[Release rule of volatile components of moxa sticks with increase of temperature].

OBJECTIVE: To systematically investigate the changes rule of volatile oil and its main components released from moxa sticks under different headspace temperatures and combustion conditions, so as to guide the clinical rational selection of the temperature for moxa sticks. METHODS: Using the headspace gas chromatography-mass spectrometry (HS-GCMS) technique, the released gas from moxa sticks was collected at the headspace temperature (from room temperature [25 ℃] to 190 ℃) and during combustion. One mL of the gas was injected into 6890/5973N gas chromatography-mass spectrometry (GCMS). The release rates of volatile components of moxa sticks were calculated by total ion chromatography (TIC) and butanone internal standard method. The volatile components of moxa sticks were qualitatively analyzed by analyzing the mass spectra of each volatile component and matching the Nist 14 standard mass spectrometry library. By comparing and analyzing the peak intensity changes rule of 1,8-cineole and its main harmful components (benzene, toluene and phenol) under different headspace temperatures and combustion conditions, the optimal temperature for clinical use of moxa sticks was found. RESULTS: At room temperature and 50 ℃, the release rate of volatile components from moxa sticks was very low, and it showed a significant increase trend with the increase of temperature. When the headspace temperature was 190 ℃, the release rate of volatile components from moxa sticks reached 0.864 2%, which was 2 161 times as same as that at room temperature. After combustion, it dropped sharply to 0.027 9%, which was 96.8% lower than that at the headspace temperature of 190 ℃. When the headspace temperature was 125 ℃ and 150 ℃, the content of 1,8-cineole, a typical beneficial component in the volatile components of moxa sticks, was the highest. When the headspace temperature was higher than 150 ℃, its content showed a significant downward trend. Under combustion conditions, a large number of harmful substances, such as benzene, toluene and phenol, were detected. CONCLUSION: The combustion condition is not conducive to the efficient utilization of the volatile oil of moxa sticks. Temperature of 125-150 ℃ is the best for releasing the volatile components of moxa sticks, which is not only conducive to the release of the beneficial volatile components of moxa sticks, but also can greatly inhibit the production of harmful components.

Construction of photonic crystals with thermally adjustable pseudo-gaps.

Photonic crystals (PCs) are periodic dielectric structures with photonic bandgaps and they can be used to control and manipulate photons effectively. Novel photonic crystal materials with tunable bandgaps can be prepared by changing the refractive index of the dielectric or lattice parameters under external stimuli, while using temperature to adjust the photonic band gap is a simple and convenient method. In this paper, silica PCs having different pseudo-gaps in the range of 450-750 nm were prepared with colloidal SiO2 spheres of different sizes. Thermo-sensitive PNIPAM hydrogel was then infiltrated into the PCs to obtain PNIPAM-PCs, whose pseudo-gap blue-shifted when the temperature was changed from 24 to 34 °C and exhibited good reversibility. The PCs with tunable bandgaps are significant for the development of integrated photonic devices, sensors, and in detection and other technologies.

Superhydrophilicity and strong salt-affinity: Zwitterionic polymer grafted surfaces with significant potentials particularly in biological systems.

In recent years, zwitterionic polymers have been frequently reported to modify various surfaces to enhance hydrophilicity, antifouling and antibacterial properties, which show significant potentials particularly in biological systems. This review focuses on the fabrication, properties and various applications of zwitterionic polymer grafted surfaces. The "graft-from" and "graft-to" strategies, surface grafting copolymerization and post zwitterionization methods were adopted to graft lots type of the zwitterionic polymers on different inorganic/organic surfaces. The inherent hydrophilicity and salt affinity of the zwitterionic polymers endow the modified surfaces with antifouling, antibacterial and lubricating properties, thus the obtained zwitterionic surfaces show potential applications in biosystems. The zwitterionic polymer grafted membranes or stationary phases can effectively separate plasma, water/oil, ions, biomolecules and polar substrates. The nanomedicines with zwitterionic polymer shells have "stealth" effect in the delivery of encapsulated drugs, siRNA or therapeutic proteins. Moreover, the zwitterionic surfaces can be utilized as wound dressing, self-healing or oil extraction materials. The zwitterionic surfaces are expected as excellent support materials for biosensors, they are facing the severe challenges in the surface protection of marine facilities, and the dense ion pair layers may take unexpected role in shielding the grafted surfaces from strong electromagnetic field.