Multi-compartment linear circulation mathematical model for targeted drug delivery systems was established on the bases of compartment theory and mass conservation theory. The function formulas of drug concentration-time in blood and target organ were established. According to this model, the drug concentration-time curve for the target organ can be plotted with reference to the data on blood. Based on the target organ drug concentration-time curve,the pharmacokinetics parameters of the target organ can also be calculated by the statistical moment. We further detected the practicability of the models by using the experimental data of drug concentration-time curve in blood and target organ of microspheres. The drug concentration-time curve in blood and in target organ predicted by mathematical model was agreed with that observed.
Albumins ; administration & dosage ; Drug Delivery Systems ; Humans ; Microspheres ; Models, Theoretical ; Pharmacokinetics

The mechanism of drug release from swellable polymer was studied. The model which can explain the drug release from glassy polymer was developed by coupling drug diffusion equation and solvent diffusion equation. The effect of viscoelastic stress of polymer was also considered. The Deborah number and swelling interface number were used to describe the mechanism of drug release, especially relax controlled mechanism.
Delayed-Action Preparations ; Diffusion ; Drug Delivery Systems ; Models, Chemical ; Polymers ; chemistry ; Tablets

Sugar-containing monomer vinylbenzylglycosylallyamide (VBG) was synthesized by vinylbenzyl amine and delta-gluconolactone in dimethylformamide(DMF) solution. The sugar-based hydrogel was prepared by free radical crosslinking copolymerization of VBG, itaconic acid (IA) and acrylamide (AM). The release properties of Aspirin from xerogels matrices and from hydrogel in different pH solutions and different concentration NaCl solutions were studied respectively. The release mechanism of Aspirin was further confirmed by evaluating the n value in Peppas equation. The results indicated that the drug release increased with the increase of pH values and with the decrease of NaCl concentration.
Acrylic Resins ; chemistry ; Anti-Inflammatory Agents, Non-Steroidal ; administration & dosage ; chemistry ; Aspirin ; administration & dosage ; chemistry ; Delayed-Action Preparations ; chemical synthesis ; chemistry ; Humans ; Hydrogel, Polyethylene Glycol Dimethacrylate ; chemical synthesis ; chemistry ; Hydrogen-Ion Concentration ; Succinates ; chemistry ; Vinyl Compounds ; chemistry

Sugar-containing monomer glycosylallylamide (AAG) was synthesized by allyl amine and delta-gluconolactone in dimethylformamide (DMF) solution. The sugar-based hydrogels were prepared by free radical crosslinking copolymerization of AAG and acrylamide (AM). The release properties of Aspirin from xerogels matrices were studied and the release mechanism of Aspirin was further identified by evaluating the n value in Peppas equation. The results indicate that the drug release decreases with the increase of the sugar content of hydrogel.
Acrylamide ; chemical synthesis ; chemistry ; Aspirin ; pharmacokinetics ; Delayed-Action Preparations ; Gluconates ; chemical synthesis ; chemistry ; Hydrogels ; chemical synthesis ; chemistry ; Lactones ; Polymers ; chemical synthesis ; chemistry

Germ cells make two major decisions when they move from an indeterminate state to their final stage of gamete production. One decision is sexual commitment for sperm or egg production, and the other is to maintain mitotic division or entry into meiosis. It is unclear whether the two decisions are made as a single event or separate events, because there has been no evidence for the presence of germ cell sex prior to meiosis. Here we report direct evidence in the fish rainbow trout that gonia have distinct sexuality. We show that dazl expression occurs in both male and female gonia but exhibits differential intracellular distribution. More strikingly, we show that boule is highly expressed in male gonia but absent in female gonia. Therefore, mitotic gonia possess sex, sperm/egg decision and mitosis/meiosis decision are two independent events, and sperm/egg decision precedes mitosis/meiosis decision in rainbow trout, making this organism a unique vertebrate model for mechanistic understanding of germ cell sex differentiation and relationship between the two decisions.
Animals ; Female ; Fish Proteins ; genetics ; Gene Expression Regulation ; Male ; Meiosis ; Oncorhynchus mykiss ; genetics ; physiology ; Ovary ; cytology ; metabolism ; Ovum ; cytology ; metabolism ; RNA, Messenger ; genetics ; metabolism ; RNA-Binding Proteins ; genetics ; Sex Determination Processes ; Spermatozoa ; cytology ; metabolism ; Testis ; cytology ; metabolism

Objective:To examine the social isolation(SI)status among the elderly population in China and its effect on cardiovascular and cerebrovascular diseases(CCVD).Methods:Utilizing data from the Fourth China Urban and Rural Elderly Living Conditions Sample Survey, the social isolation(SI)score was determined based on four components: marital status, living arrangements, frequency of contact with relatives and friends, and social participation.The χ2 test was employed to examine variations among socially isolated individuals, regional disparities within each province, and subgroups within each covariate.Additionally, Logistic regression was conducted to evaluate the impact of SI and its associated factors on CCVD. Results:The final analysis included 218 329 elderly individuals, revealing that the incidence and number of SI in Shandong Province are the highest in China at 18.95%(3 360 out of 17 735).The incidence of SI in the Eastern coastal provinces is notably higher than in the Western region.Factors contributing to a higher prevalence of SI include living in rural areas, being female, older age, belonging to ethnic minorities, having low educational attainment, facing economic disadvantages, smoking, drinking alcohol, lack of exercise, loneliness, poor sleep quality, and dissatisfaction with housing conditions.The study found that SI increased the risk of developing cardiovascular disease even after adjusting for negative emotional experiences or poor lifestyle choices( OR=1.190, 95% CI: 1.016-1.296, P=0.016, OR=1.208, 95% CI: 1.131-1.291, P<0.001), and the risk further increased when both factors were simultaneously adjusted for( OR=1.237, 95% CI: 1.160-1.319, P<0.001). Conclusions:Combining SI with poor lifestyle and negative emotions significantly raises the risk of cardiovascular disease, highlighting the importance of addressing these factors in the elderly population.

Objective To monitor the antifungal resistance of clinical isolates of Candida spp.in the East China region.Methods MALDI-TOF MS or molecular methods were used to re-identify the strains collected from January 2018 to December 2022.Antifungal susceptibility testing was performed using the broth microdilution method.The susceptibility test results were interpreted according to the breakpoints of 2022 Clinical and Laboratory Standards Institute(CLSI)documents M27 M44s-Ed3 and M57s-Ed4.Results A total of 3 026 strains of Candida were collected,65.33％of which were isolated from sterile body sites,mainly from blood(38.86％)and pleural effusion/ascites(10.21％).The predominant species of Candida were Candida albicans(44.51％),followed by Candida parapsilosis complex(19.46％),Candida tropicalis(13.98％),Candida glabrata(10.34％),and other Candida species(0.79％).Candida albicans showed overall high susceptibility rates to the 10 antifungal drugs tested(the lowest rate being 93.62％).Only 2.97％of the strains showed dose-dependent susceptibility(SDD)to fluconazole.Candida parapsilosis complex had a SDD rate of 2.61％and a resistance rate of 9.42％to fluconazole,and susceptibility rates above 90％to other drugs.Candida glabrata had a SDD rate of 92.01％and a resistance rate of 7.99％to fluconazole,resistance rates of 32.27％and 48.24％to posaconazole and voriconazole non-wild-type strains(NWT),respectively,and susceptibility rates above 90％to other drugs.Candida tropicalis had resistance rates of 29.55％and 26.24％to fluconazole and voriconazole,respectively,resistance rates of 76.60％and 21.99％to posaconazole and echinocandins non-wild-type strains(NWT),and a resistance rate of 2.36％to echinocandins.Conclusions The prevalence and species distribution of Candida spp.in the East China region are consistent with previous domestic and international reports.Candida glabrata exhibits certain degree of resistance to fluconazole,while Candida tropicalis demonstrates higher resistance to triazole drugs.Additionally,echinocandins resistance has emerged in Candida albicans,Candida glabrata,Candida tropicalis,and Candida parapsilosis.