Comparison of nutrient cycling in a surface-flow constructed wetland and in a facultative pond treating secondary effluent.

There is a growing interest in the possibilities offered by combinations of waste stabilisation ponds (WSP) and constructed wetlands (CW). The purpose of our study was to compare treatment performances and nutrient cycling in a surface-flow wetland (SFW) and in a WSP treating secondary effluent. In the period between 2000 and 2003, a pilot SFW and a pilot WSP were constructed at the outlet of the wastewater treatment plant and their performance monitored while both were active under the same conditions. The SFW was planted with Phragmites australis and Eichhornia crassipes, while in the WSP development of algae was spontaneous. Performance efficiency was monitored by means of evaluation of physical and chemical parameters in water, by measurement of plant productivity and by analysis of N and P contents in biomass. The SFW with macrophytes proved more efficient in decreasing the suspended solids (64.6%), settleable solids (91.8%), organic N (59.3%), total N (38%), COD (67.2%) and BOD5 (72.1%) than the WSP. The WSP with algae was more efficient in treatment of ammonia nitrogen (48.9%) and ortho-phosphate (43.9%). The results of this study provide data that are of help in optimising combinations of SFW and WSP.     

Compact implementation of high-performance CMOS current mirror

A high-performance compact current mirror implementation with very low input resistance, very high output resistance, high copying accuracy, low input and output voltage supply requirements and high bandwidth is proposed. The circuit characteristics are validated with simulations in 0.5 /spl mu/m CMOS technology and with experimental results.     

Low Electrical Percolation Threshold of Silver and Copper Nanowires in Polystyrene Composites

Silver and copper nanowires have been synthesized using a scalable method of AC electrodeposition into porous aluminum oxide templates, which produces gram quantities of metal nanowires ca. 25 nm in diameter and up to 5 and 10 μm in length for Ag and Cu, respectively. The nanowires have been used to prepare polystyrene nanocomposites by solution processing. Electrical resistivity measurements performed on polymer nanocomposites containing different volume fractions of metal indicate that low percolation thresholds of nanowires are attained between compositions of 0.25 and 0.75 vol %.     

Preparation of autologous bone marrow grafts for cryopreservation using the AS104 cell separator

The heterocomplex of glycoproteins E and NS1 of tick-borne encephalitis (TBE) virus was isolated from culture fluid of continuous SPEV (porcine embryo kidney) cells by affinity chromatography on CL4B sepharose with immobilized monoclonal antibodies to TBE virus protein NS1. Comparison of the TBE E-NS1 heterocomplex from culture fluid and cells showed the predominance of secreted extracellular form. A similar TBE virus heterocomplex E-NS1 was revealed in the blood sera of patients with TBE but not in their lymphocytes. Extracellular localization of the E-NS1 complex at the late stage of infection rules out its hypothesized participation in the replication of TBE virus. Virtual absence of the heterocomplex and presence of proteins E and NS1 in high concentrations in the cells makes the nonspecific aggregation of these proteins impossible. Evidently, the extracellular heterocomplex E-NS1 may react with virusspecific antibodies or with cytotoxic T lymphocytes.     

Trends in registered psychiatric morbidity and forecasting psychotropic drug needs in Bulgarian hospitals

Registered psychiatric morbidity in Bulgaria as a whole and particularly in Plovdiv, the second largest region of the country, was assessed. Three aspects of psychotropic drug usage were analysed, namely, changes in registered psychotropic drugs, the prescribed daily dose (PDD) values for 2 years, and the preferred therapeutic schemes, and drug usage and needs in a psychiatric hospital with 365 beds. This was done by time series analysis for evaluation of psychiatric morbidity and drug consumption data, calculation of PDD for psychotropic medicines, and, based on a modification of the World Health Organization's morbidity method, assessment and prediction of drug use and needs in Plovdiv hospital. The results indicated that the registered morbidity had increased by 4% over the period 1989-93 to 2,427 psychiatric patients per 100,000 people. The increased consumption of especially benzodiazepines and sedative medicines was analyzed. Diazepam was prescribed the most often (91.1%), followed by levomepromazine (86.4%), haloperidol (82.7%), etc. Future drug consumption in Plovdiv hospital is expected to decrease because therapeutic practice in hospitals has been revised and improved on the basis of the World Health Organization's recommendations.     

Modulation of cAMP-dependent protein kinase by derivatives of chondroitin sulfate

Here, we report investigations about the direct effect of glycosaminoglycans, such as dermatan sulfate, chondroitin 4- and 6-sulfate upon cAMP-dependent protein kinase activity. The results indicate that glycosaminoglycans strongly influence the phosphorylation activity of this enzyme against histone type IIa and [Val6, Ala7]-kemptide. While chondroitin 4-sulfate and dermatan sulfate exhibit inhibitory effects, chondroitin 6-sulfate shows a stimulating effect. In addition, the chondroitin 6-sulfate is also able to reduce the chondroitin 4-sulfate and dermatan sulfate specific inhibition.     

Intrathecal fentanyl with small-dose dilute bupivacaine: better anesthesia without prolonging recovery

Recent concern regarding lidocaine neurotoxicity has prompted efforts to find alternatives to lidocaine spinal anesthesia. Small-dose dilute bupivacaine spinal anesthesia yields a comparably rapid recovery profile but may provide insufficient anesthesia. By exploiting the synergism between intrathecal opioids and local anesthetics, it may be possible to augment the spinal anesthesia without prolonging recovery. Fifty patients undergoing ambulatory surgical arthroscopy were randomized into two groups receiving spinal anesthesia with 3 ml 0.17% bupivacaine in 2.66% dextrose without (Group I) or with (Group II) the addition of 10 microg fentanyl. Median block levels reached T7 and T8, respectively (P = not significant [NS]). Mean times to two-segment regression, S2 regression, time out of bed, time to urination, and time to discharge were 53 vs 67 min (P < 0.01), 120 vs 146 min (P < 0.05), 146 vs 163 min (P = NS), 169 vs 177 min (P = NS), and 187 vs 195 min (P = NS) respectively. Motor blockade was similar between groups, but sensory blockade was significantly more intense in Group II (P < 0.01). Six of 25 blocks failed in Group I, whereas none failed in Group II. The addition of 10 microg fentanyl to spinal anesthesia with dilute small-dose bupivacaine intensifies and increases the duration of sensory blockade without increasing the intensity of motor blockade or prolonging recovery to micturition or street fitness. IMPLICATIONS: Concerns about the neurotoxicity of lidocaine have prompted efforts to find alternatives to lidocaine spinal anesthesia. We studied 50 patients undergoing ambulatory surgical arthroscopy and found that although small-dose bupivacaine alone is inadequate for this procedure, the addition of fentanyl makes it reliable.     

The predominant contribution of oligopeptide transporter PepT1 to intestinal absorption of beta-lactam antibiotics in the rat small intestine

Although recent evidence suggests that certain beta-lactam antibiotics are absorbed via a specific transport mechanism, its nature is unclear. To confirm whether peptide transport in the rat can be largely ascribed to the intestinal oligopeptide transporter PepT1, the transporter has been functionally characterized and its significance in the intestinal absorption of beta-lactam antibiotics was evaluated. For evaluation of transport activity complementary RNA (cRNA) of rat PepT1 was synthesized in-vitro and expressed in Xenopus laevis oocytes. cRNA induced uptake of several beta-lactam antibiotics and the dipeptide [14C]glycylsarcosine; this was specifically inhibited by various dipeptides and tripeptides but not by their constituent amino acids or by tetra- or pentapeptides. The transport activity of PepT1 for beta-lactam antibiotics correlated well with their in-vivo intestinal transport and absorption. Furthermore, mutual inhibitory effects on uptake were observed between glyclsarcosine and beta-lactam antibiotics. Hybrid depletion of the functional expression of rat PepT1 in oocytes injected with rat intestinal epithelial total mRNA was studied using an antisense oligonucleotide corresponding to the 5'-coding region of PepT1. In oocytes injected with rat mRNA pre-hybridized with the antisense oligonucleotide against rat PepT1, the uptake of [14C]glycylsarcosine was almost completely abolished, whereas its uptake was not influenced by a sense oligonucleotide for the same region of PepT1. Similarly, the uptake of beta-lactam antibiotics was also reduced by the antisense oligonucleotide against rat PepT1. These results demonstrate that the intestinal proton-coupled oligopeptide transporter PepT1 plays a predominant role in the carrier-mediated intestinal absorption of beta-lactam antibiotics and native oligopeptides in the rat.     

High-resolution HLA-DRB typing using denaturing gradient gel electrophoresis and direct sequencing

Skeletal development of transgenic mice with a type II collagen mutation was analyzed and compared with wild-type littermates. The single base substitution in Col2a1 resulted in a glycine to serine mutation within the helical domain and corresponded to one previously identified in a patient with the lethal human chondrodysplasia, hypochondrogenesis (Horton et al. [1992] Proc. Natl. Acad. Sci. U.S.A. 89:4583-4587). Skeletal staining of embryos from 14.5 through 18.5 days of gestation demonstrated a dwarf phenotype in the transgenic embryos, most notably short limb bones and vertebral column that was first detected at 15.5 days post-coitus. In addition to the reduced length, the extent of ossification was less in the transgenic mice. The architecture of the long bone growth plate was abnormal in the transgenic tissue, in particular there was no discernible proliferative zone. There were few stacks of characteristically flattened cells and the overall length of the growth plate in the mutant embryos was reduced. At the ultrastructural level, there were fewer collagen fibrils present in the transgenic mouse cartilage compared to that of wild-type littermates. Ultrastructural localization of collagen types II, IX and XI revealed a similar pattern between the transgenic and wild-type pups, suggesting that the collagen fibrils present in the matrix of littermates with both phenotypes had a similar composition. Skeletal analysis and cartilage histochemistry indicated that effect of the type II collagen mutation was to reduce the density of the collagen fibrils within the cartilage matrix which was associated with delayed bone formation and resulted in a short-limbed phenotype.     

Structuring communication software for quality-of-serviceguarantees

We propose architectural mechanisms for structuring host communication software to provide QoS guarantees. We present and evaluate a QoS sensitive communication subsystem architecture for end hosts that provides real time communication support for generic network hardware. This architecture provides services for managing communication resources for guaranteed QoS (real time) connections, such as admission control, traffic enforcement, buffer management, and CPU and link scheduling. The architecture design is based on three key goals: maintenance of QoS guarantees on a per connection basis, overload protection between established connections, and fairness in delivered performance to best effort traffic. Using this architecture we implement real time channels, a paradigm for real time communication services in packet switched networks. The proposed architecture features a process per channel model that associates a channel handler with each established channel. The model employed for handler execution is one of “cooperative” preemption, where an executing handler yields the CPU to a waiting higher priority handler at well defined preemption points. The architecture provides several configurable policies for protocol processing and overload protection. We present extensions to the admission control procedure for real time channels to account for cooperative preemption and overlap between protocol processing and link transmission at a sending host. We evaluate the implementation to demonstrate the efficacy with which the architecture maintains QoS guarantees on outgoing traffic while adhering to the stated design goals