^(199)Hg NHR spectra of 18 Schiff base type arylmercury compounds have been studied.It was further confirmed that in the molecule of XC_6H_4CH=NC_6H_3-2-HgC1-4-CH_3 there exists an intramolecular N→Hg coordination vi...^(199)Hg NHR spectra of 18 Schiff base type arylmercury compounds have been studied.It was further confirmed that in the molecule of XC_6H_4CH=NC_6H_3-2-HgC1-4-CH_3 there exists an intramolecular N→Hg coordination via a four-membered ring.For the series of XC_6H_4CH=NC_6H_3-2-HgCl-4-CH_3(X is a para-or mera-substituent),there is a good linear correlation between δ^(199)Hg and Hammett's o constants.The influence of substituents of C-pheny1 ring on the δ ^(199)Hg can be explained in terms of the intramolecular N→Hg coordination.展开更多
In the presence of Triton X100,the color reaction of Mercury(Ⅱ)with 2hydroxy5nitrophenyldiazoaminoazobenene(HNPDAAB)was studied.Mercury(Ⅱ)reacts with HNPDAAB and forms a 1∶1 red complex at pH=95-110 buf...In the presence of Triton X100,the color reaction of Mercury(Ⅱ)with 2hydroxy5nitrophenyldiazoaminoazobenene(HNPDAAB)was studied.Mercury(Ⅱ)reacts with HNPDAAB and forms a 1∶1 red complex at pH=95-110 buffer solution of Na2B4O7NaOH.The molar absorptivity is 256×105L·mol-1·cm-1.Beer’s law is obeyed in the concentration range of 0～12μg/25mL for Mercury(Ⅱ).The results are in agreement with those determined by the conventional method.This new method was used to determine trace mercury in wastewater.展开更多
Objective：To investigate the mechanism of action of Fuzheng Huayu Formula（扶正化瘀方,FZHY）against renal interstitial fibrosis（RIF）relating to oxidative injury and nuclear factor-kappa B（NF-κB）activity.Methods...Objective：To investigate the mechanism of action of Fuzheng Huayu Formula（扶正化瘀方,FZHY）against renal interstitial fibrosis（RIF）relating to oxidative injury and nuclear factor-kappa B（NF-κB）activity.Methods：Thirty-two Sprague-Dawley rats were randomly divided into 3 groups：normal group,model group and FZHY treatment group.The RIF model was induced by oral administration of HgC l2 at a dose of 8 mg/kg body weight once a day for 9 weeks.Meanwhile,rats in FZHY treatment group orally took FZHY at a dose of4.0 g/kg rat weight for 9 weeks.The content of hydroxyproline（Hyp）and collagen deposition in kidney were observed.The activities of superoxide dismutase（SOD）and glutathione peroxidase（GSH-Px）,the content of glutathione（GSH）and malondialdehyde（MDA）of kidney were tested.The expressions of inhibitor-κappa B（IκB）,phospho-IκB（p-IκB）,tumor necrosis factor-α（TNF-α）,matrix metalloproteinase-2（MMP-2）andα-smooth muscle actin（α-SMA）were analyzed by Western blot.α-SMA expression was also observed by immunofluorescent staining.MMP-2 activity was measured by gelatin zymography.NF-κB activation was determined by electrophoretic mobility shift assay.Results：Renal interstitial fibrosis was induced by Hg Cl2,demonstrated by remarkably increased Hyp contents and excessive collagen deposition in kidney（P〈0.01）.FZHY significantly inhibited renal interstitial collagen deposition and reduced Hyp content of the Hg Cl2-treated rats（P〈0.01）.GSH content decreased obviously,and MDA content increased significantly in HgC l2-treated rats compared with that of normal rats（P〈0.01）.FZHY significantly increased GSH content and decreased MDA content in the model rats（P〈0.01）.The expressionα-SMA was increased in model rats compared with that of normal rats,FZHY significantly decreased its expression（P〈0.01）.The expressions of p-IκB and TNF-αand MMP-2,MMP-2 activity,and NF-κB activation were increased in model group compared with that in norm展开更多
In this paper, 2-carboxybenzaldehyde rhodamine B thiohydrazine （1） was synthesized and developed as a fluorescent probe to recognize Hg2＋ in DMF/H2O （1：9, v/v） solution with high selectivity. The probe can be ap...In this paper, 2-carboxybenzaldehyde rhodamine B thiohydrazine （1） was synthesized and developed as a fluorescent probe to recognize Hg2＋ in DMF/H2O （1：9, v/v） solution with high selectivity. The probe can be applied to the quantification of rig2＋ with a linear concentration range covering from 1.0 × 10^-7 mol/L to 1.0 × 10^-5 mol/L （R2 = 0.9985） and a detection limit of 4.2 × 10^-8 mol/L. The experiment results show that the response of probe 1 to Hg2＋ is pH-independent in a wide range from 4.0 to 9.0. Moreover, the probe 1 exhibits excellent selectivity toward Hg2＋ over other common metal cations. Most importantly, the probe can be employed to monitor Hg2＋ in living cells using fluorescent imaging technique with satisfied results.展开更多
Activated carbon-supported mercuric chloride（HgCl2） is used as an industrial catalyst for acetylene hydrochlorination. However, the characteristic of easy sublimation of HgCl2 leads to the deactivation o the catalys...Activated carbon-supported mercuric chloride（HgCl2） is used as an industrial catalyst for acetylene hydrochlorination. However, the characteristic of easy sublimation of HgCl2 leads to the deactivation o the catalyst. Here, we showed that the thermal stability of the Hg/AC catalyst can be evidently improved when Cs Cl is added into the Hg/AC catalyst. Compared with the pure Hg/AC catalyst, the sublimation rate of HgCl2 from the Hg–Cs/AC catalyst decreased significantly and the Hg–Cs/AC catalyst showed bette catalytic activity and stability in the reaction. This promoting effect is related to the existence of cesium mercuric chlorides（CsxHgyCl（x＋2y）） highlighted by XRD, HR-TEM and EDX analyses. Thus, reacting HgCl2 with alkali chlorides to form alkali-mercuric chlorides may be a key to design highly efficient and thermally stable mercuric chloride catalyst for hydrochlorination reactions.展开更多
Objective This study aims to investigate the protection of procyanidins and lycopene from the renal damage induced by mercuric chloride.Methods Rats were treated with either procyanidins or lycopene 2h before HgCl 2 s...Objective This study aims to investigate the protection of procyanidins and lycopene from the renal damage induced by mercuric chloride.Methods Rats were treated with either procyanidins or lycopene 2h before HgCl 2 subcutaneously injection,once daily treatment for 2 successive days.Results In comparison with HgCl 2 group,markers of renal function such as blood urea nitrogen in serum and urinary protein were decreased to （18.45±11.63） mmol/L and （15.93±9.36） mmol/L,（4.54±0.78） g/（g Cr） and （4.40±1.12） g/（g Cr）.N‐acetyl‐beta‐D‐glucosaminidase,lactate dehydrogenase,alkaline phosphatase in urine were depressed to （125.49±11.68） U/（g Cr）,（103.73±21.79） U/（g Cr）,（101.99±12.28） U/（g Cr）,and （113.19±23.74） U/（g Cr）,（71.14±21.80） U/（g Cr）,（73.64±21.51） U/（g Cr） in procyanidins and lycopene groups.Indicators of oxidative stress,for example,Glutathion was reduced to （45.58±9.89） μmol/（g pro） and （45.33±5.90） μmol/（g pro）,and antioxidant enzymes such as superoxide dismutase,glutathione‐peroxidase were enhanced to （43.07±10.97） U/（mg pro） and （39.94±6.04） U/（mg pro）,（83.85±18.48） U/（mg pro）,and （85.62±12.68） U/（mg pro）.Malondialdehyde was lowered to （0.95±0.12） （μmol/g pro） and （1.03±0.12） μmol/（g pro） in procyanidins and lycopene groups.ROS generation was decreased by 27.63% and 16.40% and apoptosis was also decreased in procyanidins and lycopene groups respectively.Pathological changes were much better as well.Conclusion Procyanidins and Lycopene play some protective role against mercury kidney damage.展开更多
The interaction between mercuric ion and apoCopC in the absence or presence of cupric ion was investigated through difference UV spectra in Hepes buffer （10 mmol·L^-1） at pH 7.4. The results suggest that mercur...The interaction between mercuric ion and apoCopC in the absence or presence of cupric ion was investigated through difference UV spectra in Hepes buffer （10 mmol·L^-1） at pH 7.4. The results suggest that mercuric ion can bind to C- and N-terminal binding sites of apoCopC, and the conditional binding constants were calculated to be kN=（6.79± 1.12）× 10^6 mol^-1·L and kc=（3.06±0.05）× 10^5 mol^-1·L. Using urea as a chemical agent, the conformational stabilities of apoCopC and HgN^2＋ -CopC-Hgc^2＋ were monitored by fluorescence spectrum in Hepes buffer （50 mmol·L^-1） at pH 7.4. The free energy of stabilization is （14.69±0.85） and （16.66±0.55） kJ.mol^-1, respectively. HgN^2＋ -CopC-Hgc^2＋ is more stable than apoCopC.展开更多
Mercurous chloride catalyzed Mannich condensation of terminal alkynes with secondary amines and aldehydes has been developed. The reaction generated β-aminoalkynes in good yields.
Up to 1980 s,the most used preservative for herbaria specimens was HgCl2,sublimating at ambient air conditions;ionic Hg then reduces to Hg0(gaseous elemental mercury,GEM)and diffuses throughout poor ventilated environ...Up to 1980 s,the most used preservative for herbaria specimens was HgCl2,sublimating at ambient air conditions;ionic Hg then reduces to Hg0(gaseous elemental mercury,GEM)and diffuses throughout poor ventilated environments.High GEM levels may indeed persist for decades,representing a health hazard.In this study,we present new GEM data from the Central Italian Herbarium and Tropical Herbarium Studies Centre of the University of Florence(Italy).These herbaria host one of the largest collection of plants in the world.Here,HgCl2 was documented as plant preservative up to the 1920 s.GEM surveys were conducted in July 2013 and July and December 2017,to account for temporal and seasonal variations.Herbaria show GEM concentrations well above those of external locations,with peak levels within specimen storage cabinets,exceeding 50,000 ng/m3.GEM concentrations up to^7800 ng/m3 were observed where the most ancient collections are stored and no ventilation systems were active.On the contrary,lower GEM concentrations were observed at the first floor.Here,lower and more homogeneously distributed GEM concentrations were measured in 2017 than in 2013 since the air-conditioning system was updated in early2017.GEM concentrations were similar to other herbaria worldwide and lower than Italian permissible exposure limit of 20,000 ng/m3(8-hr working day).Our results indicate that after a century from the latest HgCl2 treatment GEM concentrations are still high,i.e.,the treatment itself is almost irreversible.Air conditioning and renewing is probably the less expensive and more effective method for GEM lowering.展开更多
Mercury pollution has become an important current issue as a result of its environmental effects on a global scale. The Oak Ridge Reservation, established in 1942, was the designated site for the construction of the a...Mercury pollution has become an important current issue as a result of its environmental effects on a global scale. The Oak Ridge Reservation, established in 1942, was the designated site for the construction of the atomic bomb. During a 20-year period from 1944-1963 radioactive and toxic chemical pollutants, especially mercury compounds were released into the surrounding waterways.A germination study was conducted to investigate the ability of three tree species, American sycamore (Platanus occidentalis),shortleaf pine (Pinus echinata), and loblolly pine (Pinus taeda) seeds to germinate in mercuric nitrate (Hg(NO3)2 and methylmercury chloride (CH3HgCl) solutions. A subsequent greenhouse study was conducted to assess the phytotoxic effects of different mercuric solutions on Platanus occidentalis (American Sycamore), inoculated with soils from East Fork Poplar Creek.We also measured vegetation stress by Near Infrared (NIR) spectroscopy.The wavelengths examined were those thatare specific to chlorophyll and several carotenoids, which are involved in photosynthesis: 430 nm (Chl a), 448 nm (Chl b, carotenoids), 471 nm (carotenoids), 642 nm (Chl b), 662 & 680 nm (Chl a). Principal component analysis (PCA) was performed to identify patterns in sycamore leaf spectral data.Under in vitro conditions, as mercury concentration increased above 100 mg·kg-1, germination of all species decreased, with P. echinata being the least sensitive. Germination was inhibited more when seeds were exposed to methyl mercury chloride than to mercuric nitrate. Organic species of mercury proved to be more toxic than inorganic species of mercury in our greenhouse study. Significant changes occurred in levels of all pigments sampled (p430, p448, p471, p642, p662, and p680) over the course of the experiment. NIR spectroscopy was not sensitive enough to detect other chemical changes to foliage following mercury application.展开更多
Free radicals are common outcome of normal aerobic cellular metabolism. In-built antioxidant system of body plays its decisive role in prevention of any loss due to free radicals. However, imbalanced defense mechanism...Free radicals are common outcome of normal aerobic cellular metabolism. In-built antioxidant system of body plays its decisive role in prevention of any loss due to free radicals. However, imbalanced defense mechanism of antioxidants and overproduction or incorporation of free radicals from environment to living systems leads to serious damage. It also attacks nervous system resulting in neural-degeneration. In order to evaluate the neurotoxic effect on the brain parts of mercury in our study, oxidative stress indices of enzymatic and non enzymatic components were measured in rats intoxicated with mercury (2 mg and 4 mg/kg body weight) for 60 days to adult rats. Along with gravimetry, tissue burden was also recorded. Alterations in these indices were further supported by ultrastructural studies carried out in the brain as indicated by myelin disintegration, cell organelle alterations and neuronal loss by mercury poisoning. Treatment with the antioxidant melatonin (N-acetyl 5-methoxy tryptamine, 5 mg/kg) prevented mercury exerted toxicity due to its antioxidant property. The pathological changes were also ameliorated in the brain region comparatively to support biochemical profile of brain. Thus, melatonin produced neuroprotection against mercury poisoning in rats.展开更多
The present study was performed in order to discern the effects of combined exposure to cadmium and mercury on liver function and histopathological alterations in male adult Wistar rats. In the present investigation, ...The present study was performed in order to discern the effects of combined exposure to cadmium and mercury on liver function and histopathological alterations in male adult Wistar rats. In the present investigation, cadmium (100 mg/l) and mercury (25 mg/l) were administered orally for 10 weeks separately or in combination. The rational for studying cadmium and mercury is that both of these metals are encountered frequently in the same contaminated areas. In liver, the activities of serum alanine aminotransferase (ALT) and aspartate amino tranferase (AST) increased significantly in the cadmium (Cd) and mercury (Hg) alone or in combination (Cd + Hg) compared to the control suggesting that both cadmium and mercury cause hepatotoxicity spatially when co-administrated. We noted an increase in serum lactate dehydrogenase (LDH) activity in Cd and combined Cd + Hg treated groups while it decreased in Hg treated group. There was no statistically significant change in the level of total bilirubilin. Serum urea concentration showed a significant increase in the Cd and Hg groups compared to the control group. However an increase in serum creatinine concentration was noted only in the combined treated rats showing that renal insufficiency is more serious in the co-exposed group. Light microscopic examination indicated severe histological changes in the two organs under Cd and mercury influence. Results of the present investigation clearly showed that mercury has profound effects of hepatic handling of cadmium (synergistic effect) as shown by histological and biochemical results. Moreover, we observed a antagonist effect between these two toxic metals on kidney markers such as urea.展开更多
The intermolecular reductive coupling cyclization reactions of 1,1-dicyanoalkenes promoted by Sm-0/cat. HgCl2 were studied. A possible reaction mechanism was proposed.
Objective To explore the toxic effects of mercuric chloride (HgCl 2) on vascular smooth muscle as well as its relationship to calcium antagonist. Methods By using isolated vascular tension methods, we studied the...Objective To explore the toxic effects of mercuric chloride (HgCl 2) on vascular smooth muscle as well as its relationship to calcium antagonist. Methods By using isolated vascular tension methods, we studied the effect of HgCl 2 on isolated rabbit aortic rings. Results HgCl 2 (1-100 μmol·L -1) caused a concentration-dependent contraction of rabbit aortic rings, which did not change with phentolamin or without endothelium. In KH solution with Ca 2+ , the maximum contraction amplitude reduced by(61.2±3.3)%. Nifedipine produced a concentration-dependent decrease of the maximum contraction amplitude. Conclusion Calcium antagonist has protective effects on vascular smooth muscle against damage induced by HgCl 2.展开更多
Aim: To study the effect of mercuric chloride on the membrane-bound enzymes. Methods: The effect of mercuric chloride at two different doses, 1 mg/kg (low dose) and 2 mg/kg (high dose), orally for 30 days, was observe...Aim: To study the effect of mercuric chloride on the membrane-bound enzymes. Methods: The effect of mercuric chloride at two different doses, 1 mg/kg (low dose) and 2 mg/kg (high dose), orally for 30 days, was observed on the membrane-bound enzymes in the testis of adult albino rats. Results: Mercuric chloride significantly decreased the body weight and testis weight in the high dose group (P<0.05), but not in the low dose group. The activities of 5' nucleotidase and adenosine triphosphatases were markedly decreased (P<0.01) in the testis of both groups. Alkaline phosphatase and γ-glutamyl transferase activities were significantly increased (P<0.01) in both groups. However, the effect was more pronounced in the high than in the low dose groups. Conclusion: The dose dependent effect of mercuric chloride on these enzymes may affect the membrane characteristics and thereby the fertility of the animal. (Asian J Androl 2002 Dec; 4:309-311)展开更多
文摘^(199)Hg NHR spectra of 18 Schiff base type arylmercury compounds have been studied.It was further confirmed that in the molecule of XC_6H_4CH=NC_6H_3-2-HgC1-4-CH_3 there exists an intramolecular N→Hg coordination via a four-membered ring.For the series of XC_6H_4CH=NC_6H_3-2-HgCl-4-CH_3(X is a para-or mera-substituent),there is a good linear correlation between δ^(199)Hg and Hammett's o constants.The influence of substituents of C-pheny1 ring on the δ ^(199)Hg can be explained in terms of the intramolecular N→Hg coordination.
文摘In the presence of Triton X100,the color reaction of Mercury(Ⅱ)with 2hydroxy5nitrophenyldiazoaminoazobenene(HNPDAAB)was studied.Mercury(Ⅱ)reacts with HNPDAAB and forms a 1∶1 red complex at pH=95-110 buffer solution of Na2B4O7NaOH.The molar absorptivity is 256×105L·mol-1·cm-1.Beer’s law is obeyed in the concentration range of 0～12μg/25mL for Mercury(Ⅱ).The results are in agreement with those determined by the conventional method.This new method was used to determine trace mercury in wastewater.
基金Supported by the National Natural Science Foundation of China(No.81270053)the National Science and Technology Major Project(No.2014ZX10005001)+1 种基金the International S&T Cooperation Program of China(No.2014DFA31440)"Three-Year Action Plan" for Development of TCM in Shanghai(No.ZY3-CCCX-2-1003)
文摘Objective：To investigate the mechanism of action of Fuzheng Huayu Formula（扶正化瘀方,FZHY）against renal interstitial fibrosis（RIF）relating to oxidative injury and nuclear factor-kappa B（NF-κB）activity.Methods：Thirty-two Sprague-Dawley rats were randomly divided into 3 groups：normal group,model group and FZHY treatment group.The RIF model was induced by oral administration of HgC l2 at a dose of 8 mg/kg body weight once a day for 9 weeks.Meanwhile,rats in FZHY treatment group orally took FZHY at a dose of4.0 g/kg rat weight for 9 weeks.The content of hydroxyproline（Hyp）and collagen deposition in kidney were observed.The activities of superoxide dismutase（SOD）and glutathione peroxidase（GSH-Px）,the content of glutathione（GSH）and malondialdehyde（MDA）of kidney were tested.The expressions of inhibitor-κappa B（IκB）,phospho-IκB（p-IκB）,tumor necrosis factor-α（TNF-α）,matrix metalloproteinase-2（MMP-2）andα-smooth muscle actin（α-SMA）were analyzed by Western blot.α-SMA expression was also observed by immunofluorescent staining.MMP-2 activity was measured by gelatin zymography.NF-κB activation was determined by electrophoretic mobility shift assay.Results：Renal interstitial fibrosis was induced by Hg Cl2,demonstrated by remarkably increased Hyp contents and excessive collagen deposition in kidney（P〈0.01）.FZHY significantly inhibited renal interstitial collagen deposition and reduced Hyp content of the Hg Cl2-treated rats（P〈0.01）.GSH content decreased obviously,and MDA content increased significantly in HgC l2-treated rats compared with that of normal rats（P〈0.01）.FZHY significantly increased GSH content and decreased MDA content in the model rats（P〈0.01）.The expressionα-SMA was increased in model rats compared with that of normal rats,FZHY significantly decreased its expression（P〈0.01）.The expressions of p-IκB and TNF-αand MMP-2,MMP-2 activity,and NF-κB activation were increased in model group compared with that in norm
基金supported by the National Natural Science Foundation of China(Nos.21105038,21005033,21107036)the Opening Project of State Key Laboratory of Chemo/Biosensing andChemometrics of Hunan University(No.201007)+2 种基金China Postdoc-toral Science Foundation(No.2013M541604)Postdoctoral Foundation of Jiangsu Province(No.1301047B)the Scientific Research Foundation for the Talents in Jiangsu University(Jiangsu,China,No.10JDG035)
文摘In this paper, 2-carboxybenzaldehyde rhodamine B thiohydrazine （1） was synthesized and developed as a fluorescent probe to recognize Hg2＋ in DMF/H2O （1：9, v/v） solution with high selectivity. The probe can be applied to the quantification of rig2＋ with a linear concentration range covering from 1.0 × 10^-7 mol/L to 1.0 × 10^-5 mol/L （R2 = 0.9985） and a detection limit of 4.2 × 10^-8 mol/L. The experiment results show that the response of probe 1 to Hg2＋ is pH-independent in a wide range from 4.0 to 9.0. Moreover, the probe 1 exhibits excellent selectivity toward Hg2＋ over other common metal cations. Most importantly, the probe can be employed to monitor Hg2＋ in living cells using fluorescent imaging technique with satisfied results.
文摘Activated carbon-supported mercuric chloride（HgCl2） is used as an industrial catalyst for acetylene hydrochlorination. However, the characteristic of easy sublimation of HgCl2 leads to the deactivation o the catalyst. Here, we showed that the thermal stability of the Hg/AC catalyst can be evidently improved when Cs Cl is added into the Hg/AC catalyst. Compared with the pure Hg/AC catalyst, the sublimation rate of HgCl2 from the Hg–Cs/AC catalyst decreased significantly and the Hg–Cs/AC catalyst showed bette catalytic activity and stability in the reaction. This promoting effect is related to the existence of cesium mercuric chlorides（CsxHgyCl（x＋2y）） highlighted by XRD, HR-TEM and EDX analyses. Thus, reacting HgCl2 with alkali chlorides to form alkali-mercuric chlorides may be a key to design highly efficient and thermally stable mercuric chloride catalyst for hydrochlorination reactions.
文摘Objective This study aims to investigate the protection of procyanidins and lycopene from the renal damage induced by mercuric chloride.Methods Rats were treated with either procyanidins or lycopene 2h before HgCl 2 subcutaneously injection,once daily treatment for 2 successive days.Results In comparison with HgCl 2 group,markers of renal function such as blood urea nitrogen in serum and urinary protein were decreased to （18.45±11.63） mmol/L and （15.93±9.36） mmol/L,（4.54±0.78） g/（g Cr） and （4.40±1.12） g/（g Cr）.N‐acetyl‐beta‐D‐glucosaminidase,lactate dehydrogenase,alkaline phosphatase in urine were depressed to （125.49±11.68） U/（g Cr）,（103.73±21.79） U/（g Cr）,（101.99±12.28） U/（g Cr）,and （113.19±23.74） U/（g Cr）,（71.14±21.80） U/（g Cr）,（73.64±21.51） U/（g Cr） in procyanidins and lycopene groups.Indicators of oxidative stress,for example,Glutathion was reduced to （45.58±9.89） μmol/（g pro） and （45.33±5.90） μmol/（g pro）,and antioxidant enzymes such as superoxide dismutase,glutathione‐peroxidase were enhanced to （43.07±10.97） U/（mg pro） and （39.94±6.04） U/（mg pro）,（83.85±18.48） U/（mg pro）,and （85.62±12.68） U/（mg pro）.Malondialdehyde was lowered to （0.95±0.12） （μmol/g pro） and （1.03±0.12） μmol/（g pro） in procyanidins and lycopene groups.ROS generation was decreased by 27.63% and 16.40% and apoptosis was also decreased in procyanidins and lycopene groups respectively.Pathological changes were much better as well.Conclusion Procyanidins and Lycopene play some protective role against mercury kidney damage.
基金Project supported by the National Natural Science Foundation of China （No. 20371031） and the Natural Science Foundation of Shanxi Province （No. 20031017）.
文摘The interaction between mercuric ion and apoCopC in the absence or presence of cupric ion was investigated through difference UV spectra in Hepes buffer （10 mmol·L^-1） at pH 7.4. The results suggest that mercuric ion can bind to C- and N-terminal binding sites of apoCopC, and the conditional binding constants were calculated to be kN=（6.79± 1.12）× 10^6 mol^-1·L and kc=（3.06±0.05）× 10^5 mol^-1·L. Using urea as a chemical agent, the conformational stabilities of apoCopC and HgN^2＋ -CopC-Hgc^2＋ were monitored by fluorescence spectrum in Hepes buffer （50 mmol·L^-1） at pH 7.4. The free energy of stabilization is （14.69±0.85） and （16.66±0.55） kJ.mol^-1, respectively. HgN^2＋ -CopC-Hgc^2＋ is more stable than apoCopC.
基金Project supported by the National Natural Science Foundation of China （No. 20372024）, the Excellent Scientist Foundation of Anhui Province （No.04046080）, the Natural Science Foundation of the Education Department of Anhui Province （No. 2002kj254zd）, the Scientific Research Foundation for the Returned 0verseas Chinese Scholars, the Ministry of Education of China （No. 2002247）, the Excellent Young Teacher Program of the Ministry of Education of China （No. 2024） and the Key Project of Science and Technology of the Ministry of Education of China （No. 0204069）.
文摘Mercurous chloride catalyzed Mannich condensation of terminal alkynes with secondary amines and aldehydes has been developed. The reaction generated β-aminoalkynes in good yields.
文摘Up to 1980 s,the most used preservative for herbaria specimens was HgCl2,sublimating at ambient air conditions;ionic Hg then reduces to Hg0(gaseous elemental mercury,GEM)and diffuses throughout poor ventilated environments.High GEM levels may indeed persist for decades,representing a health hazard.In this study,we present new GEM data from the Central Italian Herbarium and Tropical Herbarium Studies Centre of the University of Florence(Italy).These herbaria host one of the largest collection of plants in the world.Here,HgCl2 was documented as plant preservative up to the 1920 s.GEM surveys were conducted in July 2013 and July and December 2017,to account for temporal and seasonal variations.Herbaria show GEM concentrations well above those of external locations,with peak levels within specimen storage cabinets,exceeding 50,000 ng/m3.GEM concentrations up to^7800 ng/m3 were observed where the most ancient collections are stored and no ventilation systems were active.On the contrary,lower GEM concentrations were observed at the first floor.Here,lower and more homogeneously distributed GEM concentrations were measured in 2017 than in 2013 since the air-conditioning system was updated in early2017.GEM concentrations were similar to other herbaria worldwide and lower than Italian permissible exposure limit of 20,000 ng/m3(8-hr working day).Our results indicate that after a century from the latest HgCl2 treatment GEM concentrations are still high,i.e.,the treatment itself is almost irreversible.Air conditioning and renewing is probably the less expensive and more effective method for GEM lowering.
文摘Mercury pollution has become an important current issue as a result of its environmental effects on a global scale. The Oak Ridge Reservation, established in 1942, was the designated site for the construction of the atomic bomb. During a 20-year period from 1944-1963 radioactive and toxic chemical pollutants, especially mercury compounds were released into the surrounding waterways.A germination study was conducted to investigate the ability of three tree species, American sycamore (Platanus occidentalis),shortleaf pine (Pinus echinata), and loblolly pine (Pinus taeda) seeds to germinate in mercuric nitrate (Hg(NO3)2 and methylmercury chloride (CH3HgCl) solutions. A subsequent greenhouse study was conducted to assess the phytotoxic effects of different mercuric solutions on Platanus occidentalis (American Sycamore), inoculated with soils from East Fork Poplar Creek.We also measured vegetation stress by Near Infrared (NIR) spectroscopy.The wavelengths examined were those thatare specific to chlorophyll and several carotenoids, which are involved in photosynthesis: 430 nm (Chl a), 448 nm (Chl b, carotenoids), 471 nm (carotenoids), 642 nm (Chl b), 662 & 680 nm (Chl a). Principal component analysis (PCA) was performed to identify patterns in sycamore leaf spectral data.Under in vitro conditions, as mercury concentration increased above 100 mg·kg-1, germination of all species decreased, with P. echinata being the least sensitive. Germination was inhibited more when seeds were exposed to methyl mercury chloride than to mercuric nitrate. Organic species of mercury proved to be more toxic than inorganic species of mercury in our greenhouse study. Significant changes occurred in levels of all pigments sampled (p430, p448, p471, p642, p662, and p680) over the course of the experiment. NIR spectroscopy was not sensitive enough to detect other chemical changes to foliage following mercury application.
文摘Free radicals are common outcome of normal aerobic cellular metabolism. In-built antioxidant system of body plays its decisive role in prevention of any loss due to free radicals. However, imbalanced defense mechanism of antioxidants and overproduction or incorporation of free radicals from environment to living systems leads to serious damage. It also attacks nervous system resulting in neural-degeneration. In order to evaluate the neurotoxic effect on the brain parts of mercury in our study, oxidative stress indices of enzymatic and non enzymatic components were measured in rats intoxicated with mercury (2 mg and 4 mg/kg body weight) for 60 days to adult rats. Along with gravimetry, tissue burden was also recorded. Alterations in these indices were further supported by ultrastructural studies carried out in the brain as indicated by myelin disintegration, cell organelle alterations and neuronal loss by mercury poisoning. Treatment with the antioxidant melatonin (N-acetyl 5-methoxy tryptamine, 5 mg/kg) prevented mercury exerted toxicity due to its antioxidant property. The pathological changes were also ameliorated in the brain region comparatively to support biochemical profile of brain. Thus, melatonin produced neuroprotection against mercury poisoning in rats.
文摘The present study was performed in order to discern the effects of combined exposure to cadmium and mercury on liver function and histopathological alterations in male adult Wistar rats. In the present investigation, cadmium (100 mg/l) and mercury (25 mg/l) were administered orally for 10 weeks separately or in combination. The rational for studying cadmium and mercury is that both of these metals are encountered frequently in the same contaminated areas. In liver, the activities of serum alanine aminotransferase (ALT) and aspartate amino tranferase (AST) increased significantly in the cadmium (Cd) and mercury (Hg) alone or in combination (Cd + Hg) compared to the control suggesting that both cadmium and mercury cause hepatotoxicity spatially when co-administrated. We noted an increase in serum lactate dehydrogenase (LDH) activity in Cd and combined Cd + Hg treated groups while it decreased in Hg treated group. There was no statistically significant change in the level of total bilirubilin. Serum urea concentration showed a significant increase in the Cd and Hg groups compared to the control group. However an increase in serum creatinine concentration was noted only in the combined treated rats showing that renal insufficiency is more serious in the co-exposed group. Light microscopic examination indicated severe histological changes in the two organs under Cd and mercury influence. Results of the present investigation clearly showed that mercury has profound effects of hepatic handling of cadmium (synergistic effect) as shown by histological and biochemical results. Moreover, we observed a antagonist effect between these two toxic metals on kidney markers such as urea.
基金ProjectsupportedbytheNationalNaturalScienceFoundationofChina (No .2 0 0 72 0 33)andtheNaturalScienceFoundationofZhejiangProvince (No .2 980 6 7) .
文摘The intermolecular reductive coupling cyclization reactions of 1,1-dicyanoalkenes promoted by Sm-0/cat. HgCl2 were studied. A possible reaction mechanism was proposed.
文摘Objective To explore the toxic effects of mercuric chloride (HgCl 2) on vascular smooth muscle as well as its relationship to calcium antagonist. Methods By using isolated vascular tension methods, we studied the effect of HgCl 2 on isolated rabbit aortic rings. Results HgCl 2 (1-100 μmol·L -1) caused a concentration-dependent contraction of rabbit aortic rings, which did not change with phentolamin or without endothelium. In KH solution with Ca 2+ , the maximum contraction amplitude reduced by(61.2±3.3)%. Nifedipine produced a concentration-dependent decrease of the maximum contraction amplitude. Conclusion Calcium antagonist has protective effects on vascular smooth muscle against damage induced by HgCl 2.
文摘Aim: To study the effect of mercuric chloride on the membrane-bound enzymes. Methods: The effect of mercuric chloride at two different doses, 1 mg/kg (low dose) and 2 mg/kg (high dose), orally for 30 days, was observed on the membrane-bound enzymes in the testis of adult albino rats. Results: Mercuric chloride significantly decreased the body weight and testis weight in the high dose group (P<0.05), but not in the low dose group. The activities of 5' nucleotidase and adenosine triphosphatases were markedly decreased (P<0.01) in the testis of both groups. Alkaline phosphatase and γ-glutamyl transferase activities were significantly increased (P<0.01) in both groups. However, the effect was more pronounced in the high than in the low dose groups. Conclusion: The dose dependent effect of mercuric chloride on these enzymes may affect the membrane characteristics and thereby the fertility of the animal. (Asian J Androl 2002 Dec; 4:309-311)
