基于快速蒸发离子化质谱实时检测空气油炸鲳鱼的脂质组学轮廓

快速蒸发离子化质谱（rapid evaporative ionization mass spectrometry, REIMS）是一种无需样品预处理的新型质谱技术，通过手持智能手术刀切割样品采集数据从而获得脂质组学轮廓。本研究采用REIMS技术和主成分分析（principal component analysis, PCA）、隐结构正交投影（orthogonal projection to latent structure, OPLS）等数理统计方法实时监测鲳鱼在空气油炸过程中脂质组学轮廓变化，并探究不同空气油炸温度对鲳鱼肌肉组织脂质组成的影响。通过单因素条件优化得到适宜的REIMS系统参数，电刀输出功率20 W、电刀切割功率1 mm/s、辅助溶剂流速100 μL/min，从而获得稳定可靠的质谱轮廓图。在PCA分析的基础上进行OPLS分析，得到10个重要的特征离子（VIP>1），其中PE（O-16∶1/22∶6）只在原料中检测到，为4.61%；此外，PE（22∶5/22∶6）在10个磷脂离子中的不饱和度最高，其相对含量随油炸温度的升高而降低，同样可见于PA（18∶1/22∶6）和PI（18∶0/22∶6），说明磷脂的饱和度有随油炸温度升高而上升的趋势。经方法验证显示，REIMS检测离子的信噪比范围为49.58~205.30，日内和日间精密度的相对标准偏差为3.10%~7.28%，灵敏度和精密度均较高，因此，该方法将成为脂质组学研究过程中一种简单、高效、准确的新型技术手段。     

基于常压基质辅助激光解吸电离质谱成像技术原位检测三维肿瘤细胞球内代谢小分子

与传统培养的二维肿瘤细胞相比，三维肿瘤细胞球能从多个方面更好地模拟实体瘤的一些特征，如空间结构和药物抗性机理。本研究建立了常压基质辅助激光解吸电离-串联四极杆轨道离子阱质谱法原位检测三维肿瘤细胞球内代谢小分子。利用该方法检测分析了22种内源性代谢小分子在三维细胞球内的空间分布，其中4种涉及三羧酸循环代谢通路的小分子分布于整个细胞球区域，另外18种涉及甘油磷脂合成与降解通路的脂质分子在细胞球内的分布呈多样性。例如，PGP(O-30∶3)和PGP(30∶2)分布于细胞球中心区域；PG(O-36∶1)分布于细胞球外围区域；PE(18∶1/22∶6)分布于整个细胞球区域。区域分割分析表明，细胞球外围区域和中心区域的质谱峰信号强度有显著性差异。该研究可为进一步了解肿瘤模型的微环境以及肿瘤代谢的分子机制提供参考。     

全自动检测血清Non-HDL-C在妊娠期糖尿病中的临床应用探讨

目的:研究非高密度脂蛋白(Non-HDL-C)在妊娠期糖尿病(GDM)患者中的血清水平及临床应用价值。方法:回顾性分析我院就诊的2017年1月到2019年12月共922例妊娠期妇女的临床资料,其中GDM组495例,427例正常妊娠妇女作为对照组。分析两组间血脂指标水平差异,使用Logistic回归分析Non-HDL-C与GDM之间的相关性。结果:GDM组和正常对照组的Non-HDL-C血清水平分别4.15(3.49,4.89)mmol/L和3.60(3.11,4.23)mmol/L,GDM组血清Non-HDL-C浓度显著高于正常对照组,差异具有统计学意义(P<0.01)。Logistic回归分析显示Non-HDL-C是GDM的危险因素(P<0.01),并且Non-HDL-C的OR值为1.68(95%CI,1.45,1.93;P=0.00),高于TC、TG、LDL-C的OR值,分别为1.49(95%CI,1.31,1.70;P=0.00)、1.26(95%CI,1.13,1.40;P=0.00)和1.27(95%CI,1.10,1.48;P=0.001)。结论:Non-HDL-C相较传统血脂指标能够更全面更敏感的显示孕期的血脂代谢水平,可以作为临床监测妊娠期糖尿病中血脂代谢的有效指标。     

Electrospray mass spectrometry of phospholipids

Phospholipids play a central role in the biochemistry of all living cells. These molecules constitute the lipid bilayer defining the outer confines of a cell, but also serve as the structural entities which confine subcellular components. Mass spectrometry has emerged as a powerful tool useful for the qualitative and quantitative analysis of complex phospholipids, including glycerophospholipids and the sphingolipid, sphingomyelin. Collision induced decomposition of both positive and negative molecular ion species yield rich information as to the polar head group of the phospholipid and the fatty-acyl substituents esterified to the glycerophospholipid backbone. This review presents the current level of understanding of the mechanisms involved in the formation of various product ions following collisional activation of molecular ion species generated by electrospray ionization of the common glycerophospholipids, including phosphatidic acid, phosphatidylethanolamine, phosphatidylcholine, phosphatidylinositol, phosphatidylglycerol, phosphatidylserine, cardiolipin, and sphingomyelin. Recent advances in the application of matrix assisted laser desorption ionization is also considered. Several applications of mass spectrometry applied to phospholipid analysis are presented as they apply to physiology as well as pathophysiology.     

二维液相色谱-质谱法研究犬肾小管上皮细胞脂质组成及马兜铃酸(Ⅰ)对其影响

采用在线正反相二维液相色谱-质谱联用技术研究了犬肾小管上皮细胞脂质组成及马兜铃酸(Ⅰ)对其影响。二维色谱的第一维用于分离不同种类脂质,第二维用于分离同类脂质的不同分子,进而利用高分辨质谱对脂质分子进行检测。该方法减少了共流出,降低了电离抑制,提高了灵敏度与准确性。借助精确质荷比检索数据库、高分辨二级质谱和当量碳数与保留时间规律等方法检测了犬肾小管上皮细胞中13类脂质的1 416个脂质分子。选取11种外源性脂质标准品进行方法验证,方法的线性关系、检测限、重复性均满足检测要求。在此基础上,考察了犬肾小管上皮细胞暴露于马兜铃酸(Ⅰ)后的脂质变化情况,对改变含量2～4倍的15个脂质分子进行了鉴定。该实验结果可为马兜铃酸的毒理、病理研究和相关疾病的临床诊断提供丰富的信息,并展现了二维液相色谱 质谱法在脂质组学研究中广阔的应用前景。     

Mice embryology: A microscopic overview

In this work, we studied the embryology of mice of 12, 14, and 18 days of gestation by gross observation, light microscopy, and scanning electron microscopy. Grossly, the embryos of 12 days were observed in C‐shaped region of the brain, eye pigmentation of the retina, first, second, and third pharyngeal arches gill pit nasal region on the fourth ventricle brain, cervical curvature, heart, liver, limb bud thoracic, spinal cord, tail, umbilical cord, and place of the mesonephric ridge. Microscopically, the liver, cardiovascular system and spinal cord were observed. In the embryo of 14 days, we observed structures that make up the liver and heart. At 18 days of gestation fetuses, it was noted the presence of eyes, mouth, and nose in the cephalic region, chest and pelvic region with the presence of well‐developed limbs, umbilical cord, and placenta. Scanning electron microscopy in 18 days of gestation fetuses evidenced head, eyes closed eyelids, nose, vibrissae, forelimb, heart, lung, kidney, liver, small bowel, diaphragm, and part of the spine. The results obtained in this work describe the internal and external morphology of mice, provided by an integration of techniques and review of the morphological knowledge of the embryonic development of this species, as this animal is of great importance to scientific studies. Microsc. Res. Tech. 2012. © 2012 Wiley Periodicals, Inc.     

Localization of fatty acids with selective chain length by imaging time-of-flight secondary ion mass spectrometry

Localization of fatty acids in biological tissues was made by using TOF-SIMS (time-of-flight secondary ion mass spectrometry). Two cell-types with a specific fatty acid distribution are shown. In rat cerebellum, different distribution patterns of stearic acid (C18:0), palmitic acid (C16:0), and oleic acid (C18:1) were found. Stearic acid signals were observed accumulated in Purkinje cells with high intensities inside the cell, but not in the nucleus region. The signals colocalized with high intensity signals of the phosphocholine head group, indicating origin from phosphatidylcholine or sphingomyelin. In mouse intestine, high palmitic acid signals were found in the secretory crypt cells together with high levels of phosphorylinositol colocalized in the crypt region. Palmitic acid was also seen in the intestinal lumen that contains high amounts of mucine, which is known to be produced in the crypt cells. Linoleic acid signals (C18:2) were low in the crypt region and high in the villus region. Oleic acid signals were seen in the villi and stearic acid signals were ubiquitous with no specific localization in the intestine. We conclude that the results obtained by using imaging TOF-SIMS are consistent with known brain and intestine biochemistry and that the localization of fatty acids is specific in differentiated cells.     

氯丙嗪在不同种属肝微粒体中代谢差异研究

采用体外肝微粒体孵育实验研究氯丙嗪在鼠、猪、鸡肝微粒体的代谢速率及代谢产物。利用液相色谱-串联质谱测定不同时间点氯丙嗪的峰面积,计算氯丙嗪的体外代谢率、代谢半衰期（T1/2）及固有清除率（CLint）,通过氯丙嗪及其代谢产物的保留时间、碎片离子等信息,推断氯丙嗪的代谢产物和代谢途径。结果表明,在猪、鼠、鸡肝微粒体孵育体系中,氯丙嗪的T1/2分别为18.2、173.3、346.5 min,CLint分别为76.2、8.0、4.0 μL/(min·mg)。在3种肝微粒体孵育体系中共发现8种代谢产物,在鼠、猪和鸡肝微粒体孵育体系中分别发现5种、7种和4种氯丙嗪代谢产物,均检测出产物氯丙嗪亚砜、去甲基氯丙嗪、6-羟基氯丙嗪和7-羟基氯丙嗪。氯丙嗪在肝微粒体孵育体系中的代谢途径以氧化、羟基化和去甲基反应为主,其在猪肝微粒体孵育体系中代谢和清除速度最快,其次是鼠、鸡,在不同种属肝微粒体孵育体系中代谢产物的种类和含量存在差异。     

MALDI-TOF MS磷脂质组学快速分析三文鱼肌肉组织

建立了基质辅助激光解吸电离-飞行时间质谱(MALDI-TOF MS)快速分析三文鱼肌肉组织磷脂质组学的方法。以非自然磷脂酰胆碱DMPC(14∶0/14∶0)和磷脂酰乙醇胺DPPE(15∶0/15∶0)为标准品,分析其在正离子模式下的主要分子峰与干扰峰,并进行方法学验证。实验结果表明,各化合物平均加标回收率在74%~83%之间,相对标准偏差小于7%,日内和日间精密度的相对标准偏差均低于8.5%。将三文鱼磷脂提取物进样分析,共鉴定出28种磷脂分子,其中m/z806.40([PC38:6+H]~+和[PE38:4+K]~+)信号最强。三文鱼中多不饱和磷脂种类丰富,如m/z 824.38([PC38:8+Na]~+和[PE42:5+H]~+),m/z832.41([PC40:7+H]~+,[PC38:4+Na]~+和[PE40:5+H]~+),部分磷脂分子的脂肪酸链达到了满不饱和,如[PC42:11+H]~+,其sn-1和sn-2上两条脂肪酸链分别为二十碳五烯酸链(EPA-)和二十二碳六烯酸链(DHA-)。该方法稳定可靠,可用于鉴定三文鱼肌肉组织中的磷脂分子结构,并从脂质组学角度为三文鱼营养评价提供理论依据。     

两种不同淋巴细胞分离液对脐带血单核细胞的提取及后期诱导培养CIK细胞的影响

目的：研究两种不同的淋巴细胞分离液对脐带血单核细胞的分离效果及后期对CIK细胞的诱导培养的影响。方法：分别使用国产TBD以及进口GE healthcare牌淋巴细胞分离液分离提取脐带血单核细胞,用悬浮细胞培养法诱导培养脐带血单核细胞形成CIK细胞,再用血球计数板及台盼兰染色法检测细胞密度及活率。结果：国产的TBD牌所分离的单核细胞分层较清楚,并且方便提取,而使用进口GE healthcare的淋巴细胞分离液提取的单核细胞数量较多,但经过后期诱导培养CIK细胞发现两种分离液提取的细胞培养到后期数量逐渐接近。结论：国产TBD牌淋巴细胞分离液在用于脐带血淋巴细胞分离提取时较进口GE healthcare牌经济,并且细胞提取方便,后期培养效果无明显差别。     

HPLC-ELSD法测定几种水产品卵及生殖腺中磷脂的组成

利用高效液相色谱-蒸发光散射检测(HPLC-ELSD)测定方法,对阿拉斯加狭鳕鱼卵、鲟鱼鱼籽、鸢乌贼卵、虾夷扇贝精巢及卵巢、海胆生殖腺中磷脂组成进行了检测.以ZORBAX Rx-SIL型正相硅胶色谱分析柱(4.6mm×250mm)为分离柱,使用氯仿∶甲醇∶氨水(80∶19.5∶0.5,V/V/V)及氯仿∶甲醇∶水∶氨水(60∶34∶0.5∶5.5,V/V/V/V)为流动相进行二元梯度洗脱,流速为1.0 mL/min,柱温30℃.蒸发光散射检测器漂移管温度65℃,雾化气(氮气)压力4.5Mpa流速为2.0L/min.在上述条件下对各水产品卵/生殖腺所提取磷脂中的心磷脂(CL)、磷脂酰乙醇胺(PE)、磷脂酰胆碱(PC)、磷脂酰肌醇(PI)、磷脂酰丝氨酸(PS)、鞘氨醇磷脂(SM)溶血磷脂酰胆碱(LPC)等组分进行了测定,结果发现各磷脂组成在各自浓度检测范围内线性关系良好,方法精密度较高,将该方法用测定于水产品卵/生殖腺来源磷脂样品中磷脂组成,可以获得快速、准确的分析结果,对于其它来源的磷脂样品测定也具有重要的参考价值.     

4′-氯地西泮和二氯西泮的大鼠肝微粒体体外代谢研究

为研究4′-氯地西泮和二氯西泮在人体内的代谢产物,本研究通过体外温孵体系肝微粒体代谢模型进行实验,在Wistar大鼠雌雄混合肝微粒体中分别加入4′-氯地西泮和二氯西泮对照品各1μg,模拟人体内的代谢过程孵育4 h后,采用Agilent Eclipse plus C18色谱柱(100 mm×2.1 mm×5μm)进行分离...     

Optimising tolerance allocation for mechanical components correlated by selective assembly

Selective assembly can enlarge the tolerances of mechanical components for easier manufacturing. However, the non-independent dimensions of correlated components make it difficult to optimise tolerance allocation for an assembly. This paper proposes a solution for this constrained optimisation problem consisting of tolerances and non-independent dimensions as design variables. The approach is to develop a simplified algorithm applying a Lagrange multiplier method to evaluate the optimal tolerances efficiently. The solution is shown to be a global optimum at the given correlation coefficients. The correlation coefficients are key elements in determining the optimal solution, which is demonstrated in the given examples. The results are helpful in designing tolerances for selective assembly.Notation A _j coefficient matrix off _j - B _i coefficient of cost function - C total manufacturing cost function - C _i manufacturing cost function forx _i - F _j thejth dimensional constraint function - f _j thejth quadratic constraint function - f quadratic constraint vector - H _j thejth Hessian matrix - J _kj element ofn×m Jacobian matrix - L Lagrangian - m number of assembly dimensions - n number of component dimensions - p number of equality dimensional constraints - T tolerance vector of component dimensions [mm] or [°] - tolerance ofx _i [mm] or [°] - tolerance ofZ _j [mm] or [°] - x component dimension vector - x midpoint vector - x _i component dimension [mm] or [°] - x _i midpoint ofx _i [mm] or [°] - Z _j assembly dimension [mm] or [°] - _j confidence coefficient forZ _j - _i confidence coefficient forx _i> - _j given design value ofZ _j [mm] or [°] - Lagrange multiplier vector - _j thejth Lagrange multiplier - * Lagrange multiplier vector at the optimum solution - correlation coefficient forx _i andx _k - _x standard deviation vector - _x ^* standard deviation vector at the optimum solution - _x ⁰ candidate point satisfying the constraintsf( _x ^* )=0 - standard deviation ofx _i      

UPLC-HRMS结合质谱分子网络高通量分析人血浆中的代谢物

本文建立了超高效液相色谱-高分辨质谱（UPLC-HRMS）结合质谱分子网络（MSMN）分析血浆中代谢物的方法。采用Folch方法提取血浆中的代谢物,运用UPLC-HRMS技术同时检测水相和有机相中的多种代谢物。以标准品准确定性的代谢物为种子化合物,采用MSMN筛选与种子化合物质谱特征相似的代谢物,扩展代谢物定性范围,提高代谢物定性效率。将该方法用于人血浆中代谢物的定性分析,共检测到187个代谢物。其中,在水相中定性检测到氨基酸、脂肪酸、糖类等80个代谢物,在有机相中定性检测到107个脂类代谢物,实现了人血浆中多类代谢物的高通量分析。     

Morphological characterization of the progenitor blood cells in canine and feline umbilical cord

The umbilical cord blood (UCB) is an important source of hematopoietic stem cells with great deal of interest in regenerative medicine. The UCB cells have been extensively studied as an alternative to the bone marrow transplants. The challenge is to define specific methods to purify and characterize these cells in different animal species. This study is aimed at morphological characterization of progenitor cells derived from UCB highlighting relevant differences with peripheral blood of adult in dog and cats. Therefore, blood was collected from 18 dogs and 5 cats' umbilical cords from fetus in various developmental stages. The mononuclear cells were separated using the gradient of density Histopaque-1077. Characterization of CD34+ cells was performed by flow cytometric analysis and transmission electron microscopy. Granulocytes (ancestry of the basophiles, eosinophiles, and neutrophiles) and agranulocytes (represented by immature lymphocytes) were identified. We showed for the first time the ultrastructural features of cat UCB cells.     

Nanoscale imaging of morphological changes of umbilical cord in pre-eclampsia

It is known that pre‐eclampsia affects the structure of the umbilical cord including changes in diameter and wall thickness. In this work, the morphological changes of umbilical cords associated with pre‐eclampsia were investigated using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The SEM images showed the overall structural changes in the umbilical cord, and the AFM imaged the surface of the cord in the nanometer range. The amount of Wharton's jelly was reduced in the cords of pre‐eclampsia patients and it was holed along the boundary. Compared to a normal pregnancy, the surface of a pre‐eclampsia cord was relatively smooth. In all components (Wharton's jelly, veins, and arteries), the values for surface roughness, Sa (average value of the roughness), Sq (root mean square), and Sz (peak to peak value), were smaller than those of the control (P < 0.05). Especially, the values for Sa of veins were ～fourfold less than those of the controls (P < 0.05). In pre‐eclamptic cords, the amount of elastin in veins was increased while that of the artery was decreased. Microsc. Res. Tech. 2012. © 2012 Wiley Periodicals, Inc.     

高效液相色谱法测定鸡蛋中的脑磷脂和卵磷脂

目的:建立鸡蛋中脑磷脂和卵磷脂的高效液相色谱测定方法。方法:取冻干鸡蛋粉30mg,加入5mL甲醇,超声波震荡20min后离心取上清液进样检测。色谱条件为:色谱柱ZorbaxSIL硅胶柱(4.6mm×250mm),流动相为甲醇?1%磷酸(50?1,V/V),流速0.5mL/min,柱温20℃,紫外检测器波长为205nm,进样量5μL。结果:脑磷脂在529.2～5292ng/μL浓度范围内呈线性关系(R2=0.9999),卵磷脂在4455～44550ng/μL浓度范围内呈线性关系(R2=0.9997),脑磷脂和卵磷脂的平均回收率分别为97.54%和96.42%。结论:应用本方法能快速准确同时测定鸡蛋中脑磷脂和卵磷脂的含量,样品前处理简单易行。     

基于质谱技术的黄芩治疗2型糖尿病的粪便代谢组学研究

采用粪便代谢组学方法,运用超高效液相色谱-四极杆飞行时间质谱（UPLC-Q-TOF MS）技术研究了黄芩治疗2型糖尿病大鼠的作用机制。采用主成分分析（PCA）和正交偏最小二乘法判别分析方法 （OPLS-DA）对健康对照组、2型糖尿病模型组和黄芩治疗组的大鼠粪便中内源性代谢物进行分析,寻找黄芩治疗2型糖尿病大鼠的潜在生物标志物。结果表明,健康对照组、2型糖尿病模型组和黄芩治疗组的大鼠粪便代谢图谱有显著的区分;发现并鉴定了11种潜在的生物标志物。黄芩对2型糖尿病大鼠的鞘脂类代谢和脂肪酸代谢具有调节作用;对三羟基三甲基吲哚酮、白三烯E4、亮氨酰脯氨酸和雌二醇的含量具有调节作用;同时,大鼠体重和空腹血糖的变化趋势表明,黄芩具有改善糖尿病症状的作用。     

The Contribution of Thin PFPE Lubricants to Slider-Disk Spacing. 3. Effect of Main Chain Flexibility

We have investigated the effect of main chain flexibility of a perfluoropolyether lubricant, Zdol 4000, on dynamic slider-disk spacing. The major conclusion of this work is that increasing the Zdol chain flexibility results in a decrease in the dynamic slider-disk spacing. The Zdol main chain flexibility is quantified by ab initio computations of the barriers to internal rotation about C-O and C-C bonds in model structures containing -CF₂O- and -CF₂CF₂O- monomer units. C-O bond rotations for -CF₂O- monomer units bordered by -CF₂O- monomer units are relatively unhindered with a barrier to internal rotation of 1.7 kcal/mol. C-O and C-C bond rotations in -CF₂OCF₂CF₂O- units have barriers to internal rotation of 8 and 5 kcal/mol, respectively. The presence of the C-C bond imparts considerable rigidity to the Zdol chain.