Separation and determination of the two components of glycerol formal by high-performance liquid chromatography

The two isomeric components of glycerol formal, 1,3-dioxan-5-ol and 1,3-dioxolane-4-methanol, are marginally separated (R_s = 1.0) by polar-bonded-phase high-performance liquid chromatography (HPLC) on a cyanopropyl column with acetone—hexane as the eluent. Esterification of these components with 3,5-dinitrobenzoyl chloride produces derivatives which are, however, completely resolved (R_s > 2) by normal-phase HPLC on silica; derivatization has the added advantage of introducing an ultraviolet-absorbing chromophore into each component. Preparative scale chromatography is used to isolate each of the derivatives, which are characterized by their UV, NMR and mass spectral properties. These esters are used as reference standards for an analytical method based on derivatization and normal-phase chromatography. In this way a sample of glycerol formal is calibrated for use as a standard in the direct determination of the two components by polar-bonded-phase HPLC.     

剥夺睡眠—睡眠联合诱发脑电图在癫痫诊断中的应用

目的研究剥夺睡眠-睡眠联合诱发试验在癫痫诊断中的价值及适应症。方法对58例临床诊断为癫痫的患者行常规脑电图(EEG)和剥夺睡眠-睡眠联合诱发EEG检查,并将两种方法进行比较;剥夺睡眠后清醒时EEG描记结果与睡眠时EEG描记结果进行比较。结果剥夺睡眠-睡眠EEG痫样放电检出率比常规EEG痫样放电检出率明显提高,前者为86.2％(50/58),后者为41.4％(24/58),两者比较有极其显著性差异(P<0.001)。剥夺睡眠清醒时EEG与剥夺睡眠后睡眠EEG痫样放电检出率比较,有显著性差异(P<0.05)。剥夺睡眠后睡眠EEG可起补充作用,且很易记录到睡眠EEG。结论剥夺睡眠-睡眠联合诱发EEG对痫样放电的检出率有明显提高,对癫痫 的诊断、治疗有重要意义。     

含P6A寡肽血液的HPLC分离分析

目的：建立可用于寡肽血液浓度测定并可与ESI-MS对接的HPLC方法。方法：以ARPAK溶栓寡肽为模型化合物，考察其对色谱系统的稳定性，选择适宜的洗脱系统，消除寡肽与血浆蛋白的相互作用，确定柱温与寡肽峰面积及保留时间的关系，寻找血液中寡肽降解酶抑制剂，比较不同的填料对从血液中提取寡肽的影响，优化寡肽柱前衍生化的温度、时间、pH环境和试剂。结果：含ARPAK的小鼠血浆在50℃、pH8．5的条件下与丹酰氯反应70min，衍生化程度可达峰值。含ARPAK的血浆溶液丹酰氯衍生化后用HClO4处理，可以有效地使被测的丹酰氯衍生化的ARPAK从蛋白中游离。pH9．4的磷酸盐缓冲溶液可以有效地阻滞ARPAK在任意时刻的降解。采用自装的XAD-2柱，可以定量从鼠血浆中回收ARPAK。ARPAK在A相为pH2．1磷酸盐缓冲液，B相为乙腈的流动相中显示最佳的分离度。室温进样，20％A：80％B至45％A：55％B，10min；45％A：55％B至70％A：30％B，1min，丹酰氯衍生化ARPAK的保留时间为11．77min，检测限为10ng。结论：上述HPLC条件以及样品前处理方法可用于寡肽血样HPLC/ESI-MS研究。     

柱前衍生HPLC法测定鸦胆子油中的脂肪酸含量

目的建立HPLC法测定鸦胆子油中的脂肪酸的方法。方法以2,4′-二溴苯乙酮为衍生化试剂,18-冠-6醚为相转移催化剂,采用KromasilC8(250mm×4mm,5μm)反相柱,波长254nm,以乙腈-水(80∶20)为流动相等度洗脱,柱温室温,体积流量为1.3mL/min,正十七烷酸为内标,一次基线分离5种脂肪酸。结果亚油酸的线性范围为0.022～0.330μg,软脂酸的线性范围为0.014～0.213μg,油酸线性范围为0.028～0.416μg,硬脂酸的线性范围为0.012～0.177μg。平均回收率分别为99.2%、97.2%、101.8%、97.8%,RSD分别为1.2%、1.5%、0.4%、2.3%。结论该方法重现性好,定量准确,可作为鸦胆子油中脂肪酸的定量方法。     

柱前衍生高效液相色谱法测定人血浆中尿囊素浓度

目的:建立血浆中尿囊素的浓度测定方法.方法:采用柱前衍生反相高效液相色谱法,尿囊素与2,4-二硝基苯肼(DNPH)反应生成2,4-二硝基苯腙,色谱柱为PhenomeneJx,D Luna C18色谱柱(150mm×4.6mm,5μm),柱温为室温.流动相A为0.2%冰醋酸(用三乙胺调pH至5.0),流动相B为乙腈.梯度洗脱程序:A与B的体积比变化为0～3min 85∶15～65∶35(曲线系数为7),3～5min 65∶35～15∶85 (曲线系数为7),5～9min 15∶85～15∶85 (曲线系数为6),9～10min 15∶85～85∶15(曲线系数为6),10～15min 85∶15(曲线系数为6).PAD检测波长:340nm,流速1.0mL·min-1.内标为加替沙星.结果:在此色谱条件下,尿囊素衍生物与血浆中其他成分的分离完全,线性检测范围为2.5～40mg·L-1,最低检测浓度为2.5mg·L-1,相对回收率在99.35%～103.14%之间,日内及日间精密度RSD小于2.1%.结论:柱前衍生反相高效液相色谱法稳定、灵敏、可靠,可用于人体血浆中尿囊素浓度的测定.     

柱前衍生化HPLC法测定百多宁注射液中的脂肪酸含量

目的建立以HPLC法测定百多宁注射液中脂肪酸含量的方法。方法采用无水硫酸钠破乳方法分离百多宁注射液中的油相。以 2 ,4′ 二溴苯乙酮为衍生化试剂 ,18-冠 - 6醚为相转移催化剂 ,采用C8反相柱 ,以乙腈 -水 (V∶V =75∶2 5 )为流动相等度洗脱 ,正十七烷酸为内标 ,一次基线分离 4种脂肪酸。结果亚油酸在 4 6～ 30 7ng内、软脂酸在 2 7 2～ 181 0ng内、油酸在 14 4～96 0ng 内、硬脂酸在 9 7～ 6 5 1ng内质量与相对峰面积线性关系良好 ,相关系数分别为 0 9997、0 9999、0 9995、0 9996。平均回收率分别为 98 2 %、97 5 %、99 8%、10 2 3% ,RSD分别为2 6 %、3 0 %、1 2 %、2 4 %。结论方法重现性好、定量准确 ,可作为百多宁注射液中脂肪酸测定的定量方法     

How modality-specific is morphology?

Writing has long been considered to be dependent on speaking. However, modality-specific dissociations between written and spoken word production imply that word production is supported by distinct neural mechanisms in writing, which can be impaired or spared regardless of the intactness of spoken word production. Rapp et al. (2015). Modality and morphology: What we write may not be what we say. Psychological Science, 26, 892–902 documented a double dissociation where problems with regular inflections were selectively restricted to writing or speaking. We report on two English-speaking aphasic individuals who exhibit this same modality-specific dissociation of inflectional processing, replicating the original findings. We expand on Rapp et al.’s study by examining whether the dissociations observed with regular inflections extend to other morphological forms, such as derivation and irregular inflection. Results showed that the dissociation holds for derivation; however, both participants were impaired with irregular inflections in both output modalities. Implications of these findings for morphological processing and the independence of the orthographic system are discussed.     

盐酸二甲双胍肠溶胶囊中二甲胺残留量的测定

目的:建立盐酸二甲双胍肠溶胶囊中二甲胺残留量的柱前衍生HPLC测定方法.方法:用十八烷基硅烷键合硅胶为填充剂,以1.0%甲酸溶液-乙腈为流动相,采用梯度洗脱程序,检测波长为265 nm.结果:在选定的色谱条件下,二甲胺在0.254~4.065μg·mL-1的浓度范围内线性关系良好(r>0.999);精密度试验的RSD为1.6%,稳定性试验的RSD为1.5%;回收率为100.3%(n=9,RSD<1.5%).二甲胺的检测限为0.0508μg·mL-1,在测定的3批样品中,3批均检出二甲胺分别为0.01%,0.04%,0.02%.结论:本方法专属性强,准确度高,重现性好,能控制盐酸二甲双胍肠溶胶囊中二甲胺残留量.     

Silent Adenoma Subtype 3 of the Pituitary—Immunohistochemical and Ultrastructural Classification: A Review of 29 Cases

The silent adenoma subtype 3 (SAS-3) of undetermined cellular derivation is a seemingly nonfunctioning aggressive pituitary tumor with a high recurrence rate. At the time of diagnosis SAS-3s are macro- or giant adenomas particularly aggressive in young individuals, especially women. They are usually associated with mild hyperprolactinemia and are unremarkable by histology. Immunohistochemistry, demonstrating scattered immunoreactivity mostly for GH, PRL, TSH, and α-subunit, is not diagnostic. Presently, only TEM permits conclusive diagnosis. Ultrastructurally, the large polar adenoma cells contain abundant RER, masses of SER, extensive multipolar Golgi apparatus, and unevenly clustered mitochondria, displaced by RER and SER, which may show close spatial relationship to RER. Cell membranes often form plexiform interdigitations. Nuclear pleomorphism and nuclear inclusions are common. The 100- to 200-nm secretory granules accumulate heavily in cell processes, which is a hallmark of glycoprotein hormone cell differentiation. The endothelial cells may contain tubuloreticular inclusions. Complete surgical removal of the large often invasive tumors is difficult necessitating postoperative treatment. SAS-3 is sensitive to conventional radiation. Some tumors express somatostatin receptors and respond well to somatostatin analogues, offering long-term control in patients with residual tumor. Possible derivation of SAS-3 from rostral thyrotrophs, a cell type presently known in rodents is comtemplated.     

粪便内中短链脂肪酸柱前衍生化UHPLC-QTOF-MS/MS分析方法研究

建立柱前衍生化超高效液相色谱-串联四级杆飞行时间质谱(UHPLC-QTOF-MS/MS)定性、定量表征小鼠粪便内中短链脂肪酸的方法,并用于评价其在抗生素处置前后小鼠粪便样品中的变化。动物实验方案获得江苏省中医药研究院动物实验伦理委员会的批准。以3-硝基苯肼为衍生化试剂,对衍生化反应条件、色谱及质谱条件进行优化,建立了粪便中16个中短链脂肪酸的定性、定量方法。所有分析物在各自浓度范围内线性关系良好(R2>0.99),日内、日间精密度RSD均小于10%,重复性RSD小于6%,加样回收率介于80%~120%之间,样品36 h内稳定性RSD小于7%;联合抗生素处置后小鼠粪便内的中短链脂肪酸种类和含量均发生了明显改变。其中,甲酸、乙酸、丙酸、丁酸、异丁酸、戊酸、乳酸等含量明显降低,而庚酸和丁二酸的含量明显增加。该方法准确、可靠,可作为粪便内中短链脂肪酸的表征方法。