Analysis on status of follow-up testing among young HIV/AIDS students aged 15-24 in Guangdong Province，2008-2019 / 中国学校卫生

Objective@#To analyze the status of follow-up cell testing of HIV/AIDS cases among young students aged 15-24 in Guangdong Province from 2008 to 2019.@*Methods@#Using the historical database downloaded from the AIDS Comprehensive Prevention and Control Information System from January 1, 2018 to December 31, 2019, eligible newly discovered cases were screened by year and were linked with follow-up database. Joinpoint regression model and trend test were used to explore the annual changes in the follow-up and CD4 testing status, and Logistic regression was used to analyze relevant influencing factors.@*Results@#The number of infected students showed a rapid upward trend before 2015(APC=41.7，β=0.3，P<0.01), and the growth rate slowed down(APC=3.6，β=-0.3，P<0.01). The proportion of follow-up and CD4 testing completed within one year increased from 58.3% in 2008 to 93.6% in 2019, and the timely detection rate increased from 33.3% in 2008 to 86.2% in 2019. The Cochran Armitage trend test was statistically significant. Pairwise comparison test showed time trends of the idnex differed in regions and education groups (Z=4.7，8.7，9.8，P<0.01). The Pearl River Delta region, cases from other cities in the province, with precise transmission routes, from voluntary counseling and testing, and cases flowing within the province, the proportion of follow up and testing completed within one year is relatively high (P<0.05).@*Conclusion@#The growth rate of HIV/AIDS cases among young students aged 15-24 in Guangdong Province has slowed down in recent years. The route of infection, source and flow of cases affect follow-up and testing compliance. And to do a good job of referrals for off-site mobility, and explore and promote student-friendly VCT service models.

Field-assisted nanopatterning of metals, metal oxides and metal salts.

The tip-based nanofabrication method called field-assisted nanopatterning or FAN has now been extended to the transfer of metals, metal oxides and metal salts onto various receiving substrates including highly ordered pyrolytic graphite, passivated gold and indium-tin oxide. Standard atomic force microscope tips were first dip-coated using suspensions of inorganic compounds in solvent. The films prepared in this manner were non-uniform and contained inorganic nanoparticles. Tip-based nanopatterning on chosen substrates was conducted under high electric field conditions. The same tip was used for both nanofabrication and imaging. Arbitrary patterns were formed with dimensions that ranged from tens of microns to sub-20 nm and were controlled by tuning the tip bias during fabrication. Most tip-based nanopatterning techniques are limited in terms of the type of species that can be deposited and the type of substrates onto which the deposition occurs. With the successful deposition of inorganic species reported here, FAN is demonstrated to be a truly versatile tip-based nanofabrication technique that is useful for the deposition of a wide variety of both organic and inorganic species including small molecules, large molecules and polymers.

Self-assembly of long chain alkanes and their derivatives on graphite.

We combine scanning tunneling microscopy (STM) measurements with ab initio calculations to study the self-assembly of long chain alkanes and related alcohol and carboxylic acid molecules on graphite. For each system, we identify the optimum adsorption geometry and explain the energetic origin of the domain formation observed in the STM images. Our results for the hierarchy of adsorbate-adsorbate and adsorbate-substrate interactions provide a quantitative basis to understand the ordering of long chain alkanes in self-assembled monolayers and ways to modify it using alcohol and acid functional groups.

Thermal, sonochemical, and mechanical behaviors of single crystal [60]fullerene nanotubes.

Although related to conventional carbon nanotubes in both shape and construction, fullerene nanowhiskers and fullerene nanotubes have received far less attention. A modified liquid-liquid interfacial precipitation technique is described to produce relatively uniform batches of [60]fullerene nanotubes in high yield. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) reveal that the tubes possess approximately 100-nm inside diameters and 300-nm outside diameters. The [60]fullerene nanotubes degrade slowly at 180 degrees C, eventually collapsing into micron scale [60]fullerene discs and rods, as revealed by optical microscopy and AFM. Ultrasonic cavitation chops [60]fullerene nanotubes into smaller segments within seconds. Longer ultrasonic bathing leads to considerable structural damage in which the sidewalls rupture. Mechanical stress tests using an AFM microscope tip effectively dent and break [60]fullerene nanowhiskers, revealing a hollow interior.