[Preparation and Synchronized Release Behavior on Porosity Osmotic Pump Tablets of Total Glucosides of Paeony].

Objective: To prepare porosity osmotic pump tablets of total glucosides of paeony( TGP),and to study the behavior on synchronous release of its main components. Methods: Taking the accumulative release of TGP as indexes, through single-factor test and orthogonal design to investigate the optimal formulation porosity osmotic pump tablets of TGP. The main components, paeoniflorin, albiflorin and benzoylpaeoniflorin were employed to study synchronous release of the optimal formulation. Results: The membrane weight, and the content of PEG 400,and diethyl phthalate( DEP) were the main factors influencing the behavior of TGP release. The accumulated release of the prepared osmotic pump release tablets achieved about 90%. Three main components achieved the desired zero-order release profile and had a synchronized release behavior. Conclusion: The prepared porosity osmotic pump tablets of TGP can achieve the behavior of synchronized release of multi-components with good reproducibility.

[Effect of Microplastics and Phenanthrene on Soil Chemical Properties, Enzymatic Activities, and Microbial Communities].

Microplastic and polycyclic aromatic hydrocarbon (PAHs) pollution have received increasing attention due to their ubiquitous distribution and potential risks in soils. However, the effects of microplastics-PAHs combined pollution on soil ecosystems remain unclear. Polyethylene (PE)/polypropylene (PP) and phenanthrene (PHE) were selected as the representatives of microplastics and PAHs, respectively. A 300-day soil microcosm experiment was conducted to study the single and combined effects of PE/PP and PHE on soil chemical properties, enzymatic activities, and bacterial communities (i.e., quantity, composition, and function), using the soil agricultural chemical analysis method and 16S amplicon sequencing technology. The interactions of soil properties, enzyme activities, and flora in the presence of PE/PP and PHE were analyzed. The results showed that the addition of PE/PP and PHE slightly changed the pH, available phosphorus (AP), and microbial quantity (i.e., bacteria, actinomycetes, and mold) but considerably increased the fluorescein diacetate hydrolase (FDAse) activity. There was a significant enhancement of soil organic matter (SOM) and urease activity in PE, PP, PHE-PE, and PHE-PP amended systems. PHE, PHE-PE, and PHE-PP obviously increased the dehydrogenase/neutral phosphatase activities and available nitrogen (AN) content. PHE had little effect on the microbial community. The PE, PP, PHE-PE, and PHE-PP addition influenced the microbial community to some extent. PE/PP and PHE showed positive effects on the energy production, growth, and reproduction of soil microorganisms and then accelerated the metabolism/degradation of pollutants and membrane transport. The changes in AN and SOM induced by PE/PP and PHE were the key factors affecting soil enzyme activities. Alterations in AN, AP, and pH were mainly responsible for the increase in microbial population. The changes in the microbial community were related to soil chemical properties and enzyme activities, and SOM had a significant effect on the microbial community. The presence of different carbon sources (PE/PP and PHE) in the soil and the microbial interaction also affected the microbiota. In conclusion, the addition of single or combined pollutants of PE/PP and PHE influenced the soil chemical properties, enzymatic activities, bacterial communities, and their interaction processes, thus facilitating the adaptation of the microbial community to pollutant stress.

Multifunctional biodegradable polymer nanoparticles with uniform sizes: generation and in vitro anti-melanoma activity.

We present a simple, yet versatile strategy for the fabrication of uniform biodegradable polymer nanoparticles (NPs) with controllable sizes by a hand-driven membrane-extrusion emulsification approach. The size and size distribution of the NPs can be easily tuned by varying the experimental parameters, including initial polymer concentration, surfactant concentration, number of extrusion passes, membrane pore size, and polymer molecular weight. Moreover, hydrophobic drugs (e.g., paclitaxel (PTX)) and inorganic NPs (e.g., quantum dots (QDs) and magnetic NPs (MNPs)) can be effectively and simultaneously encapsulated into the polymer NPs to form the multifunctional hybrid NPs through this facile route. These PTX-loaded NPs exhibit high encapsulation efficiency and drug loading density as well as excellent drug sustained release performance. As a proof of concept, the A875 cell (melanoma cell line) experiment in vitro, including cellular uptake analysis by fluorescence microscope, cytotoxicity analysis of NPs, and magnetic resonance imaging (MRI) studies, indicates that the PTX-loaded hybrid NPs produced by this technique could be potentially applied as a multifunctional delivery system for drug delivery, bio-imaging, and tumor therapy, including malignant melanoma therapy.

Tooth Loss, Denture Use, and Cognitive Impairment in Chinese Older Adults: A Community Cohort Study.

BACKGROUND: Evidence regarding the associations of tooth loss and denture use with incident cognitive impairment is inconclusive in older adults, and few prospective studies have examined the potential interaction between tooth loss and denture use in these specific populations. METHODS: Data were assessed from 17 079 cognitively normal older adults aged ≥65 years, participating in the Chinese Longitudinal Healthy Longevity Survey. The outcome of interest was cognitive impairment (assessed by the Chinese version of Mini-Mental State Examination). The number of natural teeth and status of denture use were collected by a structural questionnaire. RESULTS: A total of 6456 cases of cognitive impairment were recorded during 88 627 person-years of follow-up. We found that compared with participants with 20+ teeth, those with 10-19, 1-9, and 0 teeth had increased risks of incident cognitive impairment (p-trend < .001). Participants without dentures also had a higher risk of incident cognitive impairment, compared with those who wore dentures. Effect modification by denture use was observed (p-interaction = .010). Specifically, among those without dentures, the adjusted hazard ratio (95% confidence interval) for participants with 10-19, 1-9, and 0 teeth were 1.19 (1.08, 1.30), 1.28 (1.17, 1.39), and 1.28 (1.16, 1.41), respectively, as compared to those with 20+ teeth. In contrary, among denture users, detrimental effect was only observed among those with 0 teeth (hazard ratio 1.14, 95% confidence interval: 1.16, 1.41). CONCLUSIONS: In Chinese older adults, maintaining 20+ teeth is important for cognitive health; denture use would attenuate the detrimental effects of tooth loss, especially for partial tooth loss, on cognitive impairment.

Toxicity and activity inhibition of metal-organic framework MOF-199 to nitrogen-fixing bacterium Azotobacter vinelandii.

Metal-organic framework (MOF) materials with fantastic properties have found important applications in various areas. Learning the lessons from plastics and microplastics, it is urgent to investigate the environmental impacts of emerging materials to avoid potential pollution. However, the environmental toxicity and risks of MOF materials are seldom reported. Herein, we studied the toxicity and activity inhibition of MOF-199 to nitrogen-fixing bacterium Azotobacter vinelandii. MOF-199 significantly suppressed the growth of A. vinelandii and led to cell death at 40 mg/L. MOF-199 penetrated the cell wall and induced the shrinking of bacterial cells. MOF-199 reduced the nitrogen fixation activity of A. vinelandii at 40 mg/L by decreasing the gene nifH levels and inhibiting the Ca2+Mg2+-ATPase activity, which was further confirmed by the changes in oxidative phosphorylation related genes. Complete growth inhibition and activity loss of A. vinelandii occurred at 60 mg/L of MOF-199. The toxicological mechanism of MOF-199 to A. vinelandii was assigned to the oxidative stress, which occurred at 20 mg/L and higher. Both Cu2+ release and particulates themselves contributed to the toxicity of MOF-199 to A. vinelandii. These findings highlighted the environmental hazards and risks of MOF materials to nitrogen-fixing bacteria and nitrogen fixation in the biogeochemical cycle.

Lignin-First Monomers to Catechol: Rational Cleavage of C-O and C-C Bonds over Zeolites.

A catalytic route is developed to synthesize bio-renewable catechol from softwood-derived lignin-first monomers. This process concept consists of two steps: 1) O-demethylation of 4-n-propylguaiacol (4-PG) over acidic beta zeolites in hot pressurized liquid water delivering 4-n-propylcatechol (4-PC); 2) gas-phase C-dealkylation of 4-PC providing catechol and propylene over acidic ZSM-5 zeolites in the presence of water. With large pore sized beta-19 zeolite as catalyst, 4-PC is formed with more than 93 % selectivity at nearly full conversion of 4-PG. The acid-catalyzed C-dealkylation over ZSM-5 zeolite with medium pore size gives a catechol yield of 75 %. Overall, around 70 % catechol yield is obtained from pure 4-PG, or 56 % when starting from crude 4-PG monomers obtained from softwood by lignin-first RCF biorefinery. The selective cleavage of functional groups from biobased platform molecules through a green and sustainable process highlights the potential to shift feedstock from fossil oil to biomass, providing drop ins for the chemicals industry.

A Motion Interference-Insensitive Flexible Dry Electrode.

OBJECTIVE: A novel dry electrode is developed to improve the comfortability and the capability of alleviating motion interference by combining microneedles array (MNA) with flexible substrate. METHODS: Silicon MNA with sharp tips and limited height is fabricated and transferred on a flexible Polydimethylsiloxane (PDMS) substrate through bonding. Poly (3, 4-ethylenedioxythiophene) doped with poly (styrenesulfonate) (PEDOT/PSS) is coated on the surface of flexible MNA to form a conductive layer. RESULTS: Flexible dry electrode with 1.2 cm diameter is successfully fabricated. The mean impedance magnitudes (measured on skin) at 10 Hz are 61.2 ±31.3 kΩ·cm(2) for flexible dry electrode, while the values are 114.9 ±36.1 kΩ·cm(2) for wet electrode and 335.7 ±110.5 kΩ·cm(2) for flexible planar dry electrode, respectively. In the process of biopotential recording, the flexible dry electrode has the similar performance as that of wet electrode. It exhibits more stable recording stability than rigid dry electrode in the movement state. CONCLUSION: By integrating flexible PDMS substrate, sharp and hard MNA structure, as well as PEDOT/PSS coated surface together, a novel dry electrode is developed to meet the comfortable and antimotion interference requirement of wearable equipment. SIGNIFICANCE: The novel flexible dry electrode provides a simple and comfortable method to record biopotential signals in daily life.