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21.
目的 探讨多功能红外治疗宫颈糜烂的疗效。方法 将 171例宫颈糜烂患者随机分为两组 ,治疗组用多功能红外治疗仪探头点状光凝子宫颈 ,每点 2~ 3秒 ,对照组用CO2 激光治疗。结果 治疗组治愈 84例 ,占 97.67% ,对照组治愈 73例 ,占 85.88% ,两组疗效比较P <0 .0 5。结论 采用多功能红外治疗仪治疗宫颈糜烂疗效明显优于对照组。 相似文献
22.
Photoacoustic Fourier transform infrared (PA-FT-IR) depth profiling spectra of the enamel of an intact human tooth are obtained in a completely nondestructive fashion. The compositional and structural changes in the tissue are probed from the enamel surface to a depth of about 200 m. These changes reflect the state of tissue development. The subsurface carbonate gradient in the enamel could be observed over the range of about 10–100 m. The carbonate-to-phosphate ratio increases in the depth profile. The depth profile also reveals changes in the substitutional distribution of carbonate ions. Type A carbonates (hydroxyl substituted) increase relative to type B carbonates (phosphate substituted) with increasing thermal diffusion length. In addition to the changes in the carbonate ion distribution and content, the PA-FT-IR depth profile clearly indicates a dramatic increase in the protein content relative to the phosphate content with increased depth. The changes in the carbonate content and distribution, along with the changes in the protein content, may be responsible for the changes observed in the apatitic structure in the depth profile of the enamel. 相似文献
23.
Durrer Carlo Irache Juan Manuel Puisieux Francis Duchêne Dominique Ponchel Gilles 《Pharmaceutical research》1994,11(5):674-679
A Fourier transform infrared spectroscopy/attenuated total reflection technique for direct quantification of adsorbed poly(styrene) latexes on rat intestinal mucosa was developed for deposited latex amounts up to 1.5 g/m2. The method agreed well with another dosage assay of adsorbed particles by turbidimetry after denaturation of the mucus. Adsorption kinetics were made under static conditions at latex concentrations of 4 g/L in physiological saline. Ninety percent of equilibrium was reached after 10 min for a particle size of 230 nm, 20 min for a size of 320 nm, and 30 min for a size of 670 nm. The plateaus were between 0.6 and 0.9 g/m2 (adsorbed mass per apparent surface of mucosa). The first phase of the kinetics was theoretically approached by a diffusion model in the suspension medium. Mucosa from rat jejunum and ileum could be considered as a homogeneous biological model for latex adsorption. 相似文献
24.
The effects of unilateral sciatic neurectomy (USN) on the development of the femur were studied in 15 growing Wistar-derived
rats (age, 5 weeks). The rats were divided into four groups: USN-operated group (right femur), USN-nonoperated group (left
femur), sham-operated group (right femur), and sham-nonoperated group (left femur). Bone mineral density (BMD), bone mineral
content (BMC), bone area, periosteal circumference, and endosteal circumference were measured by peripheral quantitative computed
tomography (pQCT) and the mineral/matrix ratio was evaluated by Fourier transform infrared spectroscopy (FTIR). The USN-operated
group showed a significant decrease in cortical BMC, bone area, and periosteal circumference compared with the other groups
(P < 0.05). The cortical BMD did not vary significantly between the groups. In the cancellous bone, the USN-operated group showed
a significant decrease in BMD and BMC at the metaphysis compared with the other groups (P < 0.05). The mineral/matrix ratio of the cortical bone did not differ significantly between the USN-operated and USN-nonoperated
groups. These results suggest that in cortical bone, USN inhibits periosteal bone formation but has no significant effect
on the mineral/matrix ratio of cortical bone in femurs. In cancellous bone, USN induces bone loss at the metaphysis.
Received: Nov. 19, 1998 / Accepted: Feb. 12, 1999 相似文献
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目的以单纯胰岛素为对照,采用傅立叶红外光谱(Fourier transform infrared, FTIR)研究包裹在脂质体内部胰岛素二级结构的变化。方法分别对单纯胰岛素、胰岛素与空白脂质体混合物(样品I)及包裹胰岛素的脂质体(II)样品进行测定。结果样品I和样品II中胰岛素的FTIR谱图形状与单纯胰岛素相比基本一致,仅α-螺旋百分比略有下降(由36.09%分别下降到31.68%和31.45%),β-折叠百分比略有增加(由47.83%分别增加到53.29%和51.36%)。样品I和样品II中胰岛素的二级结构无明显差别(α-螺旋百分比为31.68%和31.45%,β-折叠百分比为53.29%和51.36%)。结论包裹在脂质体内部胰岛素的二级结构与单纯胰岛素相比无明显变化。 相似文献
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29.
目的研究琥珀酸胆固醇酯(CHEMS)对二棕榈酰磷脂酰胆碱(DPPC)脂质体的膜稳定作用以及作用机制;以CHEMS和DPPC为膜材制备柴胡皂苷-D(SSD)脂质体,考察其包封率和溶血性。方法差示扫描量热法(DSC)和荧光释放实验考察CHEMS的膜稳定作用,傅立叶红外(FT-IR)研究CHEMS与DPPC膜的作用机制,沉降实验研究CHEMS与SSD相互作用,溶血实验考察了以CHEMS为膜材包裹SSD脂质体的溶血性。结果CHEMS在膜稳定性上优于胆固醇(CHOL),CHEMS与DPPC的极性端头同时有氢键和静电作用;CHEMS与SSD不会形成不溶性复合物(INCOM),用DPPC和CHEMS为膜材制备了稳定的SSD包裹的脂质体,其溶血性大大降低。结论CHEMS对DPPC膜的稳定作用大于CHOL,并可取代CHOL作为制备胆固醇依赖性的溶血性皂苷脂质体的膜稳定剂。 相似文献
30.
Abstract: Although the effect of sucrose on the physical stability of proteins has been well documented, its impact on their chemical stability is largely unknown. The aim of this study was to investigate the potential effects of sucrose on the structural conformation of human brain natriuretic peptide [hBNP (1–32)] and the synthetic human parathyroid hormone [hPTH (1–34)], and link these effects to chemical degradation pathways of these peptides. The stability of hBNP (1–32) and hPTH (1–34) was studied at pH 5.5. Aggregation was monitored using size exclusion high‐performance liquid chromatography (SE‐HPLC), whereas oxidation and deamidation products were measured by reversed phase (RP) HPLC. Fourier transform infrared (FT‐IR) spectroscopy was used to study the peptides’ conformation. Sucrose retarded aggregation, deamidation, and oxidation of hBNP (1–32) and hPTH (1–34), with a maximum effect at relatively high concentrations (as much as 1 m ). FT‐IR spectroscopy indicated that sucrose maintained the native conformation of hBNP (1–32) and induced small conformation changes in the hPTH (1–34) structure. Sucrose enhanced the stability of hBNP (1–32) and hPTH (1–34) in liquid formulations. The stabilizing effect of sucrose was due to a large extent to retardation of oxidation and deamidation of hBNP (1–32) and hPTH (1–34). 相似文献