http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Qing L. Chen (검색결과 2 건)
- 무료
- 기관 내 무료
- 유료
-
Qi Zhang,Xiang C. Ma,Chang He,Qing L. Chen,Bing J. Zhang 한국탄소학회 2023 Carbon Letters Vol.33 No.7
Modification of the surface of raw activated carbon using chemical solvents can significantly improve the adsorption performance of activated carbon. Triethylenetetramine is one of the most important chemical solvents used to modify raw activated carbon for formaldehyde removal indoor. We conducted the liquid impregnation experiments at different initial concentrations, temperatures, adsorbent dosage and time ranges to fully investigate the adsorption of triethylenetetramine on the surface of raw activated carbon for modification. We found that the Langmuir isotherm model and pseudo-first-order kinetic model fit quite well with the experimental data and the R2 are 0.9883 and 0.9954, respectively. The theoretical maximum adsorption capacity is 166.67 mg/g. The change in Gibbs free energy (ΔG0), enthalpy change (ΔH0) and entropy change (ΔS0) were also calculated to study the direction and driving force of the liquid adsorption process. In order to understand the adsorption process at the molecular level, a new activated carbon model based on the actual physical and chemical properties of activated carbon was carefully established in the Materials Studio to simulate the liquid-phase adsorption. The pore structure, elemental composition, functional group content, density, pore volume, and porosity of the activated carbon model converge close to the actual activated carbon and the adsorption isotherms obtained from the simulation agree well with the experimental results. The results show that the adsorption of triethylenetetramine on activated carbon is a spontaneous, endothermic and monolayer physical adsorption process.
-
Sha Liao,Shi-Yong Fan,Qin Liu,Chang-Kun L,Jia Chen,Jing-Lai Li,Zhi-Wei Zhang,Zhen-Qing Zhang,Bo-Hua Zhong,Jian-Wei Xie 대한약학회 2014 Archives of Pharmacal Research Vol.37 No.11
Chronic hepatitis B virus (HBV) infection maylead to liver cirrhosis and hepatocellular carcinoma, butfew drugs are available for its treatment. Acyclic nucleosidephosphonates (ANPs) have remarkable antivirusactivities but are not easily absorbed from the gastrointestinaltract and accumulate in the kidneys, resulting innephrotoxicity. Therefore, there is a need to find effectiveliver site-specific prodrugs. The dipivaloyloxymethyl esterof 9-(2-phosphonylmethoxyethyl)adenine (PMEA)—adefovirdipivoxil (ADV)—is a first-line therapy drug forchronic hepatitis B with a low therapeutic index because ofrenal toxicity and low hepatic uptake. In this study, a seriesof PMEA derivatives were synthesized to enhance plasmastability and liver release. The metabolic stability of ADV(Chemical I) and its two analogues (Chemicals II and III)was evaluated in rat plasma and liver homogenate in vitro. An ion-pair reverse-phase HPLC–UV method and a hybridion trap and high-resolution time-of-flight mass spectrometry(LC-IT-TOF-MS) were used to evaluate the degradationrate of the analogues and to identify their intermediatemetabolites, respectively. Chemicals I and II were hydrolyzedby cleavage of the C–O bond to give monoesters. Sufficient enzymatic activation in the liver homogenatethrough a relatively simple metabolic pathway, in additionto a favorable stability profile in rat plasma, made ChemicalII an optimal candidate. Next, six analogues based onthe structure of Chemical II were synthesized and evaluatedin plasma and liver homogenate. Compared toChemical II, these compounds generated less active PMEAlevels in rat liver homogenate. Therefore, chemical modificationof Chemical II may lead to new promising PMEAderivatives with enhanced plasma stability and liveractivation.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
