[en] The detection of hazard exposure is a current priority, including the detection of traces of explosive molecules in different environments like luggage storage rooms and public places, and is becoming a major requirement for homeland security. In the present study we carried out a preliminary investigation on the binding capacities of four forms of the lipocalin odorant-binding protein (OBP) for the detection of explosive components such as diphenylamine, dimethyl-phthalate, resorcinol and dinitrotoluene. The experimental results, showing that OBP binds these compounds with affinity constants ranging between 80 nM and 10.6 mM, indicate that this protein can be used as a probe for the realization of a biosensor to sense explosive compounds

[en] In this study, we report the synthesis of 2,3-dihydroxybenzaldehyde (catechol)-linked chitosan (cat-chitosan) and the preparation of its composite with carbon (cat-chitosan/carbon) to construct a catechol-modified electrode. The synthesis is similar to our previous work on hydroquinone–chitosan/carbon composite electrode. We synthesized catechol-linked chitosan polymer and prepared the its composite electrode with carbon. The catchitosan/carbon composite electrode shows a reversible confined redox behavior by the catechol functional group. The electrode catalyzes the oxidation of NADH. It has Cu"2"+ ion-binding capability and its binding constant 8.7 μM.

[en] Published in summary form only

[en] The MO LCAO method has been used to study the structure of the molecular and ionized forms of brompyrogallol red (BPGR) and its complex compounds with rare earths. The calculations performed reveal that addition of rare earth ions to BPGR is possible both with respect to the orthooxyquinone group to give a complex with a short wavelength absorption peak and the dioxy group to give a complex compound absorbing in the long wavelength region

[en] The nitrogen doped porous carbon nanopolyhedrons (N-PCNPs)-multi-walled carbon nanotubes (MWCNTs) hybrid materials were prepared for the first time. Combining the excellent catalytic activities, good electrical conductivities and high surface areas of N-PCNPs and MWCNTs, the simultaneous determination of hydroquinone (HQ), catechol (CC) and resorcinol (RE) with good analytical performance was achieved at the N-PCNPs-MWCNTs modified electrode. The linear response ranges for HQ, CC and RE are 0.2-455 μM, 0.7-440 μM and 3.0-365 μM, respectively, and the detection limits (S/N = 3) are 0.03 μM, 0.11 μM and 0.38 μM, respectively. These results are much better than that obtained on some graphene or CNTs-based materials modified electrodes. Furthermore, the developed sensor was successfully applied to simultaneously detect HQ, CC and RE in the local river water samples

[en] The electrode reactions for the complexes of Cd(II) and Pb(II) with β-resorcylic acid (-βRA) were found to be reversible and diffusion controlled. They form 1:1 complexes. The dissociation constants of Cd(II)-βRA and Pb(II)-βRA complexes have been found to be 2.455 x 10^-3 and 6.457 x 10^-4 respectively at 25deg C +- 0.1 in acetate buffer (pH 4.1) and μ = 0.1 M KNO₃. (auth.)

No abstract available

[en] Formation of water soluble deeply colored ternary complexes of Th^lV and U^VI metal ions with pyrogallol red (PGR) in presence of cationic surfactant cetyldimethylethylammonium bromide (CDMEAB) have been observed. CDMEAB sensitize the color reactions of Th^lV and U^VI with pyrogallol red with enhancement in molar absorptivities and sensitivities at the shifted wavelength of ternary complexes with stoichiometric composition 1:2:4 (M-PGR-CDMEAB) have been observed for both the metal ions. The ternary complexes of thorium (IV) at pH 4.0 and uranium (VI) at pH 7.0 exhibit absorption maxima at 660 and 650 nm with molar absorptivities 61120 and 52470 L mol^-1 cm^-2 respectively. Beer's law were obeyed in concentration range 0.23-3.24 ppm for Th^lV and 0.27-3.51 ppm for U^VI in presence of CDMEAB. Conditional formation constants and various analytical parameters have been evaluated and compared the results of newly formed ternary complexes with binary complexes reported earlier. Enhancement in the molar absorptivities in presence of CDMEAB clearly indicated the usefulness of these colored reactions for microdetermination. (author)

[en] In 1971, medical studies determined that DES causes a rare type of vaginal cancer in a small number of daughters of mothers who took DES during pregnancy. Subsequently, medical studies determined that exposure to DES can cause other vaginal abnormalities in the daughters, some of which may be precancerous. As a result of these discoveries, many lawsuits have been filed by these daughters against DES manufacturers. Many DES suits may be barred by statutes of limitations, both because the number of years between the daughters' exposure to DES in utero and the discovery that DES can cause injuries exceeds the statutory period, and because the cancer or other injuries caused by DES may not develop for many additional years. This Note discusses two methods that DES plaintiffs may be able to use to overcome the potential statutes of limitations bar: the discovery rule, and state provisions which toll the statute of limitations for minors. The Note contends that courts should apply an expanded discovery rule to DES suits to avoid the unfair result of barring a claim before the plaintiff could have known that she had a cause of action. In addition, the Note argues that the injury which causes the statute of limitations to begin to run in DES suits should not be rigidly defined. Finally, the Note urges that courts allow eligible DES plaintiffs to take advantage of applicable state provisions that toll the statute of limitations for minors

[en] The synthesis of a series of tetracatecholate ligands designed to be specific for Pu(IV) and other actinide(IV) ions has been achieved. Although these compounds are very effective as in vivo plutonium removal agents, potentiometric and voltammetric data indicate that at neutral pH full complexation of the Pu(IV) ion by all four catecholate groups does not occur. Spectroscopic results indicate that the tetracatecholates, 3,4,3-LICAMS and 3,4,3-LICAMC, complex Am(III). The Am(IV)/(III)-catecholate couple (where catecholate = 3,4,3-LICAMS or 3,4,3-LICAMC) is not observed, but may not be observable due to the large currents associated with ligand oxidation. However, within the potential range where ligand oxidation does not occur, these experiments indicate that the reduction potential of free Am(IV)/(III) is probably greater than or equal to + 2.6 V vs NHE or higher. Proof of the complexation of americium in the trivalent oxidation state by 3,4,3-LICAMS and 3,4,3-LICAMC elimates the possibility of tetracatholates stabilizing Am(IV) in vivo