A wearable sensor for the detection of sodium and potassium in human sweat during exercise.

The SwEatch platform, a wearable sensor for sampling and measuring the concentration of electrolytes in human sweat in real time, has been improved in order to allow the sensing of two analytes. The solid contact ion-sensitive electrodes (ISEs) for the detection of Na and K have been developed in two alternative formulations, containing either poly(3,4-ethylenedioxythiophene) (PEDOT) or poly(3-octylthiophene-2,5-diyl) (POT) as a conductive polymer transducing component. The solution-processable POT formulation simplifies the fabrication process, and sensor to sensor reproducibility has been improved via partial automation using an Opentron® automated pipetting robot.

High-Valent d Ni versus d Cu Oxidants in PCET.

Oxygenases have been postulated to utilize d Fe and d Cu oxidants in proton-coupled electron transfer (PCET) hydrocarbon oxidation. In order to explore the influence the metal ion and d-electron count can hold over the PCET reactivity, two metastable high-valent metal-oxygen adducts, [Ni(OAc)(L)] () and [Cu(OAc)(L)] (), L = ,-(2,6-diisopropylphenyl)-2,6-pyridinedicarboxamidate, were prepared from their low-valent precursors [Ni(OAc)(L)] () and [Cu(OAc)(L)] (). The complexes /-/ were characterized using nuclear magnetic resonance, Fourier transform infrared, electron paramagnetic resonance, X-ray diffraction, and absorption spectroscopies and mass spectrometry.

Hydrogen Atom Transfer by a High-Valent Nickel-Chloride Complex.

Oxo-metal-halide moieties have often been implicated as C-H bond activating oxidants with the terminal oxo-metal entity identified as the electrophilic oxidant. The electrophilic reactivity of metal-halide species has not been investigated. We have prepared a high-valent nickel-halide complex [Ni(Cl)(L)] (2, L = N,N'-(2,6-dimethylphenyl)-2,6-pyridinedicarboxamide) by one-electron oxidation of a [Ni(Cl)(L)] precursor.

Indirect evidence for a Ni-oxyl oxidant in the reaction of a Ni complex with peracid.

The reaction of a Ni complex and meta-chloroperoxybenzoic acid (m-CPBA) resulted in the formation of a long-lived Ni-chlorobenzoate complex that is a capable hydrocarbon oxidant. Analysis of the post-reaction decay products showed the formation of oxidised derivatives of the supporting ligand (a benzoxazine), and heterolytic O-O bond scission in m-CPBA. This evidence indicates formation of a more potent transient Ni-oxyl species, which was further supported by DFT calculations.

Modulation of Nickel Pyridinedicarboxamidate Complexes to Explore the Properties of High-valent Oxidants.

High-valent Ni oxidants have been implicated in hydrocarbon oxidation catalysis, however, little is understood about the properties of these oxidants. Herein, a family of Ni complexes supported by a pyridinedicarboxamidate ligand and different ancillary ligands was synthesized. The series spans coordination numbers 4, 5, and 6, and contains neutral, mono- and di-anionic donor types.

Tuning the Reactivity of Terminal Nickel(III)-Oxygen Adducts for C-H Bond Activation.

Two metastable Ni complexes, [Ni(OAc)(L)] and [Ni(ONO)(L)] (L = N,N'-(2,6-dimethylphenyl)-2,6-pyridinedicarboxamidate, OAc = acetate), were prepared, adding to the previously prepared [Ni(OCOH)(L)], with the purpose of probing the properties of terminal late-transition metal oxidants. These high-valent oxidants were prepared by the one-electron oxidation of their Ni precursors ([Ni(OAc)(L)] and [Ni(ONO)(L)]) with tris(4-bromophenyl)ammoniumyl hexachloroantimonate. Fascinatingly, the reaction between any [Ni(X)(L)] and NaOCl/acetic acid (AcOH) or cerium ammonium nitrate ((NH)[Ce(NO)], CAN), yielded [Ni(OAc)(L)] and [Ni(ONO)(L)], respectively.

Characterization and reactivity of a terminal nickel(III)-oxygen adduct.

High-valent terminal metal-oxygen adducts are hypothesized to be the potent oxidizing reactants in late transition metal oxidation catalysis. In particular, examples of high-valent terminal nickel-oxygen adducts are scarce, meaning there is a dearth in the understanding of such oxidants. A monoanionic Ni(II)-bicarbonate complex has been found to react in a 1:1 ratio with the one-electron oxidant tris(4-bromophenyl)ammoniumyl hexachloroantimonate, yielding a thermally unstable intermediate in high yield (ca.

Nucleophilic reactivity of a copper(II)-superoxide complex.

Metal-bound superoxide intermediates are often implicated as electrophilic oxidants in dioxygen-activating metalloenzymes. In the nonheme iron α-ketoglutarate dependent oxygenases and pterin-dependent hydroxylases, however, Fe(III)-superoxide intermediates are postulated to react by nucleophilic attack on electrophilic carbon atoms. By reacting a Cu(II)-superoxide complex (1) with acyl chloride substrates, we have found that a metal-superoxide complex can be a very reactive nucleophile.

Treatment with modified heparins inhibits experimental metastasis formation and leads, in some animals, to long-term survival.

Two chemically modified heparins with low anticoagulant activity were studied in terms of their antimetastatic activity in the B16-BL6 melanoma model. The two heparins were a very low molecular weight heparin (VLMW-H) and a low molecular weight heparin with 100% succinylation of desulfated N groups (Succ100-LMW-H). Both heparins, VLMW-H more so than Succ100-LMW-H, were highly effective in decreasing the number of lung metastasis on day 21 when administered once subcutaneously 10 min before intravenous injection of melanoma cells or 2 times/week for 3 weeks.

In vitro and in vivo effects of cisplatin on the generation of lymphokine-activated killer cells.

Pretreatment of human peripheral blood lymphocytes (PBL) with cisplatin (CDDP) before in vitro culture with interleukin-2 (IL-2) inhibited the generation of lymphokine-activated killer (LAK) cells and strongly inhibited proliferation. This inhibition was dose dependent, was significant only at concentrations greater than 6 microM, and it required exposure to the drug for more than 1 hour. This period of IL-2 unresponsiveness was maximum at 6 hours, but was spontaneously recovered within 24-48 hours and was more rapidly restored by increasing dosages of IL-2.

Killing of tumor cells with pleiotropic drug resistance by OK432-activated effector cells.

The inactivate streptococcal preparation OK432 activates the cytotoxic function of natural killer (NK) cells. Moreover, it induces cytotoxic activity against freshly isolated tumor cells. The present study was aimed at assessing whether OK432-activated effector cells expressed cytotoxicity against tumor cells pleiotropically resistant to cancer chemotherapy agents.

Lymphocytes infiltrating ovarian carcinoma: modulation of functional activity by intraperitoneal treatment with biological response modifiers.

A better understanding of the immunobiology of tumor-associated lymphocytes (TAL) may have considerable bearing on the therapeutic perspective of human neoplasia. We have identified ovarian cancer as a clinical condition privileged for studies on immunity and its in vitro and in vivo modulation. Our previous studies on the mechanisms of natural resistance have shown that TAL from ovarian carcinoma have defective natural killer cell activity when compared to peripheral blood lymphocytes from the same patient.

T-cell receptor gene rearrangements and expression in normal human large granular lymphocytes (LGL) and their pathological expansions.

The lineage to which normal large granular lymphocytes/natural killer (LGL/NK) cells belong is controversial; in fact they share some surface markers and functional activities with monocytes, but also with T lymphocytes. The relationship of LGL to the T cell lineage by analysis with the T cell receptor (T-rec) gene has been investigated. Pure preparations of human LGL and their CD11(+) CD8(-) and CD11(-) CD8(+) subsets had the Tβ gene in its unrearranged germline configuration.

Perinatal transmission of the hepatitis B virus and of the HBV-associated delta agent from mothers to offspring in northern Italy.

We report a prospective study on infants born to hepatitis B surface antigen (HBsAg) carrier mothers to estimate the incidence of perinatal transmission of HBV and HBV-associated delta agent in Northern Italy. The risk of infection to the infant was related to the presence of the HBe antigen-antibody system, HBV-specific DNA polymerase activity and antibody to delta in maternal sera, and to the titer of anti-HBe in babies at birth. The data of this study indicate: 1.