With the increasing occurrence of haze during the summer, the physicochemical characteristics and toxicity differences in PM_2.5 in different seasons are of great concern. Hangzhou is located in an area that has a subtropical monsoon climate where the humidity is very high during both the summer and winter. However, there are limited studies on the seasonal differences in PM_2.5 in these weather conditions. In this test, PM_2.5 samples were collected in the winter and summer, the morphology and chemical composition of PM_2.5 were analyzed, the toxicity of PM_2.5 to human bronchial cells BEAS-2B was compared, and the correlation between PM_2.5 toxicity and the chemical composition was discussed. The results showed that during both the winter and summer, the main compounds in the PM_2.5 samples were water-soluble ions, particularly SO₄^2-, NO₃^-, and NH₄⁺, followed by organic components, while heavy metals were present at lower levels. The higher the mass concentration of PM_2.5, the greater its impact on cell viability and ROS levels. However, when the mass concentration of PM_2.5 was similar, the water extraction from the summer samples showed a greater impact on BEAS-2B than that from the winter samples. The cytotoxicity of PM_2.5 was closely associated with heavy metals and organic pollutants but less related to water-soluble ions.
Air Pollutants/toxicity* ; Bronchi/metabolism* ; Carbon/chemistry* ; Environmental Monitoring ; Humans ; Ions ; Metals, Heavy ; Organic Chemicals ; Particle Size ; Particulate Matter/toxicity* ; Seasons ; Temperature ; Water

This study was conducted to measure the concentrations of strontium (Sr), barium (Ba), cadmium (Cd), copper (Cu), zinc (Zn), manganese (Mn), chromium (Cr), antimony (Sb), selenium (Se), and lead (Pb) in canine liver, renal cortex, and renal medulla, and the association of these concentrations with age, gender, and occurrence of chronic kidney disease (CKD). Tissues from 50 dogs were analyzed using inductively coupled plasma mass spectrometry. Cu, Zn, and Mn levels were highest in the liver followed by the renal cortex and renal medulla. The highest Sr, Cd, and Se concentrations were measured in the renal cortex while lower levels were found in the renal medulla and liver. Female dogs had higher tissue concentrations of Sr (liver and renal medulla), Cd (liver), Zn (liver and renal cortex), Cr (liver, renal cortex, and renal medulla), and Pb (liver) than male animals. Except for Mn and Sb, age-dependent variations were observed for all element concentrations in the canine tissues. Hepatic Cd and Cr concentrations were higher in dogs with CKD. In conclusion, the present results provide new knowledge about the storage of specific elements in canine liver and kidneys, and can be considered important reference data for diagnostic methods and further investigations.
Aging ; Animals ; Dog Diseases/*metabolism ; Dogs ; Female ; Kidney/*chemistry ; Liver/*chemistry ; Male ; Metals/chemistry/*metabolism ; Renal Insufficiency, Chronic/*metabolism

In this study, we investigate the bioaccessibility of heavy metals (Cu, Pb, As, Cd and Hg) in wild Artemisia annua and use target hazard quotients (THQ) proposed by US Environmental Protection Agency to assess the health risk under the heavy metal exposure. The results showed that the bioaccessibility of Cu, Pb, As, Cd and Hg in A. annua are 0.77, 0.66, 0.46, 0.68 and 0, respectively, and that the value of THQ for adults and children were 0.030 and 0.025 calculated by risk assessment model. The results indicated that the heavy metals in A. annua were not able to be completely absorbed by human body and that their contents were in a safe range. In this study, by combining the bioavailability of heavy metal and health risk assessment, we assessed the security of heavy metals of wild A. annua, which will provide reference for the standard of heavy metals for medicinal materials.
Artemisia annua ; chemistry ; metabolism ; Consumer Product Safety ; Drug Contamination ; Humans ; Metals, Heavy ; analysis ; metabolism ; Risk Assessment ; Soil Pollutants ; analysis ; metabolism

Six heavy metals, including As, Cu, Hg, Cd, Pb and Cr in Panax notoginseng were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) combined with wet digestion method. The samples of P. notoginseng were collected in 12 different regions, including Yunnan and Guangxi Province. Green Standards of Foreign Trading Medicinal Plants & Preparations was used as the standard to evaluate the pollution status of As, Cu, Hg, Cd, Pb and Cr in P. notoginseng. The results showed that content of As and Cd exceeded the limit of the standard and the percentage was 32.4% and 29.7%, respectively, while Cu, Hg and Pb were all bellow the limit. The SPSS 16.0 software was used to analyze the data. The occurrence of contained heavy metals has been discussed.
China ; Drug Contamination ; Drugs, Chinese Herbal ; analysis ; Metals, Heavy ; analysis ; metabolism ; Panax notoginseng ; chemistry ; metabolism ; Soil Pollutants ; analysis ; metabolism

We cloned the lipoxygenase gene (ana-LOX) from Anabaena sp. PCC 7120 and expressed it in Escherichia coli BL21 (DE3) pLysS. We determined the active site of the recombinant ana-LOX through site-directed gene mutagenesis and obtained the shortest length of the functional gene. Meanwhile, we studied the properties of recombinant ana-LOX after purification. The C-terminal of the Aos (allene oxide synthase)-LOX fusion gene in Anabaena sp. PCC 7120 genome was found belonging to LOXs family by bioinformatics analysis. Further results of site-directed gene mutagenesis confirmed that the active sites of ana-LOX were His197, His202, His369, Asn373and Ile455. The shortest length of functional gene was identified to be 1 254 bp based on the strategy of shortening the gene length gradually. The highest activity of recombinant ana-LOX of 6 750 U/mL could be achieved when constructed to pET-32a vector and expressed at low temperature 16 degrees C. We purified the enzyme by Ni-NTA chelating affinity chromatography, with 60.89% yield and specific activity of 11.4 x 10(4) U/mg. The optimum reaction temperature and pH for ana-LOX were 45 degrees C and 6.0, respectively. Furthermore, the obtained ana-LOX was stable at room temperature. The effect of metal ions on ana-LOX was determined also. Fe2+, Mg2+ Ca2+ could markedly promote the activity of this enzyme whereas Fe3+ and Cu2+ had a strong inhibitory effect on it. Finally, the ana-LOX could improve the microscopical structure of dough. The results of this study will provide a basis for future improvements and food industrial applications of ana-LOX.
Anabaena ; enzymology ; genetics ; Catalytic Domain ; Cloning, Molecular ; Enzyme Stability ; Escherichia coli ; metabolism ; Lipoxygenase ; chemistry ; genetics ; Metals, Heavy ; chemistry ; Mutagenesis, Site-Directed ; Recombinant Proteins ; chemistry ; genetics

The process in the studies on physiological effects of rare earth elements in plants and their action mechanisms were summarized in the aspects of seed germination, photosynthesis, mineral metabolism and stress resistance. And the applications of rare earth elements in traditional Chinese medicine (TCM) in recent years were also overviewed, which will provide reference for further development and application of rare earth elements in TCM.
Medicine, Chinese Traditional ; Metals, Rare Earth ; analysis ; metabolism ; Photosynthesis ; Plants, Medicinal ; chemistry ; growth & development ; metabolism ; Soil ; analysis

Cation transporters play important roles in modulating the concentration of intracellular metal ions. The vacuole is an important storage organelle for many ions. Cation (Ca+)/H+ antiporters (CAXs) located at vacuolar membrane are mainly involved in the Ca2+ flux into the vacuole, and appear to be capable of transporting various divalent cations to some degree. Several CAX genes have been isolated and characterized from various plants in recent years. Four domains of plant CAXs have been identified: NRR regulates Ca2+ transport by a mechanism of N-terminal autoinhibition; Ca domain and C domain confer Ca2+ and Mn2+ specificity among CAX transporters, respectively; D domain plays a part in the regulation of cytosolic pH. AtCAXs identified in Arabidopsis thaliana are involved in the growth, development and stress adaption of plant. AtCAX3 is the mainly Ca2+/H+ transporter in response to salt stress; AtCAX2 and AtCAX4 participate in transportation and detoxicification of heavy metal ions (Cd2+, Zn2+, and Mn2+) in cells under heavy metal stress, and impact root/shoot Cd partitioning in plant. These suggest that CAX genes may be useful for nutritional enhancement of plants, and for increasing phytoremediation potential. Here, the classification, structure and function of CAXs in plants are reviewed.
Antiporters ; chemistry ; physiology ; Arabidopsis ; chemistry ; Arabidopsis Proteins ; chemistry ; physiology ; Calcium ; metabolism ; Cation Transport Proteins ; chemistry ; physiology ; Membrane Proteins ; physiology ; Metals, Heavy ; metabolism ; Plant Physiological Phenomena ; Plant Proteins ; physiology ; Plants ; chemistry ; Proton Pumps ; chemistry ; physiology ; Vacuoles ; metabolism ; physiology

The interaction mechanism between rhaponticin (RT) and human serum albumin (HSA) has been studied by fluorescence spectroscopy and absorbance spectra. The mediation effect that the metal ions took part in the interaction has also been discussed in this paper. Based on different theoretical models of fluorescence quenching, the binding constant (K) and binding sites (n) of the interaction were determined and analyzed comparatively. The quenching mechanism of the binding reaction has also been discussed. The binding distance (r) and energy-transfer efficiency (E) between RT/RT-Co(II)/RT-Ni(II) and HSA were also obtained by virtue of the Förster theory of non-radiation energy transfer. The effect of RT acting on the HSA's conformation was analyzed by synchronous fluorescence spectroscopy. The result showed that the result calculated by different theoretical models is generally equivalent and RT bound HSA strongly by forming stable complex, which indicates that HSA under physiological conditions can act as a carrier for RT to be transported to exert effects. The microconformation of HSA changed significantly due to hydrophobicity change in the chemical environment of some fluorescence chromophores in the subdomain IIA and IIB of HSA. Metal ions Co(II) and Ni(II) can mediate RT-HSA interaction, making the binding of the drug to protein stronger, which indicates that Co(II) and Ni(II) can enhance rhaponticin's medical efficacy under physiological conditions.
Binding Sites ; Drug Interactions ; Energy Transfer ; Humans ; Hydrophobic and Hydrophilic Interactions ; Ions ; pharmacology ; Metals ; pharmacology ; Models, Molecular ; Protein Binding ; Protein Conformation ; Serum Albumin ; chemistry ; metabolism ; Spectrometry, Fluorescence ; Spectrophotometry, Ultraviolet ; Stilbenes ; chemistry ; metabolism

OBJECTIVETo find out the variation of 11 mental element contents in Dendrobium officinale with different germplasms and harvesting ages, the results can provide scientific basis for the quality evaluation and the breeding of D. officinale.

METHOD32 samples with 1-3 ages were collected from cultivated fields of Zhejiang and 11 samples were collected from markets. The 11 mental element contents of samples were determined by ICP-MS or AAS.

RESULTThe average contents of K, Ca, Mg, Mn, Zn, Cr, and Cu were 1,205.23, 766.82, 158.25, 31.06, 4.28, 8.28, and 0.97 mg x kg(-1), the contents of As, Hg, Pb, and Cd were all in limits except Cd content of one sample exceeded the standard limit 0.07 mg x kg(-1); germplasms and physiological ages impacted mental elements contents accumulation significantly.

CONCLUSIONThere were rich essential mental elements in D. officinale. D. officinale from Zhejiang province and medical materials from market were all safe; the breeding of D. officinale can increase the contents of essential mental elements and reduce contents of heavy mental elements; the effect of physiological age on metal elements contents was related to each element's physiological and biochemical function.

Dendrobium ; chemistry ; metabolism ; Drugs, Chinese Herbal ; chemistry ; metabolism ; Metals ; analysis

OBJECTIVETo analyze the contents of harmful heavy metals, sulfur and trace elements from Paeoniae Radix Alba before and after sulfur-fumigated process.

METHODSamples were pretreated by wet digestion and then subjected to elements analysis by inductively coupled plasma-atomic emission spectrometry (ICP-AES).

RESULTThe contents of Cu and S elements were increased, while the content of Zn element was decreased in Paeoniae Radix Alba after sulfur-fumigated process compared with the samples dried in the sun. Moreover, heavy metallic elements, such as As and Hg, were detected in Paeoniae Radix Alba after sulfur-fumigated process.

CONCLUSIONSulfur fumigated process may cause residual of heavy metals and sulfur which are harmful to human body and change the contents of some trace elements.

Fumigation ; methods ; Humans ; Metals, Heavy ; analysis ; Paeonia ; chemistry ; Spectrophotometry, Atomic ; methods ; Sulfur ; analysis ; metabolism ; Trace Elements ; analysis