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1.
Autopsy of 29-year old woman suspicious of committing suicide by the ingestion of As2O3 yielded contradictory findings. All pathological findings as well as clinical symptoms suggested acute poisoning, while a highly elevated As level of 26.4 μg g−1 in her hair collected at the autopsy, which was determined with inductively coupled plasma mass spectrometry indicated chronic poisoning. To elucidate this discrepancy, instrumental neutron activation analysis (INAA) with proven accuracy was performed of another set of sectioned hair samples. Levels of As found by INAA in the range of 0.16–0.26 μg g−1 excluded chronic poisoning, because the person died after approximately 14 h after the As2O3 ingestion. Two reasons for the discordant As results obtained by ICP-MS and INAA are considered: (1) accidental, non-removed contamination of hair on the As2O3 ingestion; (2) erroneous performance of ICP-MS.  相似文献   

2.
In the course of an investigation of an electrostatic precipitation technique as a sampling method for airborne dust particles, elevated concentrations of As were found in the data collected during New Years Eve celebrations in Vienna. The original study confirmed the applicability of the new sampling device as a useful sampling method, showing elevated values for the elements Na, Mg, Al, Si, S, K, Cu, As, Br, Rb, Sr, Sb, Te and Ba, all associated with the use of pyrotechnics. The measured values for As could not be explained as a impurity in some other substances used. Thus, several unburned pyrotechnic products were investigated to find the source of As in the dust collected. The results showed only one product with higher than expected As contents (1.4 μg g?1), leading to the assumption of intentional—but illicit—use of arsenic compounds in pyrotechnics as a colouring agent for the production of blue light.  相似文献   

3.
The Dumarey equation has been the dominant relationship used to calculate the mass concentration of saturated elemental mercury vapour in air for the calibration of mercury vapour measurement equipment for over 25 years. However, the origin of the equation, and the validation data supporting its accuracy have never been published. This paper addresses that deficiency, compares the Dumarey equation with other data sets to which it has been wrongly attributed in the past, and describes why it remains superior to the use of mercury vapour pressure data in combination with the ideal gas law, for the purposes of calibrating mercury vapour measurement equipment.  相似文献   

4.
Neil Tarrant 《Ambix》2018,65(3):210-231
In the latter half of the sixteenth century the Roman Inquisition developed criteria to prosecute a series of operative arts, including various forms of divination and magic. Its officials had little interest in alchemy. During that period the Roman Inquisition tried few people for practising alchemy, and it was rarely discussed in official documents. Justifications for prosecuting alchemists did exist, however. In his influential handbook, Directorium inquisitorum, the fourteenth-century inquisitor Nicholas Eymerich had developed a clear rationale for the investigation and prosecution of alchemists as heretics. His position was endorsed in the 1570s by Francisco Peña in his commentary on Eymerich’s handbook. In this article I explore the reasons why alchemy held this ambiguous status. I argue that members of the Dominican Order developed two traditions of thinking about alchemy from Aquinas’s thought. The first, and closest to Aquinas’s own belief, held that alchemy was a natural art that posed no danger to the Christian faith. The second, developed by Eymerich from a selective reading of Aquinas’s writings, indicated specific circumstances in which alchemists could be investigated. The Roman Inquisition’s response to alchemy vacillated between the positions advocated by Aquinas and Eymerich.  相似文献   

5.
The Hungarian-born American chemistry Nobel laureate George A. Olah used superacids to give longer life to carbocations. He resolved a long-standing debate on reaction mechanism in organic chemistry and, more importantly, opened new vistas in hydrocarbon chemistry to produce hosts of new compounds. The concerted utilization of organic synthesis, physical techniques, and computational methods led to spectacular achievements in hydrocarbon chemistry. Olah has always been on the lookout for the practical applications of his discoveries in fundamental chemistry. He continued his research after his Nobel award and has worked out the idea, which he labeled “the methanol economy.” Olah’s example shows that a great researcher can also be a devoted and caring human being.  相似文献   

6.
A total of 205 bluefin and yellowfin tuna samples were examined for mercury detection in order to verify possible differences and have a detailed risk assessment of the two tuna species. The results showed significant higher mercury concentration in muscle tissue of bluefin tuna respect yellowfin tuna (p < 0.001) with mean concentration of 0.84 mg/kg and maximum value of 1.94 mg/kg. These differences can be due the different biological and ecological aspects of the two tuna species and to different oceanographic aspects between Atlantic Ocean and Mediterranean sea. The results obtained in this study suggest an advisable containment of the sources of pollution and further studies on the closed-loop farming of bluefin tuna, in order to ensure the product safety.  相似文献   

7.
The effect of the electrolyte composition, deposition potential, temperature, and the salt-solvent’s cation on the oxygen coefficient (atomic ratio [O]/[U]) of uranium oxides is studied. The oxides are obtained by potentiostatic electrolysis of the M2EO4-M2E2O7-UO2EO4 melts (M = Li, Na, K, Cs; E = W, Mo, S). The oxygen coefficient of the cathodic product is found to increase with the melt temperature. Shifting the deposition potential toward more electronegative values, raising the M2E2O7 concentration, and lowering the concentration of UO2EO4 in the oxide salt electrolytes promotes the formation of uranium oxides at the cathode with smaller values of the oxygen coefficient. All other conditions being equal, the latter diminishes with increasing radius of the salt-solvent’s cation in a series of alkali metals. The electrolytes on the basis of Li2WO4 and Li2MoO4 are discovered to behave abnormally. Replacing the tungstate electrolytes by the molybdate ones with the same cationic composition (at constant \(c_{M_2 E_2 O_7 } \), \(c_{UO_2 EO_4 } \), and T) amplifies the oxygen coefficient of the cathodic product. The results of the study are satisfactorily explained in the framework of a model for the ionic composition of uranyl-containing oxide salt electrolytes, which is based on the notions concerning the complexing and stepwise solvolysis of the uranyl ions.  相似文献   

8.
The position of the lone pair of 17 amines has been located with the help of Baders AIM methodology. This position has been compared with those estimated with simple geometrical models. It appears that these models are convenient only for some symmetrical or undistorted cases.  相似文献   

9.
By using the adsorbent Saccharomyces cerevisiae immobilized on sepiolite an adsorption-elution method was developed for the preconcentration of Cu, Zn, and Cd followed by flame atomic absorption spectrometry (FAAS). Recoveries were 98.3 ± 0.4% for Cu, 94.2 ± 0.3% for Zn, and 99.04 ± 0.04% for Cd at 95% confidence level obtained by the column method. The influence of sea water matrix elements on the separation of the trace elements was also assessed by using the column procedure. The breakthrough capacities were found to be 74 μmol/g for copper, 128 μmol/g for zinc and 97 μmol/g for cadmium. After optimization the proposed method was applied to the trace metal determination in sea and river water.  相似文献   

10.
By using the adsorbent Saccharomyces cerevisiae immobilized on sepiolite an adsorption-elution method was developed for the preconcentration of Cu, Zn, and Cd followed by flame atomic absorption spectrometry (FAAS). Recoveries were 98.3 ± 0.4% for Cu, 94.2 ± 0.3% for Zn, and 99.04 ± 0.04% for Cd at 95% confidence level obtained by the column method. The influence of sea water matrix elements on the separation of the trace elements was also assessed by using the column procedure. The breakthrough capacities were found to be 74 μmol/g for copper, 128 μmol/g for zinc and 97 μmol/g for cadmium. After optimization the proposed method was applied to the trace metal determination in sea and river water. Received: 8 June 1998 / Revised: 8 September 1998 / Accepted: 16 September 1998  相似文献   

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Two methods for determining total nitrogen (TN) contents of complex wastewaters were compared: Devarda’s alloy method and a method involving high temperature oxidation (HTO) followed by chemiluminescence detection (CLD). In the latter multiple standard additions were used for quantification purposes since the CLD response was found to be dependent on the structure of the analysed nitrogen-containing compounds. For both methods, sample dilution steps were necessary to achieve acceptable accuracy. The accuracies for selected compounds used in tests were within the 65–105% range. In a long-term interlaboratory investigation the HTO-CLD method yielded significantly (p < 0.05) higher results than Devarda’s alloy method and greater precision (within-assay repeatability approximately 1% RSD, while the corresponding within-day repeatability for Devarda’s alloy method was approximately 7% RSD).  相似文献   

13.
A cranium stored in the Stiftung Mozarteum in Salzburg/Austria which is believed to be that of Mozart, and skeletal remains of suspected relatives which have been excavated from the Mozart family grave in the cemetery in Salzburg, have been subjected to scientific investigations to determine whether or not the skull is authentic. A film project by the Austrian television ORF in collaboration with Interspot Film on this issue was broadcast at the beginning of the “Mozart year 2006”. DNA analysis could not clarify relationships among the remains and, therefore, assignment of the samples was not really possible. In our work this skull and excavated skeletal remains have been quantified for Pb, Cr, Hg, As, and Sb content by laser ablation-inductively coupled plasma-mass spectrometry (LA–ICP–MS) to obtain information about the living conditions of these individuals. A small splinter of enamel (less than 1 mm3) from a tooth of the “Mozart cranium” was also available for investigation. Quantification was performed by using spiked hydroxyapatite standards. Single hair samples which are recorded to originate from Mozart have also been investigated by LA–ICP–MS and compared with hair samples of contemporary citizens stored in the Federal Pathologic–Anatomical Museum, Vienna. In general, Pb concentrations up to approximately 16 μg g−1 were found in the bone samples of 18th century individuals (a factor of 7 to 8 higher than in recent samples) reflecting elevated Pb levels in food or beverages. Elevated Pb levels were also found in hair samples. The amount of Sb in the enamel sample of the “Mozart cranium” (approx. 3 μg g−1) was significantly higher than in all the other tooth samples investigated, indicating possible Sb ingestion in early childhood. Elevated concentrations of elements in single hair samples gave additional information about possible exposure of the individuals to heavy metals at a particular point in their life.  相似文献   

14.
Journal of Solid State Electrochemistry - The influence of long-term ageing in the Ringer’s solution at 37&nbsp;°C on the passivity and corrosion behaviour of Ti–10Mo–4Zr...  相似文献   

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Japanese scholars in the eighteenth and nineteenth centuries concentrated their efforts translating Western scientific books. Due to fact that only Dutch merchants were permitted to trade with Japan, mainly books in Dutch were introduced into Japan. Thus Dutch translations of books from England, Germany, France, Sweden and Italy were imported. Udagawa Youan was a member of a Japanese family of Chinese medicine doctors and Dutch translators. In the following chapters I outline his life, his vast scope of translations, and present one of his translations, Kouso Seimika, “Chemistry of the Element of Light”: On light and heat reactions with substances, based on a paragraph of the Dutch edition of Antoine Lavoisier’s Traité Élémentaire de Chimie. Youan’s skills were shown in coining new terms in his largest book Seimi Kaiso for which more than twenty-five books of foreign authors are cited as origin for its translation. The wide range of knowledge transfer between scholars of different countries in Europe emphasizes its contrast with the isolation of translation work of the Japanese scholars. Flow of scientific knowledge from Europe to Japan in the nineteenth century is manifested. Udagawa Youan’s text Kouso Seimika explains the reactions of heat and light with matter, plants, animals and mankind as was understood in Lavoisier time.  相似文献   

19.
After the nuclear accident at TEPCO’s Fukushima Dai-ichi power station in March, hydrogen explosions and reactor building explosion resulted in releases of radionuclides in the environment. Severe radioactive cesium and iodine contaminations have been observed in fallout deposition samples and soils in the East Japan. Radioactive cesium, iodine, uranium, and transuranic radionuclides were set as the monitoring targets in food safety tests. However, so far, only radioactive cesium and iodine were daily measured and reported by the Ministry of Health, Labour, and Welfare. The tedious and time consuming conventional alpha spectrometric method hampered the emergency monitoring U contamination in foods. In this work, we propose a simple and rapid analytical method for 238U and 235U/238U isotope ratio analysis in fresh vegetables. This method was applied to the emergency monitoring of radioactive contamination after the nuclear accident at TEPCO’s Fukushima Dai-ichi power station. The results showed no U contamination in fresh vegetables collected in Chiba and Ibaraki prefectures in April and May, 2011.  相似文献   

20.
In vitro tests that verify the ability of a material to form bone-like apatite precipitated (HAp) use a solution that imitates the inorganic part of blood plasma, simulated body fluid (SBF). During such tests, it is necessary to maintain a neutral pH, for which purpose the International Standards Organization recommends the TRIS (tris(hydroxymethyl)aminomethane) buffer (ISO 23,317:2014). To do this, TRIS buffer must remain inert, but, as we have previously reported, TRIS interacts with highly bioreactive materials (such as 45S5 Bioglass-derived scaffolds), thereby accelerating scaffold dissolution. In the search for an alternative to TRIS, we have also recently published results for the 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) and 3-(N-morpholino) propanesulfonic acid (MOPS) buffers, which were also unable to maintain a neutral pH in SBF. Thus, we here continue our search for a more suitable Good’s buffer by comparing BES (N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid) and TES (2-[(2-hydroxy-1,1-bis(hydroxymethyl) ethyl) amino] ethanesulfonic acid) with TRIS. 45S5-derived glass–ceramic scaffolds were tested under static–dynamic conditions for bone-like apatite formation using SBF + BES and SBF + TES solutions. The pH measurements, leachate analysis [atomic absorption spectrophotometry (AAS) (Ca2+, SiIV), UltraViolet-Visible (UV-VIS) spectrophotometry (PO4)3?], and scaffold analysis [X-Ray powder diffraction analysis (XRD), X-ray fluorescent analysis (XRF), scanning electron microscopy (SEM)/energy dispersive spectroscopy (EDS), Brunauer.Emmett.Teller specific surface area analysis (BET)] all showed that both BES and TES quickly interacted with the tested material. Moreover, the kinetics of the glass–ceramic dissolution affected the crystallinity and morphology of the precipitated HAp. Based on our previous results and the present data, it appears that Good’s buffers are not suitable for the in vitro testing of bioactivity of highly bioreactive materials.  相似文献   

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