The history of the discovery of nuclear fission

Following with the discovery of the electron by J. J. Thomson at the end of the nineteenth century a steady elucidation of the structure of the atom occurred over the next 40 years culminating in the discovery of nuclear fission in 1938–1939. The significant steps after the electron discovery were: discovery of the nuclear atom by Rutherford (Philos Mag 6th Ser 21:669–688, 1911), the transformation of elements by Rutherford (Philos Mag 37:578–587, 1919), discovery of artificial radioactivity by Joliot-Curie and Joliot-Curie (Comptes Rendus Acad Sci Paris 198:254–256, 1934), and the discovery of the neutron by Chadwick (Nature 129:312, 1932a, Proc R Soc Ser A 136:692–708, 1932b; Proc R Soc Lond Ser A 136:744–748, 1932c). The neutron furnished scientists with a particle able to penetrate atomic nuclei without expenditure of large amounts of energy. From 1934 until 1938–1939 investigations of the reaction between a neutron and uranium were carried out by E. Fermi in Rome, O. Hahn, L. Meitner and F. Strassmann in Berlin and I. Curie and P. Savitch in Paris. Results were interpreted as the formation of transuranic elements. After sorting out complex radio-chemistry and radio-physics O. Hahn and F. Strassmann came to the conclusion, beyond their belief, that the uranium nucleus split into smaller fragments, that is nuclear fission. This was soon followed in 1939 by its theoretical interpretation by L. Mietner and O. Frisch.     

Production and Characterization of Polyclonal and Monoclonal Abs Against the RNA-Binding Protein QKI

RNA-binding protein QKI, a member of the Signal Transduction and Activation of RNA family, is found to be essential in the blood vessel development and postnatal myelination in central nervous system (Woo et al., Oncogene 28:1176–1186, 2009; Lu et al., Nucleic Acids Res 31(15):4616–4624, 2003; Bohnsack et al., Genesis 44(2):93–104, 2006). However, its wide expression pattern suggests other fundamental roles in vivo (Kondo et al., Mamm Genome 10(7):662–669, 1999). To facilitate the understanding of QKI function in various systems, we prepared the polyclonal and monoclonal antibodies against QKI. To obtain the antigen, recombinant His-tagged QKI was expressed in Escherichia coli and highly purified by Ni²⁺-chelated column combined with hydrophobic and ion exchange methods. Following three types of immunizations with different adjuvants, including Freund’s, PAGE gel, and nitrocellulose membrane, only the antiserum produced with Freund’s adjuvant is effective for Western blot detection. Several McAb clones are able to recognize both endogenous and over-expressed QKI with high affinity in Western blot and immunofluorescence. The specificity of Ab was validated as weakening, and no specific signals were observed in cells with QKI knocking down. Immunohistochemistry analysis further showed positive staining of QKI in kidney where QKI mRNA was abundantly expressed, ensuring the wide applications of the QKI Abs in the ongoing mechanistic studies.     

The architecture and the Jones polynomial of polyhedral links

In this paper, we first recall some known architectures of polyhedral links (Qiu and Zhai in J Mol Struct (THEOCHEM) 756:163–166, 2005; Yang and Qiu in MATCH Commun Math Comput Chem 58:635–646, 2007; Qiu et al. in Sci China Ser B Chem 51:13–18, 2008; Hu et al. in J Math Chem 46:592–603, 2009; Cheng et al. in MATCH Commun Math Comput Chem 62:115–130, 2009; Cheng et al. in MATCH Commun Math Comput Chem 63:115–130, 2010; Liu et al. in J Math Chem 48:439–456 2010). Motivated by these architectures we introduce the notions of polyhedral links based on edge covering, vertex covering, and mixed edge and vertex covering, which include all polyhedral links in Qiu and Zhai (J Mol Struct (THEOCHEM) 756:163–166, 2005), Yang and Qiu (MATCH Commun Math Comput Chem 58:635–646, 2007), Qiu et al. (Sci China Ser B Chem 51:13–18, 2008), Hu et al. (J Math Chem 46:592–603, 2009), Cheng et al. (MATCH Commun Math Comput Chem 62:115–130, 2009), Cheng et al. (MATCH Commun Math Comput Chem 63:115–130, 2010), Liu et al. (J Math Chem 48:439–456, 2010) as special cases. The analysis of chirality of polyhedral links is very important in stereochemistry and the Jones polynomial is powerful in differentiating the chirality (Flapan in When topology meets chemistry. Cambridge Univ. Press, Cambridge, 2000). Then we give a detailed account of a result on the computation of the Jones polynomial of polyhedral links based on edge covering developed by Jin, Zhang, Dong and Tay (Electron. J. Comb. 17(1): R94, 2010) and, at the same time, by using this method we obtain some new computational results on polyhedral links of rational type and uniform polyhedral links with small edge covering units. These new computational results are helpful to judge the chirality of polyhedral links based on edge covering. Finally, we give some remarks and pose some problems for further study.     

Towards more fair and effective doping tests based on chromatography with mass spectrometric detection

Van Eenoo and Delbeke in Accred Qual Assur (2009) have criticized Faber (in Accred Qual Assur, 2009) for not taking “all factors under consideration when making his claims”. Here, it is detailed that their criticism is based on a misunderstanding of examples that were merely intended to be illustrative. Motivated by this criticism, further discussion is provided that may help in the pursuit of more fair and effective doping tests, here exemplified by chromatography with mass spectrometric detection. Surely, any doping test can only be improved or even optimized if the risks of false positives and false negatives are well defined. This requirement is consistent with a basic principle concerning mathematical approximations (Parlett in “The symmetric eigenvalue problem”, Prentice-Hall, Englewood Cliffs, 1980): apart from just being good, they should be known to be good. Author’s reply to the response on “Regulations in the field of residue and doping analysis...” Papers published in this section do not necessarily reflect the opinion of the Editors, the Editorial Board and the Publisher.     

Mesophilic Digestion Kinetics of Manure Slurry

Anaerobic digestion kinetics study of cow manure was performed at 35°C in bench-scale gas-lift digesters (3.78 l working volume) at eight different volatile solids (VS) loading rates in the range of 1.11–5.87 g l⁻¹ day⁻¹. The digesters produced methane at the rates of 0.44–1.18 l l⁻¹ day⁻¹, and the methane content of the biogas was found to increase with longer hydraulic retention time (HRT). Based on the experimental observations, the ultimate methane yield and the specific methane productivity were estimated to be 0.42 l CH₄ (g VS loaded)^–1 and 0.45 l CH₄ (g VS consumed)^–1, respectively. Total and dissolved chemical oxygen demand (COD) consumptions were calculated to be 59–17% and 78–43% at 24.4–4.6 days HRTs, respectively. Maximum concentration of volatile fatty acids in the effluent was observed as 0.7 g l^–1 at 4.6 days HRT, while it was below detection limit at HRTs longer than 11 days. The observed methane production rate did not compare well with the predictions of Chen and Hashimoto’s [1] and Hill’s [2] models using their recommended kinetic parameters. However, under the studied experimental conditions, the predictions of Chen and Hashimoto’s [1] model compared better to the observed data than that of Hill’s [2] model. The nonlinear regression analysis of the experimental data was performed using a derived methane production rate model, for a completely mixed anaerobic digester, involving Contois kinetics [3] with endogenous decay. The best fit values for the maximum specific growth rate (μ _m) and dimensionless kinetic parameter (K) were estimated as 0.43 day^–1 and 0.89, respectively. The experimental data were found to be within 95% confidence interval of the prediction of the derived methane production rate model with the sum of residual squared error as 0.02.     

Solid-state mechanical properties of crystalline drugs and excipients

Thermal mechanical analysis (TMA) of crystalline drugs and excipients in their pre-melt temperature range performed in this study corroborate their newly found linear dielectric conductivity properties with temperature. TMA of crystalline active pharmacy ingredients (APIs) or excipients shows softening at 30–100 °C below the calorimetric melting phase transition, which is also observed by dielectric analysis (DEA). Acetophenetidin melts at 135 °C as measured calorimetrically by DSC, but softens under a low mechanical stress at 95 °C. At this pre-melting temperature, the crystals collapse under the applied load, and the TMA probe shows rapid displacement. The mechanical properties yield a softening structure and cause a dimensionally slow disintegration resulting in a sharp dimensional change at the melting point. In order to incorporate these findings into a structure–property relationship, several United States Pharmacopeia (USP) melting-point standard drugs were evaluated by TMA, DSC, and DEA, and compared to the USP standard melt temperatures. The USP standard melt temperature for vanillin (80 °C) [1], acetophenetidin (135 °C) [2], and caffeine (235 °C) [3] are easily verified calorimetrically via DSC. The combined thermal analysis techniques allow for a wide variety of the newly discovered physical properties of drugs and excipients.     

Non-isothermal crystallization kinetics of some aventurine decorative glaze

Thermal and structural properties of three clays (sepiolite and two kaolinites) from Turkey were studied by thermal analysis (TG–DTA), X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier transform infrared (FT-IR), and surface area measurement techniques The adsorption of sulfur dioxide (SO₂) gas by these clays was also investigated. SO₂ adsorption values of K1, K2, and S clay samples were measured at 20 °C and pressures up to 106 kPa. Sepiolite sample (S) primarily consists of pure sepiolite, only dolomite present as accompanying mineral. Both kaolinite samples, K1 and K2, mainly contain kaolinite as the major clay mineral and quartz as impurity. In K2 sample, muscovite phase is also present. Simultaneous TG–DTA curves of all clay samples were obtained at three different heating rates 10, 15, and 20 °C min⁻¹ over the temperature range 30–1200 °C. It was found that the retention value of SO₂ by S clay (2.744 mmol/g) was higher than those of K1 (0.144 mmol/g) and K2 (0.164 mmol/g) samples.     

Synthesis and Insecticidal Activity of New 4-Hydroxy-2H-1-benzopyran-2-one Derivatives

Several stable and storable anticoagulant rodenticides involving both merits of acute and chronic rodenticides have been synthesized (Holbrook et al. in Arch Intern Med 165:1095–1106, 2005; Baglin et al. in Br J Haematol 132:277–285, 2006). The structures of synthesized compounds were confirmed by IR, ¹H NMR. The compounds were also evaluated for their anticoagulant and acute biologic activity (Lipton et al., JAMA 252:3004–3005, 3).     

Characterization of unstable enzyme systems which evolve according to a three-exponential equation

The time course of an enzyme catalyzed reaction is normally followed either by monitoring the instantaneous concentration or velocity of an enzyme species or a product. In many enzyme catalyzed reactions these time variations are multi-exponential. The accurate fit of the relevant curves to obtain the kinetic parameters involved can be difficult using conventional methods (Galvez et al. in J Theor Biol 89:37–44, 1981; Garcia-Canovas et al. in Biochim Biophys Acta 912:417–423, 1987; Tudela et al. in Biochim Biophys Acta 912:408–416, 1987; Teruel et al. in Biochim Biophys Acta 911:256–260, 1987; Garrido del Solo et al. in Biochem J 294:459–464, 1993; Varon et al. in Int J Biochem 25:1889–1895, 1993; Garrido del Solo et al. in An Quim 89:319–324, 1993; Varon et al. in J Mol Catal 83:273–285, 1993; Garrido del Solo et al. in Biochem J 303(Pt 2):435–440, 1994; Garrido del Solo and Varon in An Quim 91:13–18, 1995; Garrido del Solo et al. in Biosystems 38:75–86, 1996; Garrido del Solo et al. in Int J Biochem Cell Biol 28:1371–1379, 1996; Garrido del Solo et al. in Int J Biochem Cell Biol 30:735–743, 1998; Varon et al. in J Mol Catal 59:97–118, 1990). In order to circumvent such difficulties Arribas et al. (J Math Chem 44:379–404, 2008) proposed an evaluation method which is applicable regardless of the complexity of the kinetic equation. This procedure is based on the numerical determination of statistical moments from experimental time progress curves. The fitting of these experimentally obtained moments to the corresponding theoretical symbolic expressions allows, in most cases, all the individual rate constants involved to be evaluated. In this paper we perform a general analysis that can be applied to any unstable enzyme system described by a three-exponential equation and apply it to a substrates induced enzyme inactivation process that is described by this type of equation. To verify the goodness of the method we have simulated time progress curves and applied the suggested procedure to these curves, obtaining kinetic parameters values very close to those used to obtain simulated curves. Finally, we compare our results with those obtained in previous contributions in which other procedures were used.     

Lactose does not interfere with the analysis of sialic acids as their 1,2-diamino-4,5-methylenedioxybenzene derivatives

In 2007, Martin et al. developed a method for the analysis of sialic acids by HPLC following 1,2-diamino-4,5-methylenedioxybenzene (DMB) derivatisation (Martín et al., Anal Bioanal Chem 387:2943–2949, 2007). Within the article, the authors noted that lactose interfered with the analysis, giving erroneously high results when lactose-containing products were analysed. Such an observation is important when analysing milk-based products, yet was contradictory to the observations of Nakamura et al. (Chem Pharm Bull 35(2):687–692, 1987) who demonstrated that DMB was specific for α-keto acids and did not react with simple sugars such as glucose or lactose. In order to clarify the situation, this phenomenon was investigated and it was confirmed that lactose does not interfere with the analysis. However, it was found that most commercial preparations of lactose do contain small amounts of sialic acids, either as the free monosaccharide or bound to lactose in the form of 3′- and 6′-sialyllactose.     

Reply to the comment by F. Malatesta on: “Factorizing of a concentration function for the mean activity coefficients of aqueous strong electrolytes into individual functions for ionic species” by A. Ferse and H.-O. Müller

The arguments of Malatesta (J Solution Chem 29:771–779, 2000; Fluid Phase Equil 295:244–248, 2010) exclude the experimental determination of individual ion activity coefficients. I agree that a measurement of single-ion activity coefficients is impossible. But the comment of Malatesta (J Solid State Electrochem (in press), 2011) in the connection with the purely mathematical procedure developed by Ferse and Müller (J Solid State Electrochem (in press), 2011) is senseless because there is no new aspect which is not also given in the paper of Ferse and Müller (J Solid State Electrochem (in press), 2011). All of the mentioned problems are already discussed and clarified in the publication by Ferse and Müller (J Solid State Electrochem (in press), 2011). The purely mathematical method is a possibility to obtain the concentration functions for the individual activity coefficients of the complementary ion species by factorizing a product function of the experimentally accessible concentration dependence of the mean activity coefficients to the required power.     

IonCCD Detector for Miniature Sector-Field Mass Spectrometer: Investigation of Peak Shape and Detector Surface Artifacts Induced by keV Ion Detection

A recently described ion charge coupled device detector IonCCD (Sinha and Wadsworth, Rev. Sci. Instrum. 76(2), 2005; Hadjar, J. Am. Soc. Mass Spectrom. 22(4), 612–624, 2011) is implemented in a miniature mass spectrometer of sector-field instrument type and Mattauch-Herzog (MH)-geometry (Rev. Sci. Instrum. 62(11), 2618–2620, 1991; Burgoyne, Hieftje and Hites J. Am. Soc. Mass Spectrom. 8(4), 307–318, 1997; Nishiguchi, Eur. J. Mass Spectrom. 14(1), 7–15, 2008) for simultaneous ion detection. In this article, we present first experimental evidence for the signature of energy loss the detected ion experiences in the detector material. The two energy loss processes involved at keV ion kinetic energies are electronic and nuclear stopping. Nuclear stopping is related to surface modification and thus damage of the IonCCD detector material. By application of the surface characterization techniques atomic force microscopy (AFM) and X-ray photoelectrons spectroscopy (XPS), we could show that the detector performance remains unaffected by ion impact for the parameter range observed in this study. Secondary electron emission from the (detector) surface is a feature typically related to electronic stopping. We show experimentally that the properties of the MH-mass spectrometer used in the experiments, in combination with the IonCCD, are ideally suited for observation of these stopping related secondary electrons, which manifest in reproducible artifacts in the mass spectra. The magnitude of the artifacts is found to increase linearly as a function of detected ion velocity. The experimental findings are in agreement with detailed modeling of the ion trajectories in the mass spectrometer. By comparison of experiment and simulation, we show that a detector bias retarding the ions or an increase of the B-field of the IonCCD can efficiently suppress the artifact, which is necessary for quantitative mass spectrometry.     

Rational groups and integer-valued characters of Thompson group <Emphasis Type="Italic">Th</Emphasis>

According to the main result of W. Feit and G. M. Seitz (Illinois J Math 33(1):103–131, 1988), the Thompson group Th is non-rational or unmatured group (S. Fujita in Bull Chem Soc Jpn 71:2071–2080, 1998). Using the concept of markaracter tables proposed by S. Fujita (Bull Chem Soc Jpn 71:1587–1596, 1998), we are able to obtain tables of integer-valued characters for finite unmatured groups. In this paper, the integer-valued character for Thompson group is successfully derived for the first time.     

Molecular orientation in the Nematic Ordered Cellulose film using polarized FTIR accompanied with a vapor-phase deuteration method

Previously, the authors reported “Nematic Ordered Cellulose (NOC)” that is a well-ordered state of β-1,4-glucan chains without exhibiting typical X-ray diffraction patterns of any cellulose polymorphs (Togawa and Kondo 1999; Kondo et al. 2001; Kondo 2007). The NOC was prepared by stretching water-swollen gel-like films at the draw ratio of 2.0 to provide highly oriented β-1,4-glucan molecular chains of cellulose, which was proved by the high resolution TEM observation. In this paper, a detailed study of the unique ordered state of the NOC was attempted to characterize orientation of the main chains as well as the OH groups of molecules using polarized FTIR accompanied with a vapor-phase deuteration method. The dichroic analysis suggested that the main chains were fairly oriented in the stretching direction whereas the OH groups remained unoriented. The disordered state of the OH groups regardless of the oriented state for the main chain may hinder the oriented crystallization during the preparation of NOC films.     

Preliminary demonstration of an IonCCD as an alternative pixelated anode for direct MCP readout in a compact MS-based detector

We report on the preliminary testing of a new position-sensitive detector (PSD) by combining a microchannel plate (MCP) and a charge-sensitive pixilated anode with a direct readout based on charge-coupled detector (CCD) technology, which will be referred to as IonCCD (Hadjar et al. J Am Soc Mass Spectrom 22(4):612–623, 2011; Johnson et al. J Am Soc Mass Spectrom 22(8):1388–1394, 2011; Hadjar et al. J Am Soc Mass Spectrom 22(10):1872–1884, 2011). This work exploits the recently discovered electron detection capability of the IonCCD (Hadjar et al. J Am Soc Mass Spectrom 22(4):612–623, 2011), allowing it to be used directly behind an MC. This MCP-IonCCD configuration potentially obviates the need for electro-optical ion detector systems (EOIDs), which typically feature a relatively difficult-to-implement 5-kV power source as well as a phosphorus screen behind the MCP for conversion of electrons to photons prior to signal generation in a photosensitive CCD. Thus, the new system (MCP-IonCCD) has the potential to be smaller, simpler, more robust, and more cost efficient than EOID-based technologies in many applications. The use of the IonCCD as direct MCP readout anode, as opposed to its direct use as an ion detector, will benefit from the instant three-to-four-order-of-magnitude gain of the MCP with virtually no additional noise. The signal/noise gain can be used for either sensitivity or speed enhancement of the detector. The speed enhancement may motivate the development of faster IonCCD readout speeds (currently at 2.7 ms) to achieve the 2 kHz frame rate for which the IonCCD chip was designed, a must for transient signal applications. The presented detector exhibits clear potential not only as a trace analysis detector in scan-free mass spectrometry and electron spectroscopy but also as a compact detector for photon and particle imaging applications.     

Thermal unimolecular decomposition mechanism of 2,4,6-trinitrotoluene: a first-principles DFT study

Simple C–NO₂ homolysis, 4,6-dinitroanthranil (DNAt) production by dehydration, and the nitro-nitrite rearrangement–homolysis for gas-phase TNT decomposition were recently studied by Cohen et al. (J Phys Chem A 111:11074, 2007), based on DFT calculations. Apart from those three pathways, other possible initiation processes were suggested in this study, i.e., CH₃ removal, O elimination, H escape, OH removal, HONO elimination, and nitro oxidizing adjacent backbone carbon atom. The intermediate, 3,5-dinitro-2(or 4)-methyl phenoxy, is more favor to decompose into CO and 3,5-dinitro-2(or 4)-methyl-cyclopentadienyl than to loss NO following nitro-nitrite rearrangement. Below ~1,335 K, TNT condensing to DNAt by dehydration is kinetically the most favor process, and the formations of substituted phenoxy and following cyclopentadienyl include minor contribution. Above ~1,335 K, simple C–NO₂ homolysis kinetically dominates TNT decomposition; while the secondary process changes from DNAt production to CH₃ removal above ~2,112 K; DNAt condensed from TNT by dehydration yields to that by sequential losses of OH and H above ~1,481 K and to nitro-nitrite rearrangement–fragmentation above ~1,778 K; O elimination replaces DNAt production above ~2,491 K, playing the third role in TNT decomposition; H escaping directly from TNT thrives in higher temperature (above ~2,812 K), as the fourth largest process. The kinetic analysis indicates that CH₃ removal, O elimination, and H escape paths are accessible at the suggested TNT detonation time (~100–200 fs), besides C–NO₂ homolysis. HONO elimination and nitro oxidizing adjacent backbone carbon atom paths are negligible at all temperatures. The calculations also demonstrated that some important species observed by Rogers and Dacons et al. are thermodynamically the most favor products at all temperatures, possibly stemmed from the intermediates including 4,6-dinitro-2-nitroso-benzyl alcohol, 3,5-dinitroanline, 2,6-dinitroso-4-nitro-phenylaldehyde, 3,5-dinitro-1-nitrosobenzene, 3,5-dinitroso-1-nitrobenzene, and nitrobenzene. All transition states, intermediates, and products have been indentified, the structures, vibrational frequencies, and energies of them were verified at the uB3LYP/6-311++G(d,p) level. Our calculated energies have mean unsigned errors in barrier heights of 3.4–4.2 kcal/mol (Lynch and Truhlar in J Phys Chem A 105:2936, 2001), and frequencies have the recommended scaling factors for the B3-LYP/6-311+G(d,p) method (Andersson and Uvdal in J Phys Chem A 109:2937, 2005; Merrick et al. in J Phys Chem A 111:11683, 2007). All calculations corroborate highly with the previous experimental and theoretical results, clarifying some pertinent questions.     

Thermal stability and mechanical properties of sisal in cycle process

Differential thermal analysis (DTA) was the first thermal analysis technique used to qualitatively characterize natural clays and respective curves has been used since more than 60 years as their ‘fingerprint’. With the development of microprocessed equipments in the last decades, derivative thermogravimetric (DTG) curves also may be used for this purpose in some cases, which also may allow a quantitative characterization of clay components. TG and DTG curves are more indicated than DTA or DSC curves to identify and to better analyze the several decomposition steps of natural or synthetic organoclays. These questions are discussed in applications developed to characterize Brazilian kaolinitic clays, bentonites and organophilic clays.     

Microstructuralism and macromolecules: the case of moonlighting proteins

Microstructuralism in the philosophy of chemistry is the thesis that chemical kinds can be individuated in terms of their microstructural properties (Hendry in Philos Sci 73:864–875, 2006). Elements provide paradigmatic examples, since the atomic number should suffice to individuate the kind. In theory, Microstructuralism should also characterise higher-level chemical kinds such as molecules, compounds, and macromolecules based on their constituent atomic properties. In this paper, several microstructural theses are distinguished. An analysis of macromolecules such as moonlighting proteins suggests that all the forms of microstructuralism cannot accommodate them.     

Counting minimal reactions with specific conditions in $${\mathbb{R} ^4}$$

We give the sharp lower bound on the number of minimal reactions when no “parallel” species (isomers or multiples) are allowed and all the species are built up from at most four kinds of atoms in Theorem 16. This continues the investigations in Kumar and Pethő (Intern Chem Eng 25:767–769, 1985) through Szalkai and Laflamme (Electr J Comb 5(1), 1998) which results we briefly summarize in the first Section.