THE INFLUENCE OF PVA.cI.CITRIC ACID/CHITOSAN MEMBRANE HYDROPHICILITY ON THE TRANSPORT OF CREATININE AND UREA

The influence of cross-linking and membrane hydrophilicity on the transport rate had been studied using a membrane prepared from a mixture of chitosan/PVA cross-linked citric acid (PVA.cl.CA) for creatinine and urea transport. The optimum mole ratio of PVA:citric acid as well as the best composition of chitosan:PVA.cl.CA were determined using creatinine transport study. Using the optimum compositions, further study was done using different thickness of the membrane in transporting creatinine, urea and a mixture of 3 species (creatinine, urea and vitamin B12). Membrane characterization was done using FT-IR spectrophotometer, water absorption test, TG/DTG and SEM. The results showed that the optimum composition PVA:citric acid was obtained to be 90:1, having % WU of 113.74% and creatinine transport percentage of 18.16%. Meanwhile, the optimum composition of chitosan:PVA.cl.CA was found at 4:6 ratio having % WU and % transport of 136.67% and 24.26%, respectively. The optimum transport capacity was found for membrane thickness of 50 pm with WU% at 139.61% and the percent transport of creatinine and urea each was 38.93% and 60.36%. The presence vitamin 812 in the solution of is proved to disturb the transport of. creatinine and urea through the membrane. Finally, hydrophilicity seemed to give substantial contribution in the transport process as well as the mechanical strength of the membrane. Transpor kreatinin dan urea melalui membran campuran kitosan/citric acid crosslinked PVA (PVA.cLCA) telah dikaji untuk mempelajari pengaruh sambung-silang dan hidrofilisitas membran terhadap laju transport. Rasio mot PVA:asam sitrat dan perimbangan kitosan:PVA.ci.CA terbaik diuji dengan transpor kreatinin. Membran dengan komposisi terbaik divariasi ketebalannya dan digunakan untuk uji transpor kreatinin, urea serta transpor paduan 3 spesies (kreatinin, urea dan vitamin B12). Karakterisasi membran dilakukan menggunakan spektrofotometer FT-IR, uji serapan air, TG/DTG, SEM. Hashl penelitian menunjukkan bahwa komposisi asam sitrat optimal pada perbandingan mol PVA:asam sitrat 90:1 dengan % WU sebesar 113,74% dan persentase transpor kreatinin sebesar 18,16%. Perimbangan terbaik antara kitosan/PVA.ci.CA pada perbandingan 4:6 dengan % WU sebesar 136,67% dan persentase transpor sebesar 24,26%. Kemampuan transpor terbaik dimiliki oleh membran dengan ketebalan 50 pm dengan % WU sebesar 139,61% dan persentase transpor kreatinin dan urea masing-masing sebesar 38,93% dan 60,36%. Keberadaan vitamin B12 dalam larutan sedikit mengganggu transpor kreatinin dan urea oleh membran. Hidrofolisitas membran memberi kontribusi nyata pada proses transport dan kekuatan mekanik membran

EXTENDING THE LIFETIME OF POLYMER INCLUSION MEMBRANE CONTAINING COPOl Y (EUGENOl-DVB) AS CARRIER FOR PHENOL TRANSPORT

A study of phenol transport was conducted in correlation to the evaluation of copoly(eugenol-divinylbenzene, DVB) as carrier using polymer inclusion membrane (PIM) method. The performance of copoly(eugenol-DVB) was observed based on the parameters of Membrane Liquid (ML) loss. Some variations, including the effect of plasticizer concentration, stirring speed, and measurement of lifetime of the membrane, were studied. Related to the lifetime, the effect of the concentration of NaNO3 salt was also studied. The tensile strength of membrane before and after the transport was measured and their morphology was characterized using SEM (Scanning Electron Microscope). Results of the study indicate that the value of the tensile strength of the membrane after the transport was lower than that before the transport. The lifetime of the membrane was not only depending on the capacity of the membrane in restraining ML loss, but also on the concentration of salt that was added to the solution of source phase. In addition, the lifetime of the membrane had correlation to the number of ML loss, i.e. the addition of salt lead to lower amount of ML loss and gave longer lifetime. With the addition of 0.1 M NaNO3, the lifetime of the membrane extended to 62 days, which is longer tHan the lifetime without the addition of Na03 which was only 7 days. Telah dilakukan penelitian tentang transpor fenol yang berkaitan dengan evaluasi kopoly(eugenoldivinilbenzena, OVB) sebagai senyawa pembawa (carrier) menggunakan metode polymer inclusion membrane (PIM). Pada tulisan ini kopoly(eugenol-OVB) 12% diobservasi berdasarkan pada parameter membrane liquid (ML) loss. Beberapa variasi, termasuk pengaruh konsentrasi plasticizer, kecepatan pengadukan, dan pengukuran waktu hidup (lifetime) membran telah diteliti. Berkaitan dengan waktu hidup, juga telah dipelajari pengaruh konsentrasi ga~am NaNO3. Tensile strength (kuat tarik) membran sebelum dan sesudah transpor diukur dan dikarakterisasi mfJnggunakan SEM (Scanning Electron Microscope). Hasil penelitian menunjukkan bahwa nilai tensile strength membran setelah transpor lebih kecil dibandingkan sebelum transpor. Waktu hidup membran, tidak hanya tergantung pada kemampuan membran dalam menahan ML loss, tetapi juga tergantung pada konsentrasi garam yang ditambahkan pada larutan fasa sumber. Hasil penelitian menunjukkan bahwa waktu hidup membran berkaitan dengan jumlah ML loss, dengan penambahan konsentrasi garam menghasilkan jumlah ML loss yang rendah dan waktu hidup yang tinggi. Pada penambahan konsentrasi garam 0,1 M, membran mempunyai waktu hidup sampai 62 hari lebih lama dibandingkan tanpa penambahan garam yang memiliki waktu hidup hanya 7 hari

Electron transfer channel in the sugar recognition system assembled on nano gold particle

Existence of 1D spin diffusion in the electrochemical sugar recognition system consisting of a nano-sized gold particle (GNP), a ruthenium complex and a phenylboronic acid was investigated by NMR and muSR. When sugar molecules are recognized by the phenylboronic site, the response of electrochemical voltammetry of the Ru site changes, enabling the system to work as a sensitive sugar-sensor. In this recognition process, the change in the electronic state at the boron site caused by sugar must be transferred to the Ru site via alkyl chains. We have utilized the muon-labelled electrons method and the proton NMR to find out a channel of the electron transfer from the phenylboronic acid site to the gold nano particle via the one dimensional alkyl chain. If this transfer is driven by diffusive spin channel, characteristic field dependence is expected in the longitudinal spin relaxation rate of muSR and 1H-NMR. We have observed significant decrease in the spin relaxation rates with increasing applied field. The result is discussed in terms of low dimensional spin diffusion

THE INFLUENCE OF PVA.cl.CITRIC ACID/CHITOSAN MEMBRANE HYDROPHICILITY ON THE TRANSPORT OF CREATININE AND UREA

The influence of cross-linking and membrane hydrophilicity on the transport rate had been studied using a membrane prepared from a mixture of chitosan/PVA cross-linked citric acid (PVA.cl.CA) for creatinine and urea transport. The optimum mole ratio of PVA:citric acid as well as the best composition of chitosan:PVA.cl.CA were determined using creatinine transport study. Using the optimum compositions, further study was done using different thickness of the membrane in transporting creatinine, urea and a mixture of 3 species (creatinine, urea and vitamin B12). Membrane characterization was done using FT-IR spectrophotometer, water absorption test, TG/DTG and SEM. The results showed that the optimum composition PVA:citric acid was obtained to be 90:1, having % WU of 113.74% and creatinine transport percentage of 18.16%. Meanwhile, the optimum composition of chitosan:PVA.cl.CA was found at 4:6 ratio having % WU and % transport of 136.67% and 24.26%, respectively. The optimum transport capacity was found for membrane thickness of 50 µm with WU% at 139.61% and the percent transport of creatinine and urea each was 38.93% and 60.36%. The presence vitamin B12 in the solution of is proved to disturb the transport of creatinine and urea through the membrane. Finally, hydrophilicity seemed to give substantial contribution in the transport process as well as the mechanical strength of the membrane

(1,4,7,10-Tetra­oxacyclo­dodeca­ne)(trideuteroacetonitrile)lithium perchlorate

In the title compound, [Li(C8H16O4)(CD3CN)]ClO4, the Li atom is penta­coordinate. The O atoms of the 12-crown-4 ether form the basal plane, whereas the N atom of the trideutero­aceto­nitrile occupies the apical position. The Li+ atom is displaced by 0.794 (6) Å toward the apical position from the plane formed by the O atoms because the Li+ atom is too large to fit in the cavity of the 12-crown-4 ether, resulting in a distorted square-pyramidal geometry about the Li+ atom

(μ-1,4,7,10-Tetra­oxacyclo­dodeca­ne)bis­[(1,4,7,10-tetra­oxacyclo­dodeca­ne)lithium] bis­(perchlorate)

12-Crown-4 ether (12C4) and LiClO4 combine to form the ionic title compound, [Li2(C8H16O4)3](ClO4)2, which is com­posed of discrete Li/12C4 cations and perchlorate anions. In the [Li2(12C4)3]2+ cation there are two peripheral 12C4 ligands, which each form four Li—O bonds with only one Li+ atom. Additionally there is a central 12C4 in which diagonal O atoms form one Li—O bond each with both Li+ atoms. Therefore each Li+ atom is penta­coordinated in a distorted square-pyramidal geometry, forming four longer bonds to the O atoms on the peripheral 12C4 and one shorter bond to an O atom of the central 12C4. The cation occupies a crystallographic inversion centre located at the center of the ring of the central 12C4 ligand. The Li+ atom lies above the cavity of the peripheral 12C4 by 0.815 (2) Å because it is too large to fit in the cavity

Induction of microRNAs, mir-155, mir-222, mir-424 and mir-503, promotes monocytic differentiation through combinatorial regulation

Acute myeloid leukemia (AML) involves a block in terminal differentiation of the myeloid lineage and uncontrolled proliferation of a progenitor state. Using phorbol myristate acetate (PMA), it is possible to overcome this block in THP-1 cells (an M5-AML containing the MLL-MLLT3 fusion), resulting in differentiation to an adherent monocytic phenotype. As part of FANTOM4, we used microarrays to identify 23 microRNAs that are regulated by PMA. We identify four PMA-induced micro- RNAs (mir-155, mir-222, mir-424 and mir-503) that when overexpressed cause cell-cycle arrest and partial differentiation and when used in combination induce additional changes not seen by any individual microRNA. We further characterize these prodifferentiative microRNAs and show that mir-155 and mir-222 induce G2 arrest and apoptosis, respectively. We find mir-424 and mir-503 are derived from a polycistronic precursor mir-424-503 that is under repression by the MLL-MLLT3 leukemogenic fusion. Both of these microRNAs directly target cell-cycle regulators and induce G1 cell-cycle arrest when overexpressed in THP-1. We also find that the pro-differentiative mir-424 and mir-503 downregulate the anti-differentiative mir-9 by targeting a site in its primary transcript. Our study highlights the combinatorial effects of multiple microRNAs within cellular systems.Comment: 45 pages 5 figure

miRò: a miRNA knowledge base

miRò is a web-based knowledge base that provides users with miRNA–phenotype associations in humans. It integrates data from various online sources, such as databases of miRNAs, ontologies, diseases and targets, into a unified database equipped with an intuitive and flexible query interface and data mining facilities. The main goal of miRò is the establishment of a knowledge base which allows non-trivial analysis through sophisticated mining techniques and the introduction of a new layer of associations between genes and phenotypes inferred based on miRNAs annotations. Furthermore, a specificity function applied to validated data highlights the most significant associations. The miRò web site is available at: http://ferrolab.dmi.unict.it/miro

EXTENDING THE LIFE TIME OF POLYMER INCLUSION MEMBRANE CONTAINING COPOLY(EUGENOL-DVB) AS CARRIER FOR PHENOL TRANSPORT

A study of phenol transport was conducted in correlation to the evaluation of copoly(eugenol-divinylbenzene, DVB) as carrier using polymer inclusion membrane (PIM) method. The performance of copoly(eugenol-DVB) was observed based on the parameters of Membrane Liquid (ML) loss. Some variations, including the effect of plasticizer concentration, stirring speed, and measurement of lifetime of the membrane, were studied. Related to the lifetime, the effect of the concentration of NaNO3 salt was also studied. The tensile strength of membrane before and after the transport was measured and their morphology was characterized using SEM (Scanning Electron Microscope). Results of the study indicate that the value of the tensile strength of the membrane after the transport was lower than that before the transport. The lifetime of the membrane was not only depending on the capacity of the membrane in restraining ML loss, but also on the concentration of salt that was added to the solution of source phase. In addition, the lifetime of the membrane had correlation to the number of ML loss, i.e. the addition of salt lead to lower amount of ML loss and gave longer lifetime. With the addition of 0.1 M NaNO3, the lifetime of the membrane extended to 62 days, which is longer than the lifetime without the addition of NaO3 which was only 7 days