304 research outputs found

    Heterogeneous Batch Distillation Processes: Real System Optimisation

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    In this paper, optimisation of batch distillation processes is considered. It deals with real systems with rigorous simulation of the processes through the resolution full MESH differential algebraic equations. Specific software architecture is developed, based on the BatchColumn® simulator and on both SQP and GA numerical algorithms, and is able to optimise sequential batch columns as long as the column transitions are set. The efficiency of the proposed optimisation tool is illustrated by two case studies. The first one concerns heterogeneous batch solvent recovery in a single distillation column and shows that significant economical gains are obtained along with improved process conditions. Case two concerns the optimisation of two sequential homogeneous batch distillation columns and demonstrates the capacity to optimize several sequential dynamic different processes. For such multiobjective complex problems, GA is preferred to SQP that is able to improve specific GA solutions

    JNK3 Is Required for the Cytoprotective Effect of Exendin 4.

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    Preservation of beta cell against apoptosis is one of the therapeutic benefits of the glucagon-like peptide-1 (GLP1) antidiabetic mimetics for preserving the functional beta cell mass exposed to diabetogenic condition including proinflammatory cytokines. The mitogen activated protein kinase 10 also called c-jun amino-terminal kinase 3 (JNK3) plays a protective role in insulin-secreting cells against death caused by cytokines. In this study, we investigated whether the JNK3 expression is associated with the protective effect elicited by the GLP1 mimetic exendin 4. We found an increase in the abundance of JNK3 in isolated human islets and INS-1E cells cultured with exendin 4. Induction of JNK3 by exendin 4 was associated with an increased survival of INS-1E cells. Silencing of JNK3 prevented the cytoprotective effect of exendin 4 against apoptosis elicited by culture condition and cytokines. These results emphasize the requirement of JNK3 in the antiapoptotic effects of exendin 4

    JNK3 is abundant in insulin-secreting cells and protects against cytokine-induced apoptosis

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    Aims/hypothesis: In insulin-secreting cells, activation of the c-Jun NH2-terminal kinase (JNK) pathway triggers apoptosis. Whereas JNK1 and JNK2 are ubiquitously produced, JNK3 has been described exclusively in neurons. This report aims to characterise the expression and role in apoptosis of the three JNK isoforms in insulin-secreting cells exposed to cytokines. Methods: Sections of human and mouse pancreases were used for immunohistochemistry studies with isoform-specific anti-JNK antibodies. Human, pig, mouse and rat pancreatic islets were isolated by enzymatic digestion and RNA or protein extracts were prepared. RNA and protein levels were determined by quantitative RT-PCR and western blotting respectively, using JNK-isoform-specific primers and isoform-specific antibodies; activities of the three JNK isoforms were determined by kinase assays following quantitative immunoprecipitation/depletion of JNK3. JNK silencing was performed with small interfering RNAs and apoptotic rates were determined in INS-1E cells by scoring cells displaying pycnotic nuclei. Results: JNK3 and JNK2 mRNAs are the predominant isoforms expressed in human pancreatic islets. JNK3 is nuclear while JNK2 is also cytoplasmic. In INS-1E cells, JNK3 knockdown increases c-Jun levels and caspase-3 cleavage and sensitises cells to cytokine-induced apoptosis; in contrast, JNK1 or JNK2 knockdown is protective. Conclusions/interpretation: In insulin-secreting cells, JNK3 plays an active role in preserving pancreatic beta cell mass from cytokine attacks. The specific localisation of JNK3 in the nucleus, its recruitment by cytokines, and its effects on key transcription factors such as c-Jun, indicate that JNK3 is certainly an important player in the transcriptional control of genes expressed in insulin-secreting cell

    PERBANDINGAN HASIL TANGKAPAN IKAN DENGAN JARING INSANG TETAP (Set Gill Net) PADA SIANG DAN MALAM HARI DI SUNGAI KUMBE DISTRIK MALIND KABUPATEN MERAUKE

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    Tujuan penelitian ini adalah untuk mengetahui komposisi jenis hasil tangkapan, keanekaragaman dan untukmengetahui perbandingan hasil tangkapan jaring insang tetap (set gill net) pada siang dan malam hari di SungaiKumbe Distrik Malind Kabupaten Merauke. Penelitian ini dilaksanakan di Sungai Kumbe Distrik Malind dari bulanFebruari 2018 - Maret 2018 pada dua stasiun pengamatan yang merupakan area penangkapan ikan oleh masyarakatnelayan setempat: stasiun I pada bagian muara; stasiun II ±1500 meter dari bagian muara. Alat tangkap yangdigunakan adalah jarring insang tetap (set gill net) dengan ukuran mata jaring: 4 dan 7 inci. Sampel ikan yangdiperoleh langsung diidentifikasi di lapangan dengan menggunakan buku identifikasi, Parameter biologi yangdiamati adalah komposisi jenis, indeks keanekaragaman (H’), dan indeks dominansi (C). Hasil jumlah jenis ikanyang tertangkap di Sungai Kumbe terdiri dari 11 jenis ikan, yakni : Ikan Kakap putih (Lates calcarifer), IkanGulama (Pridoceina amoyensis), Ikan Baung Putih (Cinetodus crassilabris), Ikan Baung Merah (Cinetodusfroggatti), Ikan Kuru sirip kuning (Eleutheronema tetradactylum), Ikan Tulang - tulang (Thryssa scratchleyi), IkanBelanak (Mugil sp.), Ikan Kaca (Kurtus gulliveri), Ikan Mujair (Oreochromis mossambicus), Ikan Sembilan(Neosilurus sp.) dan Ikan Bambit (Scatopargus argus). Ikan - ikan tersebut merupakan komuditas ikan yang biasamenyebar di Sungai Kumbe tangkapan malam hari, yaitu 10 jenis ikan sebanyak 32 ekor. Sedangkan jumlah hasiltangkapan pada siang hari 3 jenis ikan sebanyak 18 ekor. Hasil penelitian diperoleh dari komposisi jenis : Cinetoduscrassilabris yang terbanyak dan terendah adalah Thryssa Scrstchleyi. ikan yang mendominasi adalah Cinetoduscrassilabris pada stasiun I sedangkan pada stasiun II yang mendominasi adalah Lates calcalifer. Kata kunci : Komposisi jenis, Perbandingan hasil tangkap ikan siang dan malam hari, Sungai Kumbe

    Furosemide stimulation of parathormone in humans: role of the calcium-sensing receptor and the renin-angiotensin system.

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    Interactions between sodium and calcium regulating systems are poorly characterized but clinically important. Parathyroid hormone (PTH) levels are increased shortly after furosemide treatment by an unknown mechanism, and this effect is blunted by the previous administration of a calcimimetic in animal studies. Here, we explored further the possible underlying mechanisms of this observation in a randomized crossover placebo-controlled study performed in 18 human males. Volunteers took either cinacalcet (60 mg) or placebo and received a 20 mg furosemide injection 3 h later. Plasma samples were collected at 15-min intervals and analyzed for intact PTH, calcium, sodium, potassium, magnesium, phosphate, plasma renin activity (PRA), and aldosterone up to 6 h after furosemide injection. Urinary electrolyte excretion was also monitored. Subjects under placebo presented a sharp increase in PTH levels after furosemide injection. In the presence of cinacalcet, PTH levels were suppressed and marginal increase of PTH was observed. No significant changes in electrolytes and urinary excretion were identified that could explain the furosemide-induced increase in PTH levels. PRA and aldosterone were stimulated by furosemide injection but were not affected by previous cinacalcet ingestion. Expression of NKCC1, but not NKCC2, was found in parathyroid tissue. In conclusion, our results indicate that furosemide acutely stimulates PTH secretion in the absence of any detectable electrolyte changes in healthy adults. A possible direct effect of furosemide on parathyroid gland needs further studies

    Seed systems smallholder farmers use

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    Seed can be an important entry point for promoting productivity, nutrition and resilience among smallholder farmers. While investments have primarily focused on strengthening the formal sector, this article documents the degree to which the informal sector remains the core for seed acquisition, especially in Africa. Conclusions drawn from a uniquely comprehensive data set, 9660 observations across six countries and covering 40 crops, show that farmers access 90.2 % of their seed from informal systems with 50.9 % of that deriving from local markets. Further, 55 % of seed is paid for by cash, indicating that smallholders are already making important investments in this arena. Targeted interventions are proposed for rendering formal and informal seed sector more smallholder-responsive and for scaling up positive impacts

    A tetragonal-to-monoclinic phase transition in a ferroelectric perovskite: the structure of PbZr(0.52)Ti(0.48)O3

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    The perovskite-like ferroelectric system PbZr(1-x)Ti(x)O3 (PZT) has a nearly vertical morphotropic phase boundary (MPB) around x=0.45-0.50. Recent synchrotron x-ray powder diffraction measurements by Noheda et al. [Appl. Phys. Lett. 74, 2059 (1999)] have revealed a new monoclinic phase between the previously-established tetragonal and rhombohedral regions. In the present work we describe a Rietveld analysis of the detailed structure of the tetragonal and monoclinic PZT phases on a sample with x= 0.48 for which the lattice parameters are respectively: at= 4.044 A, ct= 4.138 A, at 325 K, and am= 5.721 A, bm= 5.708 A, cm= 4.138 A, beta= 90.496 deg., at 20K. In the tetragonal phase the shifts of the atoms along the polar [001] direction are similar to those in PbTiO3 but the refinement indicates that there are, in addition, local disordered shifts of the Pb atoms of ~0.2 A perpendicular to the polar axis.. The monoclinic structure can be viewed as a condensation along one of the directions of the local displacements present in the tetragonal phase. It equally well corresponds to a freezing-out of the local displacements along one of the directions recently reported by Corker et al.[J. Phys. Condens. Matter 10, 6251 (1998)] for rhombohedral PZT. The monoclinic structure therefore provides a microscopic picture of the MPB region in which one of the "locally" monoclinic phases in the "average" rhombohedral or tetragonal structures freezes out, and thus represents a bridge between these two phases.Comment: REVTeX, 7 figures. Modifications after referee's suggestion: new figure (figure 5), comments in 2nd para. (Sect.III) and in 2nd & 3rd para. (Sect. IV-a), in the abstract: "...of ~0.2 A perpendicular to the polar axis.

    The nNOS-p38MAPK Pathway Is Mediated by NOS1AP during Neuronal Death

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    Neuronal nitric oxide synthase ( nNOS) and p38MAPK are strongly implicated in excitotoxicity, a mechanism common to many neuro-degenerative conditions, but the intermediary mechanism is unclear. NOS1AP is encoded by a gene recently associated with sudden cardiac death, diabetes-associated complications, and schizophrenia (Arking et al., 2006; Becker et al., 2008; Brzustowicz, 2008; Lehtinen et al., 2008). Here we find it interacts with p38MAPK-activating kinase MKK3. Excitotoxic stimulus induces recruitment of NOS1AP to nNOS in rat cortical neuron culture. Excitotoxic activation of p38MAPK and subsequent neuronal death are reduced by competing with the nNOS: NOS1AP interaction and by knockdown with NOS1AP-targeting siRNAs. We designed a cell-permeable peptide that competes for the unique PDZ domain of nNOS that interacts with NOS1AP. This peptide inhibits NMDA-induced recruitment of NOS1AP to nNOS and in vivo in rat, doubles surviving tissue in a severe model of neonatal hypoxia-ischemia, a major cause of neonatal death and pediatric disability. The highly unusual sequence specificity of the nNOS: NOS1AP interaction and involvement in excitotoxic signaling may provide future opportunities for generation of neuroprotectants with high specificity
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