ABSTRACT
Objective To develop a high-speed data acquisition system for very high frequency medical ultrasonic echo signals. Methods The chip LTC2285 with two integrated ADC channels was adopted to realize analog-to-digital conversion of ultrasonic echo signals. The sampling rate was 120 MHz. The converted digital signals were then input to the FPGA to realize parallel to serial conversion, and high-speed digital signals with a sampling rate of 240 MHz were obtained. Finally, the data were transferred through USB interface to the computer terminal to display. Results A timing simulation experiment, a resolution detection experiment, and an in vivo experiment of normal human eyes were carried out in this system. A preferable simulation result and real-time image were obtained. Conclusion The multi-channel and FPGA technology are used in the design of the system. Lastly, this technology simplifies the overall design of the system and improves the speed and reliability of the high speed data acquisition system.
ABSTRACT
Objective To compare the effects of chemical penetration enhancers and negative electret in promoting percutaneous penetrationof 5-fluorouracil (5-FU) through rat scar and dorsal skin in vitro, so as to lay a foundation for preparing delayed-release 5-FU electret transdermal patch. Methods The in vitro transdermal behaviors of 5-FU through rat scar and dorsal skin under the actions of 1 % azone, 10% ethyl oleate, —1 000 V electret, —1 500 V electret and —2 000 V electret were studied using improved Franze diffusion cell and high performance liquid chromatography (HPLC). Results (1) Both 1% azone and 10% ethyl oleate promoted the penetration of 5-FU through rat scar and dorsal skin, with the promoting effect of 10% ethyl oleate being better than that of 1% azone. (2) Although the transdermal behaviors of 5-FU were similar through scar skin and dorsal skin at the presence of chemical enhancers, the cumulative penetration amount through the scar skinwas less than that through the dorsal skin. (3) The negative electrets used in this study had satisfactory penetration promoting effect, with the promoting effect from strong to weak being —2 000 V electret > — 1 500 V electret > — 1 000 V electret Moreover, the scar skin also had less cumulative penetration amount of 5-FU than that of the dorsal skin under the action of electrets. Conclusion Both the chemical enhancers and electrets can enhance the transdermal delivery of 5-FU. 10% ethyl oleate and — 2 000 V electret have the best enhancing effect on 5-FU transdermal delivery and can be considered for preparation of 5-FU electret transdermal patch.
ABSTRACT
<p><b>OBJECTIVES</b>To determine the incidence and outcome of severe sepsis in Newborn Intensive Care Unit (NICU) and to characterize their demographics and infection pattern.</p><p><b>METHODS</b>Characteristics of 243 newborns admitted to NICU from June 1st, 2006 to May 31st, 2007 were retrospectively analyzed.</p><p><b>RESULTS</b>Analysis of data derived from 243 newborns admitted to NICU over an 1-year period with 48 (19.8%) cases diagnosed as severe sepsis, and 70.8% of them were males. The median age of severe sepsis patients was 2 (1-6 ) days. In 56.3% of the patients bacteria were isolated, and E. coli was the predominant microbe. PRISM score and mortality rate were higher in those with severe sepsis, while their Apgar score was lower than other cases. The overall hospital mortality of severe sepsis was 45.8%. Risk factors for hospital mortality included higher PRISM score, severe organ dysfunction, circulatory system dysfunction, and hematological or central nervous system dysfunction.</p><p><b>CONCLUSIONS</b>This study shows that severe sepsis is a common, frequently fatal morbid condition in critical ill newborns in NICU, showing similar disease pattern with other investigations. Further multiple-center investigations are helpful to prevent, control and salvage critically ill children suffering from severe sepsis.</p>
Subject(s)
Female , Humans , Infant, Newborn , Male , Incidence , Intensive Care Units, Neonatal , Retrospective Studies , Sepsis , EpidemiologyABSTRACT
Diphtheria toxin A fragment (DTA) is an essential catalytic domain of diphtheria toxin (DT)-based immunotoxin. DTA protein and its antibodies play an important role in the studies on toxicology, purification and identification of DT-based immunotoxins. In this paper, DTA was expressed and purified from E. coli. After Q-Sepharose FF chromatography and (Ni+)-Sepharose affinity chromatography, 6 x His-DTA fusion protein with 90% purity was achieved. Using the purified DTA as antigen to immunize BalB/c mice, 2 hybridoma cell lines (designated as 3B6 and 3B9, respectively) secreting monoclonal antibodies (McAbs) against DTA were established. Investigations showed that both McAbs were characterized as IgG1 with titers of 1: 10(6). The binding of the McAbs to DTA was competitively inhibited by horse sera against DT. The fact that anti-DTA McAbs could be used in western blot analysis and affinity chromatography purification of DT-based immunotoxins implied that they will be useful agents in the studies on DT-based immunotoxins.