Quantitative analysis of glutamate compounds in the swine brain following central analgesics nasal spray using proton magnetic resonance spectroscopy and linear combination model

BACKGROUND： In localized brain proton magnetic resonance spectroscopy （^1H-MRS）, metabolite levels are often expressed as ratios, rather than absolute concentrations. Frequently, the denominator is creatine, which is assumed to be stable in normal, as well as many pathological, states. However, in vivo creatine levels do not remain constant. Therefore, absolute metabolite measurements, which provide the precise concentrations of certain chemical compounds, are superior to metabolite ratios for determining pathological and evolutional changes. OBJECTIVE： To investigate the feasibility of quantification analysis of brain metabolite changes caused by central analgesics nasal spray using the ^1H-MRS and linear combination model （LCModel） methods. DESIGN, TIME AND SETTING： This neuroimaging, observational, animal study was performed at the Laboratory of the Department of Medical Imaging, Second Affiliated Hospital, Medical College, Shantou University, China from July to December 2007. MATERIALS： Butorphanol tartrate nasal spray, as a mixed agonist-antagonist opioid analgesic, was purchased from Shanghai Hengrui Pharmacy, China. A General Electric Signa 1.5T System （General Electric Medical Systems, Milwaukee, WI, USA） and LCModel software （Stephen Provencher, Oakville, Ontario, Canada） were used in this study. METHODS： MRS images were acquired in ten healthy swine aged 2 weeks using single-voxel point-resolved spectroscopic sequence. A region of interest （2 cm × 2 cm × 2 cm） was placed in the image centers of maximum brain parenchyma. Repeated MRS scanning was performed 15-20 minutes after intranasal administration of 1 mg of butorphanol tartrate. Three settings of repetition time/echo time were selected before and after nasal spray administration 3 000 ms/30 ms,1 500 ms/30 ms, and 3 000 ms/50 ms. Metabolite concentrations were estimated by LCModel software. MAIN OUTCOME MEASURES： ^1H-MRS spectra was obtained using various repetition time/echo time settings. Concentrations of glutamate compounds （glutamate ＋ glutamine）, N-acetyl aspartate, and choline were detected in swine brain prior to and following nasal spray treatment. RESULTS： The glutamate compounds curve was consistent with original spectra, when a repetition time/echo time of 3 000 ms/30 ms was adopted. Concentrations of glutamate compounds, N-acetyl aspartate, and choline decreased following administration. The most significant reduction was observed in glutamate compound concentrations from （9.28 ± 0.54） mmol/kg to （7.28 ± 0.54） mmol/kg （P 〈 0.05）. CONCLUSION： ^1H-MRS and LCModel software were effectively utilized to quantitatively analyze and measure brain metabolites. Glutamate compounds might be an important neurotransmitter in central analgesia.

Composition and distribution of NSO compounds in two different shales at the early maturity stage characterized by negative ion electrospray ionization coupled with Fourier transform ion cyclotron resonance mass spectrometry

Gas chromatography/mass spectrometry （GC/MS） can only analyze volatile molecular compounds, and it has limitations when applied to determine the complex components of crude oils and hydrocarbon source rocks. Based on Fourier transform ion cyclotron resonance mass spectrometry （FT-ICR-MS） and GC/MS analyses, the molecular compositions of NSO compounds in extracts from the Permian Dalong Formation, Sichuan Basin and the Permian Lucaogou Formation, Junggar Basin in China were compared. Analyses of types of heteroatoms present （S~, $2, $3, OS, OS2, 02S, NS, and NOS compounds） suggest that marine shales from the Dalong Formation are mainly composed of carboxylic acids （02 com- pounds） with a high abundance of fatty acids, indicating a marine phytoplankton organic source. However, lacustrine shales from the Lucaogou Formation are dominated by pyrrolic compounds （N1 compounds） with abundant dibenzocar- bazole. It suggests that the organic source materials may be derived from lower aquatic organisms and lacustrine algae. Overall, FT-ICR-MS has potential for applications in analyses and determination of depositional environments and organic sources in petroleum geology.

Brain injury due to acute organophosphate poisoning Magnetic resonance imaging manifestation and pathological characteristics

BACKGROUND： Acute organophosphate poisoning can cause injuries of multiple visceras; especially,central nervous system injury can increase risk factors of patients with severe acute organophosphate poisoning. An application of modem image may increase diagnostic rate of brain injury in an earlier period and provide evidences for clinical treatment.OBJECTIVE： To reveal imaging manifestations, pathological characteristics and multi-ways injured mechanism of brain injury due to acute organophosphate poisoning.DESIGN： Contrast observational study.SETTING： Department of Medical Image, the Second Hospital of Hebei Medical University.MATERIALS： The experiment was carried out in the Department of Nerve Molecule Imaging Medicine and Laboratory of Neurology, the Second Hospital of Hebei Medical University from August 2003 to February 2004. A total of 30 healthy cats weighing 2.8 - 3.5 g and of both genders were selected from Animal Experimental Center of Hebei Medical University.METHODS： Thirty healthy cats were randomly divided into control group （n =5） and intoxication group （n=25）. Cats in the control group were subcutaneously injected with 0.3 mL/kg saline at four points; while, cats in the intoxication group were subcutaneously injected with 400 g/L 0.3 mL/kg O,O-dimethyl-S-（methoxycarbonylmethyl） thiophosphate at four points. Two minutes after intoxication, cats received muscular injection with 0.5 mg/kg atropine sulfate, and then, brain tissues were collected from parietal lobe, basal ganglia, hippocampus, cerebellum and brain stem were observed at 3, 6, 24 hours, 3 and 7 days after intoxication respectively under optic microscope and electron microscope and expressions of acetylcholinesterase （AChE）, choline acetyltransferase （ChAT）, glial fibrillary acidic protein （GFAP）,glutamic acid （Glu） and γ-amino butyric acid after immunohistochemical staining.MAIN OUTCOME MEASURES： Results of MRI examinations; histological changes under optic microscope and electron microscope; expressions of AChE, ChAT, GFAP, Glu and γ -amino butyric acid after immunohistochemical staining.MAIN OUTCOME MEASURES： Results of MRI examinations; histological changes under optic microscope and electron microscope; expressions of AChE, ChAT, GFAP, Glu and γ -amino butyric acid after immunohistochemical staining.RESULTS： All 30 healthy cats were involved in the final analysis. ① Imaging and pathological observation： Image manifestations of brain injury induced by acute organophosphate poisoning showed as cerebral edema and symmetry signal abnormality of bilateral basal ganglia; while, pathological manifestations also showed as cerebral edema. ② Observation of immunohistochemical staining： As compared with the control group, after organophosphate poisoning, area of AChE immune-positive cells was decreased obviously （P〈0.01）, but area of ChAT immune-positive cells was not changed （P〉0.05）; in addition, positive cells of GFAP were increased remarkably （P〈0.01）, positive cells of γ -amino butyric acid in cerebral cortex were increased obviously （P〈0.05）, but numbers of positive cells of Glu were not changed （P〈0.05）.CONCLUSION： Multi-ways injured mechanism invovled in acute organophosphate poisoning. An application of modern image can increase diagnostic rate of brain injury in an earlier period and provide evidences for clinical treatment.

Synthesis Characterization and Biological Activities of an Enamine Derivative and Its Coordination Compounds

The medicinal uses and applications of metal complexes are of increasing clinical and commercial importance;this is as a result of some level of success achieved so far. In this regard, novel enamine free-base ligands were synthesized by the condensation of terephthalaldehyde and 2-(methylamino)ethanol. This afforded a dinegative ONNO donor enamine, free base, characterized using 1H and 13C NMR, Fourier-transformed infrared and UV-vis spectroscopy. Coordination compounds of the enamine were also synthesized using Cu(II), Ni(II), Co(II) and VO(IV) ions. These complexes were characterized by electronic, IR spectrophotometry, mass spectrometry, magnetic susceptibility and EDX. The compounds were thereafter evaluated for their antimicrobial and cytotoxic activities. The data obtained were supportive of an octahedral geometry for the Cu(II) complex, a square-pyramidal geometry for the vanadium complex and a 4-coordinate square-planar geometry for both the cobalt and nickel complexes. The magnetic susceptibility data revealed that the complexes are magnetically dilute and mononuclear with exception of the cobalt complex. The ligands and the complexes did not exhibit significant antimicrobial and cytotoxic assays, indicative of the nontoxicity of the ligand and complexes.

Optimization of Sound Absorption and Insulation Performances of a Dual-Cavity Resonant Micro-Perforated Plate

This study investigates a dual-cavity resonant composite sound-absorbing structure based on a micro-perforated plate.Using the COMSOL impedance tube model,the effects of various structural parameters on sound absorption and sound insulation performances are analyzed.Results show that the aperture of the micro-perforated plate has the greatest influence on the sound absorption coefficient;the smaller the aperture,the greater is this coefficient.The thickness of the resonance plate has the most significant influence on the sound insulation and resonance frequency;the greater the thickness,the wider the frequency domain in which sound insulation is obtained.In addition,the effect of filling the structural cavity with porous foam ceramics has been studied,and it has been found that the porosity and thickness of the porous material have a significant effect on the sound absorption coefficient and sound insulation,while the pore size exhibits a limited influence.

Isolation and structural elucidation of antifungal compounds from Curcuma amada

Objective: To isolate and identify the antifungal compounds from Curcuma amada. Methods: The antifungal activity was measured by the diameter of colonies grown on Petri dish,microscopic observation,and CLSI microdilution methods. The antifungal compounds were isolated through bioactivity guided purification by using silica gel and high-performance liquid chromatography. Structural identification of the antifungal compounds was conducted using 1 H NMR,13 C NMR,and liquid chromatography-tandem mass spectrometry. Results: The purified antifungal compounds were zederone and furanodienone. These two compounds showed dose-dependent antifungal activity against Fusarium solani sensu lato. The concentration required for 50% growth inhibition(IC50) of FSSL ranged from 115 to 129 μM and 82 to 91 μM for zederone and furanodienone,respectively. Conclusion: This study suggested that the isolated compounds from Curcuma amada could be promising natural antifungal agents to control the diseases caused by Fusarium solani sensu lato.

Compositional Characterization of Nitrogen Compounds in Changqing Crude Oil and Its Heavy Distillates

The nitrogen-containing compounds in Changqing crude oil, its atmospheric residue(AR), and vacuum reside(VR) were characterized by negative and positive ion electrospray ionization(ESI) Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS). The heteroatom compounds(N_1, N_2, N_1O_1, O_1, and O_2 class species) could be identified by the negative ESI analysis, while the positive mode could only detect the N_1, N_2, and N_1O_1 class species. Among them, the N_1 class species were found to be predominant in crude oil, as confirmed by either negative or positive ESI analyses,which were similar in composition to AR and VR. These compounds with higher abundance were characterized by double bond equivalent(DBE) values and carbon numbers. The composition of these compounds in crude oil and its AR as well as VR was correlated with their different boiling range, DBE values and carbon numbers. The negative ESI analysis showed that the abundant N_1 class species in crude oil and AR were centered at a DBE value of 12, and these species were likely benzocarbazoles, while the N_1 class species with the DBE value ranging from 13 to 16 having more complicated molecular structures were dominant in VR. And the positive ESI analysis gave the information of the abundant N_1 class species in crude oil, AR, and VR having the DBE values in the range of 10, 9―11, and 10―16, respectively, which were likely the compounds with the core of quinoline and benzoquinoline. The analysis confirmed that the distillation process in refinery preferentially removed the low DBE value and low molecular N-class species and brought them into the light and medium distillates, while those N-class species having a high molecular condensation in the molecules with large carbon number remained in the residual oil and could continually affect the downstream oil refining process.

复合助剂对低温喷雾干燥蓝靛果粉理化性质的影响

为保证低温喷雾干燥后蓝靛果粉品质,采用黄金分割法研究复合助剂(麦芽糊精、β-环糊精和乳清蛋白)对喷雾干燥蓝靛果粉理化性质的影响,分析低温进风温度(50~90℃)对蓝靛果粉花青素保留率、集粉率和含水率的影响规律。结果表明,在麦芽糊精、β-环糊精的质量比例为85.4%、14.6%时,集粉率高达37.96%;随进料溶液中麦芽糊精质量比例增加,蓝靛果粉玻璃化转变温度、水溶性指数、堆积密度、亮度L^(*)值、红度a^(*)值和色差值ΔE呈增加趋势,含水率、花青素含量和黄度b^(*)值呈下降趋势;在麦芽糊精、β-环糊精和乳清蛋白质量比例为72.9%、12.5%、14.6%时,集粉率达到最高(40.11%);随料液中乳清蛋白质量比例增加,蓝靛果粉含水率、花青素含量呈上升趋势,其玻璃化转变温度、水溶性指数、亮度L^(*)值、红度a^(*)值、黄度b^(*)值和色差值ΔE等指标呈下降趋势;复合助剂显著提高蓝靛果粉集粉率(P<0.05),对其中的花青素起到较强保护作用,其含水率、水溶性指数、堆积密度等理化指标均接近于最优水平。低温喷雾干燥研究发现,随进风温度上升,集粉率和含水率呈负相关,在进风温度90℃时,集粉率最高的配方中可实现较高花青素保留率(89.94%)。低频核磁共振波谱以及质子密度图像信息分析表明,加入的助剂与蓝靛果果汁中水分通过氢键、静电结合力和疏水作用等分子间作用力,形成稳定性高水合物、增强液滴聚结抵抗力,提高料液玻璃态转换温度,从而实现高集粉率和高花青素保留率的蓝靛果果粉低温喷雾干燥;红外光谱分析表明,复合助剂可在蓝靛果果粉中形成分子间氢键,并对花青素等活性物质进行固定包埋保护。研究结果可为蓝靛果粉喷雾干燥加工生产提供理论支撑和参考依据。

定量核磁共振波谱法快速测定灭火剂材料中全氟辛烷磺酰基化合物

泡沫灭火剂中全氟辛烷磺酰基化合物(PFOS)的使用受到严格管控.针对灭火剂中PFOS快速测定的需求,建立了基于19F的定量核磁共振波谱(qNMR)检测方法.方法以全氟丁基磺酸钾为标准物质,通过计算全氟丁基磺酸钾的-CF3在化学位移δ-78.94处19F特征峰和PFOS的-CF2在化学位移δ-117.12处19F特征峰的积分面积比值,进而实现PFOS定量分析.经测试,全氟丁基磺酸钾百分含量与定量峰面积线性相关系数为0.9955,检出限为0.024%,定量限为0.080%.8种灭火剂产品的定性测定结果与实际标注情况相吻合,其中4种泡沫灭火剂产品中PFOS含量在0.106%~1.339%之间.研究结果表明,方法受基质干扰小、检测速度快、灵敏度高,可为泡沫灭火剂中PFOS的管控提供可靠的检测方法与数据支撑.

六种香精化合物核磁共振法纯度定值

建立了核磁共振氢谱法(1HNMR)测定6种香精化合物(香豆素、香兰素、甲基香兰素、乙基香兰素、麦芽酚、乙基麦芽酚)纯度的定值方法。选择合适的溶剂、内标,通过测定样品的定量信号的纵向弛豫时间(T 1)来计算准确定量所需的理论弛豫时间(D 1),比较样品在不同弛豫时间下测得的实际纯度来对D 1进行优化的数据,实验结果显示两种D 1优化方法结果一致。分析样品中每个合适的定量信号所得到的定值结果并找到定值结果差异的原因。最终6种样品的纯度结果分别为99.79%、99.80%、99.78%、99.82%、99.86%、99.53%,扩展不确定度(k=2)分别为0.16%、0.10%、0.22%、0.18%、0.14%、0.14%。其不仅适用于香豆素等香精化合物的含量测定,在弛豫时间及定量峰的确定方面也适用于其他化合物,以确保更精确的定值。

酰胺化合物的核磁共振氢谱

酰胺是一类非常重要的化合物,广泛存在于多肽和生物碱等生物活性分子中,在化工、染料以及药物研发等领域也具有重要的应用价值。因此,学习酰胺化合物的合成以及结构鉴定具有重要的意义。由于酰胺化合物的氮原子上的孤对电子能够离域到羰基(C=O)上,导致酰胺RCO―N上的C―N键表现出部分双键性质,C―N键不能自由旋转,使得酰胺化合物的核磁共振氢谱较复杂。本文总结了酰胺的核磁共振氢谱特征,探讨了酰胺异构化的一些影响因素。通过酰胺核磁共振氢谱的学习,培养学生对核磁共振谱图解析的能力,并加深对酰胺类化合物的理解和认识。

中低温煤焦油重质馏分的化合物组成及表征

对中低温煤焦油的综合高效利用有助于提高煤炭作为化工原料的综合利用效能,因而利用联用技术对典型中低温煤焦油重质馏分进行分子表征,可为其后续高效的加工利用提供数据支撑。利用电喷雾电离源(ESI)和大气压光致电离源(APPI)结合傅里叶变换离子回旋共振质谱仪(FT-ICR MS)在分子水平上表征影响典型中低温煤焦油重质馏分加工利用方式的含氮化合物、含氧化合物以及芳烃化合物,探讨含氮和含氧化合物、芳烃类化合物的组成和碳数分布。结果表明,采用正离子电喷雾(+ESI)结合FT-ICR MS共鉴定出N_(1)、N_(2)、N_(1)O_(1)、N_(1)O_(2)、N_(1)O_(3)、N_(2)O_(1)、N_(2)O_(2)、N_(1)O_(1)S_(1)共8种不同分子组成的碱性氮化物;采用负离子(-ESI)模式下FT-ICR MS检测出N_(1)、N_(2)、N_(1)O_(1)、N_(1)O_(2)、N_(1)O_(3)、N_(2)O_(1)、N_(1)O_(1)S_(1)共7类非碱性氮化物,检测出O_(1)、O_(1)S_(1)、O_(2)、O_(2)S_(1)、O_(3)、O 4共6类酸性氧化物;采用APPI正离子模式结合FT-ICR MS检测出4_(1)67种芳烃化合物,其中碱性氮化物相对丰度较高的为N_(1)、N_(1)O_(1)类化合物,而非碱性氮化物相对丰度较高的为N_(1)O_(1)、N_(1)O_(2)类化合物,O_(1)、O_(2)、O_(3)类酸性氧化物具有较高的相对丰度。依据各化合物的等效双键数和碳数分布可推测其分子组成,N_(1)类碱性氮化物母核结构主要为喹啉、吖啶、菲啶、二苯并喹啉和苯并吖啶等2~4环的多芳环结构;N_(1)O_(1)类碱性氮化物的主要母核结构为苯并喹啉、吖啶、菲啶、二苯并喹啉、苯并吖啶、二苯并吖啶同时并有呋喃、氧芴等结构;N_(1)O_(1)、N_(1)O_(2)类非碱性氮化物与碱性氮化物相比,其侧链相对较短,其母核结构为吡咯、吲哚、咔唑并环氧烷、呋喃以及部分苯环结构,氧以羟基、醚基、羰基或酰基形式存在;O_(1)类酸性氧化物种类较多,母核结构主要为萘酚、蒽酚、菲酚、苯并蒽酚、苯并萘酚,还有少量的芘酚;O_(2)类酸性氧化物的种类较少,母核结构主要为萘二酚、蒽二酚、菲二酚,同时也存在羧基官能团的长链烷烃。O_(3)类酸性氧化物的种类介于O_(1)类和O_(2)类之间,母核结构有可能为萘二酚并呋喃、蒽二酚、菲二酚,烷基侧链中含有羟基、醚键或羧基等结构;芳烃化合物主要为烷基侧链较长的2~3环稠环芳烃。

酒石酸唑吡坦关键中间体的有关物质检测与主要杂质合成

目的控制酒石酸唑吡坦关键中间体化合物3的质量。方法采用高效液相色谱法检测化合物3中有关物质,色谱柱为Agilent Pursuit 5 C_(18)柱(150 mm×3.9 mm,5μm),流动相为pH 6.0磷酸盐缓冲液-甲醇-乙腈(梯度洗脱),流速为1.2 mL/min,柱温为30℃,检测波长为254nm,进样量为20μL。合成化合物3中的主要杂质,并通过质谱法、核磁共振波谱法对其进行结构确认。结果化合物3的质量浓度在0.0928~556.7689μg/mL范围内与峰面积线性关系良好(r=0.9997,n=5);检测限为1.0 ng,定量限为2.0 ng;精密度、稳定性、重复性试验的结果均符合要求。6批化合物3的纯度均大于90%,均检出有关物质杂质1、杂质2、未知杂质、化合物2,其相对保留时间分别为0.32,1.12,2.23,1.67。以化合物3为原料,合成得到杂质1和杂质2,纯度分别为99.04%和98.72%。结论该方法专属性强、准确度高、稳定性好,可为酒石酸唑吡坦的质量控制提供参考。合成的杂质纯度高,可作为杂质对照品使用。

干崖子橐吾的萜类成分研究

目的 对橐吾属药用植物干崖子橐吾Ligulariakanaitzensis (Franch .)Hand . Mazz .药用部位的化学成分进行研究。方法 通过多次柱层析和重结晶分离纯化 ,并用现代光谱技术进行结构鉴定。结果 分离鉴定了 2个倍半萜成分 :11 hydroper oxy 6 ,9 eremophiladien 8 one(Ⅰ ) ,6α hydroxy 7(11) eremopholen 12 ,8β olide(Ⅱ )和 4个三萜成分 :齐敦果酸 (Ⅲ ) ,β 香树脂醇(Ⅳ ) ,β 香树脂醇乙酸酯 (Ⅴ ) ,羽伞豆醇 (Ⅵ )。 结论 上述 6个化合物均为首次从干崖子橐吾中分离得到 ,化合物Ⅰ为一过氧化物 ,其碳谱数据系首次报道。

磁耦合谐振式无线电能传输系统频率复合控制方法

频率的稳定及精确控制是磁耦合谐振式无线电能传输系统高效稳定运行的基础。提出一种基于PI锁相环频率跟踪控制和动态补偿调谐相结合的频率复合控制方法,实现了常规频率控制方法无法同时实现的大范围、高精度和快速频率调节。首先,根据建立的磁耦合谐振式无线电能传输系统数学模型,从原理上分析发生频率失谐的原因,给出了合理的频率失谐检测方法,并分析了系统等效阻抗角与谐振频率之间的对应关系;建立频率跟踪控制与动态补偿调谐的数学模型,以计算并确定锁相环PI参数及动态补偿参数;随后进行仿真并搭建试验平台验证,仿真结果表明该方法对谐振频率的调节速度快、精度高,试验结果验证该方法可以实现谐振频率的快速跟踪,保证系统工作在谐振状态。

大鼠全脑照射后早期放射性脑损伤的磁共振波谱与病理对照研究

目的探讨磁共振波谱(MRS)揭示放射性脑损伤的细胞代谢改变及病理早期动态演变价值。材料与方法将成年SD大鼠25只随机分为对照组、10Gy、20Gy、30Gy单次照射组和30Gy分次(每周1次,每次10Gy)照射组,用6MeV电子线作垂直全脑照射,各组大鼠于照射后1个月均行MRI及1HMRS检查,分析NAA、Cho和Cr等信号强度改变,以积分面积进行比较,计算NAA/Cr、Cho/Cr和NAA/Cho。各组大鼠在行1HMRS检查后,立即断头处死取大脑后分两侧大脑半球,一侧大脑半球行常规病理HE染色检查,另一侧行电子显微镜检查。结果所有被检查大鼠的大脑MRI均未见异常表现;各照射组大鼠大脑的NAA/Cr、Cho/Cr和NAA/Cr值与对照组相比均有统计学差异。结论用1HMRS来监测大鼠全脑照射后脑组织内的NAA、Cho和Cr的浓度变化,在形态学发生改变之前就可检测出脑组织的代谢异常,并能反映大鼠全脑照射后早期脑组织内超微结构改变,且对放射性脑损伤的病情发展作出准确的估测。

用谐振来解释超声加工中的“局部共振”现象

本文采用机械阻抗方法分析了超声加工系统中出现的“局部共振”现象,通过对不同截面积比的变幅杆和工具杆组合系统的计算,得出“局部共振”是超声加工系统的某些固有频率和工具杆固有频率相接近时的现象,此时整个系统仍是全谐振。

含氮固体物质的核四极共振远程探测仪

本文介绍一台结构简单，造价低廉的１４Ｎ核四极共振远程探测仪。它利用脉冲傅立叶变换技术，将获得的核自由感应衰减信号或回波信号进行相干累加以提高信噪比。整个系统分硬件和软件两部分。前者由射频脉冲放大器（有效值功率输出约３００Ｗ）、探头、接收机和ＩＢＭ—ＰＣ机构成。后者由ＰＣ机上的脉冲序列程序和数字信号处理程序组成。利用这台谱仪。

氢质子磁共振波谱监测乳腺癌新辅助化疗疗效的应用研究

目的:探讨乳腺癌氢质子磁共振波谱(1H-MRS)的谱线特征及早期监测乳腺癌新辅助化疗疗效的价值。方法:前瞻性研究一组98例在术前进行新辅助化疗的乳腺癌患者(99个病灶,98个浸润性导管癌,1个黏液腺癌),比较按疗程随访的1H-MRS结果(化疗前,一疗程后),观察分析胆碱共振峰的峰高、峰下面积及胆碱信噪比,以评估新辅助化疗疗效。所有病例均经手术病理证实。结果:①1H-MRS可用于乳腺癌监测(成功率83.8%),乳腺癌可出现明显的胆碱复合峰,敏感度75.9%(63/83)。②48个成功随访病灶中,8个治疗无效,40个有效;③比较治疗有效、无效组Cho峰高、峰下面积及信噪比,P<0.05,差异有统计学意义。④治疗有效组一疗程后Cho峰高、峰下面积及信噪比的变化有显著统计学意义,P<0.001,肿瘤Cho峰有下降趋势或部分消失;无效组Cho峰变化无统计学意义(P>0.05)。结论:1H-MRS可用于乳腺癌的诊断,并可在乳腺癌新辅助化疗早期通过Cho的变化,评价、预测新辅助化疗疗效,提供早期判断疗效的有价值信息。

超声复合振动系统中的“局部共振”现象──20年来的应用和机理分析情况

本文作者及当时合作者在《应用声学》的创刊号中报道了超声振动系统中“局部共振”现象的发现及其一项应用．２０年来，国内一些作者或者分别介绍了本现象在不同场合的应用，或者分别分析了这个现象的机理．值此《应用声学》庆祝创刊２０周年之际，本文回顾了这些前期工作，提出了自己的一种关于机理的观点，并对“局部共振”现象的实用意义作了新的评价，希望能进一步促进这个现象的应用和对它的讨论．