Acute and chronic toxic effects of bisphenol a on Chlorella pyrenoidosa and Scenedesmus obliquus

The acute and chronic toxic effects of Bisphenol A (BPA) on Chlorella pyrenoidosa (C. pyrenoidosa) and Scenedesmus obliquus (S. obliquus) were not well understood. The indoor experiments were carried out to observe and analyze the BPA‐induced changes. Results of the observations showed that in acute tests BPA could significantly inhibit the growth of both algae, whereas chronic exposure hardly displayed similar trend. Superoxide dismutase (SOD) and Catalase (CAT) activities of both algae were promoted in all the treatments. Chlorophyll a synthesis of the two algae exhibited similar inhibitory trend in short‐term treatments, and in chronic tests C. pyrenoidosa hardly resulted in visible influence, whereas in contrast, dose‐dependent inhibitory effects of S. obliquus could be clearly observed. The experimental results indicated that the growth and Chlorophyll a syntheses of S.obliquus were more sensitive in response to BPA than that of C. pyrenoidosa, whereas for SOD andCAT activities, C. pyrenoidosa was more susceptible. This research provides a basic understanding of BPA toxicity to aquatic organisms. © 2012 Wiley Periodicals, Inc. Environ Toxicol 29: 714–722, 2014.     

Three new diphenylpropanes from Celastrus hindsii

Three new diphenylpropanes, Hindsiipropane A–C (1–3), together with one known arylpropyl quinone Griffithane D (4), were isolated from Celastrus hindsii. Their structures were established by 1D and 2D nuclear magnetic resonance spectroscopic analysis, and mass spectroscopy. Compound 4 was firstly obtained in this genus. All the isolated compounds were evaluated in vitro for cytotoxicity against four human tumor cell lines (A549, HCT116, MDA-MB-231, BEL7404) by the MTT assay.     

缬沙坦的合成工艺研究

目的研究缬沙坦的新合成方法。方法以N-(三苯基甲基)-5-(4'-溴甲基联苯-2-基)四氮唑为原料,经Kornblum氧化、还原胺化、酰化、去保护基制得N-[2'-(1H-四氮唑)-5-基]-[(1,1'-联苯-4-基)-甲基]-N-戊酰-L-缬氨酸甲酯,后经水解、酸化得缬沙坦。结果与结论目标化合物的结构经1H-NMR谱确证,总收率为37.6%。新方法避免了消旋化,为合成缬沙坦提供了新的思路。     

Three-channel capillary NF membrane with PAMAM-MWCNT-embedded inner polyamide skin layer for heavy metals removal

Nanofiltration (NF) membranes with simultaneous high rejection of divalent cations and anions and high water permeation were designed and fabricated via interfacial polymerization (IP) on three-channel capillary ultrafiltration (UF) membranes. MWCNTs-COOH were modified with poly(amidoamine) (PAMAM) and the as-synthesized MWCNTs-PAMAM were embedded into the inner polyamide skin-layer of the NF membranes by incorporating them into a piperazine (PIP) aqueous solution, followed by IP with trimesoyl chloride (TMC). The rigid MWCNTs and the dendrimer PAMAM molecules endow the as-fabricated NF membranes with high porosity and good hydrophilicity. Additionally, the –NH₂ groups of PAMAM introduce some positive sites into the polyamide layer. The as-prepared NF membranes with incorporated MWCNTs-PAMAM exhibit a pure water flux of 48.7 L m⁻² h⁻¹ and 92.6% and 88.5% rejection for Na₂SO₄ and MgCl₂, respectively, at 4 bar. Moreover, the NF membranes display high rejection for sulfates and metal cations, including heavy metal ions. The practicability of the membranes for mine-wastewater treatment was tested, and the membranes showed above 80% rejection of heavy metals and solution flux of about 30 L m⁻² h⁻¹. In addition, their separation performance and stability were satisfactory during the long-term run. The high rejection of the membranes for metal cations is ascribed to the positive sites offered by MWCNTs-PAMAM and the narrow membrane pores since both electrostatic repulsion and size exclusion play a role during membrane filtration. The good separation performance of the membranes for multivalent anions and heavy metal cations illustrates their potential for applications in heavy metal wastewater treatment.

MWCNTs-PAMAM were incorporated into the polyamide layer of NF membranes and the prepared membranes showed good permeation and rejection performances.     

Near-infrared fluorescent probes for imaging of amyloid plaques in Alzheimer?s disease

One of the early pathological hallmarks of Alzheimer׳s disease (AD) is the deposition of amyloid-β (Aβ) plaques in the brain. There has been a tremendous interest in the development of Aβ plaques imaging probes for early diagnosis of AD in the past decades. Optical imaging, particularly near-infrared fluorescence (NIRF) imaging, has emerged as a safe, low cost, real-time, and widely available technique, providing an attractive approach for in vivo detection of Aβ plaques among many different imaging techniques. In this review, we provide a brief overview of the state-of-the-art development of NIRF Aβ probes and their in vitro and in vivo applications with special focus on design strategies and optical, binding, and brain-kinetic properties.KEY WORDS: Alzheimer׳s disease, Blood-brain barrier, Fluorescence probe, Near-infrared fluorescence, Optical imaging, Amyloid-β plaguesAbbreviations: Aβ, amyloid-β, Ach, acetylcholine, AD, Alzheimer’s disease, APP, amyloid peptide precursor, BAP, BODIPY-based Ab imaging probe, BBB, blood-brain barrier, Cy, cyanine dyes, ICG, indocyanine green dyes, MRI, magnetic resonance imaging, NIR, near-infrared, NIRF, near-infrared fluorescence, PET, positron emission tomography, ROS, reactive oxygen species, SPECT, single photon emission computed tomography     

Dual-generation dendritic mesoporous silica nanoparticles for co-delivery and kinetically sequential drug release

Although multi-drug synergetic therapy is increasingly important in clinical application, sophisticated delivery systems with the ability to deliver multiple drugs and realize sequential release with independently tunable kinetics at different stages are highly desirable. In this study, a dual-generation mesoporous silica nanoparticle (DAMSN) with three-dimensional dendrimer-like structure as an adaptable dual drug delivery system is developed. The DAMSN was synthesized via a heterogeneous interfacial reaction and was of uniformly spherical morphology (150–170 nm) with dendritic structures and hierarchical pores (inner pore, 3.5 nm; outer pore, 8.3 nm). And the inner generation of DAMSN was modified with 3-aminopropyltriethoxysilane (APTMS). The IBU and BSA as model drugs were loaded into the inner generation via covalent conjugation and the outer generation by electrostatic adsorption, respectively. Intriguingly, DAMSN underwent a rapid bio-degradation for about 4 days, partly due to its center-radial dendritic channel structure. The release results showed that IBU was of a typical two-phase release profile with almost zero release in the first 12 h and more sustained release for the following 88 h, while BSA was sustained over a long period of 100 h. Notably, the release behaviors of both drugs can be independently tailored by changing the intrinsic properties of the DAMSN. In addition, DAMSN exhibited good bio-compatibility. These results indicated that the dual-generation, dendrimer-like MSN structure could spatiotemporally present different drugs to realize sequential drug release, and has potential use in the field of tissue engineering and regenerative medicine.

The designed DAMSN could simultaneously load IBU and BSA, and realize sequential drug release efficiently.     

The add-on effect of dengzhan shengmai capsules on secondary prevention of ischemic stroke: A multicentre,randomised, placebo-controlled clinical trial

ObjectiveThe Dengzhan Shengmai (DZSM) capsule is a commercially available type of Chinese herbal medicine frequently administered to improve neurological impairment after stroke. Its ability to prevent recurrent stroke, however, has not been determined. This study therefore evaluated the ability of DZSM as an add-on to conventional secondary preventive agents to prevent recurrent ischemic stroke.MethodsIn this randomised, double-blind, placebo-controlled trial, conducted at 83 hospitals in Mainland China, 3143 patients in 14–180 days after the initial onset of ischemic stroke, were randomly allocated to the DZSM (0.36 g, twice daily for 12 months) or the placebo group. All patients in both groups received standard secondary preventive medications. The primary outcome was the 1-year incidence of stroke. Between group differences were assessed using the Cox proportional hazards model.ResultsIntent-to-treat analysis showed that 58 (3.8%) participants in the DZSM group and 82 (5.4%) in the placebo group experienced new stroke events (hazard ratio = 0.70, 95% confidence interval = 0.50–0.98, P = 0.036). The type and incidence of adverse events were similar in the DZSM and placebo groups.ConclusionsThe addition of DZSM capsules to standard secondary preventive agents provides additional benefits after the initial onset of ischemic stroke, reducing recurrent stroke without increasing severe adverse events. However, further study is needed to elucidate the role of DZSM on the updated practice of conventional secondary prevention for ischemic stroke.     

Food environment,walkability, and public open spaces are associated with incident development of cardio-metabolic risk factors in a biomedical cohort

We investigated whether residential environment characteristics related to food (unhealthful/healthful food sources ratio), walkability and public open spaces (POS; number, median size, greenness and type) were associated with incidence of four cardio-metabolic risk factors (pre-diabetes/diabetes, hypertension, dyslipidaemia, abdominal obesity) in a biomedical cohort (n=3205). Results revealed that the risk of developing pre-diabetes/diabetes was lower for participants in areas with larger POS and greater walkability. Incident abdominal obesity was positively associated with the unhealthful food environment index. No associations were found with hypertension or dyslipidaemia. Results provide new evidence for specific, prospective associations between the built environment and cardio-metabolic risk factors.