Chronotoxicity of a Copper (II) Complex with a Linear Tetradentate Ligand in Mice

In vitro copper (II) complex presents antimitotic effects. In this work, we have studied the in vivo seasonal toxic effects of copper (II), ligand (H₂L) and the complex [Cu(H₂L)(H₂O)₂]Cl₂·4H₂O in male Swiss mice. During spring, an i.p. injection of CuCl₂ in aqueous NaCl (9 g·l^-1) up to 0.05 µmol·kg^-1 b.w. (body weight) killed 60% of the rodents after 6 days. LD100 was up to 0.3 µmol·kg^-1; H₂L was well tolerated, while the complex was 30% lethal with 50 µmol·kg^-1. In autumn, mice were less sensitive to CuCl₂, and both ligand and complex were equally tolerated and this leads to the conclusion that, in vivo, chronotoxicities of copper (II) and complex in NaCl aqueous solutions are quite different in spring and autumn seasons.     

Hepatic CYP1A induction in rainbow trout (Oncorhynchus mykiss) after exposure to benzo[a]pyrene in water

Juvenile rainbow trout were exposed to unlabelled benzo[a]pyrene BaP and ³H benzo a pyrene (³H BaP), in a static exposure system for 2 days. The initial concentration was 30 μg l^-1 and 0.625 μCi l^-1, corresponding to 6 mg kg^-1 body weight and 125 μCi kg^-1 body weight. Hepatic 7-ethoxyresorufin-O-deethylase (EROD) activity was measured during the exposure and depuration periods, elucidating the time course pattern of CYP1A induction. Maximum induction (11-fold) of EROD activity was observed on day 2 after addition of BaP to the water. Tissue distribution of ³H-BaP was studied by liquid scintillation counting and whole body autoradiography. The concentration of ³H-BaP-derived radioactivity was highest in the bile at all sampling times. High levels of radiolabelled compound were also present in the gills, liver and the olfactory organ. There was an overall decrease in all tissues during the depuration period. The elimination of ³H-BaP-derived radioactivity from the gills, however, was slow compared with liver and blood (6.2 days vs 2.7 and 2.9 days, respectively).     

Effects of water hardness and alkalinity on the toxicity of uranium to a tropical freshwater hydra (Hydra viridissima)

In tropical Australian freshwaters, uranium (U) is of potential ecotoxicological concern, largely as a consequence of mining activities. Although the toxicity of uranium to Australian freshwater biota is comprehensive, by world standards, few data are available on the effects of physicochemical variables, such as hardness, alkalinity, pH and organic matter, on uranium speciation and bioavailability. This study determined the individual effects of water hardness (6.6, 165 and 330 mg l^-1 as CaCO₃) and alkalinity (4.0 and 102 mg l^-1 as CaCO₃), at a constant pH (6.0), on the toxicity (96 h population growth) of uranium to Hydra viridissima (green hydra). A 50-fold increase in hardness (Ca and Mg concentration) resulted in a 92% (two-fold) decrease in the toxicity of uranium to H. viridissima [i.e . an increase in the EC₅₀ value and 95% confidence interval from 114 (107-121) to 219 (192-246) µg l^-1]. Conversely, at a constant hardness (165 mg l-1 as CaCO₃), the toxicity of uranium to H. viridissima was not significantly (P > 0.05) affected by a 25-fold increase in alkalinity (carbonate concentration) [i.e. EC₅₀ values of 177 (166-188) and 171 (150-192) µg l^-1 at 4.0 and 102 mg l^-1 as CaCO₃, respectively]. A knowledge of the relationship between water chemistry variables, including hardness and alkalinity, and uranium toxicity is useful for predicting the potential ecological detriment in aquatic systems, and can be used to relax national water quality guidelines on a site-specific basis.     

铜尾矿区土壤与凤丹植株重金属富集研究

对安徽铜陵铜尾矿区凤丹种植地的土壤和凤丹中重金属污染状况进行了研究.结果表明,尾矿库区种植地极端贫瘠,有机质含量仅1.1～3.4g·kg^-1,而土壤Cu、Cd、Pb、Zn含量皆高于对照土壤,其中Cu含量达587.43～1176.44mg·kg^-1,Cd含量达3.08～5.16mg·kg^-1,约达国家土壤二级标准的10倍.凤丹各部位的Cu、Cd和Pb含量均超过了药用植物的限量标准,尤其是根皮部位Cu含量达31.50～64.00mg·kg^-1,Cd含量达0.98～1.45mg·kg^-1,超出标准1.6～3.6倍,表明种植地和凤丹都受到严重污染.凤丹不同部位中的Zn、Cd、Pb和Cu分别以茎、叶、叶和根皮中的含量最高.凤丹对Cd、Zn的富集比Cu和Pb高,但在根皮中的富集系数均较小.     

Ascorbate and glutathione contents in duckweed, Lemna minor, as biomarkers of the stress generated by copper, folpet and diuron

Glutathione and ascorbate are essential components of the general antioxidative strategy to overcome oxidative stress due to environmental constraints such as pollution. The variation of glutathione and ascorbate contents in duckweed (Lemna minor) was investigated after a 48 h exposure to copper, diuron and folpet under laboratory conditions in order to determine whether changes in their level could serve as suitable and early biomarkers of pollution. One could observe that diuron and folpet caused the glutathione level to increase, its redox status remaining unchanged, while copper led to a depletion of this antioxidant and to an increase in its oxidation rate. When duckweed was contaminated by folpet and the metal, an increase of the ascorbate pool size occurred from concentrations as low as 1 mg l^-1 and 50 μg l^-1 respectively. While the ascorbate pool became more oxidized because of exposure to copper concentrations ≤ 200 μg l^-1, folpet caused an increase in its reduction rate. Diuron was responsible for depletion of ascorbate, the redox status of which remained unchanged. Because it is an adaptation to stress and a defence process, the increase in the antioxidant pool size was proposed as a biomarker of exposure to an unsafe environment. Since depletion of antioxidant and an increase in its oxidation rate weakened cellular defences and indicated a precarious state, they could constitute early indicators of toxicity. So they were proposed as potential biomarkers of toxicity. It was concluded that the antioxidant content in duckweed might serve as a useful biomarker for monitoring water quality.     

Pongamia pinnata influences the circadian variations of liver marker enzymes in hyperammonemic rats

In this study, the influences of Pongamia pinnata, an indigenous medicinal plant used in Ayurvedic and traditional Medicine in India, on the circadian variations of liver marker enzymes in ammonium chloride (AC) induced hyperammonemic rats were studied. Experimental rats (160 - 180 g) were divided into control, AC (daily i.p. injection of AC (100 mg kg^-1 body weight)) treated, AC + P. pinnata ethanolic leaf extract (PPEt) (300 mg kg^-1 body weight) treated and PPEt treated groups. Temporal characteristics (acrophase, amplitude and mesor) of liver marker enzymes; alkaline phosphatase (ALP), aspartate and alanine transaminases (ALT and AST) and γ-glutamyl transferase (GGT) were analyzed. Elevated liver marker enzymes (increased mesor and delayed acrophase of AST, ALT, ALP and GGT) were found in hyperammonemic rats. Administration of PPEt significantly alters these changes. Variations in acrophase, amplitude and r values were also found in control and experimental rats. The detectable circadian rhythms of hepatic marker enzymes and their alterations during AC/PPEt treatments, in the present study, deserve further investigation for the diagnosis and for the therapeutic efficacy of hyperammonemia.     

胶州湾互花米草湿地氮、磷元素的垂直分布及季节变化

为了研究胶州湾互花米草湿地N、P的垂直分布及季节变化特征,分别于2015年4、7、9、10、11和12月对该区域互花米草湿地和光滩土壤全氮(TN)、铵态氮(NH₄⁺-N)、全磷(TP)、速效磷(AP)、总有机碳(TOC),以及pH、盐度、含水量进行了测定.结果表明: 胶州湾互花米草湿地土壤TN、NH₄⁺-N、TP、AP含量平均值分别为0.396 g·kg^-1、12.14 mg·kg^-1、0.419 g·kg^-1、16.52 mg·kg^-1,光滩平均值分别为0.385 g·kg^-1、8.13 mg·kg^-1、0.423 g·kg^-1、19.57 mg·kg^-1.总体来说,它们的含量随着土壤深度(0～60 cm)的增加逐渐降低;互花米草湿地N、P含量的季节变化明显,互花米草湿地土壤全氮含量在春季最高,秋季最低,而光滩土壤随着季节变化逐渐降低;二者土壤全磷含量的季节变化趋势相反,而速效磷含量的季节变化趋势一致;胶州湾互花米草湿地土壤TN、TP与土壤TOC含量呈显著相关,而在光滩土壤中无显著相关关系.pH、盐度显著影响互花米草湿地和光滩土壤N、P含量.     

铜胁迫对国槐幼苗生长及叶片生理特性的影响

采用盆栽方法研究了不同浓度处理水平的铜对国槐(Sophora japonica)生长及叶片部分生理指标的影响.结果表明:国槐幼苗的株高及地径随铜胁迫浓度的增加表现出先增加后下降的趋势,在浓度1000 mg·kg^-1时,株高和地径与对照相比达到极显著差异(检验水平,P<0.01).在浓度<500 mg·kg^-1时,叶绿素含量的呈下降趋势,细胞膜透性呈增加趋势,与对照相比差异不显著;脯氨酸含量与超氧化物歧化酶(SOD)活性迅速上升,与对照处理相比差异显著,表现出一定的适应能力.随着铜胁迫浓度的增加(>500 mg·kg^-1),叶绿素含量及SOD活性显著下降,MDA含量、相对电导率、脯氨酸含量显著上升,表明国槐幼苗受害明显加重.     

Effects of trematode parasitism on the behaviour and ecology of a common marine snail (Littorina littorea (L.))

Cryptocotyle lingua (Creplin) is a digenean trematode parasite of the littoral prosobranch gastropod Littorina littorea (L.). The literature suggests the snails become infected by grazing guano of the final host, the herring gull, Larus argentatus Pontoppidan. The parasite emerges from the snail as free-swimming cercariae. Interactions between the snail and the parasite at cellular and life-history levels are well established, but little is known of the influences the interaction has on the behaviour and the ecology of the snail. We tested the response of the snail to encounters with cercariae, examined the longevity of the guano on-shore and tested the responses of the snail to encounters with guano. Over half the L. littorea tested were able to detect both cercariae and a filtered homogenate of cercariae in conspecific mucus trails, approximately one-third of animals refusing to cross the treatments. Chemoreception by the mouth or foot is considered the most likely means of detection. Guano samples (mean weight 3.22 g) naturally deposited at approximately mid-tide level were completely washed away by one tidal inundation. We consider this period too brief to allow for ingestion of eggs in guano by the snail. Further, snails would not cross guano placed in conspecific trails. Most snails would not cross guano diluted by 10³×(10 mg ml⁻¹) and some snails could still detect guano diluted by 10⁶×(10 μg ml⁻¹), though all were prepared to cross it. Detection of guano is again believed to be by chemoreception by the mouth or foot. These results are discussed in terms of the mating and aggregating behaviour of L. littorea. Ingestion of the parasite by L. littorea is likely to take place once the guano has washed away as the eggs are negatively buoyant in seawater and may adhere to rock (biofilm) or algal fronds which may be grazed by the snail.     

铜锈环棱螺对藻华水体理化指标的影响

采用池塘围隔对比试验的方法,研究了不同密度(392 ind·m^-2、196 ind·m^-2、98 ind·m^-2、0 ind·m^-2)铜锈环棱螺(Bellamyaaeruginosa)对藻华水体主要理化因子的影响.实验从2009年9月14日开始,持续60d.结果显示:环棱螺可以明显提高藻华水体的透明度(SD),实验中、后期,三个处理组围隔水体的SD均能保持在60cm以上,而对照组SD改变不明显,波动于29～40.3cm之间;多数时间内处理组水体的溶解氧(DO)含量都显著低于对照组,说明环棱螺的存在可直接或间接降低水体DO浓度.试验表明,单一投放螺类可有效降低藻华水体的叶绿素a(Chl-a)含量,但难以削减营养盐浓度.实验条件下,围隔水体总氮和正磷酸盐浓度的下降趋势均与螺的密度呈现负相关性(R=-0.9851,p<0.05;R=-0.9678,p<0.05);对SD、DO、pH、Chl-a、NH₄⁺-N、NO₃^--N、PO₄^3--P等7个主要理化指标数据进行了Duncan多重比较分析以及聚类分析,结果显示对照组和处理组在p<0.05水平上均存在显著差异,说明环棱螺的投放能在一定程度上调控水体质量.     

An epidemiological study of reproductive function biomarkers in male welders

In a cross-sectional study, the serum concentrations of inhibin B and prolactin of 96 male current welders were compared with the concentrations measured in 96 age-matched referents. Also, 23 patients who were all former welders diagnosed as having welding-related manganism were studied. The current welders' geometric mean (GM) airborne exposure to manganese (Mn) was 121 µg m^-3 (range 7-2320). The serum concentrations of prolactin adjusted for age and smoking habits (GM 193 mIU l^-1 vs. 166 mIU l^-1; p=0.047) and inhibin B adjusted for alcohol consumption (arithmetic mean (AM) 151 ng l^-1 vs. 123 ng l^-1; p=0.001) were higher in the welders compared with the referents. The whole blood Mn concentration was associated with the serum prolactin concentrations. Tobacco smoking resulted in lower serum prolactin concentrations. The GM serum prolactin concentrations of the patients did not significantly differ from that of the referents, but their AM serum inhibin B concentration was statistically significantly lower. The results may suggest an effect of Mn on the pituitary that is reversible upon cessation of exposure. Lower inhibin B concentrations in the patients could point to a functional impairment of the testicular Sertoli cells, that may be caused by a welding fume component or other factors in their work environment.     

莱菔子乙醇提取物对ApoE-/-小鼠血脂血糖及肝脂肪变性的影响*

目的:探讨莱菔子乙醇提取物(AERS)对ApoE^-/-小鼠血脂血糖及肝脂肪变性的影响及其机制。方法:随机将60只ApoE^-/-小鼠分为对照组(CG)、生理盐水组(NG)、罗格列酮组(RG)、AERS治疗组,后者再分成AERS低、中、高剂量组(AERS-L/M/H),每组10只。除CG常规饲料外,其他动物均以高脂高糖高盐饲料饲养9周,CG和NG分别每天以等容量NS灌胃1次,RG每天灌胃罗格列酮(1.33 mg·kg^-1,NS稀释成等容量溶液,每次0.2 ml·10 g^-1),AERS组动物每天分别予AERS灌胃(100、300和900 mg·kg^-1)9周后。肝病理学观察,检测FPG、FIns,计算胰岛素抵抗指数(IRI)和肝系数(LC)。检测血清ALT、AST、瘦素(LEP)、TNF-α及血脂水平(TC、FFA等)。Western blot检测肝脂质代谢相关蛋白表达(HMG-R、LDL-R、LEP-R)。结果:与CG相比,NG和RG肝脏外观(色泽、肿胀情况等)和病理学(脂肪变性、肝细胞坏死等)改变明显,而AERS-M/H与CG相似;与CG相比,血清FPG、Fins、IRI、ALT、AST、TNF-α、LC、TG、LDL-C、FFA、LEP等指标明显升高(P＜0.05);与NG相比,AERS呈现剂量依赖性降低(P＜0.05);与RG相比,AERS-H的FPG、Fins明显升高(P＜0.05),而IRI明显降低(P＜0.05);与NG和RG相比,AERS组的HMG-R和LEP-R蛋白表达呈剂量依赖性减少,而LDL-R蛋白表达呈剂量依赖性增加(P＜0.05)。结论:AERS能阻止高脂高糖饲料诱导ApoE^-/^-小鼠血脂血糖升高及肝脂肪变性,其机制与减少FFA和LEP的生成,抑制TNF-α、HMG-R、LEP-R蛋白表达和促进LDL-R的蛋白表达有关。     

Validation of urinary thiocyanate as a biomarker of tobacco smoking

Thiocyanate ion (SCN) is the major detoxication product of cyanide, which is converted to SCN by a thiosulphate sulphurtransferase, mainly in hepatic mitochondria. Low-level cyanide exposure for man is caused by factors such as dietary intake of cyanogenic glucosides, tobacco smoking, drug administration and occupational exposure to organic nitriles. Urinary SCN concentration was determined through a commercial kit for the analysis of cyanide in water. Spot urine samples were collected at 7:30 h and 12:30 h, from 99 healthy male white-collar office workers (non-smokers n=72, smokers n=27). Comparison of SCN excretion values did not show any difference between the morning and midday samples. The SCN median value of non-smokers was 24 μmol l^-1 (range 9-24 μmol l^-1) and was statistically different from that of smokers (SCN = 92 μmol l^-1, range 33-275 μmol l^-1) (     

Stoichiometric characteristics of carbon,nitrogen and phosphorus of Sibiraea angustata shrub on the eastern Qinghai-Xizang Plateau

Aims Little is known about the stoichiometric characteristics of carbon (C), nitrogen (N) and phosphorus (P) in plateau shrubs across China. Sibiraea angustata is a typical and representative shrub species on the eastern Qinghai- Xizang Plateau, and exploring its C, N and P distribution patterns and stoichiometric properties in different organs (including root, shoot, leaf, twig and fruit) would help us better understand the mechanisms of C, N and P cycling and balance in the S. angustata dominated shrub ecosystem.
Methods Sixteen sampling sites were selected on the eastern Qinghai-Xizang Plateau by the stratified sampling method. The height and coverage of the dominant shrubs, latitude, longitude and altitude of the sites were recorded. Three 5 m × 5 m plots were selected at each site. At least 128 biological samples of plant organs of S. angustata were collected and measured, respectively. The C and N concentrations of plant samples were analyzed using an elemental analyzer (2400 II CHNS). The P concentration was analyzed using the molydate/ascorbic acid method after H₂SO₄-H₂O₂ digestion.
Important findings The C, N and P concentrations of different organs followed the order of: shoot (495.07 g·kg^-1) > twig (483.37 g·kg^-1) > fruit (480.35 g·kg^-1) > root (468.47 g·kg^-1) > leaf (466.33 g·kg^-1); leaf (22.27 g·kg^-1) > fruit (19.74 g·kg^-1) > twig (7.98 g·kg^-1) > shoot (4.54 g·kg^-1) > root (4.00 g·kg^-1) and fruit (2.85 g·kg^-1) > leaf (1.92 g·kg^-1) > twig (0.96 g·kg^-1) > root (0.52 g·kg^-1) > shoot (0.45 g·kg^-1), respectively. The ranges of the coefficient of variation (CV) for C, N and P concentrations were 1.71%-4.44%, 14.49%-25.50% and 11.46%-46.15%, respectively. Specifically, the C concentration was relatively high and stable, and the maximum CV values for N and P were found in roots. The N:P value of different organs varied from 7.12-12.41 and the minimum CV for N:P was found in twig, which indicated that N:P in twig had higher internal stability. In addition, correlation analysis indicated that the C concentration was significantly negatively correlated with N and P concentrations and correlation coefficients were -0.407 and -0.342, respectively. However, N concentration had dramatically positive correlation with P concentration and the correlation coefficient was 0.814. These results also could indicate that the C, N and P stoichiometric characteristics in the S. angustata shrub accorded with the homeostatic mechanism and growth rate hypothesis to some extent, the distributions of C, N and P concentrations were closely related to the function of the organs and it should be prudent to use ecological stoichiometric ratios to judge the condition of nutrient limitation at the species level.     

Characteristics of microsomal reduction of benzo[a]pyrene 4,5-oxide

NADPH-reduction of benzo[a]pyrene 4,5-oxide (BP-4,5-oxide) to BP required four components from rat liver: cytochrome P-450, NADPH cytochrome P-450 reductase, phosphatidylcholine and a soluble, heat-sensitive factor which was present in 105 000 × g supernatant and was also released from microsomes by sonication. The requirement for this factor contrasts with recently reported results from Sugiura et al. (Cancer Res., 40 (1980) 2910). Oxide-reduction was 40 times faster under anaerobic conditions, but oxygen did not affect the stimulation factor. This stimulation was highest (× 15) at low concentrations of microsomal protein (<0.1 mg/ml) and was almost absent at high concentrations of microsomal protein (>1 mg/ml). Oxide-reduction activity was proportional to microsomal protein concentration in the presence of added 105 000 × g supernatant, but for microsomes alone (>0.1 mg/ml) exhibited a parallel plot with an intercept at 0.08 mg/ml microsomal protein. Stimulation was highest at high concentrations of BP-4,5-oxide and a linear plot of V⁻¹ vs. [BP-4,5-oxide]⁻¹ was only obtained in the presence of 105 000 × g supernatant (K_m = 3 μM, V_max = 3.3 nmol/mg/min). Microsomal hydration of BP-4,5-oxide (inhibited in reductase assays) was unaffected by 105 000 × g supernatant, suggesting that stimulation of oxide-reduction did not derive from solubilization of BP-4,5-oxide. Stimulation was observed in the initial rate of reaction and was independent of incubation time. Inhibition of lipid peroxidation, removal of peroxides and deoxygenation were all excluded as explanations of the stimulatory effect.     

铲草和施肥对降香黄檀与印度檀香混交林土壤氮素矿化淋溶的影响

珍贵树种降香黄檀与印度檀香混交种植是当前华南地区人工林发展的一种重要模式.本研究设置对照(不做处理)、铲草、施肥、铲草+施肥4个处理,研究抚育措施对林地土壤净矿化速率、净硝化速率、净铵化速率和氮素淋溶速率的影响.结果表明:4个处理0~10 cm土层在春、秋季有最大净氮矿化速率,分别为18.92、18.13 mg·kg^-1·month^-1;在春、秋季有最大硝化速率,分别为20.35、18.85 mg·kg^-1·month^-1;夏、冬季有最大铵化速率,分别为0.22、0.26 mg·kg^-1·month^-1;秋季的氮素淋溶最严重,为15.98 mg·kg^-1·month^-1,全年最大淋溶为86.69 mg·kg^-1.铲草、施肥、铲草+施肥都在一定程度上抑制了土壤氮的净矿化和硝化速率,铲草、施肥、铲草+施肥处理年氮矿化量分别下降26.2%、16.1%、6.3%,年氮硝化量分别下降17.1%、16.6%、1.4%,同时也抑制了土壤铵态氮的累积.铲草、施肥、铲草+施肥处理全年氮素淋溶量依次减少25.2%、8.6%、6.1%.相对于铲草、施肥、铲草+施肥抚育措施,季节因素对土壤氮素矿化和淋溶过程的影响更显著.铲草、施肥、铲草+施肥措施在一定程度上抑制了土壤氮素硝化和铵化过程,减少了土壤氮素的矿化和淋溶损失量,有利于土壤肥力的保存和氮素的累积.     

Enzymatic synthesis of new aromatic and aliphatic esters of flavonoids using Candida antarctica lipase as biocatalyst

Enzymatic acylation of rutin and esculin with aromatic, aliphatic and aryl-aliphatic acids using Candida antarctica lipase in tert amyl alcohol as solvent was investigated under low water content. Whatever the acyl donor used, the conversion yields and initial rates for esculin were higher than for rutin. For a given flavonoid, the performance of these reactions depended on the acyl donor structures. For aliphatic acids, conversion yields and initial rates of both flavonoids were respectively in the ranges of 68-90% and of 9.5×10^-2-72×10^-2 mmol l^-1 h^-1. For aromatic acids, the reaction occurred only with the aryl subgroup (cinnamic, hydrocinnamic, 3,4-dihydroxyhydrocinnamic and 4-hydroxyphenyl acetic acids) and was drastically influenced by the presence of side chain and substitution patterns of the aromatic ring. Except for hydrocinnamic acid (75%, 23.4×10^-2 mmol l^-1 h^-1), with these acids the conversion yields and initial rates were lower and in the range of 10-45% and of 0.7×10^-2 to 12.1×10^-2 mmol l^-1 h^-1. Unsaturation of the side chain of the hydrocinnamic acid decreased the esculin conversion rate from 75 to 13% and initial rate from 23.4 to 1.76×10^-2 mmol l^-1 h^-1. The presence of hydroxyl or nitro-groups on the aromatic ring of the aryl aliphatic acid also reduced conversion yields and initial rates. Even without a spacer, the non-phenolic ring acid (quinic acid) was reactive and lead to conversion yields of about 20 and 23% respectively for rutin and esculin.     

Clara cell protein (CC16) in serum and bronchoalveolar lavage fluid of subjects exposed to asbestos

The Clara cell protein (CC16) is a small and readily diffusible protein of 16kDa secreted by bronchiolar Clara cells in the distal airspaces. These epithelial cells are altered in several pulmonary pathological processes induced by various lung toxicants. In the search for a new biomarker of asbestos-induced lung impairment, we used a sensitive immunoassay to determine the levels of CC16 in bronchoalveolar fluid (BALF) and serum of subjects exposed to asbestos compared with a group of healthy controls. In the BALF of asbestos-exposed subjects there was an insignificant trend towards CC16 elevation compared with controls, with a (mean ±SD of 0.81 ±0.65mg l^-1 for asbestos-exposed subjects (n = 23) versus 0.39 ±0.19mg l^-1 for controls (n = 11) (p = 0.09). In serum, CC16 concentration was significantly increased among asbestos-exposed subjects, with values of 27.2 ±24.0 µg l^-1 for asbestos-exposed subjects (n = 34) versus 16.1 ±7.6 µg l^-1 for controls (n = 34) (p = 0.01). Regarding the effects of smoking, there were significant differences between generally lower CC16 levels in serum and BALF (p = 0.05 and 0.001, respectively) of smokers compared with the higher levels in non-smokers. Serum CC16 levels positively correlated with those in BALF, which is consistent with a diffusional transfer of CC16 from the bronchoalveolar space into the serum. No association, however, emerged between the levels of CC16 in serum or BALF and either the duration of asbestos exposure or the severity of the lung impairment as assessed by chest X-ray. These findings suggest that exposure to asbestos elicits early changes in the local and, importantly, also the systemic levels of CC16. This pneumoprotein therefore appears as a promising non-invasive biomarker of asbestos-induced lung injury and occupational disease in both smoking and non-smoking exposed subjects.     

基于FvCB模型分析盐分胁迫对棉花叶片光合作用的影响

为深入理解叶片光合特性对盐胁迫的响应机理,以棉花为试验材料,设置5个盐分(NaCl)浓度处理:0(CK)、50、100、150和200 mmol·L^-1,利用FvCB模型分析盐胁迫对棉花幼苗叶片光合特性的影响。结果表明:与CK相比,50和100 mmol·L^-1盐分处理增加了棉花叶片的最大羧化速率(V_{c max})和最大电子传递速率(J_max),但150和200 mmol·L^-1盐分处理显著降低了V_{c max}和J_max。叶片净光合速率(P_n)、叶肉导度(g_m)和暗呼吸速率(R_d)随盐分浓度升高而下降;与CK相比,50和100 mmol·L^-1盐分处理对g_m无显著影响,但P_n和R_d显著降低。150和200 mmol·L^-1盐分处理明显降低了P_n、g_m和R_d,且与0、50和100 mmol·L^-1盐分处理间存在显著差异;利用FvCB模型模拟了不同盐分胁迫下叶片净光合速率。与不考虑g_m的模拟结果相比,考虑g_m提高模拟值和实测值间的决定系数,并降低了平均绝对误差。棉花幼苗耐盐阈值为100～150 mmol·L^-1,随盐分浓度的增加,光合限制因素由叶肉因素转变为光合机构受损;引入g_m可以提高FvCB模型的模拟精度。