癌的临床应用价值研究

为探讨经直肠超声与前列腺特异抗原密度(PSAD)联合检查诊断前列腺癌的临床应用价值,选取本院2013年9月~2018年9月期间内接收的97例血清前列腺特异性抗原(PSA)患者实施研究。所有患者均行经直肠超声与前列腺特异抗原密度(PSAD)联合检查,并与手术病理结果进行对比。观察PSAD检查结果,分析经直肠超声与PSAD联合检查的诊断符合率,并对比病理结果与经直肠超声和PSAD联合检查的准确率、灵敏性、特异性情况,分析前列腺癌患者经直肠超声检查的影像学特征及内部回声情况。与病理结果对比,经直肠超声与PSAD联合检查对前列腺癌、移行细胞癌、黏液腺癌检出率均稍低(P>0.05);经直肠超声与PSAD联合检查的准确率、灵敏性、特异性较病理检查均稍低(P>0.05)。经直肠超声检查后根据图像表现可将疾病分为弥漫性、结节型、无结节型3型,不同类型的影像学特征及内部回声情况表现不同,表明经直肠超声与PSAD联合诊断前列腺癌准确性较高,并且可清晰地对不同疾病类型的内部回声作出反映,临床实用价值较高,值得加以推广。     

高危良性前列腺增生的术式探讨

目的探讨经尿道前列腺剜除术与经尿道双极等离子前列腺电切术治疗高危良性前列腺增生的临床疗效。方法选取高危良性前列腺增生患者86例,随机分为实验组和对照组,两组患者分别应用经尿道前列腺剜除术、经尿道双极等离子前列腺电切术治疗,对比两组患者的手术效果。结果两组患者的临床疗效及不良反应均无明显差异(P>0.05),但实验组患者的手术时间、膀胱冲洗时间及住院时间均短于对照组,术中出血量少于对照组,差异有统计学意义(P<0.01)。结论经尿道前列腺剜除术与经尿道双极等离子前列腺电切术治疗高危良性前列腺增生均安全有效,但经尿道前列腺剜除术的手术时间、膀胱冲洗时间及住院时间更短,术中出血量更少。     

盐酸左布诺洛尔的合成工艺改进

以回收的盐酸左布诺洛尔废料为原料,经NaOH碱化,HBr水解得5-羟基-α-萘满酮(2);2经醚化、氨化、用右旋酒石酸拆分得到盐酸左布诺洛尔,其结构经1H NMR和IR确证。2的回收率90%,总收率80.6%。     

2-噻吩乙酸的合成

以噻吩为原料,经乙酰基反应、氧化重排生成2-噻吩乙酸甲酯(2),2经水解得2-噻吩乙酸(3),总收率53．0％,其结构经IR和^1H NMR确证。     

合成双醋瑞因的新方法

以芦荟素为原料,经脱苷、氧化反应得到大黄酸(4);4经三氟甲磺酸锌催化的乙酰化反应合成了双醋瑞因,总收率86.2%,其结构经1H NMR,IR和MS确证。     

R-兰索拉唑的合成新方法

2-氯甲基-3-甲基-4-（2,2,2-三氟乙氧基）吡啶盐酸盐和2-巯基苯并咪唑经缩合反应得到兰索拉唑硫醚;以L-亮氨酸经结构修饰得到的二齿手性氨基醇为催化剂、叔丁基过氧化氢为氧化剂,不对称氧化兰索拉唑硫醚得到R-兰索拉唑粗品。经分离纯化得到产物,e.e.值99.5%,两步反应总收率43.3%。产物经IR、MS、^1H-NMR、手性HPLC确证。     

2-氯烟酸绿色合成工艺

以烟酸为原料,经双氧水氧化制得N-氧化烟酸（2）; 2经氯化、水解并精制得2-氯烟酸,总收率76.8%,纯度≥99.5%,其结构经¹H NMR和¹³C NMR确证。     

1-氨基-2-(2'-甲基-4'-丙酸甲酯)苯氧基-4-羟基蒽醌的合成

邻甲苯酚与丙烯腈经Friedel-Crafts反应得到了2-甲基-4-β-氰基乙基苯酚,其与1-氨基-2-溴-4-羟基蒽醌经亲核取代形成的产物经水解、酯化得到目标化合物。给出了该化合物及其中间体的质谱、核磁共振氢谱、元素分析、可见光谱及熔点等数据。     

胞嘧啶的合成工艺改进

以氰乙酸乙酯、尿素、原甲酸三乙酯为原料,经缩合、环化和水解反应合成了5-羧基胞嘧啶(6);6经催化脱羧合成了胞嘧啶,总收率65.7%,其结构经1H NMR和ESI-MS确证。     

On the structure of amorphous calcium carbonate--a detailed study by solid-state NMR spectroscopy

The calcium carbonate phases calcite, aragonite, vaterite, monohydrocalcite (calcium carbonate monohydrate), and ikaite (calcium carbonate hexahydrate) were studied by solid-state NMR spectroscopy ( (1)H and (13)C). Further model compounds were sodium hydrogencarbonate, potassium hydrogencarbonate, and calcium hydroxide. With the help of these data, the structure of synthetically prepared additive-free amorphous calcium carbonate (ACC) was analyzed. ACC contains molecular water (as H 2O), a small amount of mobile hydroxide, and no hydrogencarbonate. This supports the concept of ACC as a transient precursor in the formation of calcium carbonate biominerals.     

Water as the Key to Proto‐Aragonite Amorphous CaCO3

Temperature and pH value can affect the short‐range order of proto‐structured and additive‐free amorphous calcium carbonates (ACCs). Whereas a distinct change occurs in proto‐vaterite (pv) ACC above 45 °C at pH 9.80, proto‐calcite (pc) ACC (pH 8.75) is unaffected within the investigated range of temperatures (7–65 °C). IR and NMR spectroscopic studies together with EXAFS analysis showed that the temperature‐induced change is related to the formation of proto‐aragonite (pa) ACC. The data strongly suggest that the binding of water molecules induces dipole moments across the carbonate ions in pa‐ACC as in aragonite, where the dipole moments are due to the symmetry of the crystal structure. Altogether, a (pseudo‐)phase diagram of the CaCO₃ polyamorphism in which water plays a key role can be formulated based on variables of state, such as the temperature, and solution parameters, such as the pH value.     

Determination of 1-aminocyclopropane-1-carboxylic Acid in Apple and Peach Extracts by High Performance Liquid Chromatography Coupled to a Fluorescence Detector

A new, sensitive, and simple HPLC method was described for the determination of 1-aminocyclopropane-1-carboxylic acid (ACC) in apple and peach extracts. The method was based on the derivatization of ACC with fluorescamine in borate buffer systems of pH 8.0 to yield a highly fluorescent product. The experimental parameters affecting the derivatization reaction efficiency were optimized by fluorimetric analysis. Under optimum derivatization conditions, the derivative product of ACC in apple and peach extracts without extra purification was successfully chromatographed on a C-18 column by HPLC coupled to fluorescence detection. The derivative product of ACC with fluorescamine could be well separated from other concomitant substances or their derivatives that might interfere with the determination of ACC. The linearity of ACC was measured in the range of 23.82–238.82 µg · L^?1 with a good correlation coefficient of 0.9997. Based on signal-to-noise ratio of 3, a low detection limit of 5.0 µg · L^?1 could be reached. The proposed method was applied successfully to the determination of ACC in the crude apple and peach extracts without extra purification with low RSDs of 0.19–1.9% and good recoveries of 90.89–104.4%. The sensitive HPLC quantitative method is of great significance for the investigations of ACC metabolism in plants.     

Determination of 1-aminocyclopropane-1-carboxylic acid in apple extracts by capillary electrophoresis with laser-induced fluorescence detection

A rapid and sensitive method for the determination of 1-aminocyclopropane-1-carboxylic acid (ACC) in apple tissues has been described. This method is based on the derivatization of ACC with 3-(2-furoyl)quinoline-2-carboxaldehyde (FQ), and separation and quantification of the resulting FQ-ACC derivative by capillary electrophoresis coupled to laser-induced fluorescence detection (CE-LIF). Our results indicated that ACC derivatized with FQ could be well separated from other interfering amino acids using 20 mM borate buffer (pH 9.35) containing 40 mM sodium dodecyl sulfate and 10 mM Brij 35. The linearity of ACC was determined in the range from 0.05 to 5 microM with a correlation of 0.9967. The concentration detection limit for ACC was 10 nM (signal-to-noise = 3). The sensitivity and selectivity of this described method allows the analysis of ACC in crude apple extracts without extra purification and enrichment procedure.     

In vitro germination of Striga hermonthica and Striga aspera seeds by 1-aminocyclopropane-1-carboxylic acid

Treatment of conditioned seeds of four isolates of Striga hermonthica and one isolate of Striga aspera with various concentrations of the ethylene precursor, 1-aminocyclopropane-1-carboxylic acid (ACC), caused complex stimulation of germination patterns. GR 24, the strigol analogue served as a positive control and its stimulatory activity was comparable to that of ACC. When conditioned Striga seeds were treated with negative control that did not contain ACC, the stimulatory effect was lost. Overall, the germination data suggested a hormonal mode of action by ACC, which involves indirect stimulation of biosynthesis of ethylene that then triggers seed germination. The various mechanisms that have been proposed for the chemical and biological oxidation of ACC to generate ethylene are discussed.     

Amphiphilic phosphoprotein-controlled formation of amorphous calcium carbonate with hierarchical superstructure

Amorphous calcium carbonate (ACC) plays important roles in biomineralization, and the phosphoproteins extracted from biogenic stable ACC can induce and stabilize synthetic ACC in vitro. Here, mineralization of square-shaped ACC plates with micrometer-sized channels has been reported in the presence of the amphiphilic phosphoprotein casein. Casein can be assumed to take a key role during ACC plate formation, where it serves as an effective stabilization agent for ACC and assembles spherical ACC particles into ACC plates. The stabilizing effect of casein arises from the electrostatic attraction between phosphate groups as well as carbonate groups (especially the former) and the calcium ions, preventing the transformation from unstable ACC to the more stable crystalline phase of CaCO(3). The assembling effect of casein mainly comes from the hydrophobic interaction between casein molecules bound on CaCO(3) particle surface. The inclusion of casein in ACC plates revealed by the thermogavimetric analysis confirms the proposed stabilizing and assembling mechanism. The ability to fabricate such novel hierarchical structured ACC holds the promise for creating more complex micro- and nanostructured materials by use of biological proteins with special structure.     

Factors involved in the formation of amorphous and crystalline calcium carbonate: a study of an ascidian skeleton.

The majority of invertebrate skeletal tissues are composed of the most stable crystalline polymorphs of CaCO(3), calcite, and/or aragonite. Here we describe a composite skeletal tissue from an ascidian in which amorphous and crystalline calcium carbonate coexist in well-defined domains separated by an organic sheath. Each biogenic mineral phase has a characteristic Mg content (5.9 and 1.7 mol %, respectively) and concentration of intramineral proteins (0.05 and 0.01 wt %, respectively). Macromolecular extracts from various biogenic amorphous calcium carbonate (ACC) skeletons are typically glycoproteins, rich in glutamic acid and hydroxyamino acids. The proteins from the crystalline calcitic phases are aspartate-rich. Macromolecules extracted from biogenic ACC induced the formation of stabilized ACC and/or inhibited crystallization of calcite in vitro. The yield of the synthetic ACC was 15-20%. The presence of Mg facilitated the stabilization of ACC: the protein content in synthetic ACC was 0.12 wt % in the absence of Mg and 0.07 wt % in the presence of Mg (the Mg content in the precipitate was 8.5 mol %). In contrast, the macromolecules extracted from the calcitic layer induced the formation of calcite crystals with modified morphology similar to that expressed by the original biogenic calcite. We suggest that specialized macromolecules and magnesium ions may cooperate in the stabilization of intrinsically unstable amorphous calcium carbonate and in the formation of complex ACC/calcite tissues in vivo.     

A carbonate controlled-addition method for amorphous calcium carbonate spheres stabilized by poly(acrylic acid)s

Stable amorphous calcium carbonate (ACC) composite particle with a size-controlled monodispersed sphere was obtained by a new simple carbonate controlled-addition method by using poly(acrylic acid) (PAA) (Mw = 5000), in which an aqueous ammonium carbonate solution was added into an aqueous solution of PAA and CaCl2 with a different time period. The obtained ACC composite products consist of about 50 wt % of ACC, 30 wt % of PAA, and H2O. Average particle sizes of the ACC spheres increased from (1.8 +/- 0.4) x 102 to (5.5 +/- 1.2) x 102 nm with an increase of the complexation time of the PAA-CaCl2 solution from 3 min to 24 h, respectively. The ACC formed from the complexation time for 3 min was stable for 10 days with gentle stirring as well as 3 months under a quiescent condition in the aqueous solution. Moreover, the ACC was also stable at 400 degrees C. Stability of the amorphous phase decreased with an increase of the complexation time of the PAA-CaCl2 solution. No ACC was obtained when the lower molar mass PAAs (Mw = 1200 and 2100) were used. In the higher molar mass case (Mw = 25 000), a mixture of the amorphous phase and vaterite and calcite crystalline product was produced. The present results demonstrate that the interaction and the reaction kinetics of the PAA-Ca2+-H2O complex play an important role in the mineralization of CaCO3.     

Effect of electrochemical oxidation of activated carbon fiber on competitive and noncompetitive sorption of trace toxic metal ions from aqueous solution

A viscose-rayon-based activated carbon cloth (ACC) was electrochemically oxidized to enhance its cation sorption capacity for comparison with as-received ACC. The ACCs were characterized by sodium capacity measurement, pH titration, zeta potential measurement, elemental analysis, Brunauer-Emmet-Teller surface area, and pore size distribution. Batch sorption experiments showed that electrochemically oxidized ACC (EO) is more effective for the removal of lead and copper ions compared to unoxidized ACC (UO) for both competitive and noncompetitive sorption. For electrochemically oxidized fibers the copper and lead sorption capacities of ACC increased 17 and 4 times, respectively, for noncompetitive sorption and 8.8 and 8.6 times, respectively, for competitive sorption. However, reduction in the sorption capacities for both metals was observed for the competitive sorption. The sorption of lead and copper onto EO was by ion exchange, while that onto UO was likely to be due to surface complex formation. The affinity order of the two metal ions sorbed by UO and EO is Pb(2+)>Cu(2+). The effect of pH on sorption isotherms indicated that metal uptake increased with an increase in solution pH.     

Determination of 1-aminocyclopropane-1-carboxylic acid and its structural analogue by liquid chromatography and ion spray tandem mass spectrometry

Liquid chromatography coupled to ion spray tandem mass spectrometry was developed as a method for the simultaneous analysis of the amino acid 1-aminocyclopropane-1-carboxylic acid (ACC) and its structural analogue, cyclopropane-1,1-dicarboxylic acid (CDA). ACC and CDA fragmentation as well as optimization of MS parameters were investigated in positive ion mode. In selective reaction monitoring mode the protonated molecule [M+H]+ was selected as parent ion for both ACC and CDA, while the immonium ion from ACC and the [M+H-H2O]+ ion from CDA were selected, respectively, as product ions. In spite of the high selectivity of MS/MS among the 20 protein amino acids potentially present with ACC and CDA in the plant material analyzed, Glu and Thr can interfere with the signal of ACC. As a result, their chromatographic separation is necessary. This was achieved in less than 4 min by ion-pair reversed-phase chromatography with nonafluoropentanoic acid as ion-pair reagent. A linear response within a concentration range of 1-5 mg l(-1) was observed for this LC method and the detection limit was found to be 20 pmol for ACC and 150 pmol for CDA (using a 20-microl loop). This methodology was successfully applied to the detection of ACC in apple tissue.