全文获取类型
收费全文 | 260篇 |
免费 | 27篇 |
国内免费 | 8篇 |
专业分类
电工技术 | 1篇 |
综合类 | 14篇 |
化学工业 | 107篇 |
金属工艺 | 4篇 |
建筑科学 | 1篇 |
轻工业 | 113篇 |
无线电 | 3篇 |
一般工业技术 | 49篇 |
原子能技术 | 1篇 |
自动化技术 | 2篇 |
出版年
2024年 | 2篇 |
2023年 | 4篇 |
2022年 | 6篇 |
2021年 | 25篇 |
2020年 | 8篇 |
2019年 | 9篇 |
2018年 | 9篇 |
2017年 | 13篇 |
2016年 | 11篇 |
2015年 | 12篇 |
2014年 | 8篇 |
2013年 | 23篇 |
2012年 | 22篇 |
2011年 | 17篇 |
2010年 | 22篇 |
2009年 | 6篇 |
2008年 | 8篇 |
2007年 | 11篇 |
2006年 | 13篇 |
2005年 | 10篇 |
2004年 | 5篇 |
2003年 | 9篇 |
2002年 | 16篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 6篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1993年 | 4篇 |
1991年 | 1篇 |
1990年 | 1篇 |
排序方式: 共有295条查询结果,搜索用时 46 毫秒
11.
脂质体不同制备方法对其包裹率的影响 总被引:4,自引:0,他引:4
周威 《武汉工业学院学报》2001,(2):28-29
脂质体作为新型药物载体,具有靶向性和长效缓释作用,又降低药物的毒性和提高药物的稳定性,具有较大的发展前途。笔者探讨了在相同的条件下用反相蒸发法、研磨法、冻融法制备溶茵酶脂质体。通过对其包裹率的测定,结果表明:反相蒸发法包裹率高,反相蒸发法为最佳工艺。 相似文献
12.
Antioxidant activity of grape extracts in a lecithin liposome system 总被引:15,自引:0,他引:15
Ock-Sook Yi Anne S. Meyer Edwin N. Frankel 《Journal of the American Oil Chemists' Society》1997,74(10):1301-1307
Extracts of 14 different grapes were tested for their antioxidant activities in a copper-catalyzed lecithin liposome oxidation
assay and analyzed for their phenolic components by high-performance liquid chromatography (HPLC). The total phenolic contents
of the grape extracts varied from 176 to 1236 mg gallic acid equivalents (GAE)/L. Extracts of red wine grape varieties contained
higher concentrations of phenolics than other varieties. When compared at the same 20 μM GAE basis, the grape extracts inhibited
formation of conjugated diene hydroperoxides by 25.1 to 67.9%, and hexanal formation by 49.3 to 97.8%. Extracts of red table
grape varieties Red Globe and Emperor and white wine grape varieties Chardonnay and Sauvignon Blanc gave the highest antioxidant
activities. The relative percentage inhibition of conjugated dienes and hexanal correlated with total phenols (r=0.86 and 0.89). HPLC analyses showed that anthocyanins were the most abundant phenolic compounds in extracts of red grapes,
and flavonols were most abundant in extracts of white grapes. 相似文献
13.
环胞苷二棕榈酸酯脂质体粒度分布及微黏度的测定 总被引:3,自引:1,他引:3
对环胞苷二棕榈酸酯脂质体的物理稳定性进行了评价。用反相蒸发法制备环胞苷二棕榈酸酯脂质体,将其与空白脂质体对照,分别测定了它们受热前后的粒度分布及微黏度。结果表明,经37℃,40 h温育后其平均粒径仅增加了0.54μm,而空白脂质体增加了1.35μm。环胞苷二棕榈酸酯脂质体的微黏度比空白脂质体提高了近一倍。环胞苷二棕榈酸酯载于脂质体上提高了脂质体的物理稳定性。 相似文献
15.
The interaction of surfactants with liposomes eventually leads to the rupture of such structures and the solubilization of
the phospholipid components. In this paper, solubilization is regarded as a decrease in light scattering of liposome suspensions.
To this end, in accordance with the nomenclature, adopted by Lichtenberg, three parameters were considered as corresponding
to the effective surfactant/lipid molar ratios (Re) at which light scattering starts to decrease, Resat; reaches 50% of the original value, Re50; and shows no further decrease, Resol. These parameters corresponded to the Re at which the surfactant (i) saturated the liposomes, (ii) resulted in a 50% solubilization
of vesicles and (iii) led to a total solubilization of liposomes. The surfactants tested were the nonionic surfactant octylphenol
ethoxylated with 10 units of ethylene oxide or Triton X-100 (OP-10EO), two anionic surfactants, sodium dodecyl sulfate and
sodium dodecyl ether sulfate, and an amphoteric surfactant dodecyl betaine (D-Bet). Unilamellar liposomes formed by egg phosphatidylcholine
containing increasing amounts of phosphatidic acid were used. The Re parameters were the lowest for D-Bet, followed by OP-10EO,
whereas the anionic surfactants always showed the highest values regardless of the electrical charge of the lipid bilayers.
These parameters seem also to be inversely related to the critical micelle concentration (CMC) of the surfactant, except for
OP-10EO. Moreover, the CMC values of the surfactant/lipid systems at 0.5 mM lipid concentration corresponded in all cases
to the surfactant concentration at which liposomes were saturated by surfactants. As a consequence, this ratio can be regarded
as an interesting parameter associated with the mixed micelle formation in liposome solubilization. 相似文献
16.
为提高甘氨酸螯合铁的稳定性,采用薄膜-超声法制备了甘氨酸螯合铁脂质体。以包封率为指标,考察了胆固醇、芯材、吐温80的量和水相体积对脂质体的影响,得到了最佳的工艺条件为:胆固醇:芯材:吐温80:大豆卵磷脂=0.2:0.1:0.5:1(wt.:wt.:wt.:wt.),水相体积10mL;最大包封率为63.92%。体外释放结果显示,经过5h,脂质体在模拟胃液和模拟肠液中的释放率分别为24.05%和15.35%;因而,脂质体对芯材甘氨酸螯合铁有较好的保护及缓释效果。 相似文献
17.
《Drug development and industrial pharmacy》2013,39(8):1023-1031
ABSTRACTTransferrin-conjugated cationic liposome (Tf -DDAB liposome) was developed as a targeted gene delivery system by using heterobifunctional cross-linking agent, N-succimidyl-3-(2-pyridyldithio)propionate (SPDP), and gradient metrizamide ultracentrifugation method. Physico-chemical properties of Tf -liposome were determined by scanning/transmission electron microscopy (SEM/TEM) and dynamic laser-light scattering method (DLS) with a mean diameter of 584±15 nm. Gel retardation assay was performed using various DDAB:DNA ratios, and proved that the 6:1 weight ratio formulation gave the most neutralized complex. In vitro transfection was done in human cervical cancer cells, HeLa, and the transfection efficiency of Tf -liposome was found to be fivefold higher than that of unconjugated (plain) DDAB liposome and twofold higher than that of Lipofectin?. In conclusion, a target-oriented Tf -DDAB liposome was made successfully and proved to be very efficient in DNA delivery into the cervical cancer cells in culture. 相似文献
18.
This study was designed to evaluate the prolonged antimicrobial stability of nisin-loaded liposome (LipoN) nanoparticles against Listeria monocytogenes and Staphylococcus aureus. The sizes of bare liposomes and LipoN were uniformly distributed between 114 and 125 nm. The nanoparticles were homogeneously dispersed in water with less than 0.2 of polydispersity index. The zeta potential value of LipoN was +17.1 mV due to the positive charged nisin, attaining 70% of loading efficiency. The minimum inhibitory concentration of LipoN against L. monocytogenes and S. aureus was 320 international unit/mL. The LipoN significantly enhanced the antimicrobial stability in brain heart infusion agar compared to free nisin. The numbers of L. monocytogenes and S. aureus exposed to LipoN were effectively reduced by more than 6 log colony-forming unit/mL after 48 and 72 h of incubation, respectively. These results provide useful information for the development of antimicrobial delivery system to improve food safety. 相似文献
19.
响应曲面法优化石榴皮多酚脂质体的制备及质量评价 总被引:1,自引:0,他引:1
以包封率作为评价指标,采用响应曲面法(RSM)研究逆向蒸发法制备石榴皮多酚脂质体工艺及制备过程中卵磷脂与胆固醇的质量比(SPC/CH)、有机相与水相体积比(O/A)、缓冲液pH及其交互作用对包封率的影响,利用软件优化出最佳的工艺配方,并对其理化性质进行评价。结果表明,制备石榴皮多酚脂质体的最佳工艺为:卵磷脂与胆固醇的质量比(SPC/CH)为3.08、有机相与水相体积比(O/A)为4、缓冲液pH为6.17,在此条件下制备的石榴皮多酚脂质体包封率理论值为55.08%,实际值为54.87%。有效粒径为(91.13±2.5)nm,Zeta电位为-55.7mV,体外释放程度缓慢,缓释率延长32h,缓释效果明显,稳定性方面,在4℃条件下储存稳定性良好,60d之内,包封率共下降13.72%。逆向蒸发法制备脂质体工艺简单可行,包封率高,粒度均匀,稳定性好,可用于石榴皮多酚脂质体的制备。 相似文献
20.