Surface area or diameter – which factor really determines the antibacterial activity of silver nanoparticles grown on TiO₂ coatings?

Titanium dioxide coatings were prepared on Si wafers using the sol–gel method. Four different types of coatings with silver nanoparticles (AgNPs) were synthesized. The diameter and surface density of AgNPs were conditioned by the concentration of Ag+ ions in the initial solution, time and UV illumination source. The bactericidal activity of AgNPs on the titanium dioxide coatings against the S. aureus strain were calculated as the percentage of the inhibition of bacterial growth after 24 hour incubation of microorganisms at 37°C on TiO₂ coatings with AgNPs. Control samples were coated with titanium dioxide without AgNPs. We concluded that the titanium dioxide coatings modified with silver nanoparticles had a high antibacterial activity. Moreover, we demonstrated strong dependence between surface areas of AgNPs and inhibition of bacterial growth. The obtained results evidence that the surface area of AgNPs grown on titanium dioxide coatings is a major factor determining their antimicrobial potential

The effect of intensive insulin therapy on the body mass index and lipids in patients with type 1 diabetes mellitus : retrospective analysis

WSTĘP. Celem pracy jest analiza retrospektywna efektów leczenia metodą intensywnej insulinoterapii u chorych na cukrzycę typu 1, a w szczególności wykazanie wpływu tej metody leczenia na wskaźnik masy ciała (BMI, body mass index), profil lipidowy, wyrównanie cukrzycy i dobowe zapotrzebowanie na insulinę. MATERIAŁ I METODY. Analizie poddano historie chorób osób z cukrzycą typu 1 hospitalizowanych w Klinice Chorób Metabolicznych Szpitala Uniwersyteckiego w latach 1995-1999. Podczas hospitalizacji u wszystkich chorych wdrożono model intensywnej insulinoterapii (IIT) oraz przeprowadzono cykl szkoleń. WYNIKI. U 72 chorych w wieku 31,85 ± 11,88 lat (37 kobiet i 35 mężczyzn) po okresie 1-4 lat oceniono wyniki badań kontrolnych. Stwierdzono statystycznie istotny wzrost wskaźnika BMI po okresie 1-4 lat leczenia IIT (22,84 ± 3,05 vs. 24,07 ± 3,29 kg/m2, p < 0,001). Statystycznie istotnie podwyższyło się stężenie cholesterolu całkowitego (4,75 ± ± 1,10 vs. 5,07 ± 1,21 mmol/l, p < 0,05), a także stężenie cholesterolu frakcji HDL (1,44 ± 0,49 vs. 1,63 ± ± 0,38 mmol/l, p < 0,05). Nie stwierdzono istotnych różnic w zakresie stężenia triglicerydów, cholesterolu frakcji LDL oraz wskaźnika aterogenności. Po okresie 1-4 lat stosowania IIT stwierdzono statystycznie istotną poprawę wyrównania cukrzycy (HbA1c: 8,50 ± 2,37 vs. 7,40 ± 1,69%, p < 0,01), a także statystycznie istotną dodatnią zależność pomiędzy BMI i stężeniem cholesterolu frakcji LDL (r = 0,41, p < 0,005) oraz HbA1c i stężeniem triglicerydów (r = 0,53, p < 0,05) w badaniach końcowych. WNIOSKI. Przeprowadzona analiza wskazuje, że wprowadzenie IIT do leczenia chorych na cukrzycę typu 1 pozwoliło na lepszą kontrolę glikemii. Niekorzystnym zjawiskiem był przyrost masy ciała wyrażony wskaźnikiem BMI, któremu nie towarzyszył aterogenny profil lipidów, o czym świadczy wzrost stężenia cholesterolu frakcji HDL. Korzystne zmiany profilu lipidowego, mimo wzrostu BMI, mogą wynikać z lepszego wyrównania cukrzycy, osiąganego w czasie leczenia IIT.OBJECTIVE. The purpose of the study was a retrospective analysis of intensive insulin therapy in patients with type 1 diabetes mellitus with special consideration of its effects on the body mass index (BMI), lipid profile, diabetes control and daily insulin requirement. RESEARCH DESING AND METHODS. Case histories of type 1 diabetics hospitalised in the Department of Metabolic Diseases between 1995 and 1999 were analysed. Each hospitalised patient received intensive insulin therapy (IIT) and attended a course on diabetes education. RESULTS. In 72 patients (37 women and 35 men) with a mean age of 31,85 ± 11,88 years the results of control examinations were evaluated at 1 to 4 years after IIT. BMI was found to increase significantly (22,84 ± 3,05 vs. 24,07 ± 3,29 kg/m2, p < 0,001). Total cholesterol was significantly higher (4,75 ± ± 1,10 vs 5,07 ± 1,21 mmol/l, p < 0,05), similar to HDL cholesterol (1,44 ± 0,49 vs. 1,63 ± 0,38 mmol/l, p <0,05). No significant differences were seen in triglycerides, LDL cholesterol and atherogenic index. At 1-4 years after IIT diabetes control was significantly improved (HbA1c: 8,50 ± 2,37 vs. 7,40 ± 1,69%, p < 0,01). There was a significant positive correlation between BMI and LDL cholesterol (r = 0,41, p < 0,005) and between HbA1c and triglycerides (r = 0,53, p < 0,05). CONCLUSIONS. The retrospective analysis shows that IIT in patients with type 1 diabetes mellitus improved glycaemia control. Body weight gain expressed as BMI was an unfavourable effect. The increased BMI was not associated with the atherogenic lipid profile based upon increased HDL cholesterol. The favourable changes in the lipid profile despite the increased BMI may result from improved diabetes control due to IIT

Research and Design of a Routing Protocol in Large-Scale Wireless Sensor Networks

无线传感器网络，作为全球未来十大技术之一，集成了传感器技术、嵌入式计算技术、分布式信息处理和自组织网技术，可实时感知、采集、处理、传输网络分布区域内的各种信息数据，在军事国防、生物医疗、环境监测、抢险救灾、防恐反恐、危险区域远程控制等领域具有十分广阔的应用前景。 本文研究分析了无线传感器网络的已有路由协议，并针对大规模的无线传感器网络设计了一种树状路由协议，它根据节点地址信息来形成路由，从而简化了复杂繁冗的路由表查找和维护，节省了不必要的开销，提高了路由效率，实现了快速有效的数据传输。 为支持此路由协议本文提出了一种自适应动态地址分配算——ADAR（AdaptiveDynamicAddre...As one of the ten high technologies in the future, wireless sensor network, which is the integration of micro-sensors, embedded computing, modern network and Ad Hoc technologies, can apperceive, collect, process and transmit various information data within the region. It can be used in military defense, biomedical, environmental monitoring, disaster relief, counter-terrorism, remote control of haz...学位：工学硕士院系专业：信息科学与技术学院通信工程系_通信与信息系统学号：2332007115216

Plasticity of the inner cell mass in mouse blastocyst is restricted by the activity of FGF/MAPK pathway

Abstract In order to ensure successful development, cells of the early mammalian embryo must differentiate to either trophectoderm (TE) or inner cell mass (ICM), followed by epiblast (EPI) or primitive endoderm (PE) specification within the ICM. Here, we deciphered the mechanism that assures the correct order of these sequential cell fate decisions. We revealed that TE-deprived ICMs derived from 32-cell blastocysts are still able to reconstruct TE during in vitro culture, confirming totipotency of ICM cells at this stage. ICMs isolated from more advanced blastocysts no longer retain totipotency, failing to form TE and generating PE on their surface. We demonstrated that the transition from full potency to lineage priming is prevented by inhibition of the FGF/MAPK signalling pathway. Moreover, we found that after this first restriction step, ICM cells still retain fate flexibility, manifested by ability to convert their fate into an alternative lineage (PE towards EPI and vice versa), until peri-implantation stage