Potential of N2/O2 atmospheric pressure needle-water DC microplasmas for nitrogen fixation: nitrite-free synthesis of nitrates

A needle-water DC microplasma system working at atmospheric pressure in N₂/O₂ gas mixtures is used to study the fundamental mechanisms of nitrate/nitrite synthesis in highly complex and yet little-known plasma-water systems. Plasma properties are investigated by means of optical emission spectroscopy while the activated water is analyzed following the treatment using ionic chromatography and UV-Vis absorbance spectroscopy. Experiments highlight that the energy efficiency and selectivity of the process are influenced by the oxygen content and the plasma-induced water heating, with strong differences when the water surface is the anode or the cathode electrode. Nitrates are successfully synthesized without residual nitrites in the solution with a comparatively higher energy efficiency when the water is the cathode. The possible reactions involved in the gas phase and aqueous phase chemistry are presented and future scope for the optimization of the system is discussed.

Occupational exposure to platinum drugs during intraperitoneal chemotherapy. Biomonitoring and surface contamination

BACKGROUND

Hyperthermic intraperitoneal chemotherapy (HIPEC) has been introduced over the last decade for the treatment of peritoneal carcinomatosis. In this procedure, heated cytotoxic drugs are administered directly into the abdominal cavity, ensuring cancer cells to be exposed while reducing systemic toxicity. More recently, pressurized intraperitoneal aerosol chemotherapy (PIPAC), where the chemotherapeutic drug is injected into the peritoneal cavity as an aerosol under pressure, has been proposed to patients in palliative situation, as a new approach. The amount of drug used is up to 10 fold lower than in HIPEC. The use of cytotoxic drugs poses an occupational risk for the operating room personnel. This study investigated the potential exposure of the medical staff by biomonitoring and surface contamination measurements, during a HIPEC procedure and a PIPAC procedure.

METHOD

Wipe samples were collected from various locations in operating rooms including gloves, hands, devices and floor. Urines samples were collected from 10 volunteers of the medical staff and from a control group. The platinum analysis was performed by inductively coupled plasma mass spectrometry.

RESULTS

Significant contaminations were observed on the floor, gloves, shoes and devices. However, urinary platinum was below the limit of quantification (<10 ng/L) for more than 50% of samples from the healthcare workers performing HIPEC and PIPAC. Concentrations did not differ significantly from those reported for the control group.

CONCLUSION

There appears to be little risk of exposure to platinum drugs during HIPEC and PIPAC providing the adequate safety measures are implemented.

Measurement and comparison of individual external doses of high-school students living in Japan, France, Poland and Belarus-the 'D-shuttle' project

Twelve high schools in Japan (of which six are in Fukushima Prefecture), four in France, eight in Poland and two in Belarus cooperated in the measurement and comparison of individual external doses in 2014. In total 216 high-school students and teachers participated in the study. Each participant wore an electronic personal dosimeter 'D-shuttle' for two weeks, and kept a journal of his/her whereabouts and activities. The distributions of annual external doses estimated for each region overlap with each other, demonstrating that the personal external individual doses in locations where residence is currently allowed in Fukushima Prefecture and in Belarus are well within the range of estimated annual doses due to the terrestrial background radiation level of other regions/countries.

Biochemical separations by continuous-bed chromatography

Innovations in column-packing media for biomolecule purification have progressed from large spherical, porous polysaccharide beads to advanced polymeric supports. Continuous-bed technology is a radical new technology for chromatography based on the polymerization of advanced monomers and ionomers directly in the chromatographic column. The polymer chains form aggregates which coalesce into a dense, homogeneous network of interconnected nodules consisting of microparticles with an average diameter of 3000 A. The voids or channels between the nodules are large enough to permit a high hydrodynamic flow. Due to the high cross-linking of the polymer matrix, the surface of each nodule is nonporous yet the polymeric microparticles provide a very large surface area for high binding capacity. This paper will demonstrate the properties and advantages of using a continuous bed support for high resolution biomolecule separations at high flow-rates without sacrificing capacity.

[A peculiar mechanism of hydrocephalus: the "water-hammering" effect]

BACKGROUND AND PURPOSE

Aneurysms of the basilar artery can cause hydrocephalus due to compression of the third ventricle or the sylvian aqueduct. The observation of a particular case led to discuss another possible mechanism of hydrocephalus.

CLINICAL PRESENTATION AND RADIOLOGICAL STUDIES

An aneurysm of the basilar artery was revealed by an ischemic stroke in a 65-year-old man. Hydrocephalus developed during the following months. The MRI studies showed that it could not be explained merely by a permanent compression. However, the patient improved clearly after a ventriculo-peritoneal derivation.

CONCLUSION

The hydrocephalus could be explained by a "water-hammering" effect due to the pulsating blood in the ectatic vessel, which created a cerebrospinal fluid outflow impairment through the third ventricle.

[Late cerebral radionecrosis of cystic aspect]

Two cases of delayed cerebral radionecrosis with cystic presentation are reported. The patients had received radiation therapy for a cutaneous tumor 16 and 12 years before. Surgical extirpation of the cerebral lesion permitted to confirm the diagnosis and to treat the patients with success. A cystic aspect has been reported rarely in the neuroradiologic descriptions of the cerebral radionecrosis in the literature. Its mechanism is discussed. The treatment of the delayed cerebral radionecrosis is not clearly established, but a cystic presentation is an argument for surgery.

Immunocytochemistry of the taurine biosynthesis enzyme, cysteine sulfinate decarboxylase, in the cerebellum: evidence for a glial localization

Immunocytochemistry of cysteine sulfinate decarboxylase was developed in the cerebellum with an antiserum that we have recently produced using as immunogen a homogeneous fraction purified about 2000-fold from liver. In the rat, this antiserum immunoprecipitated the enzymatic activity from brain, labeled one band (molecular weight = 51,000) on immunoblots of an enriched fraction from brain but none with a brain crude extract and thus appeared to be specific. In the cerebellum numerous immunolabeled cells were found in the white matter that were typically arranged in rows like oligodendrocytes. A few immunolabeled cells were scattered in the granular layer. Around the Purkinje cells numerous small satellite cells were immunostained that sent faintly labeled radial fibers through the molecular layer. These cells were thus identified as Golgi epithelial cells with their Bergmann fibers. Purkinje cells were not labeled either at the cell body or at the nerve ending levels. In the molecular layer no cells were found consistently and convincingly immunolabeled that could correspond to the stellate cells. No immunopositive punctae typical of the interneuron nerve endings were ever observed. A significant cysteine sulfinate decarboxylase activity was also measured in glial cell fractions enriched in oligodendrocytes and astrocytes respectively. The glial localization of taurine biosynthesis enzyme in the cerebellum does not support the hypothesis that it could be involved in neurotransmission, but rather suggests that taurine is manufactured by glial cells and accordingly may play a physiological role in relation to glial function.

Specific antiserum and monoclonal antibodies against the taurine biosynthesis enzyme cysteine sulfinate decarboxylase: identity of brain and liver enzyme

Cysteine sulfinate decarboxylase (CSD), the putative biosynthetic enzyme for taurine, was purified 1,800-fold with a 1% yield from rat liver, where it was found to be 20-fold enriched compared with brain. The final fraction was homogeneous, as ascertained through sodium dodecyl sulfate-polyacrylamide gel electrophoresis and reverse-phase HPLC. An antiserum was raised in the rabbit that (a) quantitatively immunoprecipitated CSD activity and (b) immunolabeled only one band (MW = 51,000) on an immunoblot from liver homogenate. Monoclonal antibodies were also raised that recognized the CSD protein and immunolabeled the same 51-kilodalton protein on an immunoblot from liver homogenate. In a brain extract, two CSD activities had been previously found and named CSDI and CSDII, according to their chromatographic elution patterns. We have compared the properties of CSDI from brain--the most likely enzyme involved in the biosynthesis of taurine in the brain, according to previous investigations-and CSD from liver: Both activities (a) were similarly eluted on ion-exchange and hydroxyapatite chromatographies, (b) showed the same elution pattern on gel filtration with an apparent native molecular weight of approximately 63,000, and (c) were immunoprecipitated in a strictly identical manner by the antiserum against liver CSD. Moreover, this antiserum as well as the monoclonal antibodies immunolabeled a single band (51 kilodaltons) on an immunoblot from brain CSD-enriched fraction or liver fraction. All these data show that CSDI from brain and liver CSD are the same monomeric enzyme. They also indicate that a specific antiserum against rat liver CSD has been raised that can be used for immunocytochemical visualization of CSD-containing cells in the brain.