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1.
A. Politano 《Plasmonics (Norwell, Mass.)》2013,8(2):357-360
A novel low-energy collective mode of electrons near the Fermi energy has been detected at 5 meV for (9?×?9)-Ag/Cu(111) by high-resolution electron energy loss spectroscopy. This collective electronic excitation does not exist on the bare Cu substrate or on a silver monolayer deposited on Ni(111). It has been assigned to the excitation of the Friedel oscillations in the silver adlayer. Such finding is important for understanding dynamic electron screening at a metal/metal interface. In particular, this work provides the grounds for more accurate theoretical studies aimed at describing the surface loss function and low-energy collective electronic modes in Ag/Cu(111). 相似文献
2.
Hong-qun Zhang Ning Li Zheng Zhang Shan Gao Hong-yin Yin Dong-mei Guo Xibao Gao 《Biological trace element research》2009,131(1):25-32
Sera of 890 healthy Jinan residents were chosen randomly, and the concentrations of serum Zn and Cu were detected by atomic
absorption spectrometry. The mean serum Zn and Cu concentrations and Zn/Cu were 1.32 ± 0.49 mg/l, 0.99 ± 0.26 mg/l, and 1.41 ± 0.56,
respectively. Significantly higher levels of serum Zn and Zn/Cu but lower serum Cu were found in the men. Descending tendency
of serum Zn and Zn/Cu was observed with social-economic status and age but not significant. Alcohol consumption produced higher
level of serum Zn and Zn/Cu but lower Cu concentration. Smoking caused significant lower level in serum Cu concentration but
no significance in serum Zn and Zn/Cu. Serum Zn and Zn/Cu were normal only when hours of sleep a night were kept within 7–9 h.
Higher level of serum Zn and Cu concentrations and Zn/Cu were observed in individuals with regular physical exercise, but
still no significant difference existed. No clear relationship between educational levels with serum Zn and Cu concentrations
and Zn/Cu was observed. 相似文献
3.
S. Suzuki Kazuya Yamaguchi Kunishige Kataoka Kazuo Kobayashi Seiichi Tagawa Takamitsu Kohzuma Sohsuke Shidara Hidekazu Iwasaki Deligeer 《Journal of biological inorganic chemistry》1997,2(2):265-274
Native nitrite reductases (NIRs) containing both type 1 and 2 Cu ions and type 2 Cu-depleted (T2D) NIRs from three denitrifying
bacteria (Achromobacter cycloclastes IAM 1013, Alcaligenes xylosoxidans NCIB 11015, and Alcaligenes xylosoxidans GIFU 1051) have been characterized by electronic absorption, circular dichroism, and electron paramagnetic resonance spectra.
The characteristic visible absorption spectra of these NIRs are due to the type 1 Cu centers, while the type 2 Cu centers
hardly contribute in the same region. The intramolecular electron transfer (ET) process from the type 1 Cu to the type 2 Cu
in native NIRs has been observed as the reoxidation of the type 1 Cu(I) center by pulse radiolysis, whereas no type 1 Cu in
T2D NIRs exhibits the same reoxidation. The ET process obeys first-order kinetics, and observed rate constants are 1400–1900
s–1 (t1/2 = ca. 0.5 ms) at pH 7.0. In the presence of nitrite, the ET process also obeys first-order kinetics, with rate constants
decreased by factors of 1/12–1/2 at the same pH. The redox potential of the type 2 Cu site is estimated to be +0.24 - +0.28 V,
close to that of the type 1 Cu site. Nitrate and azide ions bound to the type 2 Cu site change the redox potential. Nitrite
also would shift the redox potential of the type 2 Cu by coordination, and hence the intramolecular ET rate constant is decreased.
Pulse radiolysis experiments on T2D NIRs in the presence of nitrite demonstrate that the type 1 Cu(I) site is slowly oxidized
with a first-order rate constant of 0.03 s–1 at pH 7.0, suggesting that nitrite bound to the protein accepts an electron from the type 1 Cu. This result is in accord
with the finding that T2D NIRs show enzymatic activities, although they are lower than those of the native enzymes.
Received: 9 July 1996 / Accepted: 30 January 1997 相似文献
4.
Böyük A Banlı O Gümüş M Evliyaoğlu O Demirelli S 《Biological trace element research》2011,143(3):1282-1288
Laparoscopic adjustable gastric banding (LAGB) causes significant weight loss in morbidly obese adults. However, its consequences
on nutritional status still remain unclear. There are a few studies determining the nutritional status after LAGB and none
have focused on the serum levels of zinc (Zn), copper (Cu), and ceruloplasmin (CP). We aimed to investigate the effects of
LAGB surgery on plasma Zn, Cu, and CP levels. Thirty patients with LAGB with morbid obesity were included. Blood samples were
collected preooperatively and in the postoperative third month to determine plasma Zn, Cu, and CP levels. The mean preoperative
and postoperative body mass indexes (BMI) were 44.9 ± 7.4 kg/m2 and 44.1 ± 6.5 kg/m2, respectively. The mean weight loss was 12.9 ± 3.3 kg at the postoperative third month. The postoperative Zn (500 ± 130 ng/ml),
Cu (280 ± 80 ng/ml), and CP (23.9 ± 8.8 mg/dl) values were statistically significantly lower than the preooperative Zn (740 ± 230 ng/ml),
Cu (370 ± 80 ng/ml) and CP (33.3 ± 15.7 mg/dl) levels (p < 0.05). Decreases in the plasma levels of Zn, Cu, and CP were seen postoperatively following LAGB surgery. The nutritional
status of LAGB-applied patients should be monitored and mineral supplementation may be considered. 相似文献
5.
Electrochemical prevention of marine biofouling on a novel titanium-nitride-coated plate formed by radio-frequency arc spraying 总被引:1,自引:0,他引:1
T. Nakayama H. Wake K. Ozawa N. Nakamura T. Matsunaga 《Applied microbiology and biotechnology》1998,50(4):502-508
We have developed a new method for forming titanium-nitride(TiN)-coated plates using radio-frequency arc spraying (RFAS).
A TiN coating formed by RFAS has been used for electrochemical prevention of marine biofouling. X-ray diffraction and X-ray
photoelectron spectroscopy indicate that a TiN composite film containing Ti was formed on a polyethylene terephthalate plate
surface when Ti was sprayed by RFAS under atmospheric pressure. A cyclic voltammogram (scan rate 20 mV/s) of the TiN formed
by RFAS revealed no oxidative and reductive peak currents in the range −0.6 V to 1.2 V against a saturated silver/silver chloride
(Ag/AgCl) electrode. When a potential of 1.0 V against Ag/AgCl was applied to the electrode in seawater, no dissolved Ti was
detected. Changes in pH and the chlorine concentration were not observed in this range. In all, only 4.5% of the Vibrio alginolyticus cells attached to the electrode survived when a potential of 0.8 V against Ag/AgCl was applied in seawater for 30 min. In
field experiments, attachment of the organisms to the TiN electrode was inhibited by applying an alternating potential of
1.0 V and −0.6 V against Ag/AgCl. The TiN film can be formed by RFAS on large and intricately shaped surfaces, and it is a
practical electrode for the electrochemical prevention of fouling of various marine structures.
Received: 17 April 1998 / Received revision: 5 June 1998 / Accepted: 19 June 1998 相似文献
6.
Salehifar E Shokrzadeh M Ghaemian A Aliakbari S Saeedi Saravi SS 《Biological trace element research》2008,125(2):97-108
Changes in the cupper (Cu) and zinc (Zn) concentrations have been reported previously in idiopathic dilated cardiomyopathy
(IDCMP). As a result of controversial results, the aim of this study was to compare the Zn and Cu concentrations and Zn/Cu
ratio of IDCMP patients to healthy volunteers. In addition, the correlation of Cu and Zn levels with age has been evaluated.
The study population consisted of 18 IDCMP patients and 27 healthy volunteers. IDCMP patients had normal angiography with
echocardiography supporting cardiomyopathy without pericardial and valvular diseases. Exclusion criteria were renal or hepatic
insufficiency, alcohol usage, and intake of supplements containing Cu or Zn within 1 week ago. Cu and Zn levels have been
assayed with atomic absorption spectrophotometry. Statistical analysis was performed with SPSS 10 software with independent
sample t test for comparing the level of Cu and Zn of IDCMP patients with normal subjects and Pearson correlation to determine the
correlation between numeric data. P < 0.05 was considered as significant differences. There was a trend for a lower Zn level in IDCMP patients compared to healthy
volunteers. (0.97 ± 0.25 mg/l vs. 1.12 ± 0.42 mg/l, respectively). The mean Cu levels of IDCMP and normal subjects were 1.33 ± 0.20 mg/l
and 1.31 ± 0.23 mg/l, respectively. There was a significant difference in Zn/Cu ratio among patients based on the NYHA classification
of heart failure (P = 0.003). Age was negatively correlated with Zn levels in IDCMP group (P = 0.037) and positively with Cu levels in healthy volunteers (P = 0.012). A lower Zn level in IDCMP patients compared to healthy volunteers and specially a significant difference in Zn/Cu
ratio of patients based on their NYHA classification would suggest a critical role of zinc and Cu imbalance in development
of IDCMP. 相似文献
7.
C. Immoos Michael G. Hill Donita Sanders James A. Fee Claire E. Slutter John H. Richards Harry B. Gray 《Journal of biological inorganic chemistry》1996,1(6):529-531
The electrochemistry of a water-soluble fragment from the CuA domain of Thermus thermophilus cytochrome ba
3
has been investigated. At 25 °C, CuA exhibits a reversible reduction at a pyridine-4-aldehydesemicarbazone-modified gold electrode (0.1 M Tris, pH 8) with E° = 0.24 V vs NHE. Thermodynamic parameters for the [Cu(Cys)2Cu]+/0 electrode reaction were determined by variable-temperature electrochemistry (ΔS°rc = –5.4(12) eu, ΔS° = –21.0(12) eu, ΔH° = –11.9(4) kcal/mol;ΔG° = –5.6 (11) kcal/mol). The relatively small reaction entropy is consistent with a low reorganization energy for [Cu(Cys)2Cu]+/0 electron transfer. An irreversible oxidation of [Cu(Cys)2Cu]+ at 1 V vs NHE confirms that the CuII:CuII state of CuA is significantly destabilized relative to the CuII state of analogous blue-copper proteins.
Received: 3 June 1996 / Accepted: 26 August 1996 相似文献
8.
Evstaf’yeva E. V. Zalata O. A. Evstaf’yeva I. A. shchegoleva M. G. 《Neurophysiology》2011,43(3):258-260
In 10- to 16-year-old children, inhabitants of industrial towns of Ukraine, an X-ray fluorescence analysis of the content
of some chemical elements in hair samples allowed us to find a deficiency of Zn and Cu against the background of excesses
of Ca, Cr, Ni, Mo, and Cd. Comparison of the parameters of EEG frequency components and levels of Ca, Zn, Cu, Fe, Mn, Co,
Cr, Mo, Ni, Sr, Pb, and Cd showed that there are significant correlations between the normalized values of spectral powers
of many frequency components of the ongoing EEG recorded in different functional states (eyes closed/open, solving an arithmetic
task, and phono-/photostimulation) and concentrations of ten of the above-mentioned trace elements. Comparative estimation
of the neurotropicity of the elements showed the following sequence of numbers of significant correlations (shown in parentheses)
from the total set of possible comparisons: Cd (35) > Ni (31) > Cr (19) > Sr (17) > Pb (16) > > Ca (10) > Cu (7) > Mo (3) > Zn
(2) > Fe (1). The intensity of correlations (values of the correlation coefficients) varied from 0.26 to 0.42 at 0.05 < P < 0.001; more frequently, such correlations were observed under conditions of EEG recording with the eyes closed (39) and
upon solving an arithmetic task (33). 相似文献
9.
Deficiencies in Cu, Se, and Zn impair one or more biochemical functions, and excess are associated with toxicity. Baseline
studies on the Ghanaian population are scanty. The study was undertaken to determine whether significant rural/urban differences
in the serum levels of Cu, Se, and Zn did exist. Forty males/60 females from rural and 50 males/50 females from urban Ghanaian
communities were sampled. Serum Cu, Se, and Zn were determined using flame atomic absorption spectrometry. Cu level for rural
and urban subjects was 997 ± 333 and 979 ± 290 μg/L, respectively (p = 0.68). However, Cu levels were significantly higher in the rural females (1,063 ± 367 μg/L) than the rural males (898 ± 249 μg/L;
p = 0.0085). Se levels for rural/urban subjects were 97 ± 36 and 87 ± 31 μg/L, respectively (p = 0.03). Zn levels in the rural/urban subjects were 312 ± 218 and 150 ± 102 μg/L, respectively (p = 0.002). Additionally, Zn was significantly higher in rural females (428 ± 204 μg/L) than the urban females (166 ± 103 μg/L;
p = 0.0002). Finally, Zn was significantly higher in rural females (428 ± 204 μg/L) than males (172 ± 116 μg/L; p = 0.0028). In conclusion, Cu, Se, and Zn were higher in the rural group compared to the urban group, and the generally low
Zn levels were confirmed in another cohort follow-up study. 相似文献
10.
Mohammad Abbasi Nazari Farzad Kobarfard Payam Tabarsi Jamshid Salamzadeh 《Biological trace element research》2009,128(2):161-166
Ethambutol is an oral anti-tuberculosis agent with chelating effects owing to its chemical structure which is similar to that
of penicillamine. Copper (Cu) is an essential trace element that has important roles in physiological function of the body
organs. The aim of present study was to determine (1) whether ethambutol usage can alter serum Cu concentration in patients
with tuberculosis and (2) whether there is any relationship between age, sex, and smoking habit of patients with changes in
serum Cu levels. Sixty patients with diagnosis of pulmonary tuberculosis were enrolled the study. Blood samples were obtained
before treatment (baseline) and 10 days after starting anti-tuberculosis therapy. The amounts of serum Cu were determined
in all samples by atomic absorption. Mean ± SD levels of Cu at baseline and on the 10th day of ethambutol use were 0.94 ± 0.24
and 0.64 ± 0.24 μg/mL, respectively. Statistical analysis confirmed a significant difference (p < 0.0001). Also, there was not any relationship between changes in Cu concentration and study variables of age, sex, and
smoking habit. Our findings endorse the chelating effect of ethambutol leading to a decrease in serum levels of cationic trace
elements, e.g., Cu. 相似文献
11.
Abakay A Gokalp O Abakay O Evliyaoglu O Sezgi C Palanci Y Ekici F Karakus A Tanrikulu AC Ayhan M 《Biological trace element research》2012,145(2):151-157
The aim of this study was to investigate the respiratory function disorders that could be related to dust exposure during
the production of copper mine in copper mineworkers (CMWs). The study included 75 male CMWs (mean age, 32.0 ± 7.1 years, 58.6%
smokers) and 75 male age- and smoking status-matched healthy control subjects. Serum Cu level was significantly higher in
the CMW group (0.80 ± 0.62 μg/ml) than the control group (0.60 ± 0.39 μg/ml) (p = 0.017). Significant negative correlations were found between serum Cu level and forced expiratory volume in first second
(r = −0.600; p < 0.001) and between serum Cu level and forced vital capacity (r = −0.593; p = <0.001) in CMWs. Serum Cu level was significantly higher in the restrictive type pulmonary function disorders group (1.36 ± 0.62 μg/ml)
than obstructive type (0.90 ± 0.55 μg/ml) and normal pulmonary function pattern group (0.53 ± 0.43 μg/ml) (p < 0.001). Patients with radiological parenchymal abnormalities had significantly higher serum copper levels than those without
abnormalities (1.53 ± 0.52 vs. 0.71 ± 0.52 μg/ml, respectively; p = 0.002). In conclusion, result of the study has shown a negative association between pulmonary functions disorders and radiological
abnormalities and serum Cu levels in CMWs. 相似文献
12.
Copper (Cu) is an integral part of many important enzymes involved in a number of vital biological processes. Even though
Cu is essential to life, it can become toxic to cells, at elevated tissue concentrations. Oxidative damage due to Cu has been
reported in recent studies in various tissues. In this study, we aimed to determine the effect of excess Cu on oxidative and
anti-oxidative substances in brain tissue in a rat model. Sixteen male Wistar albino rats were divided into two groups: the
control group, which was given normal tap water, and the experimental group, which received water containing Cu in a dose
of 1 g/l. All rats were sacrificed at the end of 4 wk, under ether anesthesia. Cu concentration in the liver and in plasma
alanine aminotransferase (ALT) and aspartate transaminase (AST) activities were determined. There were multiparameter changes
with significant ALT and AST activity elevation and increased liver Cu concentration. In brain tissue, Cu concentration, superoxide
dismutase (SOD) activities, malondialdehyde (MDA) levels and glutathione (GSH) concentrations were determined. Brain Cu concentration
was significantly higher in rats receiving excess Cu, compared with control rats (p < 0.05). Our results showed that SOD activities and GSH levels in brain tissue of the Cu-intoxicated animals were significantly
lower than in the control group (p < 0.01 and p < 0,001, respectively). The brain MDA levels were found to be significantly higher in the experimental group than in the
control group (p < 0.001). The present results indicate that excessive Cu accumulation in the brain depressed SOD activities and GSH levels
and resulted in high MDA levels in brain homogenate due to the lipid peroxidation induced by the Cu overload. 相似文献
13.
Amit Jaiswal Pallab Sanpui Arun Chattopadhyay Siddhartha Sankar Ghosh 《Plasmonics (Norwell, Mass.)》2011,6(1):125-132
Water dispersible zinc sulfide quantum dots (ZnS QDs) with an average diameter of 2.9 nm were synthesized in an environment
friendly method using chitosan as stabilizing agent. These nanocrystals displayed characteristic absorption and emission spectra
having an absorbance edge at 300 nm and emission maxima (λ
emission) at 427 nm. Citrate-capped silver nanoparticles (Ag NPs) of ca. 37-nm diameter were prepared by modified Turkevich process.
The fluorescence of ZnS QDs was significantly quenched in presence of Ag NPs in a concentration-dependent manner with K
sv value of 9 × 109 M−1. The quenching mechanism was analyzed using Stern–Volmer plot which indicated mixed nature of quenching. Static mechanism
was evident from the formation of electrostatic complex between positively charged ZnS QDs and negatively charged Ag NPs as
confirmed by absorbance study. Due to excellent overlap between ZnS QDs emission and surface plasmon resonance band of Ag
NPs, the role of energy transfer process as an additional quenching mechanism was investigated by time-resolved fluorescence
measurements. Time-correlated single-photon counting study demonstrated decrease in average lifetime of ZnS QDs fluorescence
in presence of Ag NPs. The corresponding F?rster distance for the present QD–NP pair was calculated to be 18.4 nm. 相似文献
14.
Shokrzadeh M Ghaemian A Salehifar E Aliakbari S Saravi SS Ebrahimi P 《Biological trace element research》2009,127(2):116-123
Changes in the copper (Cu) and zinc (Zn) concentrations have been reported previously in ischemic cardiomyopathy (ISCMP).
Due to controversial results, the aims of this study were to compare levels of Cu, Zn, and Zn/Cu ratio of ISCMP patients with
healthy volunteers and also to investigate the possible relationship between trace elements status in ISCMP patients with
the severity of clinical disease based on the New York Heart Association (NYHA) classification. The subjects of this study
consisted of 30 ISCMP and 27 healthy volunteers. ISCMP was diagnosed with a history of previous myocardial infarction and
also coronary artery disease was confirmed by coronary angiography. Exclusion criteria were renal or hepatic insufficiency,
alcohol usage, and intake of supplements containing Cu or Zn within 1 week. Cu and Zn levels have been assayed with atomic
absorption spectrophotometry. Statistical analysis was performed with the SPSS 10 software using independent sample t test for comparing the levels of Cu and Zn between ISCMP and normal subjects. The mean Cu level of the ISCMP group (1.54 ± 0.52 mg/L)
was significantly more than the Cu levels of the healthy volunteers (1.31 ± 0.24 mg/L; p = 0.048). The mean Zn levels of the ISCMP and healthy volunteers were 1.05 ± 0.28 and 1.12 ± 0.42, respectively, without
any significant difference between groups. There was a trend for higher Cu level, lower Zn level, and lower Zn/Cu ratio in
NYHA III patients in comparison with NYHA II group. Considering the results of this study, Cu may have a role in the development
of ISCMP. Interventions such as administration of Cu chelators to relieve the symptoms or to decrease the progression of ISCMP
is needed to be examined in large clinical trials. In this study, the Zn level of ISCMP patients was not significantly different
in comparison with the healthy volunteers. 相似文献
15.
Determination of copper in human tissues and body fluids may be crucial in the diagnosis of Wilson’s disease. In this study
we evaluated urinary copper excretion and urine and blood concentration in 14 patients in whom Wilson’s disease was confirmed
(group A) and in 21 subjects in whom the disease was only suspected (group B). The following values (mean ± SD) were found:
24-h urine (μg Cu/24 h), 152 ± 135 (A) and 31.8 ± 10.9 (B); urine (μg Cu/ml), 0.091 ± 0.087 (A) and 0.028 ± 0.011 (B); and
blood (μg Cu/ml), 0.62 ± 0.25 (A) and 0.72 ± 0.09 (B). By comparison, urine copper concentration in the group of apparently
healthy subjects was 0.035 ± 0.010 (n = 50), and blood copper concentration in autopsy cases of nonpoisoned people was 0.85 ± 0.19 (n = 73). 相似文献
16.
A 2 × 3 factorial arrangement of treatments was used to investigate the effects of different levels of copper (Cu, 0, 19,
and 38 mg/kg, dry matter (DM)) and molybdenum (Mo, 0 and 5 mg/kg, DM) supplements and an interaction of these two factors
on growth performance, nutrient digestibility, and cashmere and follicle characteristics in cashmere goats. Thirty-six Liaoning
cashmere goats (approximately 1.5 years of age; 27.53 ± 1.38 kg of body weight) were assigned randomly to one of six treatments
and fed with Chinese wildrye- and alfalfa hay-based treatment diets (the basal diet contained 4.72 mg Cu/kg, 1.65 mg Mo/kg,
and 0.21% S.). Body weight was measured on two consecutive days at the start and the end of the 70-day experimental period.
On day 30, the metabolism trial was conducted to study the effects of dietary Cu and Mo on nutrient digestibility. The cashmere
and skin samples were collected on day 70. Copper supplementation increased (P < 0.05) growth performance and fiber digestion, but there were no differences (P > 0.05) between Cu-supplemented groups. Addition of 19 mg Cu/kg DM increased (P < 0.05) cashmere growth length or growth rate by increasing the number of active secondary follicles. Molybdenum supplementation
decreased (P < 0.05) growth, but did not affect (P > 0.05) nutrient digestion, cashmere, and follicle characteristics. There is a tendency or significant interaction effect
of Cu and Mo on growth performance (P = 0.057), cashmere growth (P = 0.076), or diameter (P < 0.05) which might be accomplished by changing the number of secondary follicle and active secondary follicle, and secondary
to primary follicle ratio. In conclusion, the optimal supplemental Cu level for Liaoning cashmere goats fed with the basal
diet was 19 mg/kg DM (the total dietary Cu level of 23.72 mg/kg DM), while 38 mg Cu/kg DM supplementation was found to be
needed when 5 mg Mo/kg was added in the basal diet during the cashmere growing period. 相似文献
17.
Variations of copper (Cu) concentration and ceruloplasmin (Cp) activity in serum and plasma of dairy cows at different stages
of lactation were assessed in 240 Holstein dairy cows. Furthermore, ceruloplasmin to copper ratios were also investigated.
The cows were classified according to their lactation stages into four different groups as close-up stage (3–1 week(s) antepartum),
fresh lactation stage (0–1 week postpartum), early lactation stage (3–5 weeks postpartum), and mid-lactation stage (15–18 weeks
postpartum). Each group consisted of 60 multiparous cows. Serum and heparinised plasma samples were obtained from each cow.
Concentrations of serum copper (sCu) and plasma copper (pCu) as well as activities of plasma Cp (pCp) were higher in the group
of fresh lactation stage than other groups (P < 0.05). Serum Cp (sCp) exhibited no significant difference between fresh lactation and early lactation groups (P > 0.05). Low correlations were obtained between sCp and pCu, sCp and sCu, and sCu and pCu. Plasma copper concentration and
plasma ceruloplasmin activity were higher than serum copper concentration and serum ceruloplasmin activity, respectively (P < 0.001). The ratios of Cp activity to Cu concentration (Cp/Cu) were not significantly changed in the different lactation
stages of dairy cows (P > 0.05). Use of sCp/pCu and sCp/sCu rather than pCp/pCu will reduce the calculated value of Cp/Cu. Furthermore, for evaluation
of copper status, use of sCp/sCu or sCp/pCu identified more animals as ‘low’ and ‘marginal’ than using pCp/pCu (P < 0.001). It can be concluded that ceruloplasmin and copper undergo a physiological increase just after calving; thus, their
values should be interpreted with caution during assessment of copper status. Plasma measurements should be used for calculation
of Cp/Cu, and further research is required to refine diagnosis criteria for use of such ratio in determining copper status
in dairy cows. 相似文献
18.
Valenzuela C de Romaña DL Schmiede C Morales MS Olivares M Pizarro F 《Biological trace element research》2011,143(3):1489-1496
The aim of this study is to determine the content of total iron (TFe), heme iron (HeFe), zinc (Zn), and copper (Cu) in different
cuts of meat and viscera from rabbit. Five young New Zealand rabbits were used in the study. Samples in triplicate were obtained
from three meat cuts (foreleg, hind leg, and loin) and from main viscera. TFe, Zn, and Cu concentrations from samples were
determined by wet acid digestion followed by atomic absorption spectrophotometry (AAS), while HeFe was determined by acid
extraction followed by AAS. Mean TFe, HeFe, Zn, and Cu in meat was 0.83 ± 0.09, 0.56 ± 0.11, 0.95 ± 0.35, and 0.08 ± 0.01 mg/100 g,
respectively. TFe content was less than 1 mg/100 g in all meat cuts. Sixty-seven percent of iron content was HeFe. The cut
of meat with highest Zn concentrations was the foreleg with 1.33 ± 0.12 mg/100 g. Cu content was low for all meat cuts. TFe,
HeFe, Zn, and Cu content in viscera varied greatly. The spleen was the organ with the highest TFe and Zn concentrations (82.79 ± 9.22 mg/100 g
and 3.49 ± 0.63 mg/100 g, respectively). Nevertheless, the lungs had the highest concentration of HeFe (5.79 ± 0.90 mg/100 g),
accounting for 91% of the total iron. The liver had the highest Cu content (3.89 ± 0.89 mg/100 g). Rabbit meat has low TFe
concentration, similar to that of poultry, and most of the iron is HeFe. The amount of minerals in viscera closely depends
on their function. 相似文献
19.
Five brands of antidiabetic herbal formulations as tablets, Diabetex, Divya Madhu Nashini, Jambrushila, Diabeticin, and Madhumeh Nashini, from different pharmacies were analyzed for six minor (Na, K, Ca, Cl, Mg, and P) and 20 trace (As, Ba, Br, Ce, Co, Cr, Cs,
Cu, Fe, Hg, La, Mn, Rb, Sb, Sc, Se, Sm, Th, V, and Zn) elements by thermal neutron irradiation followed by high-resolution
gamma ray spectrometry. Further Ni, Cd, and Pb were determined by atomic absorption spectrophotometry. Most elements vary
in a narrow range by a factor of 2–4 while a few others vary in a wide range, e.g., Na (0.05–0.67 mg/g), Mn (26.7–250 μg/g),
and V (0.26–2.50 μg/g). All the five brands contain K, Cl, Mg, P, and Ca as minor constituents along with mean trace amounts
of Cr (2.11 ± 0.67 μg/g), Cu (15.7 ± 7.11 μg/g), Fe (459 ± 171 μg/g), Mn (143 ± 23 μg/g), Se (238 ± 112 ng/g), and V (0.99 ± 0.93 μg/g).
Jambrushila is enriched in Na, Ca, Mg, Cl, Fe, Cu, Se, and Zn, essential nutrients responsible for curing diabetes. Dietary intake of
Mn, Fe, and Cu are greater than 10% of the recommended dietary allowance, whereas that for Zn and Se is less than 2%. Mean
contents of toxic elements (As, Cd, Hg, and Pb) were found below permissible limits except in Jambrushila. Cr and Zn were inversely correlated with r = −0.81, whereas Rb and Cs exhibit linear correlation (r = 0.93) in five brands. C, H, N analysis showed C ∼ 55%, H ∼ 12%, and N ∼ 2% with a total of ∼70% organic matter. However,
thermal decomposition studies at 700°C suggest less than 5% nonvolatile metal oxides. Herbal formulations contain minor and
trace elements in bioavailable forms that favorably influence glucose tolerance and possibly increase the body’s ability to
ameliorate development of diabetes. 相似文献
20.
With the help of quantum mechanical calculations, we have examined the series of central system X(ML)3
+(X = O, S, Se; M = Au, Ag, Cu). Using a scalar–relativistic density functional approach, we studied the geometry structures, Mulliken populations and charges of the systems. Structure parameters of the experimental systems are reproduced well with Xα method. The metallophilic interaction energy is analyzed and decomposed. For the systems with different central atoms and different metal atoms, the nature of the metallophilic attraction interaction is analyzed. 相似文献