Morphometric Studies on the Testis of Korean Ring-necked Pheasant (Phasianus colchicus karpowi) during the Breeding and Non-breeding Seasons

The purpose of this study was to obtain detailed quantitative information on all cell types in the testis interstitium of Korean ring-necked pheasants and to combine these data with changes in the steroidogenic function of the testis during the breeding and non-breeding seasons. For animals collected during the breeding season, their testis weights, sperm production, serum testosterone levels and leuteinizing hormone (LH)-stimulated testosterone secretion were significantly (p < 0.01) increased compared to the non-breeding season. Testes of the pheasants during the non-breeding season displayed a 98% reduction in testis volume that was associated with a decrease in the absolute volume of seminiferous tubules (98% reduction), tubular lumen (100%), interstitium (90%), blood vessels (84%), lymphatic spaces (97%), Leydig cells (79%), mesenchymal cells (51%) and myoid cells (61%) compared to the breeding season. The numbers of Leydig cells, mesenchymal cells and myoid cells per testis in the breeding season were much higher than in the non-breeding season. Although the mean volume of a Leydig cell was 74% lower in the non-breeding season, the mean volumes of myoid and mesenchymal cells remained unchanged. These results demonstrate that there are striking differences in the testicular structure of the Korean ring-necked pheasant during the breeding and non-breeding seasons. Every structural parameter of the Leydig cell was positively correlated with both testosterone serum levels and LH-stimulated testosterone secretion. The correlation of changes in hormonal status with the morphometric alterations of Leydig cells suggests that the Korean-ring necked pheasant may be used as a model to study structure-function relationships in the avian testis.

Drug release from the enzyme-degradable and pH-sensitive hydrogel composed of glycidyl methacrylate dextran and poly(acrylic acid)

Hydrogels composed of glycidyl methacrylate dextran (GMD) and poly(acrylic acid, PAA) were prepared by UV irradiation method for colon-specific drug delivery. GMD was synthesized by coupling of glycidyl methacrylate to dextran in the presence of 4-(N,N-dimethylamino)pyridine. GMD was photo-polymerized by ammonium peroxydisulfate as initiating system in phosphate-buffered solution (0.1 M, pH 7.4). And then, acrylic acid monomer was added and subsequently heat-polymerized by 2,2'-azobisisobutyronitrile as an initiator. The hydrogels exhibited high swelling ratio (about 20) at 37 degrees C, and showed a pH-dependent swelling behavior. In addition, the swelling ratio of the hydrogel was remarkably enhanced to about 45 times in the presence of dextranase at pH 7.4. The swelling-deswelling behavior proceeded reversibly for the GMD/PAA hydrogels between pH 2 and pH 7.4. Release of 5-aminosalicylic acid from the GMD/PAA hydrogels was evaluated in simulated gastrointestinal pH fluids in the absence or presence of dextranase. We concluded that the hydrogels prepared could be used as a dual-sensitive drug carrier for sequential release in gastrointestinal tract.

[Development of performance measure indicators in hospital nursing units]

PURPOSE

The purpose of this study was to develop performance measure indicators for hospital nursing units based on a Balanced Scorecard (BSC).

METHOD

This study was a methodological study. The development process consisted of 3 stages. The first stage was setting up strategies for nursing units from a nursing department's mission and vision. The second stage was developing performance measure indicators after a validity check. The third stage was modifying developed performance measure indicators and classifying them.

RESULTS

7 strategies were set up according to 4 perspectives of a BSC. 15 performance measure indicators for hospital nursing units were developed, and the indicators were divided into 8 independent indicators and 7 shared indicators according to the degree of performance responsibility. In addition, they were classified into two groups, 7 leading indicators and lagging indicators.

CONCLUSIONS

The result of this study suggests that performance measure indicators for hospital nursing units provide a framework and method for nursing organizations' performance management. Also, the developed indicators are expected to provide valuable information for successful organization management.

Physicochemical characterization of poly(l-lactic acid) and poly(d,l-lactide-co-glycolide) nanoparticles with polyethylenimine as gene delivery carrier

Polymer nanoparticles have been used as non-viral gene delivery systems and drug delivery systems. In this study, biodegradable poly(L-lactic acid) (PLA)/polyethylenimine (PEI) and poly(D,L-lactide-co-glycolide) (PLGA)/PEI nanoparticles were prepared and characterized as gene delivery systems. The PLA/PEI and PLGA/PEI nanoparticles, which were prepared by a diafiltration method, had spherical shapes and smooth surface characteristics. The size of nanoparticles was controlled by the amount of PEI, which acted as a hydrophilic moiety, which effectively reduced the interfacial energy between the particle surface and the aqueous media. The nanoparticles showed an excellent dispersive stability under storage in a phosphate-buffered saline solution for 12 days. The positive zeta-potentials for the nanoparticles decreased and changed to negative values with increasing plasmid DNA (pDNA) content. Agarose gel electrophoresis showed that the complex formation between the nanoparticles and the pDNA coincided with the zeta-potential results. The results of in vitro transfection and cell viability on HEK 293 cells indicated that the nanoparticles could be used as gene delivery carriers.

Association of C-509T and T869C polymorphisms of transforming growth factor-beta1 gene with susceptibility to and progression of IgA nephropathy

AIMS

Transforming growth factor (TGF)-beta1 is a cytokine with both beneficial anti-inflammatory effects and detrimental profibrotic activity in the pathophysiology and progression of glomerulonephritides. The transcriptional activity of the gene for TGF-beta1 and the plasma levels of TGF-beta1 protein are associated with C-509T polymorphism at the promoter region, and with T869C (Leu 10Pro) polymorphism at codon 10, of the TGF-beta1 gene.

METHODS

Using PCR-RFLP and the amplification refractory mutation system PCR, we investigated the C-509T and T869C polymorphisms, respectively, to elucidate whether allele frequency differences exist between IgA nephropathy (IgAN) patients who were followed up for at least 3 years (n = 108) and a normal population (n = 55). We also determined the correlations between the TGF-beta1 polymorphisms and the progression of IgAN.

RESULTS

In C-509T polymorphism, there were significant differences in genotype frequency between IgAN patients and normal controls (CC: CT: TT, 20:29:33 vs. 11:31:13, chi2 = 6.299, p = 0.043). In Kaplan-Meier survival analysis, the patients with TT genotype showed a poorer renal survival than those with CC + CT genotypes (p = 0.042). In T869C polymorphism, there were also significant differences in genotype frequency between IgAN patients and normal controls (TT : TC : CC, 4 : 79 : 25 vs. 0 : 52 : 2, chi2 = 12.552, p = 0.002). The initial serum creatinine (Scr) level was higher in the patients with CC genotype than in those with TT + TC genotypes. In Kaplan-Meier survival analysis, the patients with CC genotype showed a poorer renal survival than those with TT + TC genotypes, but not to a statistically significant extent (p = 0.076). In the combined survival analyses, the high TGF-beta1 producer group showed a poor renal survival rate (p = 0.014).

CONCLUSION

Compared to normal population, the frequencies of genotypes producing high TGF-beta1 protein were higher in IgAN patients. Moreover, patients with genotypes producing high TGF-beta1 plasma levels showed a poor renal survival rate.

A study on the treatment of antifouling paint waste from shipyard

A study on the treatment of antifouling paint waste from shipyards, including sandblast waste and ship hull washing wastewater, was performed. The sandblast waste could be effectively detoxified by heat treatment, and the efficiency was affected by the temperature of the heating vessel and treatment time. The removal efficiency of total organotin compounds from the sandblast waste was over 99% at 1000 degrees C and treatment for 1 h. For the treatment of ship hull washing wastewater by the solvent extraction, ship diesel was a good solvent for the tributyltin (TBT) extraction, and the proper amount of solvent was about 10 mL for TBT extraction from 1L of wastewater. The extraction efficiency of TBT was significantly affected by the agitation intensity. The TBT in the wash wastewater was rapidly extracted within 1 h. The level of the TBT residual in the wastewater extracted for 1h was 2.8 microg L(-1), and this was further decreased to 0.8 after 5 h extraction.

Urinary concentration of transforming growth factor-beta-inducible gene-h3(beta ig-h3) in patients with Type 2 diabetes mellitus

AIMS

The expression of TGF beta-inducible gene h3(beta ig-h3) has been used to assess the biological activity of TGF beta in the kidney. In this study, we investigated whether the urinary concentration of beta ig-h3 is associated with diabetic nephropathy in patients with Type 2 diabetes mellitus. We also evaluated the relationship between the urinary concentration of beta ig-3 and proteinuria and microalbuminuria (AER) in a normal healthy population and in Type 2 diabetes patients.

METHODS

Four hundred and seventy-nine Type 2 diabetic patients without non-diabetic kidney diseases and 528 healthy control subjects were enrolled. The study subjects were divided into five groups: a non-diabetic healthy control group with normal ACR (n = 443), a non-diabetic healthy control group with microalbuminuria (n = 85), a normoalbuminuric diabetic group (n = 198), a microalbuminuric diabetic group (n = 155) and an overt proteinuria group (n = 126). Urinary levels of beta ig-h3 were measured by enzyme-linked immunosorbent assay.

RESULTS

(i) Urinary excretion of beta ig-h3 was significantly higher in the diabetic groups than in the controls, even in the normoalbuminuric stage (25.02 +/- 8.84 vs. 18.67 +/- 6.56, P = 0.03). In diabetic patients, urinary beta ig-h3 levels increased significantly as diabetic nephropathy advanced (25.02 +/- 8.84 vs. 34.06 +/- 24.55 vs. 169.63 +/- 57.33, P < 0.001). (ii) Proteinuria was found to be significantly correlated with urinary beta ig-h3 (healthy control; r = 0.137, P = 0.019, diabetic patients; r = 0.604, P < 0.001). ACR was also found to be significantly related with urinary beta ig-h3 in diabetic patients (r = 0.383, P = 0.006). (iii) In diabetic patients, urinary beta ig-h3 was significantly related with systolic and diastolic blood pressure (systolic blood pressure: r = 0.436, P = 0.024; diastolic blood pressure, r = 0.365, P = 0.042), total cholesterol and HbA(1c) (cholesterol: r = 0.169, P = 0.03, HbA(1c); r = 0.387, P = 0.044). Logistic regression analyses showed that urinary beta ig-h3 was associated with a significant increase in the risk of microalbuminuria and proteinuria in diabetic patients.

CONCLUSIONS

Longitudinal monitoring of urinary beta ig-h3 may improve the likelihood of detecting diabetic nephropathy at an earlier stage and beta ig-h3 could be a sensitive marker of diabetic kidney disease progression.

[King Injo's disease and burnt needle therapy]

This paper investigates an interrelationship between burnt needle therapy and King Injo's disease. From 1633 (Year 11 in King Injo's reign) to May 5, 1649 (Year 27 in King Injo's reign), right before his death, King Injo was treated with burnt needles by Yi Hyeongik, an acupuncturist when the king had health problems. This study arises from two questions: why was King Injo often treated with burnt needles? and what effect did burnt needles have?Burnt needle therapy is a combined form of acupuncture and moxibustion. Yi Hyeongik was famous for eradicating pathogenic factors. He was appointed as a doctor in the Royal Hospital. The medical definition for pathogenic factors is that they are disease-causing factors. Understanding the pathogenic factor for King Injo's disease could make it possible to find the interrelationship between burnt needles and the king's disease. In the Joseon ear, the prevalent belief about diseases was that diseases could be caused by homeopathic magic. Some people thought homeopathic magic caused King Injo's disease. The actual reasons for King Injo's disease were the participation in the excessive rites of Queen Mother Inmok's funeral and the constant oppression from the Ching Dynasty after disgraceful defeat in the war. When King Injo started to be sick, homeopathic magic cases were found in the royal palace. The king's incurable disease was believed to have happened as a result of homeopathic magic. King Injo's suspicion toward Princess Jeongmyeong derived from her mother, Queen Mother Inmok. Moral justification for King Injo's coup was Gwanghaegun or Prince Gwanghae's immoral conduct toward Queen Mothe Inmok. After he was installed, King Injo obeyed the Queen Mother and showed her every attention. Meanwhile, he treated Princess Jeongmyeong with respect, maximized the moral justification for the coup, and solidified the royal authority. However, constant rebellions and treasons threatened King Injo. The king suspected that Queen Mother Inmok and Princess Jeongmyeong were involved in homeopathic magic cases because both figures could affect major rebellions and treasons. Homeopathic magic is a kind of ideological belief and psychological suspicion. Accordingly, burnt needle therapy could have an actual effect on treating the diseases of the body. It could have a psychological effect in treating pathogenic factors as well. As burnt needles were often used for the king's disease, remarkable development of acupuncture and moxibustion during the King Injo's era was a characteristic in the history of medical science in the Joseon Dynasty.

Averaging algorithm based on data statistics in magnetocardiography

An algorithm for automatic averaging of a magnetocardiogram (MCG) is described. Due to the relatively low signal-to-noise ratio in the MCG, the measured MCG data are often averaged to be analyzed. Generally, R-peaks are used as trigger points, which become anchors for superposition and we can obtain an averaged epoch eventually. However, we have to determine several parameters, such as the threshold magnitude for recognizing R-peak, the time-period of the epoch window, and which channel has dominant R-peaks. In order to determine these parameters automatically, we utilize the magnitude histogram of the root-mean-square waveform of all the channels. We can determine the threshold magnitudes for recognizing R-peaks and T-peaks, respectively, by using the characteristic distribution of the MCG signal histogram. Peak detection procedure using these thresholds records all the locations of the R-peaks and T-peaks, thus we get the average latencies of the R-T intervals and the R-R intervals. From these latencies, we estimate the full width of the epoch window. By adding a routine for processing double R-peaks, our algorithm could conduct the MCG averaging sequence fully automatically. The algorithm has been tested on recordings of 40 normal subjects and 15 patients suffering from myocardial ischemia, and we conclude that this algorithm reliably performs the averaging sequence. The MCG recordings are measured by our 62-channel planar gradiometer system in a magnetically shielded room.

Optimal sensor distribution for measuring the tangential field components in MCG

We discuss the optimal arrangement of detectors for a 52-channel magnetocardiogram (MCG) system measuring tangential components of the cardiac magnetic fields. Nowadays, most MCG instruments are designed to cover the whole heart area to maximize the information available from the myocardial magnetic field in a simultaneous measurement. In such a system, detectors should be spread over a sufficiently wide area. However, an increased diameter of the cooling dewar will result in more heat-loss and higher production and maintenance costs. Therefore, we reviewed the spatial sampling theory to determine the proper interval between detectors, and we decided on the number of channels to cover the whole heart area. In order to fit the detector array on the cylindrical dewar economically, we removed the detectors at the corners of the square array. Through simulations using the confidence region method, we verified that our design of the detector array is enough to obtain adequate information from the heart. Simulations also suggested that tangential-component MCG measurement can localize deep current dipoles better than normal-component measurement with the same confidence volume; therefore, we conclude that measurement of the tangential component is more suitable to an MCG system than the normal component.

Auranofin induces apoptosis and when combined with retinoic acid enhances differentiation of acute promyelocytic leukaemia cells in vitro

1. Acute promyelocytic leukaemia (APL) is characterized by a block in differentiation at the promyelocyte stage. Here, we describe the effects of auranofin (AF), a coordinated gold compound, on apoptosis and differentiation of APL cells. 2. Nucleosomal DNA fragmentation assay and Hoechst 33342 staining indicated that AF induced apoptosis in APL-derived NB4 cells at low concentrations (0.5-1.0 microm). The AF-induced apoptosis involved caspase-3 activation and specific cleavage of poly-ADP-ribose polymerase. 3. The AF-treated NB4 cells also produced reactive oxygen species (ROS) and cotreatment with N-acetyl-l-cysteine protected the NB4 cells from AF-induced apoptosis. 4. Expression of the CD11b cell surface marker and C/EBPepsilon was increased when the cells were treated for 4 days with 0.3 microm AF and a physiological concentration of all-trans retinoic acid (ATRA, 5 nm). Treatment with AF in combination with ATRA markedly increased the number of cells with differentiated features, such as lobed or multiple nuclei and numerous granules and vacuoles. At these low concentrations, neither AF nor ATRA alone induced significant cell differentiation. 5. These findings suggest not only that AF induces caspase-3-dependent apoptosis via a mechanism involving ROS, but also that the combined treatment with AF and ATRA induces differentiation of NB4 cells. Our results demonstrate a novel characteristic of AF from which an effective drug treatment of APL might be developed.

Quantification of polynuclear aromatic hydrocarbons in transformer oils by enzyme immunoassay

Many polynuclear aromatic hydrocarbons (PAHs) are either known or suspected carcinogens and are a common constituent of mineral oils. Due to the large number of possible PAH structures, standard quantification methods fail since they either lack specificity or are too complex, requiring individual fractionation, identification, and quantification. A rapid, low-cost, novel analytical screening method, incorporating a silica-based solid-phase extraction (SPE) method linked to co-solvent dilution and quantification of total and carcinogenic PAH levels by immunoassay, is reported here. The method yielded high extraction efficiencies and minimal matrix effects. This novel approach yielded total and carcinogenic PAH levels x 5.7 and x 126, respectively, lower than that recorded by the industry-recognised BS2000 Pt. 346 (IP346) method which estimates the polyaromatic carbon (PAC) content of oils by gravimetry. The method is expected to be of benefit where an indication of PAH levels in oils is important for purchasing, management or disposal purposes and also for risk assessment and for appropriate labelling of oils in line with current legislation.

Pharmaceutical rejection by membranes for wastewater reclamation and reuse

Various membranes, which have different materials and nominal molecular weight cut-offs (MWCO), were compared in terms of rejection of ibuprofen and removal of effluent organic matter (EfOM) from membrane bioreactor (MBR), because pharmaceutical compounds contain a potential risk and EfOM is the precursor of carcinogenic disinfection by-products when reusing for drinking water source. To provide equivalent comparison with respect to hydrodynamic condition, mass transfer parameter, J0/k ratio, was used. A tight-UF membrane with a molecular weight cut off of 8,000 daltons exhibited 25 approximately 95% removal efficiencies of ibuprofen with a molecular weight of 206 with and without presence of EfOM(MBR). EfOM(MBR) caused the reduction of ibuprofen removal efficiency for UF membrane. Rejection of EfOM(MBR) by UF and NF membranes ranged 29 approximately 47% and 69 approximately 86%, respectively. UF membrane could successfully remove ibuprofen at lower J0/k ratio range (< or = 1) in organic free water but could not efficiently reject ibuprofen with a relatively hydrophilic EfOM(MBR) (SUVA < or = 3).

Evaluation of wastewater effluents for soil aquifer treatment in South Korea

Soil batch and column experiments were performed to characterize the wastewater effluents from seven different wastewater treatment plants in the Jonnam province, South Korea, with the purpose of evaluating the effluents for possible application of a soil aquifer treatment (SAT) in Korea. Batch experiments were conducted to measure the biodegradable dissolved organic carbon (BDOC) while 1 m soil columns, for simulating SAT, were employed to further analyze dissolved organic carbon (DOC) removal. The soils were collected from a river bottom in Jonnam. The BDOC fractions and the residual DOC concentrations for the effluents ranged from 19.3 to 59.9% and from 1.0 to 7.5 mg/L, respectively, depending on the reaction time. Applying the tentative criteria based on the data obtained for the BDOC and residual DOC, three effluents, from Gwangju, Hwasoon, and Jangsung, were found to be the most suitable for SAT applications. It was also concluded that the site characteristics should be also considered with regard to the retention time when evaluating the feasibility of SAT application in a certain region.

Enhanced aerobic floc-like granulation and nitrogen removal in a sequencing batch reactor by selection of settling velocity

In order to enhance the solid-liquid separation properties and nitrogen removal efficiency of SBR, the aerobic floc-like granules were cultivated under temporal alternating aerobic and anoxic conditions without the presence of carrier material in a SBR having 15 H/D (height/diameter) ratio. Two different effluent port positions were applied to the SBR for different selection of minimum settling velocities (over 0.6 and 0.7 m/h) of granules retained in the SBR during aerobic floc-like granule formation. The effect of different minimum settling velocities as an operational parameter on the size and solid-liquid separation properties of floc-like granules and also the COD and nitrogen removal of SBR were evaluated. The reactor was operated 6 hours per cycle (aerobic 4.75 hours, anoxic 1.25 hours) under chemical oxygen demand (COD) loading rate of 2.5 kg/m3 x d (1.3 kg acetate-COD and 1.2 kg glucose-COD). When increasing the minimum settling velocity by 0.1 m/h, the following results were observed at steady state. The nitrification efficiency was not changed at about 97% but the denitrification efficiency was improved from 78 to 97%. The COD removal efficiency was improved from 82 to 97% and the concentration of biomass in the reactor was retained at lower level at about 3,000 mg MLSS/L. The average sludge volume index (SVI) value of granules was decreased about 85 to 50 mL/g and the granule sizes were increased 0.1-0.5 mm to 1.0-2.0 mm. The required time to form granules and reach steady state was significantly shortened. Based on the results, the selection of the minimum settling velocity had a significant effect on both the physical properties of granules and the SBR performance, so it is suggested to use the minimum settling velocity as an operational parameter.

Domestic wastewater reclamation by submerged membrane bioreactor with high concentration powdered activated carbon for stream restoration

This study focuses on the practical application of high concentration powdered activated carbon coupled membrane bio-reactor to domestic wastewater reclamation. The study was conducted in three parts, such as analysis of secondary domestic wastewater effluent, design and operation parameter evaluation and reclaimed water quality estimation for stream restoration. The organic concentration was 25.2-80.2 mgCOD(Cr)/L for the effluent of three domestic wastewater treatment plants. Around 50-75% of the COD was low molecular substances less than 1,000 which were quite biodegradable. The sawdust PAC was estimated to be proper adsorbent for the organics in the secondary effluents. Its Freundlich constant, K value was 5.847 and 1/n, 0.36. Using a system consists of single reactor with high concentration PAC (80 g/L) and submerged hollow fiber MF membrane module with nominal pore size of 0.1 microm, design and operation parameters were obtained, such as HRT of the bioreactor (2.5 hr), PAC concentration (80 g/L), the initial flux (less than 0.5 m/day) and intermittent suction cycle (12 min. suction and 3 min. idling). Organic removal by the system was high enough to produce reclaimed water for urban stream restoration The effluent organic concentration was at the level of 2 mg/L in terms of TOC (around 5 mg/L as COD(Cr)). Substances with molecular weight cut off < 1,000 were removed mostly by adsorption and biodegradation. Those above 1,000 were rejected at PAC cake layer on the membrane and gradually degraded by microorganisms during extended contact.

Use of the Keele injector for sample introduction for gas chromatographic analysis of vinclozolin in lettuces

We examined a Keele injector for sample introduction for gas chromatographic analysis of vinclozolin treated in lettuces. Samples in milligram quantity were introduced into a glass tube in a Keele injector at a gas chromatograph injection port. The glass tube was then crushed to allow the sample to carry onto a capillary column in a normal manner. The standard calibration curve for quantitative detection of vinclozolin was obtained by determining vinclozolin spiked in samples at variable concentrations. The calibration curve showed a linear response to vinclozolin ranging from 0.05 to 1.0 microg/g, giving a slope value of 174.8, the y-intercept value of -2.8146 and the mean r2-value of 0.9994. Limit of quantification for vinclozolin was 0.05 microg/g by this method, comparable to 0.01 microg/g by a normal injector. When samples treated previously with vinclozolin were determined by the Keele injector, vinclozolin was found to be about 30% lower as compared to a normal method, suggesting about 70% recovery of the spiked vinclozolin by the Keele injector. From these results, the Keele injector was suggested to be potential for sample introduction in gas chromatographic analysis of vinclozolin in lettuce samples.

Development of polymeric nanoparticulate drug delivery systems: evaluation of nanoparticles based on biotinylated poly(ethylene glycol) with sugar moiety

Liver specific polymeric nanoparticles were designed and synthesized from biotinylated poly(ethylene glycol) conjugated with lactobionic acid containing a galactose moiety (abbreviated as BEL). Synthesized BEL conjugate was identified by Fourier transform-infrared (FT-IR) and 1H-nuclear magnetic resonance (NMR) spectroscopy. The fluorescence spectroscopy data showed that BEL conjugate was self-assembled in water to form core-shell structure nanoparticles, and the critical association concentration (CAC) value was estimated as 0.028 g/l. From the transmission electron microscope (TEM) observation, the BEL nanoparticles were spherically shaped and ranged in size between 30 and 60 nm. The particle size distribution was measured by photon correlation spectroscopy (PCS), and the result was 41.2+/-11.7 nm. Anti-cancer drug all-trans-retinoic acid (ATRA) was loaded into the BEL nanoparticles for evaluating its efficacy as a drug delivery carrier. The crystallinities of ATRA and ATRA-loaded nanoparticles were examined by X-ray diffraction (XRD) patterns. The ATRA release kinetics from the BEL nanoparticles showed a pseudo zero-order pattern during 1-month period.

Polymeric nanoparticle composed of fatty acids and poly(ethylene glycol) as a drug carrier

Diamine-terminated poly(ethylene glycol) (ATPEG) was hydrophobically modified with long-chain fatty acids (FAs) through a coupling reaction using N,N'-dicyclohexyl carbodiimide (DCC). FA-PEG-FA conjugates have different physico-chemical properties according to the chain length of the fatty acid (FA). Synthesized FA-PEG-FA conjugate was confirmed by Fourier transform-infrared (FT-IR). Since FA-PEG-FA conjugates have the amphiphilic characteristics in aqueous solution, polymeric nanoparticles of FA-PEG-FA conjugates were prepared using a simple dialysis method in water. The results of 1H nuclear magnetic resonance (NMR) spectroscopy and fluorescent spectroscopy suggest that the FA-PEG-FA conjugate has a typical core-shell type nanoparticle structure made by a self-assembling process. From the analysis of fluorescence excitation spectra, especially, the critical micelles concentration (CMC) of this conjugate was changed unpredictably, i.e. the critical association concentration (CAC) value was decreased below a FA carbon number of 16 but, above increased a FA carbon number of 16. Transmission electron micrograph readings showed the spherical morphologies of the polymeric nanoparticles. The particle size was continuously decreased until below a FA carbon number of 20, but it was increased above a FA carbon number of 20. Clonazepam (CNZ), as a model drug, was easy to entrap into polymeric nanoparticles of the FA-PEG-FA conjugates. The drug release behavior was changed according to the FA chain length and was mainly diffusion controlled from the core portion.

Non-woven fabric filter separation activated sludge reactor for domestic wastewater reclamation

A non-woven fabric filter was experimentally evaluated for solid-liquid separation in an activated sludge reactor as an alternative membrane. A polypropylene fabric filter (70, 50 and 35 g/m2) was used for the experiment. The pilot system was operated in A/O (Anaerobic/Oxic) type in which the filter module was submerged into the oxic compartment. The filtration module consists of 10 plate type rectangular filter elements with effective filtration area, 2 m2. Gravity filtration was carried out for solid-liquid separation by changing the water head 0.05-0.5 m without backwashing during the system operation. Initial permeate flux was set at 0.4 m/d. C/N ratio of raw wastewater was controlled at 4.5 in terms of BOD/T-N. The fabric filter system showed a good performance enough for domestic wastewater treatment. Effluent solid concentration was 3.2 mg/L (93.5% removal). COD removal efficiency was 91.6% producing an effluent concentration around 13 mg/L. 66% of total nitrogen removal could be obtained at the adjusted C/N ratio of influent wastewater. However phosphorus removal was very low at 23%. It was found that the initial flux of 0.4 m/d should be maintained for stable performance of the system.

Effect of dissolved oxygen concentration on the biofilm and in situ analysis by fluorescence in situ hybridization (FISH) and microelectrodes

A better understanding of microbiology and ecology of nitrifying bacteria in inner biofilms is an important part of improving process performance and control. Microelectrodes and fluorescent in situ hybridization (FISH) in biofilm research have been used to investigate the spatial distributions of various microbial activities in biofilms and have led to new experimental findings as well as modifications of the homogeneous assumptions in the biofilm kinetic models. The objective of this study is to try the combination of two methods, both FISH and microelectrode measurements, and to provide reliable and in situ information on nitrifying bacterial activity in biofilms. The characteristics of biofilm developed on tygon slides were different according to the change of dissolved oxygen (DO). When the DO increased from 2 to 10 mg DO/L, the rate of the biofilm thickness increased and its dry density changed from 50-70 to 25-90 mg/cm3. Ammonia oxidizing bacteria were not uniformly distributed in biofilm, and were found at the deeper layer where oxygen is depleted, they were detected primarily in the upper and middle layers of the biofilm.

Nitrate removal by simultaneous sulfur utilizing autotrophic and heterotrophic denitrification under different organics and alkalinity conditions: batch experiments

The effect of various organic compounds were tested using lab-scale batch reactors. At sufficient alkalinity, the initial nitrate nitrogen concentration of 100 mg/L was completely reduced in all batch reactors. Sulfate production decreased by the addition of organics. The concentration range of organics used in this experiment did not inhibit autotrophic denitrification except for propionate. Propionate inhibited autotrophic denitrification a little, indicated by a lower sulfate production rate. Biomass in suspension increased with higher initial organic concentrations, showing higher DOC consumption. As the concentration of organics increased, alkalinity increased accordingly. Under the conditions of low alkalinity, in the case of a control reactor without organics, only about 30% of the initial nitrate was reduced. With half the theoretically required dosage of methanol, the denitrification rates increased slightly. When ethanol, acetate, and propionate were used, denitrification went to completion. When excess organics was added, however, sulfate production was significantly decreased. Interestingly, even when small amounts of organics were added, autotrophic denitrification was promoted as indicated by the sulfate production.

Development of a polymeric nanoparticulate drug delivery system

This paper reports the synthesis of polymeric nanoparticles from a sugar-containing conjugate for liver-specific drug delivery. The conjugate was composed of lactobionic acid, diamine-terminated poly(ethylene glycol) and cholic acid (abbreviated as LEC). The conjugate was characterized by (1)H NMR and FT-IR spectroscopy measurements. In aqueous media, the conjugate can self-assemble to form core-shell type nanoparticles, and the formation of a core-shell structure was observed by fluorescence spectroscopy. The critical association concentration (CAC) of the LEC conjugate nanoparticles was determined from fluorescence excitation spectra to be 0.05 g/l. The LEC nanoparticles were mostly spherical with sizes ranging from 10 to 30 nm. Clonazepam (CNZ) was used as a model hydrophobic drug, and was incorporated into the hydrophobic core of the nanoparticles. CNZ was released more slowly at a higher drug loading due to drug crystallization.