16 research outputs found
Recovery of Heavy Metals from Eletroplating Rinse Wastewater by Reverse Osmosis
Electroplating rinse wastewater contains a number of toxic
metals which are harmful to receiving waters. The Tubular B 1 Module
(PCI Membrane Systems) with AFC 99 polyamide membrane was used to
treat the aluminium anodizing rinse water at different feedwater
concentrations and diff erent transmembrane pressures. Penneate flux was
found to be directly proportional to transmembrane pressure and indirectly
proportional to natural logarithms of feedwater concentrations. Aluminium
concentration was reduced from 747.1 mg/l to 2. rejection at 65 bar transmembrane pressure and 40°C feedwater temperature. Overall conductivity rejection was in excess of 9 8% at 65 bar. Rejection
efficiency was increased with increasing transmembrane pressure. However,
permeate quality deteriorated with increasing feedwater concentrations. High
production rate was recorded with 3.3 m3/m2.d at 7% recovery and 65 bar
transmembrane pressure with a feedwater concentration of approximately
9,500 mg/l TDS (Total Dissolved Solids). Reverse osmosis penneate is
suitable for reuse as rinse water in the factory. No membrane fouling was
encountered during the study. Reverse osmosis was found to be an effective
alternative for recovery of rinse water and heavy metals from the waste
effluent compared to other conventional treatment technologie
Hemodynamic effects of HPMA copolymer based doxorubicin conjugate: A randomized controlled and comparative spectral study in conscious rats
Conjugation of Doxorubicin (DOX) to N-(2-hydroxypropyl) methylacrylamide copolymer (HPMA) has significantly reduced the DOX-associated cardiotoxicity. However, the reports on the impact of HPMA-DOX conjugates on the cardiovascular system such as blood pressure (BP) and heart rate (HR) were in restrained animals using tail cuff and/or other methods that lacked the resolution and sensitivity. Herein, we employed radiotelemetric-spectral-echocardiography approach to further understand the in vivo cardiovascular hemodynamics and variability post administration of free DOX and HPMA-DOX. Rats implanted with radio-telemetry device were administered intravenously with DOX (5mg/kg), HPMA-DOX (5mg DOX equivalent/kg) and HPMA copolymer and subjected to continuous cardiovascular monitoring and echocardiography for 140 days. We found that DOX-treated rats had ruffled fur, reduced body weight (BW) and a low survival rate. Although BP and HR were normal, spectral analysis indicated that their BP and HR variabilities were reduced. All rats exhibited typical signs of cardiotoxicity at histopathology. In contrast, HPMA-DOX rats gained weight over time and survived. Although BP, HR and related variabilities were unaffected, the left ventricular end diastolic volume (EDV) of these rats, as well as of the HPMA copolymer-treated rats, was found increased at the end of observation period. Additionally, HPMA copolymer caused microscopic injury of the heart tissue. All of these suggest the necessity of caution when employing HPMA as carrier for prolonged drug delivery. The current study also indicates the potential of radiotelemetric-spectral-echocardiography approach for improved preclinical cardiovascular risk assessment of polymer-drug conjugate and other nano-sized-drug constructs
Hemodynamic effects of HPMA copolymer based doxorubicin conjugate:A randomized controlled and comparative spectral study in conscious rats
<p>Conjugation of Doxorubicin (DOX) to <i>N</i>-(2-hydroxypropyl) methylacrylamide copolymer (HPMA) has significantly reduced the DOX-associated cardiotoxicity. However, the reports on the impact of HPMA–DOX conjugates on the cardiovascular system such as blood pressure (BP) and heart rate (HR) were in restrained animals using tail cuff and/or other methods that lacked the resolution and sensitivity. Herein, we employed radiotelemetric-spectral-echocardiography approach to further understand the <i>in vivo</i> cardiovascular hemodynamics and variability post administration of free DOX and HPMA–DOX. Rats implanted with radio-telemetry device were administered intravenously with DOX (5 mg/kg), HPMA–DOX (5 mg DOX equivalent/kg) and HPMA copolymer and subjected to continuous cardiovascular monitoring and echocardiography for 140 days. We found that DOX-treated rats had ruffled fur, reduced body weight (BW) and a low survival rate. Although BP and HR were normal, spectral analysis indicated that their BP and HR variabilities were reduced. All rats exhibited typical signs of cardiotoxicity at histopathology. In contrast, HPMA–DOX rats gained weight over time and survived. Although BP, HR and related variabilities were unaffected, the left ventricular end diastolic volume (EDV) of these rats, as well as of the HPMA copolymer-treated rats, was found increased at the end of observation period. Additionally, HPMA copolymer caused microscopic injury of the heart tissue. All of these suggest the necessity of caution when employing HPMA as carrier for prolonged drug delivery. The current study also indicates the potential of radiotelemetric-spectral-echocardiography approach for improved preclinical cardiovascular risk assessment of polymer–drug conjugate and other nano-sized-drug constructs.</p
Exploratory study on sustainability of no frills airlines in Singapore
In light of the emergence of No Frills airlines in Southeast Asia, our study aims to explore the sustainability of No Frills airlines in Singapore over the long run, in terms of availability of market demand and ability to adopt cost leadership positions
Near-Infrared Activatable Phthalocyanine–Poly-L-Glutamic Acid Conjugate: Enhanced in Vivo Safety and Antitumor Efficacy toward an Effective Photodynamic Cancer Therapy
We previously developed a new zinc(II) phthalocyanine (ZnPc) derivative (Pc 1) conjugated to poly-L-glutamic acid (PGA) (1-PG) to address the limitations of ZnPc as part of an antitumor photodynamic therapy approach, which include hydrophobicity, phototoxicity, and nonselectivity in biodistribution and tumor targeting. During this study, we discovered that 1-PG possessed high near-infrared (NIR) light absorptivity (λ max = 675 nm), good singlet oxygen generation efficiency in an aqueous environment, and enhanced photocytotoxic efficacy and cancer cell uptake in vitro. In the current study, we discovered that 1-PG accumulated in 4T1 mouse mammary tumors, with a retention time of up to 48 h. Furthermore, as part of an antitumor PDT, low dose 1-PG (2 mg of Pc 1 equivalent/kg) induced a greater tumor volume reduction (-74 ± 5%) when compared to high dose ZnPc (8 mg/kg, -50 ± 12%). At higher treatment doses (8 mg of Pc 1 equivalent/kg), 1-PG reduced tumor volume maximally (-91 ± 6%) and suppressed tumor size to a minimal level for up to 15 days. The kidney, liver, and lungs of the mice treated with 1-PG (both low and high doses) were free from 4T1 tumor metastasis at the end of the study. Telemetry-spectral-echocardiography studies also revealed that PGA (65 mg/kg) produced insignificant changes to the cardiovascular physiology of Wistar-Kyoto rats when administered in vivo. Results indicate that PGA displays an excellent cardiovascular safety profile, underlining its suitability for application as a nanodrug carrier in vivo. These current findings indicate the potential of 1-PG as a useful photosensitizer candidate for clinical PDT
Formant Frequencies of Malay Vowels Produced by Malay Children Aged Between 7 and 12 Years
Electron Movement along DNA Strands: Use of Intercalators and Electron Paramagnetic Resonance Spectroscopy
Near-Infrared Activatable Phthalocyanine–Poly‑L‑Glutamic Acid Conjugate: Enhanced in Vivo Safety and Antitumor Efficacy toward an Effective Photodynamic Cancer Therapy
We
previously developed a new zinc(II) phthalocyanine (ZnPc) derivative
(<b>Pc 1</b>) conjugated to poly-L-glutamic acid (PGA) (<b>1-PG</b>) to address the limitations of ZnPc as part of an antitumor
photodynamic therapy approach, which include hydrophobicity, phototoxicity,
and nonselectivity in biodistribution and tumor targeting. During
this study, we discovered that <b>1-PG</b> possessed high near-infrared
(NIR) light absorptivity (λ<sub>max</sub> = 675 nm), good singlet
oxygen generation efficiency in an aqueous environment, and enhanced
photocytotoxic efficacy and cancer cell uptake in vitro. In the current
study, we discovered that <b>1-PG</b> accumulated in 4T1 mouse
mammary tumors, with a retention time of up to 48 h. Furthermore,
as part of an antitumor PDT, low dose <b>1-PG</b> (2 mg of <b>Pc 1</b> equivalent/kg) induced a greater tumor volume reduction
(−74 ± 5%) when compared to high dose <b>ZnPc</b> (8 mg/kg, −50 ± 12%). At higher treatment doses (8 mg
of <b>Pc 1</b> equivalent/kg), <b>1-PG</b> reduced tumor
volume maximally (−91 ± 6%) and suppressed tumor size
to a minimal level for up to 15 days. The kidney, liver, and lungs
of the mice treated with <b>1-PG</b> (both low and high doses)
were free from 4T1 tumor metastasis at the end of the study. Telemetry-spectral-echocardiography
studies also revealed that PGA (65 mg/kg) produced insignificant changes
to the cardiovascular physiology of Wistar-Kyoto rats when administered
in vivo. Results indicate that PGA displays an excellent cardiovascular
safety profile, underlining its suitability for application as a nanodrug
carrier in vivo. These current findings indicate the potential of <b>1-PG</b> as a useful photosensitizer candidate for clinical PDT
Hemodynamic effects of HPMA copolymer based doxorubicin conjugate: A randomized controlled and comparative spectral study in conscious rats
Genome-Wide Linkage, Exome Sequencing and Functional Analyses Identify <i>ABCB6</i> as the Pathogenic Gene of Dyschromatosis Universalis Hereditaria
<div><p>Background</p><p>As a genetic disorder of abnormal pigmentation, the molecular basis of dyschromatosis universalis hereditaria (DUH) had remained unclear until recently when ABCB6 was reported as a causative gene of DUH.</p><p>Methodology</p><p>We performed genome-wide linkage scan using Illumina Human 660W-Quad BeadChip and exome sequencing analyses using Agilent SureSelect Human All Exon Kits in a multiplex Chinese DUH family to identify the pathogenic mutations and verified the candidate mutations using Sanger sequencing. Quantitative RT-PCR and Immunohistochemistry was performed to verify the expression of the pathogenic gene, Zebrafish was also used to confirm the functional role of ABCB6 in melanocytes and pigmentation.</p><p>Results</p><p>Genome-wide linkage (assuming autosomal dominant inheritance mode) and exome sequencing analyses identified <i>ABCB6</i> as the disease candidate gene by discovering a coding mutation (c.1358C>T; p.Ala453Val) that co-segregates with the disease phenotype. Further mutation analysis of <i>ABCB6</i> in four other DUH families and two sporadic cases by Sanger sequencing confirmed the mutation (c.1358C>T; p.Ala453Val) and discovered a second, co-segregating coding mutation (c.964A>C; p.Ser322Lys) in one of the four families. Both mutations were heterozygous in DUH patients and not present in the 1000 Genome Project and dbSNP database as well as 1,516 unrelated Chinese healthy controls. Expression analysis in human skin and mutagenesis interrogation in zebrafish confirmed the functional role of <i>ABCB6</i> in melanocytes and pigmentation. Given the involvement of <i>ABCB6</i> mutations in coloboma, we performed ophthalmological examination of the DUH carriers of <i>ABCB6</i> mutations and found ocular abnormalities in them.</p><p>Conclusion</p><p>Our study has advanced our understanding of DUH pathogenesis and revealed the shared pathological mechanism between pigmentary DUH and ocular coloboma.</p></div