For revealing the ore sources of the Dachang tin?polymetallic ore deposit, the lead isotopes were analyzed systematically by using the single minerals of sulphides, including pyrite, pyrrhotite, sphalerite, and galena...For revealing the ore sources of the Dachang tin?polymetallic ore deposit, the lead isotopes were analyzed systematically by using the single minerals of sulphides, including pyrite, pyrrhotite, sphalerite, and galena. Then, the mineral sources and their characteristics were discussed based on the classical lead isotope discriminating model. The results show that the lead isotope ratios of206Pb/204Pb,207Pb/204Pb, and208Pb/204Pb range from 17.478 to 18.638, 15.440 to 15.858, and 37.556 to 39.501, respectively. According to Zartman lead model, the ore lead contains the upper crust composition; however, the granite does not provide all ore leads, and other material sources exist. Obviously, the ore deposit belongs to the result of the combined effect of crust?mantle. The source rocks are characterized by a certain degree of similarity with the island arc material. Moreover, its distant origin in the upper and lower crusts may be related to the subduction island arc material or oceanic crust. The mantle-derived material may have a certain status in the source region. Meanwhile, based on the lead isotope three-dimensional topology projection vectors, the ore leads are concentrated in zoneA, which indicates the characteristics of Yangtze lead isotope province and a possible genetic relationship with Yangtze block.展开更多
Phytoremediation has been used as an emerging technology for remediation of soil contamination with polycyclic aromatic hydrocarbons(PAHs),ubiquitous persistent environmental pollutants derived from natural and anthro...Phytoremediation has been used as an emerging technology for remediation of soil contamination with polycyclic aromatic hydrocarbons(PAHs),ubiquitous persistent environmental pollutants derived from natural and anthropogenic processes,in the last decade.In this study,a pot experiment was conducted to investigate the potential of phytoremediation of pyrene from spiked soils planted with white clover(Trifolium repens)in the greenhouse with a series of pyrene concentrations ranging from 4.22 to 365.38 mg kg-1.The results showed that growth of white clover on pyrenecontaminated soils was not affected.The removal of pyrene from the spiked soils planted with white clover was obviously higher than that from the unplanted soils.At the end of the experiment(60 d),the average removal ratio of pyrene in the spiked soils with white clover was 77%,which was 31%and 57%higher than those of the controls with or without micobes, respectively.Both roots and shoots of white clover took up pyrene from the spiked soils and pyrene uptake increased with the soil pyrene concentration.However,the plant-enhanced dissipation of soil pyrene may be the result of plant-promoted microbial degradation and direct uptake and accumulation of pyrene by white clover were only a small part of the pyrene dissipation.Bioconcentration factors of pyrene(BCFs,ratio of pyrene,on a dry weight basis,in the plant to that in the soil)tended to decrease with increase in the residual soil pyrene concentration.Therefore,removal of pyrene in the contaminated soils was feasible using white clove.展开更多
In order to reveal the characteristics and climatic controls on the stable isotopic composition of precipitation over Arid Northwestern China, eight stations have been selected from Chinese Network of Isotopes in Prec...In order to reveal the characteristics and climatic controls on the stable isotopic composition of precipitation over Arid Northwestern China, eight stations have been selected from Chinese Network of Isotopes in Precipitation(CHNIP).During the year 2005 and 2006, monthly precipitation samples have been collected and analyzed for the composition of δD and δ18O.The established local meteoric water line δD=7.42δ18O+1.38, based on the 95 obtained monthly composite samples, could be treated as isotopic input function across the region.The deviations of slope and intercept from the Global Meteoric Water Line indicated the specific regional meteorological conditions.The monthly δ18O values were characterized by a positive correlation with surface air temperature(δ18O(‰) =0.33 T(℃)-13.12).The amount effect visualized during summer period(δ18O(‰) =-0.04P(mm)-3.44) though not appeared at a whole yearly-scale.Spatial distributions of δ18O have properly portrayed the atmospheric circulation background in each month over Arid Northwestern China.The quan-titative simulation of δ18O, which involved a Rayleigh fractionation and a kinetic fractionation, demonstrated that the latter one was the dominating function of condensation of raindrops.Furthermore, the raindrop suffered a re-evaporation during falling processes, and the precipitation vapor might have been mixed with a quantity of local recycled water vapor.Multiple linear regression equations and a δ18O-T relation have been gained by using meteorological parameters and δ18O data to evaluate physical controls on the long-term data.The established δ18O-T relation, which has been based on the present-day precipitation, could be considered as a first step of quantitatively reconstructing the historical environmental climate.展开更多
"The Sun Rising" is one of the most outstanding metaphysical poems of John Donne. After a general introduction about the metaphysical poetry and the author, this paper mainly aims to analyze the arresting and origin..."The Sun Rising" is one of the most outstanding metaphysical poems of John Donne. After a general introduction about the metaphysical poetry and the author, this paper mainly aims to analyze the arresting and original conceits and images used in "The Sun Rising" and comment on their effect on expressing the author's feeling and reflecting his emotions.展开更多
The determination of toxic metals in water using multiwalled carbon nanotubes (MWNTs) as a solid-phase extraction adsorbent prior to their determination by inductively coupled plasma mass spectrometry (ICP-MS) has...The determination of toxic metals in water using multiwalled carbon nanotubes (MWNTs) as a solid-phase extraction adsorbent prior to their determination by inductively coupled plasma mass spectrometry (ICP-MS) has been investigated. Standard addition method was applied for the calibration using aqueous solutions. Multiwalled carbon nanotubes (MWNTs) absorb these metals at pH 8.0, HNO3 of 1.0 mol-Ll is used for complete elusion of these metals from MWNTs. Previously investigated parameters have been applied for the determination of Pb, Cr, Ni and Mn in tap water samples. Fifteen tap water samples from different locations of Riyadh metropolitan area have been determined by ICP-MS after preconcentration with MWNTs.展开更多
As an indispensable energy source, lignite is almost exclusively used in power generation m TurKey, To assess me quality level of Turkish lignite, a multivariate statistical analysis was conducted. The relationship am...As an indispensable energy source, lignite is almost exclusively used in power generation m TurKey, To assess me quality level of Turkish lignite, a multivariate statistical analysis was conducted. The relationship among the lignite quality parameters has been investigated using a response method that is the logistic regression method. The analysis determines the effect of multiple predictor variables such as moisture, ash and sulphur presented simultaneously to predict membership of the two calorific value categories. By this way, a reliable binary response regression structure was constructed considering all the lignite fields in Turkey. Both the experiments on identifying the influential measurements and the measure of goodness of fit indicated that the overall model has a big capability to exhibit the relationship among the parameters of the Turkish lignite.展开更多
AIM: To investigate the allele and genotype frequencies and associated risk of interleukin (IL)-8-251T>A polymorphism on colorectal cancer (CRC) susceptibility risk. METHODS: Peripheral blood samples of 255 normal ...AIM: To investigate the allele and genotype frequencies and associated risk of interleukin (IL)-8-251T>A polymorphism on colorectal cancer (CRC) susceptibility risk. METHODS: Peripheral blood samples of 255 normal controls and 255 clinically and histopathologically confirmed CRC patients were genotyped for IL-8-251T>A polymorphism employing allele-specific polymerase chain reaction. The relative association of variant allele and genotypes with CRC susceptibility risk was determined by calculating the odds ratios (ORs). Corresponding χ 2 tests on the CRC patients and controls were carried out and 95% confidence intervals (CIs) were determined using Fisher's exact test. The allele frequencies and its risk association were calculated using FAMHAP, haplotype association analysis software. RESULTS: On comparing the frequencies of genotypesof patients and controls, the homozygous variant AA was significantly higher in CRC patients (P = 0.002) compared to controls. Investigation on the association of the polymorphic genotypes with CRC susceptibility risk, showed that the homozygous variant IL-8 -251AA had a significantly increased risk with OR 3.600 (95% CI: 1.550-8.481, P = 0.001). In the case of allele frequencies, variant allele A of IL-8 -251 showed a significantly increased risk of CRC predisposition with OR 1.32 (95% CI: 1.03-1.69,P = 0.003). CONCLUSION: Variant allele and genotype of IL-8 (-251 T>A) was significantly associated with CRC susceptibility risk and could be considered as a high-risk variant for CRC predisposition.展开更多
AIM:To survey irritable bowel syndrome(IBS) using Rome Ⅲ criteria among Malays from the north-eastern region of Peninsular Malaysia.METHODS:A previously validated Malay language Rome Ⅲ IBS diagnostic questionnaire w...AIM:To survey irritable bowel syndrome(IBS) using Rome Ⅲ criteria among Malays from the north-eastern region of Peninsular Malaysia.METHODS:A previously validated Malay language Rome Ⅲ IBS diagnostic questionnaire was used in the current study.A prospective sample of 232 Malay subjects(80% power) was initially screened.Using a stratified random sampling strategy,a total of 221 Malay subjects(112 subjects in a "full time job" and 109 subjects in "no full time job") were recruited.Subjects were visitors(friends and relatives) within the hospital compound and were representative of the local community.Red flags and psychosocial alarm symptoms were also assessed in the current study using previously translated and validated questionnaires.Subjects with IBS were sub-typed into constipation-predominant,diarrhea-predominant,mixed type and un-subtyped.Univariable and multivariable analyses were used to test for association between socioeconomic factors and presence of red flags and psychosocial alarm features among the Malays with IBS.RESULTS:IBS was present in 10.9%(24/221),red flags in 22.2%(49/221) and psychosocial alarm features in 9.0%(20/221).Red flags were more commonly reported in subjects with IBS(83.3%) than psychosocial alarm features(20.8%,P < 0.001).Subjects with IBS were older(mean age 41.4 years vs 36.9 years,P = 0.08),but no difference in gender was noted(P = 0.4).Using univariable analysis,IBS was significantly associated with a tertiary education,high individual income above RM1000,married status,exsmoker and the presence of red flags(all P < 0.05).In multiple logistic regression analysis,only the presence of red flags was significantly associated with IBS(odds ratio:0.02,95%CI:0.004-0.1,P < 0.001).The commonest IBS sub-type was mixed type(58.3%),followed by constipation-predominant(20.8%),diarrheapredominant(16.7%) and un-subtyped(4.2%).Four of 13 Malay females(30.8%) with IBS also had menstrual pain.Most subjects with IBS had at least one red flag(70.8%),12.5% had two red flags and 16.7% with no red flags.The commonest red flag was a bowel habit change in subjects > 50 years old and this was reported by 16.7% of subjects with IBS.CONCLUSION:Using the Rome Ⅲ criteria,IBS was common among ethnic Malays from the north-eastern region of Peninsular Malaysia.展开更多
Background: Minangkabau Malays (Melayu Minangkabau) is one of the Malay sub ethnic groups in Peninsular Malaysia. During the late 17th and early 18th centuries, migration of the Minangs from West Sumatra to the sta...Background: Minangkabau Malays (Melayu Minangkabau) is one of the Malay sub ethnic groups in Peninsular Malaysia. During the late 17th and early 18th centuries, migration of the Minangs from West Sumatra to the state of Negeri Sembilan Darul Khusus in Peninsular Malaysia took place and their descendants now form the main sub ethnic group in this state. The genetic polymorphisms of Y chromosome at DYS 287 locus were analyzed in Minangkahau Malays. Methods: A total of 41 buccal cells from healthy unrelated individual's males from Minangkabau Malays were typed for the DYS 287. The PCR products were separated on 2% (w/v) agarose gel followed by visualization under UV light. Results: Three out of 41 samples (7.32%) showed insertion (YAP+) polymorphism, while the rest of the samples (92.68%) showed deletion (YAP-) polymorphism. This is the first report concerning the YAP in Malay population at Peninsular Malysia. Conclusion: The vAluable data obtained in this study will contribute to fill in the gap in the knowledge of YAP distribution in Malaysian population and will allow continuous interpretation of the evolution of YAP.展开更多
Objective:To evaluate the effect and safety of clinical use of zoledronic acid in the treatment of malignant hypercalcemia.Methods:A multi-center,open phase II clinical trial was conducted in 15 cases with malignant h...Objective:To evaluate the effect and safety of clinical use of zoledronic acid in the treatment of malignant hypercalcemia.Methods:A multi-center,open phase II clinical trial was conducted in 15 cases with malignant hypercalcemia who received zoledronic acid intravenously for 15 min.The level of blood calcium and side effects were recorded regularly within 28 days after injection.Results:One case was dropped out due to bad compliance.The complete response rate(the corrected serum calcium was reduced to normal level)was 100.00%(14/14).The medium time of complete response rate was 5.07 days.The medium maintain time was 22.30 days.Slight,or moderate fever was observed.Conclusion:Zoledronic acid can effectively reduce the malignant hypercalcemia.The use of zoledronic acid appears to be safety and convenient.展开更多
AIM: To characterize the types of mutations present in the 23S rRNA genes of Malaysian isolates of clarithromycin-resistant Helicobacter pylori (H pylorl~. METHODS: Clarithromycin susceptibility of H pylori isolate...AIM: To characterize the types of mutations present in the 23S rRNA genes of Malaysian isolates of clarithromycin-resistant Helicobacter pylori (H pylorl~. METHODS: Clarithromycin susceptibility of H pylori isolates was determined by E test. Analyses for point mutations in the domain V of 23S rRNA genes in clarithromycin-resistant and -sensitive strains were performed by sequence analysis of amplified polymerase chain reaction products. Restriction fragment length polymorphism was performed using Bsa I and MboI enzymes to detect restriction sites that correspond to the mutations in the clarithromycin- resistant strains. RESULTS: Of 187 isolates from 120 patients, four were resistant to clarithromycin, while 183 were sensitive. The MIC of the resistant strains ranged from 1.5 to 24 pg/mL. Two isolates had an A2142G mutation and another two had A2143G mutations. A T2182C mutation was detected in two out of four clarithromycin-resistant isolates and in 13 of 14 clarithromycin-sensitive isolates. Restriction enzyme analyses with Bsa I and Mbo I were able to detect the mutations. CONCLUSION: Clarithromycin resistance is an uncommon occurrence among Malaysian isolates of Hpylori strains and the mutations A2142G and A2143G detected were associated with low-level resistance.展开更多
With the development of the Ground Positioning System (GPS) modernization and the expectable implementation of Galileo, people pay more and more attention to civil applications on multi-frequency signals. This paper p...With the development of the Ground Positioning System (GPS) modernization and the expectable implementation of Galileo, people pay more and more attention to civil applications on multi-frequency signals. This paper proposes a new and advanced positioning algorithm for the dual-frequency satellite navigation receivers, concerning the various influences of all the ranging error sources and taking advantage of the Klobuchar single-frequency ionospheric model. The paper also presents positioning precision provided by the new algorithm. Theoretical analysis and experimental results show that, the new dual-frequency positioning algorithm can achieve higher positioning accu- racy than the single-frequency positioning algorithm and the traditional dual-frequency positioning algorithm.展开更多
This study was conducted in the intention to identify and determine the fatty acid profile in freshwater fishes and marine fishes available at Malaysian wet market as well as its deterioration kept in ice storage up t...This study was conducted in the intention to identify and determine the fatty acid profile in freshwater fishes and marine fishes available at Malaysian wet market as well as its deterioration kept in ice storage up to 21 days. Three freshwater fishes: Oreochromis sp. commonly known as Tilapia, Monopterus alba commonly known as Belut, Pangasius hypothalamus commonly known as Patin and marine fish Rastrellinger kanagurta commonly known as Kembung, Thunnus tonggol commonly known as Tongkol and Epinephelus sp. commonly known as Kerapu with average weight of 500-600 g were tested with storage time of 1, 3, 6, 9, 12, 15. 18 and 21 days kept ice storage. The Fatty Acid Methyl Ester (FAMEs) were prepared using one step method and were identified by using gas chromatograph Agilent 6890N equipped with flame ionization detector. Separation was performed by injecting 1μL of a sample into the capillary column DB-225MS column (30 m length × 0.250 mm diameter × 0.25 μm film thickness). The fatty acids peaks were indentified using Agilent Technologies software 5988-5871EN and comparing their retention time against the authentic standard Supelco 37 Component FAME Mix. Statistical results showed that palmitic acid (CI6:0) were the major fatty acids among the saturated fatty acids (SFA) while oleic acid (C 18:1 n9) were the major monounsaturated fatty acids (MUFA) detected in each sample studied. Both linoliec acid (C 18:2n6) and arachadonic acid (C20:4n6) were predominant in total omega-6 polyunsaturated fatty acids (PUFA). The essential fatty acids show prominent in ecosapentanoic acid (C20:5n3) and docosahexanoic acid (C22:6n3). During ice storage polyunsaturated fatty acids (PUFA) and monounsaturated fatty acids (MUFA) decrease as the time of storage increase. There is significant decrease in polyene index (PI) index of all the species throughout the storage time, The PI in freshwater fishes decrease by 70% in Tilapia, 90.1% in Belut and 90.9% in Patin, while for marine fishes, PI in Kembung decreases by 67.8%, 85.7% in Kerapu and 65.93% in Tongkol during kept in ice storage. During ice storage, the percentage of EPA, DHA and ALA decrease in Tilapia (55.36%, 13.86% and 75.41%), Belut (78.55%, 87.74 % and 74.53%) and Patin (82.45%, 40.0% and 82.10%), respectively. The same result were also observed in the marine fishes where the percentage ofEPA, DHA and ALA decrease in Kembung (94.27%, 49.03% and 88.52%), in Kerapu (73.03%, 88.18% and 38.73%) and Tongkol (70.05%, 38.24% and 57.14%), respectively.展开更多
The objective of this study is to improve the production of L-DOPA from fungal source like Aspergillus terreus that can be further used to large-scale commercial production of this important drug from microbial source...The objective of this study is to improve the production of L-DOPA from fungal source like Aspergillus terreus that can be further used to large-scale commercial production of this important drug from microbial sources. L-DOPA, a dopamine precursor that can pass the blood-brain barrier, is presently the drug of choice for Parkinson's disease. Microbial production and isolation of L-DOPA from natural sources is yet to be achieved an economical process. In this study, the mycelial pellets ofAspergillus terreus 104 were entrapped in 2% calcium alginate and were studied for their capacity for L-3, 4-dihydroxyphenylalanine production. Results showed that the immobilized pellets produced L-DOPA to the extent of 0.74 mg·G^-1 biomass while the free pellets produced 0.8 mg·G^-1 biomass. Further, storage of immobilized pellets for 96 h at 4 ℃ resulted in the reduction of the original L-DOPA producing activity of the gel beads only 40% and that of free pellets lost completely. In order to improve the production yield, further experiments were designed. It was found that L-DOPA production could be prolonged with repeated batch wise use of immobilized mycelial pellets in calcium alginate retaining 80% of their L-DOPA producing capacity for a period of 72 h while free pellets lost completely within 24 h. Results of this kind therefore is interesting and promising for commercial scale production of L-DOPA from microbial sources.展开更多
Artemisia capillaris is a herbaceous aromatic and therapeutic plant. The genetic variability among individuals of Artemisia capillaris from state of Terengganu, Malaysia was examined by using the random amplified poly...Artemisia capillaris is a herbaceous aromatic and therapeutic plant. The genetic variability among individuals of Artemisia capillaris from state of Terengganu, Malaysia was examined by using the random amplified polymorphic DNA (RAPD) technique to assess the polymorphism at the species level, The samples from differences regional in Terengganu State. The genomic DNA was extracted from the samples leaves using Sarkosyl method. The results produced by the machine showed clear RAPD banding pattern. Fifty-seven oligonucleotide primers were screened and five primers were selected (OPA 04, OPA 09, OPA 16, OPA 17 and OPA 18) to amplify DNA from five samples of Artemisia capillaris from State of Terengganu, Malaysia. A total of 135 RAPD fragments (RAPDs) with all polymorphic fragments (100%) with size ranging from 250--3000 bp were scored from the population. Genetic distance for samples ranges from 0.0000 to 0.320000. For similarity index samples ranges from 0.0000 to 0.7547.展开更多
Analyzing the service behavior of high dams and establishing early-warning systems for them have become increasingly important in ensuring their long-term service.Current analysis methods used to obtain safety monitor...Analyzing the service behavior of high dams and establishing early-warning systems for them have become increasingly important in ensuring their long-term service.Current analysis methods used to obtain safety monitoring data are suited only to single survey point data.Unreliable or even paradoxical results are inevitably obtained when processing large amounts of monitoring data,thereby causing difficulty in acquiring precise conclusions.Therefore,we have developed a new method based on multi-source information fusion for conducting a comprehensive analysis of prototype monitoring data of high dams.In addition,we propose the use of decision information entropy analysis for building a diagnosis and early-warning system for the long-term service of high dams.Data metrics reduction is achieved using information fusion at the data level.A Bayesian information fusion is then conducted at the decision level to obtain a comprehensive diagnosis.Early-warning outcomes can be released after sorting analysis results from multi-positions in the dam according to importance.A case study indicates that the new method can effectively handle large amounts of monitoring data from numerous survey points.It can likewise obtain precise real-time results and export comprehensive early-warning outcomes from multi-positions of high dams.展开更多
With the development of vehicle gearbox to high-power-density and high-speed, how to predict and optimize the dynamic characteristics of vehicle gearbox becomes increasingly prominent. Aiming at the vehicle gearbox, t...With the development of vehicle gearbox to high-power-density and high-speed, how to predict and optimize the dynamic characteristics of vehicle gearbox becomes increasingly prominent. Aiming at the vehicle gearbox, this paper comprehensively and deeply studies the dynamic characteristics under the multi-boundary conditions. The generation mechanism of the multi-source excitations triggering the gearbox vibration is analyzed firstly. The vibration transfer path of the gearbox is explored. Secondly, the engine excitation, the gear meshing excitation and the bearing support load are numerically calculated. According to the finite element method,a fluid-solid coupling finite element model of the gearbox body is established to predict the gearbox dynamic responses based on the Galerkin method and the Hamiltonian variational principle. Finally, the effects of the excitation condition, oil height and reinforcement forms on the vibration responses of the gearbox body are thoroughly studied by simulation. The analysis indicates that it not only helps to modify and improve the method of forecasting the gearbox dynamic response, and also provides the theoretical and technical guidance for the gearbox design and optimization.展开更多
Invasive alien plants threaten biodiversity across the world.Erigeron canadensis(horseweed)is one of the most problematic agricultural weeds and represents a classic example of intercontinental invasion.Here,we studie...Invasive alien plants threaten biodiversity across the world.Erigeron canadensis(horseweed)is one of the most problematic agricultural weeds and represents a classic example of intercontinental invasion.Here,we studied the genetic diversity and population structure of invasive alien populations from the Jiangsu and Zhejiang Provinces in China and native populations from Alabama,in the USA.We used 10 polymorphic SSR loci to genotype 312 individuals from 5 native and 5 invasive populations to estimate the genetic diversity and structure.Invasive populations from Jiangsu and Zhejiang Provinces showed,on average,similar genetic diversity to native populations from Alabama,indicating no severe genetic bottlenecks during the invasion.STRUCTURE revealed that low population differentiation occurred,and that only two genetic groupings were detected in both native and invaded ranges.The high diversity observed in the invasive populations suggested multiple introductions and/or the introduction of genetically diverse propagules during initial colonization.Our study provides new insights toward understanding the invasion dynamics of this globally noxious weed in Eastern China.Preventing gene flow via seed dispersal between invasive and native populations should be examined to prevent the introduction and dispersal of herbicide-resistant individuals and inform management practices.展开更多
In this paper, we report a technique for the surface modification of poly-(p-phenylene terephthamide)(PPTA) powder coated with polydopamine(PDOPA). We used air oxidation to self-polymerize dopamine(DOPA) to ensure tha...In this paper, we report a technique for the surface modification of poly-(p-phenylene terephthamide)(PPTA) powder coated with polydopamine(PDOPA). We used air oxidation to self-polymerize dopamine(DOPA) to ensure that the PPTA powder was coated. Our results indicate that the modified surface of PPTA powder enhances compatibility with the polymer matrix without damaging its structure. Additionally, it is possible to control the coating thickness of PDOPA by regulating the reaction time. The modified PPTA powder improved the comprehensive property of ethylene-propylene-diene-terpolymer grafted maleic anhydride(EPDM-g-MAH), and it proved that this method can enhance the strength and electric insulativity of EPDM-g-MAH.展开更多
基金Project(41202051)supported by the National Natural Science Foundation of ChinaProject(S2014GK3005)supported by Hunan Industrial Science and Technology Support Program+1 种基金Project(2012M521721)supported by China Postdoctoral Science FoundationProject(CSUZC2013021)supported by the Open-end Fund for the Valuable and Precision Instruments of Central South University,China
文摘For revealing the ore sources of the Dachang tin?polymetallic ore deposit, the lead isotopes were analyzed systematically by using the single minerals of sulphides, including pyrite, pyrrhotite, sphalerite, and galena. Then, the mineral sources and their characteristics were discussed based on the classical lead isotope discriminating model. The results show that the lead isotope ratios of206Pb/204Pb,207Pb/204Pb, and208Pb/204Pb range from 17.478 to 18.638, 15.440 to 15.858, and 37.556 to 39.501, respectively. According to Zartman lead model, the ore lead contains the upper crust composition; however, the granite does not provide all ore leads, and other material sources exist. Obviously, the ore deposit belongs to the result of the combined effect of crust?mantle. The source rocks are characterized by a certain degree of similarity with the island arc material. Moreover, its distant origin in the upper and lower crusts may be related to the subduction island arc material or oceanic crust. The mantle-derived material may have a certain status in the source region. Meanwhile, based on the lead isotope three-dimensional topology projection vectors, the ore leads are concentrated in zoneA, which indicates the characteristics of Yangtze lead isotope province and a possible genetic relationship with Yangtze block.
基金Project supported by the National Natural Science Foundation of China(Nos.40432004 and 20677015)the Postdoctoral Science Foundation of China(No.20070420094)+2 种基金the Postdoctoral Science Foundation of Shanghai Municipality,China(No.08R214116)the Science and Technology Commission of Shanghai Municipality,China(No.0752nm025)theNational High-Tech Research and Development Program(No.2007AA06Z331)
文摘Phytoremediation has been used as an emerging technology for remediation of soil contamination with polycyclic aromatic hydrocarbons(PAHs),ubiquitous persistent environmental pollutants derived from natural and anthropogenic processes,in the last decade.In this study,a pot experiment was conducted to investigate the potential of phytoremediation of pyrene from spiked soils planted with white clover(Trifolium repens)in the greenhouse with a series of pyrene concentrations ranging from 4.22 to 365.38 mg kg-1.The results showed that growth of white clover on pyrenecontaminated soils was not affected.The removal of pyrene from the spiked soils planted with white clover was obviously higher than that from the unplanted soils.At the end of the experiment(60 d),the average removal ratio of pyrene in the spiked soils with white clover was 77%,which was 31%and 57%higher than those of the controls with or without micobes, respectively.Both roots and shoots of white clover took up pyrene from the spiked soils and pyrene uptake increased with the soil pyrene concentration.However,the plant-enhanced dissipation of soil pyrene may be the result of plant-promoted microbial degradation and direct uptake and accumulation of pyrene by white clover were only a small part of the pyrene dissipation.Bioconcentration factors of pyrene(BCFs,ratio of pyrene,on a dry weight basis,in the plant to that in the soil)tended to decrease with increase in the residual soil pyrene concentration.Therefore,removal of pyrene in the contaminated soils was feasible using white clove.
基金National Natural Science Foundation of China,No.40830636 No.40671034Foundation of Isotopes in Precipitation of Chinese Ecosystem Research Network
文摘In order to reveal the characteristics and climatic controls on the stable isotopic composition of precipitation over Arid Northwestern China, eight stations have been selected from Chinese Network of Isotopes in Precipitation(CHNIP).During the year 2005 and 2006, monthly precipitation samples have been collected and analyzed for the composition of δD and δ18O.The established local meteoric water line δD=7.42δ18O+1.38, based on the 95 obtained monthly composite samples, could be treated as isotopic input function across the region.The deviations of slope and intercept from the Global Meteoric Water Line indicated the specific regional meteorological conditions.The monthly δ18O values were characterized by a positive correlation with surface air temperature(δ18O(‰) =0.33 T(℃)-13.12).The amount effect visualized during summer period(δ18O(‰) =-0.04P(mm)-3.44) though not appeared at a whole yearly-scale.Spatial distributions of δ18O have properly portrayed the atmospheric circulation background in each month over Arid Northwestern China.The quan-titative simulation of δ18O, which involved a Rayleigh fractionation and a kinetic fractionation, demonstrated that the latter one was the dominating function of condensation of raindrops.Furthermore, the raindrop suffered a re-evaporation during falling processes, and the precipitation vapor might have been mixed with a quantity of local recycled water vapor.Multiple linear regression equations and a δ18O-T relation have been gained by using meteorological parameters and δ18O data to evaluate physical controls on the long-term data.The established δ18O-T relation, which has been based on the present-day precipitation, could be considered as a first step of quantitatively reconstructing the historical environmental climate.
文摘"The Sun Rising" is one of the most outstanding metaphysical poems of John Donne. After a general introduction about the metaphysical poetry and the author, this paper mainly aims to analyze the arresting and original conceits and images used in "The Sun Rising" and comment on their effect on expressing the author's feeling and reflecting his emotions.
文摘The determination of toxic metals in water using multiwalled carbon nanotubes (MWNTs) as a solid-phase extraction adsorbent prior to their determination by inductively coupled plasma mass spectrometry (ICP-MS) has been investigated. Standard addition method was applied for the calibration using aqueous solutions. Multiwalled carbon nanotubes (MWNTs) absorb these metals at pH 8.0, HNO3 of 1.0 mol-Ll is used for complete elusion of these metals from MWNTs. Previously investigated parameters have been applied for the determination of Pb, Cr, Ni and Mn in tap water samples. Fifteen tap water samples from different locations of Riyadh metropolitan area have been determined by ICP-MS after preconcentration with MWNTs.
文摘As an indispensable energy source, lignite is almost exclusively used in power generation m TurKey, To assess me quality level of Turkish lignite, a multivariate statistical analysis was conducted. The relationship among the lignite quality parameters has been investigated using a response method that is the logistic regression method. The analysis determines the effect of multiple predictor variables such as moisture, ash and sulphur presented simultaneously to predict membership of the two calorific value categories. By this way, a reliable binary response regression structure was constructed considering all the lignite fields in Turkey. Both the experiments on identifying the influential measurements and the measure of goodness of fit indicated that the overall model has a big capability to exhibit the relationship among the parameters of the Turkish lignite.
基金Supported by USM Research University Grant, No. 1001/PPSP/812032
文摘AIM: To investigate the allele and genotype frequencies and associated risk of interleukin (IL)-8-251T>A polymorphism on colorectal cancer (CRC) susceptibility risk. METHODS: Peripheral blood samples of 255 normal controls and 255 clinically and histopathologically confirmed CRC patients were genotyped for IL-8-251T>A polymorphism employing allele-specific polymerase chain reaction. The relative association of variant allele and genotypes with CRC susceptibility risk was determined by calculating the odds ratios (ORs). Corresponding χ 2 tests on the CRC patients and controls were carried out and 95% confidence intervals (CIs) were determined using Fisher's exact test. The allele frequencies and its risk association were calculated using FAMHAP, haplotype association analysis software. RESULTS: On comparing the frequencies of genotypesof patients and controls, the homozygous variant AA was significantly higher in CRC patients (P = 0.002) compared to controls. Investigation on the association of the polymorphic genotypes with CRC susceptibility risk, showed that the homozygous variant IL-8 -251AA had a significantly increased risk with OR 3.600 (95% CI: 1.550-8.481, P = 0.001). In the case of allele frequencies, variant allele A of IL-8 -251 showed a significantly increased risk of CRC predisposition with OR 1.32 (95% CI: 1.03-1.69,P = 0.003). CONCLUSION: Variant allele and genotype of IL-8 (-251 T>A) was significantly associated with CRC susceptibility risk and could be considered as a high-risk variant for CRC predisposition.
基金Supported by Malaysian Society of Gastroenterology and Hepatology Research Award 2008
文摘AIM:To survey irritable bowel syndrome(IBS) using Rome Ⅲ criteria among Malays from the north-eastern region of Peninsular Malaysia.METHODS:A previously validated Malay language Rome Ⅲ IBS diagnostic questionnaire was used in the current study.A prospective sample of 232 Malay subjects(80% power) was initially screened.Using a stratified random sampling strategy,a total of 221 Malay subjects(112 subjects in a "full time job" and 109 subjects in "no full time job") were recruited.Subjects were visitors(friends and relatives) within the hospital compound and were representative of the local community.Red flags and psychosocial alarm symptoms were also assessed in the current study using previously translated and validated questionnaires.Subjects with IBS were sub-typed into constipation-predominant,diarrhea-predominant,mixed type and un-subtyped.Univariable and multivariable analyses were used to test for association between socioeconomic factors and presence of red flags and psychosocial alarm features among the Malays with IBS.RESULTS:IBS was present in 10.9%(24/221),red flags in 22.2%(49/221) and psychosocial alarm features in 9.0%(20/221).Red flags were more commonly reported in subjects with IBS(83.3%) than psychosocial alarm features(20.8%,P < 0.001).Subjects with IBS were older(mean age 41.4 years vs 36.9 years,P = 0.08),but no difference in gender was noted(P = 0.4).Using univariable analysis,IBS was significantly associated with a tertiary education,high individual income above RM1000,married status,exsmoker and the presence of red flags(all P < 0.05).In multiple logistic regression analysis,only the presence of red flags was significantly associated with IBS(odds ratio:0.02,95%CI:0.004-0.1,P < 0.001).The commonest IBS sub-type was mixed type(58.3%),followed by constipation-predominant(20.8%),diarrheapredominant(16.7%) and un-subtyped(4.2%).Four of 13 Malay females(30.8%) with IBS also had menstrual pain.Most subjects with IBS had at least one red flag(70.8%),12.5% had two red flags and 16.7% with no red flags.The commonest red flag was a bowel habit change in subjects > 50 years old and this was reported by 16.7% of subjects with IBS.CONCLUSION:Using the Rome Ⅲ criteria,IBS was common among ethnic Malays from the north-eastern region of Peninsular Malaysia.
文摘Background: Minangkabau Malays (Melayu Minangkabau) is one of the Malay sub ethnic groups in Peninsular Malaysia. During the late 17th and early 18th centuries, migration of the Minangs from West Sumatra to the state of Negeri Sembilan Darul Khusus in Peninsular Malaysia took place and their descendants now form the main sub ethnic group in this state. The genetic polymorphisms of Y chromosome at DYS 287 locus were analyzed in Minangkahau Malays. Methods: A total of 41 buccal cells from healthy unrelated individual's males from Minangkabau Malays were typed for the DYS 287. The PCR products were separated on 2% (w/v) agarose gel followed by visualization under UV light. Results: Three out of 41 samples (7.32%) showed insertion (YAP+) polymorphism, while the rest of the samples (92.68%) showed deletion (YAP-) polymorphism. This is the first report concerning the YAP in Malay population at Peninsular Malysia. Conclusion: The vAluable data obtained in this study will contribute to fill in the gap in the knowledge of YAP distribution in Malaysian population and will allow continuous interpretation of the evolution of YAP.
文摘Objective:To evaluate the effect and safety of clinical use of zoledronic acid in the treatment of malignant hypercalcemia.Methods:A multi-center,open phase II clinical trial was conducted in 15 cases with malignant hypercalcemia who received zoledronic acid intravenously for 15 min.The level of blood calcium and side effects were recorded regularly within 28 days after injection.Results:One case was dropped out due to bad compliance.The complete response rate(the corrected serum calcium was reduced to normal level)was 100.00%(14/14).The medium time of complete response rate was 5.07 days.The medium maintain time was 22.30 days.Slight,or moderate fever was observed.Conclusion:Zoledronic acid can effectively reduce the malignant hypercalcemia.The use of zoledronic acid appears to be safety and convenient.
基金Supported by A grant from the Ministry of Science,Technology and Innovation,Malaysia
文摘AIM: To characterize the types of mutations present in the 23S rRNA genes of Malaysian isolates of clarithromycin-resistant Helicobacter pylori (H pylorl~. METHODS: Clarithromycin susceptibility of H pylori isolates was determined by E test. Analyses for point mutations in the domain V of 23S rRNA genes in clarithromycin-resistant and -sensitive strains were performed by sequence analysis of amplified polymerase chain reaction products. Restriction fragment length polymorphism was performed using Bsa I and MboI enzymes to detect restriction sites that correspond to the mutations in the clarithromycin- resistant strains. RESULTS: Of 187 isolates from 120 patients, four were resistant to clarithromycin, while 183 were sensitive. The MIC of the resistant strains ranged from 1.5 to 24 pg/mL. Two isolates had an A2142G mutation and another two had A2143G mutations. A T2182C mutation was detected in two out of four clarithromycin-resistant isolates and in 13 of 14 clarithromycin-sensitive isolates. Restriction enzyme analyses with Bsa I and Mbo I were able to detect the mutations. CONCLUSION: Clarithromycin resistance is an uncommon occurrence among Malaysian isolates of Hpylori strains and the mutations A2142G and A2143G detected were associated with low-level resistance.
文摘With the development of the Ground Positioning System (GPS) modernization and the expectable implementation of Galileo, people pay more and more attention to civil applications on multi-frequency signals. This paper proposes a new and advanced positioning algorithm for the dual-frequency satellite navigation receivers, concerning the various influences of all the ranging error sources and taking advantage of the Klobuchar single-frequency ionospheric model. The paper also presents positioning precision provided by the new algorithm. Theoretical analysis and experimental results show that, the new dual-frequency positioning algorithm can achieve higher positioning accu- racy than the single-frequency positioning algorithm and the traditional dual-frequency positioning algorithm.
文摘This study was conducted in the intention to identify and determine the fatty acid profile in freshwater fishes and marine fishes available at Malaysian wet market as well as its deterioration kept in ice storage up to 21 days. Three freshwater fishes: Oreochromis sp. commonly known as Tilapia, Monopterus alba commonly known as Belut, Pangasius hypothalamus commonly known as Patin and marine fish Rastrellinger kanagurta commonly known as Kembung, Thunnus tonggol commonly known as Tongkol and Epinephelus sp. commonly known as Kerapu with average weight of 500-600 g were tested with storage time of 1, 3, 6, 9, 12, 15. 18 and 21 days kept ice storage. The Fatty Acid Methyl Ester (FAMEs) were prepared using one step method and were identified by using gas chromatograph Agilent 6890N equipped with flame ionization detector. Separation was performed by injecting 1μL of a sample into the capillary column DB-225MS column (30 m length × 0.250 mm diameter × 0.25 μm film thickness). The fatty acids peaks were indentified using Agilent Technologies software 5988-5871EN and comparing their retention time against the authentic standard Supelco 37 Component FAME Mix. Statistical results showed that palmitic acid (CI6:0) were the major fatty acids among the saturated fatty acids (SFA) while oleic acid (C 18:1 n9) were the major monounsaturated fatty acids (MUFA) detected in each sample studied. Both linoliec acid (C 18:2n6) and arachadonic acid (C20:4n6) were predominant in total omega-6 polyunsaturated fatty acids (PUFA). The essential fatty acids show prominent in ecosapentanoic acid (C20:5n3) and docosahexanoic acid (C22:6n3). During ice storage polyunsaturated fatty acids (PUFA) and monounsaturated fatty acids (MUFA) decrease as the time of storage increase. There is significant decrease in polyene index (PI) index of all the species throughout the storage time, The PI in freshwater fishes decrease by 70% in Tilapia, 90.1% in Belut and 90.9% in Patin, while for marine fishes, PI in Kembung decreases by 67.8%, 85.7% in Kerapu and 65.93% in Tongkol during kept in ice storage. During ice storage, the percentage of EPA, DHA and ALA decrease in Tilapia (55.36%, 13.86% and 75.41%), Belut (78.55%, 87.74 % and 74.53%) and Patin (82.45%, 40.0% and 82.10%), respectively. The same result were also observed in the marine fishes where the percentage ofEPA, DHA and ALA decrease in Kembung (94.27%, 49.03% and 88.52%), in Kerapu (73.03%, 88.18% and 38.73%) and Tongkol (70.05%, 38.24% and 57.14%), respectively.
文摘The objective of this study is to improve the production of L-DOPA from fungal source like Aspergillus terreus that can be further used to large-scale commercial production of this important drug from microbial sources. L-DOPA, a dopamine precursor that can pass the blood-brain barrier, is presently the drug of choice for Parkinson's disease. Microbial production and isolation of L-DOPA from natural sources is yet to be achieved an economical process. In this study, the mycelial pellets ofAspergillus terreus 104 were entrapped in 2% calcium alginate and were studied for their capacity for L-3, 4-dihydroxyphenylalanine production. Results showed that the immobilized pellets produced L-DOPA to the extent of 0.74 mg·G^-1 biomass while the free pellets produced 0.8 mg·G^-1 biomass. Further, storage of immobilized pellets for 96 h at 4 ℃ resulted in the reduction of the original L-DOPA producing activity of the gel beads only 40% and that of free pellets lost completely. In order to improve the production yield, further experiments were designed. It was found that L-DOPA production could be prolonged with repeated batch wise use of immobilized mycelial pellets in calcium alginate retaining 80% of their L-DOPA producing capacity for a period of 72 h while free pellets lost completely within 24 h. Results of this kind therefore is interesting and promising for commercial scale production of L-DOPA from microbial sources.
文摘Artemisia capillaris is a herbaceous aromatic and therapeutic plant. The genetic variability among individuals of Artemisia capillaris from state of Terengganu, Malaysia was examined by using the random amplified polymorphic DNA (RAPD) technique to assess the polymorphism at the species level, The samples from differences regional in Terengganu State. The genomic DNA was extracted from the samples leaves using Sarkosyl method. The results produced by the machine showed clear RAPD banding pattern. Fifty-seven oligonucleotide primers were screened and five primers were selected (OPA 04, OPA 09, OPA 16, OPA 17 and OPA 18) to amplify DNA from five samples of Artemisia capillaris from State of Terengganu, Malaysia. A total of 135 RAPD fragments (RAPDs) with all polymorphic fragments (100%) with size ranging from 250--3000 bp were scored from the population. Genetic distance for samples ranges from 0.0000 to 0.320000. For similarity index samples ranges from 0.0000 to 0.7547.
基金Project supported by the National Natural Science Foundation of China (Nos. 51139001,51179066,51079046,and 50909041)
文摘Analyzing the service behavior of high dams and establishing early-warning systems for them have become increasingly important in ensuring their long-term service.Current analysis methods used to obtain safety monitoring data are suited only to single survey point data.Unreliable or even paradoxical results are inevitably obtained when processing large amounts of monitoring data,thereby causing difficulty in acquiring precise conclusions.Therefore,we have developed a new method based on multi-source information fusion for conducting a comprehensive analysis of prototype monitoring data of high dams.In addition,we propose the use of decision information entropy analysis for building a diagnosis and early-warning system for the long-term service of high dams.Data metrics reduction is achieved using information fusion at the data level.A Bayesian information fusion is then conducted at the decision level to obtain a comprehensive diagnosis.Early-warning outcomes can be released after sorting analysis results from multi-positions in the dam according to importance.A case study indicates that the new method can effectively handle large amounts of monitoring data from numerous survey points.It can likewise obtain precise real-time results and export comprehensive early-warning outcomes from multi-positions of high dams.
基金the National Natural Science Foundation of China(Nos.51505402 and 51405410)the Education and Scientific Research Projects of Young and Middle-Aged Teachers in Fujian Province in 2014(No.JA14245)
文摘With the development of vehicle gearbox to high-power-density and high-speed, how to predict and optimize the dynamic characteristics of vehicle gearbox becomes increasingly prominent. Aiming at the vehicle gearbox, this paper comprehensively and deeply studies the dynamic characteristics under the multi-boundary conditions. The generation mechanism of the multi-source excitations triggering the gearbox vibration is analyzed firstly. The vibration transfer path of the gearbox is explored. Secondly, the engine excitation, the gear meshing excitation and the bearing support load are numerically calculated. According to the finite element method,a fluid-solid coupling finite element model of the gearbox body is established to predict the gearbox dynamic responses based on the Galerkin method and the Hamiltonian variational principle. Finally, the effects of the excitation condition, oil height and reinforcement forms on the vibration responses of the gearbox body are thoroughly studied by simulation. The analysis indicates that it not only helps to modify and improve the method of forecasting the gearbox dynamic response, and also provides the theoretical and technical guidance for the gearbox design and optimization.
基金supported by the National Natural Science Foundation of China(31370548)the Natural Science Foundation of Jiangsu Province,China(BK20131192)+1 种基金the Talented Young Scientist Program,China(TYSP,India-17-001)the Science and Technology Research Program of Animal and Plant Quarantine Agency of the People’s Republic of China(JSCIQ_2014IK013).
文摘Invasive alien plants threaten biodiversity across the world.Erigeron canadensis(horseweed)is one of the most problematic agricultural weeds and represents a classic example of intercontinental invasion.Here,we studied the genetic diversity and population structure of invasive alien populations from the Jiangsu and Zhejiang Provinces in China and native populations from Alabama,in the USA.We used 10 polymorphic SSR loci to genotype 312 individuals from 5 native and 5 invasive populations to estimate the genetic diversity and structure.Invasive populations from Jiangsu and Zhejiang Provinces showed,on average,similar genetic diversity to native populations from Alabama,indicating no severe genetic bottlenecks during the invasion.STRUCTURE revealed that low population differentiation occurred,and that only two genetic groupings were detected in both native and invaded ranges.The high diversity observed in the invasive populations suggested multiple introductions and/or the introduction of genetically diverse propagules during initial colonization.Our study provides new insights toward understanding the invasion dynamics of this globally noxious weed in Eastern China.Preventing gene flow via seed dispersal between invasive and native populations should be examined to prevent the introduction and dispersal of herbicide-resistant individuals and inform management practices.
基金supported by the National Natural Science Foundation of China (51273157)Program for New Century Excellent Talents in University (NCET-10-0659)Key Program of Natural Science Foundation of Hubei Province of China (2013CFA020)
文摘In this paper, we report a technique for the surface modification of poly-(p-phenylene terephthamide)(PPTA) powder coated with polydopamine(PDOPA). We used air oxidation to self-polymerize dopamine(DOPA) to ensure that the PPTA powder was coated. Our results indicate that the modified surface of PPTA powder enhances compatibility with the polymer matrix without damaging its structure. Additionally, it is possible to control the coating thickness of PDOPA by regulating the reaction time. The modified PPTA powder improved the comprehensive property of ethylene-propylene-diene-terpolymer grafted maleic anhydride(EPDM-g-MAH), and it proved that this method can enhance the strength and electric insulativity of EPDM-g-MAH.