Mineralization characteristics of soil organic carbon under different herbaceous plant mosaics in semi-arid grasslands.

We aimed to explore the mineralization characteristics of soil organic carbon(SOC) under different plant species in semi-arid grassland and provide basic soil carbon cycling data. Leymus chinensis, Stipa krylovii Roshev, Artemisia frigida, and Agrophorn cristam (L.) Gaertn were selected as the plant species. Incubation experiment were conducted on SOC mineralization in soil aggregates with particle sizes of > 2, 1-2, 0.25-1, and < 0.25 mm. The cumulative SOC mineralization amount in L. chinensis with a particle size > 2 mm was the highest, exceeding that of A. cristam (L.) Gaertn by approximately 136.14%. S. krylovii Roshev (70.73%), L. chinensis (58.05%), and A. frigida (33.73%) exhibited pronounced promotion effects on mineralization. The potential SOC mineralization of S. krylovii Roshev was the greatest among all species at the same soil particle size. The potential SOC mineralization was highest at a particle size of > 2 mm for all plant types. All plant types increased the SOC mineralization rate and cumulative mineralization in soils with large particle sizes, the mineralization reaction occurred more strongly. Organic carbon cumulative SOC mineralization rapidly increased in all tests during the first 20 days and gradually slowed thereafter.

[Distribution Characteristics and Sources of Heavy Metals in Atmospheric Deposition During Heating and Non-heating Period in Lanzhou].

Six sampling sites were set up in Lanzhou City, and atmospheric deposition samples were collected from April 2010 to March 2018. Subsequently, the concentration of heavy metals (Fe, Mn, Zn, Pb, Cr, Cu, Ni, and Cd) was determined to explore the temporal and spatial characteristics of heavy metals. Finally, partial correlation analysis, the enrichment factor method, and the principal component analysis method were used to identify the source of heavy metals in the atmospheric deposition. The results show that the ranking of average heavy metal content in the atmospheric deposition in Lanzhou from high to low was Fe > Mn > Zn > Pb > Cr > Cu > Ni > Cd, and Cd, Zn, and Pb were all polluted. In terms of time, except for Fe and Mn, the other elements mostly showed a trend of higher content in the heating period than that in the non-heating period, and the contents of each element in the non-heating period and the heating period in 2011 and 2013 were significantly different. In terms of sites, there were certain differences between the non-heating period and the heating period in each region; however, the differences among elements were not significant except for Zn and Cd. The source analysis results show that in the non-heating period, the heavy metals in the atmospheric deposition in Lanzhou mainly came from industrial sources, followed by traffic sources and fugitive dust sources. In the heating period, the heavy metals in the atmospheric deposition in Lanzhou mainly came from coal-burning, transportation, and industry activities, followed by secondary dust and natural sources.

[Toxic effects of polystyrene and dibutyl phthalate on purple lettuce]. / èšè‹¯ä¹™çƒ¯ä¸Žé‚»è‹¯äºŒç”²é ¸äºŒä¸é ¯å ±å­˜å¯¹ç´«å¶ç”Ÿèœçš„æ¯’æ€§æ•ˆåº”.

As a carrier of environmental pollutants, microplastics have received wide concerns in recent years. However, the direct and indirect effects of the coexistence of polystyrene particles (PS) and pollutants on vegetables are still unclear. Here, the combined effects of 0.25, 0.50, 1.0 mg·mL-1 PS and 5 mg·L-1 dibutyl phthalate (DBP) on the biomass and biochemical indices of purple lettuce were investigated in hydroponic experiments. The results showed that the presence of PS increased the inhibition of DBP on lettuce biomass and increased O2-· content in roots and leaves relative to the control group with DBP alone, with positive consequences on the activities of supero-xide dismutase, ascorbic acid peroxidase, dehydroascorbate reductase and monodehydroascorbate reductase. According to transmission electron microscope analysis, plasmolysis occurred in root cells under the treatment of DBP alone, cell wall was damaged in PS-only treatment, and the negative effect was enhanced when DBP and PS coexisted. Therefore, the combined pollution of PS and DBP aggravated the toxic effect on purple lettuce.

High mobility group box-1 serves a pathogenic role in spinal cord injury via the promotion of pro-inflammatory cytokines.

Traumatic spinal cord injury (SCI) is a devastating condition marked by permanent motor, sensory, and autonomic dysfunction, in which the inflammatory response serves an important and preventable role. High mobility group box-1 (HMGB1) is a potent regulator of inflammation in numerous acute and chronic inflammatory conditions.; however, the role of HMGB1 in SCI remains unclear. The present study aimed to characterize the temporal dynamics of HMGB1 release after SCI, to investigate the role of spinal microglia activation in mediating the effects of HMGB1 on SCI, and to explore the therapeutic potential of intrathecal anti-HMGB1 polyclonal antibody on alleviating SCI. The present study demonstrated that HMGB1 expression was increased immediately after traumatic injury of a primary spinal neuron culture. It was found that neutralizing HMGB1 significantly ameliorated SCI pathogenesis and hind limb paralysis. Moreover, the levels of a number of pro-inflammatory cytokines in the SCI lesion were reduced when local HMGB1 was blocked by anti-HMGB1 antibody. In addition, the injured neuron-derived conditioned medium increased TNF-α secretion and the NF-κB pathway in the BV2 microglia cell line via HMGB1. Collectively, these results indicated that HMGB1 served an important role in SCI inflammation and suggested the therapeutic potential of an anti-HMGB1 antibody for SCI.

Putrescine regulates nitric oxide accumulation in Ganoderma lucidum partly by influencing cellular glutamine levels under heat stress.

When fungi are subjected to abiotic stresses, the polyamines (PAs) level alter significantly. Here, we reveal that the polyamine putrescine (Put) could play an important role in alleviating heat stress(HS)-induced accumulation of nitric oxide (NO). Ornithine decarboxylase (ODC)-silenced mutants that were defective in Put biosynthesis exhibited significantly lower NO levels than the wild type (WT) when subjected to HS. With addition of 5 mM exogenous Put, the ODC-silenced mutant endogenous Put obviously increased under HS. At the same time, the contents of NO in the ODC-silenced mutants recovered to approximately WT levels after the administration of exogenous Put. However, the elevated NO content in the ODC-silenced mutants disappeared when exogenous Put and carboxy-PTIO (PTIO is a specific scavenger of NO) were added. Intriguingly, the content of glutamine (Gln) was significantly increased in the ODC-silenced strains. When exogenous Put was added to the WT, the Gln content was significantly decreased. The appearance of a high level of Gln was accompanied by nitrate reductase (NR) activity reduction. Further studies showed that Put influenced ganoderic acids (GAs) biosynthesis by regulating NO content, possibly through NR, under HS. Our work reported that Put regulates HS-induced NO accumulation by changing the cellular Gln level in filamentous fungi. IMPORTANCE: In our present work, it was HS as an ubiquitous environmental stress that affects the important pharmacological secondary metabolite (GAs) content in G. lucidum. Afterwards, we began to explore the network formed between multiple substances to jointly reduce the massive accumulation of GAs content caused by HS. We firstly focused on Put, a substance that enhances resistance to multiple stresses. Further, we discovered an influence on Put could changing the NO content, which has been shown to decrease the accumulation of GAs via HS. Then, we also found the change of NO content may be due to Put level that would affect intracellular Gln content. It has never been reported. And ultimately, it is Put related network that could reduce HS-inducing secondary metabolite mess in fungi.

The Slt2-MAPK pathway is involved in the mechanism by which target of rapamycin regulates cell wall components in Ganoderma lucidum.

The fungal cell wall is very important for cell growth and survival during stress, and the target of rapamycin (TOR) pathway plays a major role in regulating cell growth in response to environmental cues. Ganoderma lucidum is an important edible and medicinal fungus, and the function of TOR in this organism remains unclear. As shown in the present study, the TOR pathway regulates cell wall integrity (CWI) in G. lucidum. Inhibition of TOR signaling by RNA interference (RNAi) or rapamycin treatment reduced the growth of G. lucidum mycelia, increased contents of the cell wall components chitin and ß-1,3-glucan, and increased cell wall thickness. Furthermore, inhibition of TOR signaling enhanced the relative level of phosphorylated Slt2, a member of the MAPK cascade involved in CWI signaling. Moreover, when treated with rapamycin, significantly lower chitin and ß-1,3-glucan contents were observed in Slt2-silenced strains than in WT strains, indicating that TOR regulates the synthesis of these cell wall components through the Slt2-MAPK pathway. These results indicate a potential relationship between TOR signaling and CWI signaling. Additionally, participation of Slt2-MAPK in TOR-mediated regulation of cell wall component production has not previously been reported in a microorganism.

Synthesis of Biphenylenes and Their Higher Homologues by Cyclization of Aryne Derivatives.

This investigation demonstrates that a series of biphenylenes can be easily prepared from their corresponding halobiphenyls by the cyclization of in situ generated 2',3'-didehydro-2-lithiobiphenyls at low temperature. Two remarkable advantages of this synthetic method include 1) the lack of any need for transition-metal catalysts or reagents in the cyclization, and 2) the ability to obtain C1-functionalized products by treating the reaction intermediate 1-lithiobiphenylene with an electrophilic reagent. π-Extended derivatives, such as benzobiphenylenes, dibenzobiphenylene, linear/angular [3]phenylenes, and biphenyleno[2,3-b]biphenylenes, were synthesized similarly using suitable biaryls or teraryls.

Alternative oxidase impacts ganoderic acid biosynthesis by regulating intracellular ROS levels in Ganoderma lucidum.

The alternative oxidase (AOX), which forms a branch of the mitochondrial respiratory electron transport pathway, functions to sustain electron flux and alleviate reactive oxygen species (ROS) production. In this article, a homologous AOX gene was identified in Ganoderma lucidum. The coding sequence of the AOX gene in G. lucidum contains 1038 nucleotides and encodes a protein of 39.48 kDa. RNA interference (RNAi) was used to study the function of AOX in G. lucidum, and two silenced strains (AOXi6 and AOXi21) were obtained, showing significant decreases of approximately 60 and 50 %, respectively, in alternative pathway respiratory efficiency compared to WT. The content of ganoderic acid (GA) in the mutant strains AOXi6 and AOXi21 showed significant increases of approximately 42 and 44 %, respectively, compared to WT. Elevated contents of intermediate metabolites in GA biosynthesis and elevated transcription levels of corresponding genes were also observed in the mutant strains AOXi6 and AOXi21. In addition, the intracellular ROS content in strains AOXi6 and AOXi21 was significantly increased, by approximately 1.75- and 1.93-fold, respectively, compared with WT. Furthermore, adding N-acetyl-l-cysteine (NAC), a ROS scavenger, significantly depressed the intracellular ROS content and GA accumulation in AOX-silenced strains. These results indicate that AOX affects GA biosynthesis by regulating intracellular ROS levels. Our research revealed the important role of AOX in the secondary metabolism of G. lucidum.

[Pharmacokinetics and Bioequiavailability of Asparaginase in Asparaginase Nanospheres].

OBJECTIVE: To determine the pharmacokinetics and bioequivalence of self-assembled hyaluronic acid-graft-poly (ethylene glycol)/hydroxypropyl-beta-cyclodextrin hollow nanospheres loaded with asparaginase (AHHPs) in SD rats. METHODS: AHHPs were prepared and observed under transmission electron microscopy. Its size, Zeta potential and entrapment efficiency were detected. Asparaginase (AAS) activities were measured after intravenous injection of AHHPs or free AAS in rats. The pharmacokinetic parameters were calculated using software DAS 2.1.1 for bioequivalence assessment. RESULTS: The self-prepared AHHPs had an average particle size of (367.43 ± 2.72) nm, Zeta potential of (-15. 70 ± 1.25) mV, and average entrapment efficiency of (66.03 ± 3.81)%. The intravenous injection of AHHPs and free AAS produced an area under concentration-time Curve (AUC)(0-48 h) of (162.06 ± 4.01) U/mL · h and (46.38 ± 1.98) U/mL · h, AUC(0-∞) of (203.74 ± 12.91) U/mL · h and (51.44 ± 3.01) U/mL · h, mean residence time (MRT) (0-72h) of (4.35 ± 0.06) h and (1.76 ± 0.06) h, MRT(0-∞) of (7.53 ± 1.05) h and (2.44 ± 0.29) h, peak concentration (Cmax) of (30.37 ± 0.43) U/mL and (26.06 ± 0.88) U/mL, and time to peak concentration (Tmax) of (0.75 ± 0.00) h and (0.08 ± 0.00) h, respectively. Compared with free AAS, the AUC(0-48 h), AUC(0-∞), MRT(0-72 h), MRT(0-∞),Cmax and Tmax of AHHPs increased by 3.5, 4.0, 2.5, 3.1, 1.2 and 9.4 times, respectively. The 90% confidential intervals of AUC(0-48 h), AUC(0.∞) and Cmax of the tested formulation were 72.6%-74.0%, 72.3%-73.7%, 94.7%-96.3%, respectively. CONCLUSION: AHHPs can improve the bioavailability of AAS, extending its biological half-life in rats. AHHPs and free AAS are not bioequivalent.

[Speciation Characteristics and Bioavailability of Heavy Metals in Oasis Soil Under Pb, Zn Combined Stress].

Pot experiments were conducted on cole (Brassica) grown in oasis soil under combined stress of lead and zinc, to study the effect of heavy metal combined pollution on cole growth as well as the speciation conversion rules and bioavailability. The result showed that the promoting effect on cole growth was shown in the low concentration treatments, especially on stem leaves. With addition of exotic heavy metals, the main speciations of Pb and Zn in the soil transformed from tight-bound to loose-bound forms as compared to the control, and the bioavailability of heavy metals was increased. And, the exchangeable Pb and the carbonate bound form of Zn were the major contributing speciations which were absorbed in different parts of cole. What's more, the capabilities of uptake and translocation of Pb and Zn by cole were stronger at lower stress levels, and the enrichment and migration coefficients decreased with the increasing content of bioavailable fraction of the corresponding element or the coexisting element. In all treatments, the Pb concentration in the stem leaves of cole exceeded the food safety threshold, therefore it is recommended to conduct detection of relevant indicators before planting foliage vegetables in this kind of soil.

[Speciation distribution and risk assessment of heavy metals in sediments in suburban outfall of industrial oasis region].

The speciation distribution and potential environmental risk of Cu, Zn, Cd, Pb, Ni, Cr in sediments in suburban outfall of industrial oasis region, Baiyin City were studied by Tessier sequential extraction method, correlation analysis, enrichment factor (EF) and risk assessment code (RAC). The results indicated that, the average concentration of heavy metals in sediments samples of Dongdagou and Xidagou streams exceeded the background levels in Gansu Province, with Cr, as an exception. The enrichment factor suggested that the enrichment of Cd in sediments of Dongdagou and Xidagou streams were very serious, which posed a strong pollution level. Furthermore, the analysis of chemical speciation indicated that Zn, Ni, and Cr in sediments of Dongdagou stream were mainly dominated by the fraction of residual, the existence of Cu and Cd was mainly in organic forms, while Pb was composed mostly by its Fe-Mn oxides fraction; Pb in sediments of Xidagou stream existed by Fe-Mn oxides fraction, other metals mainly appeared with the residual fraction. The risk assessment code (RAC) showed that the risk level of heavy metals in sediments of Dongdagou stream descended in the order: Ni > Cd > Pb > Cu > Zn > Cr, Ni posed a highest risk level. The risk level of heavy metals in sediments of Xidagou stream decreased in the order: Pb > Cd > Ni > Cu > Zn > Cr, Cd, Pb and Ni posed a highest risk level.

SP600125 reduces lipopolysaccharide-induced apoptosis and restores the early-stage differentiation of osteoblasts inhibited by LPS through the MAPK pathway in MC3T3-E1 cells.

Bone degradation is a serious complication of chronic inflammatory diseases such as septic arthritis, osteomyelitis, and infected orthopedic implant failure. Effective therapeutic treatments for bacteria-caused bone destruction are limited. In a previous study, we found that lipopolysaccharide (LPS) induced osteoblast apoptosis and inhibited early and late-stage differentiation of osteoblasts via activation of the C-Jun N-terminal kinase (JNK) pathway. This study aimed to investigate the effect of JNK inhibition by SP600125 on the apoptosis and differentiation of MC3T3-E1 osteoblasts suppressed by LPS. Following pretreatment with SP600125 for 2 h, MC3T3-E1 cells were treated LPS. Following this treatment, cell viability, activity of alkaline phosphatase (ALP) and caspase-3 were measured. mRNA and protein expression of osteoblast-specific genes, mitogen-activated protein kinases (MAPKs), Bax, Bcl-2 and caspase-3 were determined by quantitative polymerase chain reaction (qPCR) and western blot analysis. The results showed that SP600125 significantly restored LPS-inhibited cell metabolism and ALP activity and reduced the upregulated caspase-3 activity of MC3T3-E1 cells induced by LPS. SP600125 also significantly restored the LPS-suppressed mRNA and protein expression levels of early-stage osteoblast-associated genes in a dose-dependent manner. SP600125 significantly downregulated expression of Bax and caspase-3 but upregulated Bcl-2 expression in MC3T3-E1 cells stimulated by LPS. Furthermore, SP600125 selectively triggered the MAPK pathway by reducing the expression of JNK1, while enhancing the expression of extracellular signal-regulated kinase 1 (ERK1). Our results suggested that SP600125 reduced LPS-induced osteoblast apoptosis and restored early-stage differentiation of osteoblasts inhibited by LPS through MAPK signaling. These findings suggest that the therapeutic agent that inhibited JNK1 is of potential use for the restoration of osteoblast function in bacteria-induced bone diseases.

Gene-gene interaction of GJB2, SOD2, and CAT on occupational noise-induced hearing loss in Chinese Han population.

The effects of genetic factors on the noise-induced hearing loss (NIHL) are still unclear. In the present study, eight single-nucleotide polymorphisms (SNPs) included rs1227049 and rs3802711 (CDH23), rs1695 (GSTP1), rs137852540 (GJB2), rs2289274 (PMCA2), rs4880 (SOD2), rs7943316, and rs769214 within CAT that might associated with NIHL were further validated in Chinese workers. The results showed that the carriers of the T allele (AT+TT) of rs7943316 and A allele (GA+AA) of rs769214, were significantly associated with an increased risk of NIHL compared to those with AA genotype (P<0.05) and GG genotype (P<0.05). Moreover, a significant three-locus model (P=0.0107) involving rs2016520, rs9794, and rs1805192 were observed that might associated with NIHL, with 53.95% of testing accuracy. Thus, our present study provided the evidence that GJB2, SOD2, and CAT genes might account for the NIHL development in independently and/or in an interactive manner.

Preliminary research on the expression, purification and function of the apoptotic fusion protein, Sival.

The objective of the present study was to investigate cloning, expression, and functions of the recombinant protein, Siva1. Siva1 gene was synthesized by RT-PCR from HCT116 cells. Plasmids were cleaved with the restriction endonuclease, BamH1/Sal1 and products were connected to pQE30, which underwent cleavage by BamH1/Sal1. The recombinant plasmid, pQE30-Siva1, was identified after digestion with restriction endonucleases followed by transformation into E. coli M15. Expression of Siva1 was induced by IPTG and identified by SDS- PAGE following purification with affinity chromatography. The results showed that size of Siva1 was 12 kDa, consistent with the molecular weight of the His-Siva1 fusion protein. Functional test demonstrated that Siva1 significantly inhibited the invasion and migration of HCT116 cells. It may thus find clinical application for control of cancers.

[Pollution evaluation and health risk assessment of heavy metals from atmospheric deposition in Lanzhou].

In order to evaluate the contamination and health risk of heavy metals from atmospheric deposition in Lanzhou, samples of atmospheric deposition were collected from 11 sampling sites respectively and their concentrations of heavy metals were determined. The results showed that the average contents of Cu, Pb, Cd, Cr, Ni, Zn and Mn were 82.22, 130.31, 4.34, 88.73, 40.64, 369.23 and 501.49 mg x kg(-1), respectively. There was great difference among different functional areas for all elements except Mn. According to the results, the enrichment factor score of Mn was close to 1, while the enrichment of Zn, Ni, Cu and Cr was more serious, and Pb and Cd were extremely enriched. The assessment results of geoaccumulation index of potential ecological risk indicated that the pollution of Cd in the atmospheric deposition of Lanzhou should be classified as extreme degree, and that of Cu, Ni, Zn, Pb as between slight and extreme degrees, and Cr as practically uncontaminated. Contaminations of atmospheric dust by heavy metals in October to the next March were more serious than those from April to August. Health risk assessment indicated that the heavy metals in atmospheric deposition were mainly ingested by human bodies through hand-mouth ingestion. The non-cancer risk was higher for children than for adults. The order of non-cancer hazard indexes of heavy metals was Pb > Cr > Cd > Cu > Ni > Zn. The non-cancer hazard indexes and carcinogen risks of heavy metals were both lower than their threshold values, suggesting that they will not harm the health.

[Study on ecological risk assessment technology of fluoride pollution from arid oasis soil].

According to translocation regulation of fluoride in the typical oasis soil-plant system under field, an ecological risk assessment model of fluoride was established, and this model was used to assess ecological risk to fluoride pollution from suburban oasis soils in Baiyin City, which was specifically expressed with the potential ecological risk of bioavailability (ER(bc)) model to assess ecological risk of fluoride pollution in oasis regions. Results showed that the ecological risk indices of fluoride pollution from this region were 1.37-24.81, the level of risk at most sites was high to very high, the average ecological risk index was 11.28, belonged to very high risk. This indicated that in the suburb soil of Baiyin City needs to be concerned about the remediation of fluoride pollution.

Efficient Ho:LuLiF4 laser diode-pumped at 1.15 µm.

We report the first laser operation based on Ho(3+)-doped LuLiF(4) single crystal, which is directly pumped with 1.15-µm laser diode (LD). Based on the numerical model, it is found that the "two-for-one" effect induced by the cross-relaxation plays an important role for the laser efficiency. The maximum continuous wave (CW) output power of 1.4 W is produced with a beam propagation factor of M(2) ~2 at the lasing wavelength of 2.066 µm. The slope efficiency of 29% with respect to absorbed power is obtained.

[Uptake effect of Cd and Pb by rape under single Cd/Pb and Cd-Pb combined stress].

This paper investigated the effects of single Cd/Pb and Cd-Pb combined pollution of desert grey soils from the oasis regions on the uptake and translocation of Cd and Pb by rape (Brassica campestris L.), and analyzed the interaction between Cd and Pb. The results of pot experiment showed that the concentration of Cd or Pb was promoted when the concentration of Cd in soil was less than 7.0 mg x kg(-1) and the concentration of Pb in soil was less than 1 500 mg x kg(-1) in single Cd/Pb and Cd-Pb combined pollution. There was an obvious antagonism between Cd and Pb in Cd-Pb combined pollution. As the concentration of Cd in soil increased in single Cd pollution, the enrichment and translocation ability of Cd in rape was firstly improved and then reduced. As the concentration of Pb in soil increased in single Pb pollution, the enrichment and translocation ability of Pb in rape was reduced continuously. The Cd-Pb combined stress reduced the enrichment capacity of Cd and Pb as well as the migration ability of Pb, but improved the migration ability of Cd. The enrichment and translocation ability of Cd was greater than that of Pb. Models of uptake and translocation of Cd and Pb in rape under single Cd/Pb and Cd-Pb combined stress were both well fitted to quadratic equations.

[Comparative study on thin films of cadmium sulfide prepared by chemical bath deposition and radio frequency magnetron sputtering].

Thin films of cadmium sulfide (CdS) were prepared with ammonium chloride, cadmium chloride, potassium hydroxide and thiourea by chemical bath deposition (CBD). For comparison, CdS films were also deposited by radio frequency (RF) magnetron sputtering, using CdS and argon as a target and reactive gas, respectively. The films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and ultraviolet-visible spectroscopy. The results show that the CdS films prepared by the above two methods have (002) orientation, the CdS films deposited by RF magnetron sputtering are more compact and much smoother than those prepared by CBD, and have lager crystalline size of about 20-30 nm. The CdS films prepared by CBD have smaller crystalline size and more defects. The properties of CdS thin films prepared by RF magnetron sputtering are totally superior to those of CdS films by CBD, but the optical transmittance of CdS thin films at short wavelength is an exception. The energy gap of CdS films prepared by the two methods are all in the range of 2.3-2.5 eV.