Predicting prostate cancer recurrence: Introducing PCRPS, an advanced online web server.

Background: Prostate cancer (PCa) is one of the leading causes of cancer death in men. About 30% of PCa will develop a biochemical recurrence (BCR) following initial treatment, which significantly contributes to prostate cancer-related deaths. In clinical practice, accurate prediction of PCa recurrence is crucial for making informed treatment decisions. However, the development of reliable models and biomarkers for predicting PCa recurrence remains a challenge. In this study, the aim is to establish an effective and reliable tool for predicting the recurrence of PCa. Methods: We systematically screened and analyzed potential datasets to predict PCa recurrence. Through quality control analysis, low-quality datasets were removed. Using meta-analysis, differential expression analysis, and feature selection, we identified key genes associated with recurrence. We also evaluated 22 previously published signatures for PCa recurrence prediction. To assess prediction performance, we employed nine machine learning algorithms. We compared the predictive capabilities of models constructed using clinical variables, expression data, and their combinations. Subsequently, we implemented these machine learning models into a user-friendly web server freely accessible to all researchers. Results: Based on transcriptomic data derived from eight multicenter studies consisting of 733 PCa patients, we screened 23 highly influential genes for predicting prostate cancer recurrence. These genes were used to construct the Prostate Cancer Recurrence Prediction Signature (PCRPS). By comparing with 22 published signatures and four important clinicopathological features, the PCRPS exhibited a robust and significantly improved predictive capability. Among the tested algorithms, Random Forest demonstrated the highest AUC value of 0.72 in predicting PCa recurrence in the testing dataset. To facilitate access and usage of these machine learning models by all researchers and clinicians, we also developed an online web server (https://urology1926.shinyapps.io/PCRPS/) where the PCRPS model can be freely utilized. The tool can also be used to (1) predict the PCa recurrence by clinical information or expression data with high accuracy. (2) provide the possibility of PCa recurrence by nine machine learning algorithms. Furthermore, using the PCRPS scores, we predicted the sensitivity of 22 drugs from GDSC2 and 95 drugs from CTRP2 to the samples. These predictions provide valuable insights into potential drug sensitivities related to the PCRPS score groups. Conclusion: Overall, our study provides an attractive tool to further guide the clinical management and individualized treatment for PCa.

Characteristics of DOM and bacterial community in rural black and odorous water bodies under different dimensions.

Analysis of dissolved organic matter (DOM) composition and microbial characteristics is crucial for tracing the sources of rural black and odorous water bodies (BOWB). The aim of this study was to explore the DOM and microbial diversity and identify the primary environmental factors in BOWB from various pollution sources during different periods using EEMs-PARAFAC and Illumina sequencing. It was found that the physicochemical properties vary widely across different pollution types of BOWB, with higher overall content during the high-water period compared to the normal-water period. The types of dissolved organic matter in BOWB are Tyrosine proteins, Fulvic acid, Dissolved microbial metabolites, and Humic acid. During the normal-water period, DOM originates primarily from terrestrial sources in various water bodies. However, DOM affected by livestock and poultry waste and industrial effluents is influenced by both internal and external sources during periods of high water levels. In industrial waste-type BOWB, the biological sources of water are weak. Proteobacteria, Actinobacteria, Chloroflexi, Firmicutes were the dominant bacterial phyla. According to the redundancy analysis, pH (p = 0.047), Total nitrogen (TN) (p = 0.045), Organic carbon (OC) (p = 0.044), and Nickel (Ni) (p = 0.047) are the primary environmental factors influencing the composition of bacterial communities.

Appendiceal vesical fistula first presenting as giant bladder calculi: A case report and review of literature.

A 34-year-old man was admitted to the hospital presenting repeatedly urinary urgency for 3 years and yellow-green lithotripsy foreign body in urine for 1 month. Initially, he was diagnosed with a giant bladder calculi. After a cystoscopy exam and a lithotripsy for bladder calculi, Appendiceal vesical fistula was finally diagnosed and treated with a laparoscopic surgery. We report a rare case of appendiceal vesical fistula，first presenting as giant bladder calculi，and successfully treated with minimal invasive surgery We report this case and reviewed literature to improve the understanding of this disease and reduce misdiagnosis and missed diagnosis.

Efficient rural sewage treatment with manganese sand-pyrite soil infiltration systems: Performance, mechanisms, and emissions reduction.

The application of soil infiltration systems (SISs) in rural domestic sewage (RDS) is limited due to suboptimal denitrification resulting from factors such as low C/N (<5). This study introduced filler-enhanced SISs and investigated parameter impacts on pollutant removal efficiency and greenhouse gas (GHG) emission reduction. The results showed that Mn sand-pyrite SISs, with hydraulic load ratios of 0.003 m3/m2·h and dry-wet ratios of 3:1, achieved excellent removal efficiency of COD (92.7 %), NH4+-N (95.8 %), and TN (76.4 %). Moreover, N2O and CH4 emission flux were 0.046 and 0.019 mg/m2·d, respectively. X-ray photoelectron spectroscopy showed that the relative concentrations of Mn(Ⅱ) in Mn sand and Fe(Ⅲ) and SO42- in pyrite increased after the experiment. High-throughput sequencing indicated that denitrification was mainly performed by Thiobacillus. This study demonstrated that RDS treatment using the enhanced SIS resulted in efficient denitrification and GHG reduction.

Interface interaction between silica and organic macromolecule conditioned forward osmosis membranes: Insights into quantitative thermodynamics and dynamics.

Silica scaling is a rising concern in forward osmosis membrane-based water treatment process. The coexistence of ubiquitous organic macromolecules causes complex silica scaling. The silica scaling mechanism on the surface of the organic conditioned membrane remains unclear. An integrated multi scale thermodynamic and dynamic approach was used in this study to provide in-depth insights into the binding effect at the interface between the silica and the organic conditioned membrane at the molecular level. Sodium alginate (SA) was used as the model polysaccharide, bovine serum albumin (BSA) and lysozyme (LYZ) were chosen as two oppositely charged proteins. The results show that the silica scaling degree of different organic conditioned membranes follows the order LYZ > BSA > SA. The binding strength between silica and organic macromolecules and the membrane surface charge are the major factors governing the degree of silica scaling. Quartz crystal microbalance with dissipation (QCM-D), isothermal titration calorimetry (ITC), and extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) model analyses were conducted to quantify the binding capacity of silica to the organic conditioned membrane. The LYZ conditioned membrane exhibits the highest affinity for silica adsorption, and electrostatic interaction was the main molecular interaction force. This study provides fresh insights into how silica and an organic conditioned membrane interact and induce silica scaling, providing new information on potential mechanisms and control strategies to prevent membrane scaling.

Novel electro-assisted micro-aerobic cathode biological technology induces oxidative demethylation of N, N-dimethylformamide for efficient ammonification of refractory membrane-making wastewater.

Recalcitrant and toxicological membrane-making wastewater displays negative impacts on environment, and this is difficult to treat efficiently using conventional hydrolytic acidification. In this study, a novel electro-assisted biological reactor with micro-aerobic cathode (EABR-MAC) was developed to improve the biodegradation and ammonification of N, N-dimethylformamide (DMF) in membrane-making wastewater, and the metabolic mechanism using metagenomic sequencing as comprehensively illustrated. The results showed that EABR-MAC significantly improved the ammonification of refractory organonitrogen and promoted DMF oxidative degradation by driving the electron transferred to the cathode. Additionally, the inhibition rates of oxygen uptake rate and nitrification in EABR-MAC were both lower under different cathode aeration frequency conditions. Microbial community analysis indicated that the functional fermentation bacteria and exoelectrogens, which were correlated with COD removal, ammonification, and detoxification, were significantly enriched upon electrostimulation, and the positive biological connections increased to form highly connected communities instead of competition. The functional genes revealed that EABR-MAC forcefully intervened with the metabolic pathway, so that DMF converted to formamide and ammonia by oxidative demethylation and formamide hydrolysis. The results of this study provide a promising strategy for efficient conversion of organonitrogen into ammonia nitrogen, and offer a new insight into the effects of electrostimulation on microbial metabolism.

Deciphering mono/multivalent draw solute-induced microbial ecology and membrane fouling in anaerobic osmotic membrane bioreactor.

Anaerobic osmotic membrane bioreactor (AnOMBR) attracted attention due to high quality effluent production with low energy demand, and draw solute has significant effect on the system performance. However, the mutual relationship between draw solute-induced salinity accumulation and microbial community had many unknown questions to be solved. This study purpose was to construct two AnOMBR to compare the impact of draw solutes of NaCl and MgCl2 on the dynamic change of microbial ecology and membrane fouling. The result indicated that the draw solute of MgCl2 caused less salinity and more membrane biofouling than that of the draw solute NaCl. Multiple microbiological analysis methods were applied to discover keystone species related to the conductivity change and membrane fouling, especially for the MgCl2-AnOMBR system. It was found that draw solute NaCl could benefit the growth of Proteobacteria to become the most abundant phylum to affect the membrane fouling, while Mg2+ introduction could stimulate the growth of NS9, Hydrogenphilaceae and Pedosphaeraceae to potentially cause the biofouling. Furthermore, phylogenetic molecular ecological networks (pMENs) deeply analyzed the microbial structure difference under Na+ and Mg2+ introduction, and indicated that the family Lentimicrobiaceae and Candidatus_Kaiserbacteria were the keystone species in NaCl-AnOMBR, while two genus Anaerolinea and SWB02, and two families Saprospiraceae and NS9 were discovered to have key effect in MgCl2-AnOMBR due to their strong extracellular polymeric substances (EPS) production ability for survival of other microorganisms. This study was significant to give microbial targets under the impact of various draw solutes, as the reference for the engineers to further investigate how to improve the microbial structure to enhance AnOMBR performance and inhibit the membrane biofouling.

Robustness of granular activated carbon-synergized anaerobic membrane bioreactor for pilot-scale application over a wide seasonal temperature change.

A novel granular activated carbon-synergized anaerobic membrane bioreactor (GAC-AnMBR), consisted of four expanded bed anaerobic bioreactors with GAC carriers and a membrane tank, was established in pilot scale (10 m3/d) to treat real municipal wastewater (MWW) at ambient temperature seasonally fluctuating from 35 to 5 °C. It showed sound organic removal over 86% with the permeate COD less than 50 mg/L even at extremely low temperatures below 10 °C. COD mass balance analysis revealed that membrane rejection (with a contribution rate of 10%-20%) guaranteed the stable organic removal, particularly at psychrophilic temperature. The methane yield was over 0.24 L CH4 (STP)/g COD removed at mesophilic temperature and 0.21 L CH4 (STP)/g COD removed at 5-15 °C. Pyrosequencing of microbial communities suggested that lower temperature reduced the abundance of the methane producing bacteria, but the methane production was enhanced by selectively enriched Methanosaeta, syntrophic Syntrophobacter and Smithella and exoelectrogenic Geobacter for direct interspecies electron transfer (DIET) on the additive GAC. Compared with previously reported pilot-scale AnMBRs, the GAC-AnMBR in this study showed better overall performance and higher stability in a wide temperature range of 5-35 °C. The synergistic effect of GAC on AnMBR guaranteed the robustness of GAC-AnMBR against temperature, which highlighted the applicational potential of GAC-AnMBR, especially in cold and temperate climate regions.

Effects of residual ozone on the performance of microorganisms treating petrochemical wastewater.

This study investigated the effects of residual ozone on the performance of microorganisms treating petrochemical wastewater using batch experiments with low and high ozone dosages (5.0 mg/L and 50.0 mg/L, respectively). The results indicated that the low residual ozone concentration significantly increased COD removal by 24.21% in the biological process compared to control group with no ozone residual, while the high residual ozone concentration showed the opposite effect. In the reactor with low residual ozone concentration (0.45 mg/L), the amount of loosely bound (LB)-extracellular polymeric substances (EPS) in the activated sludge decreased by 23.23%, while the amount of tightly bound (TB)-EPS increased by 129.16% compared to the none-ozone residual reactor. In addition, the low residual ozone was found to improve the bioactivity of activated sludge by 139.73% in the first 30 min of the biological process. In the reactor with high residual ozone concentration (0.91 mg/L), both LB- and TB-EPS of the activated sludge increased, while bioactivity decreased. This implies that low residual ozone in a bio-reactor can enhance microbial activity by increasing contact between the pollutants and cells by removing LB-EPS covering the outer layer of the sludge. The microorganisms in the sludge samples could be classified into three groups representing those that are susceptible to ozone, tolerant to low dose of residual ozone, and resistant to high dose of residual ozone. The resistant bacteria Gemmatimonadaceae uncultured became predominant, with a relative abundance of 11.37%, under low residual ozone conditions, while it decreased at high ozone concentrations. The results showed that a certain amount of residual ozone could stimulate the activity of microorganisms by altering the EPS fraction and structure of the microbial community, and thus it is important for the removal of refractory organics from wastewater in the ozone-biological process.

Ozonation reactivity characteristics of dissolved organic matter in secondary petrochemical wastewater by single ozone, ozone/H2O2, and ozone/catalyst.

Advanced oxidation methods (e.g., ozonation systems) are used for control of recalcitrant pollutants in secondary petrochemical wastewater. For the selection of the optimal wastewater treatment method, we compared the reactivity characteristics of dissolved organic matter (DOM) in three common ozone treatment processes: single ozone, ozone/H2O2, and ozone/catalyst. The raw and ozonated DOM were fractionated into six fractions using ion exchange resins. Fluorescence spectroscopy and size exclusion chromatography were employed to characterize the fractions. The results showed that the single ozone system transformed hydrophobic components into hydrophilic components, but exhibited low mineralization ability. By contrast, the increase in hydrophilic acid fractions transformed from other fractions in the ozonation process were further mineralized in the ozone/H2O2 and ozone/catalyst systems. Ozone/H2O2 preferentially reduced hydrophobic bases, whereas ozone/catalyst preferentially reduced hydrophilic neutral components. However, ozone/H2O2 exhibited low selectivity in degrading organic compounds of different molecular weights. The highest total organic carbon (TOC) removal efficiency was achieved in the ozone/catalyst system, which promoted the transformation from fulvic acid- and humic acid-like substances into aromatic proteins and soluble microbial by-product-like substances. The single ozone system transformed high-molecular-weight compounds into low-molecular-weight compounds, resulting in an unsatisfactory TOC removal efficiency. By contrast, the ozone/catalyst system selectively removed the residual low-molecular-weight compounds in the reaction with ozone. This might have contributed to the high TOC removal efficiency of the ozone/catalyst treatment. These results can be used by other researchers and engineers to inform the selection of optimal ozone treatment based on wastewater characteristics.

Effect of influent pH on hydrolytic acidification performance and bacterial community structure in EGSB for pretreating crotonaldehyde manufacture wastewater after ozonation.

The objective of this work was to evaluate the effect of influent pH on the hydrolytic acidification (HA) performance and microbial community structure in an expanded granular sludge bed (EGSB) pretreating crotonaldehyde manufacture wastewater (CMW) after ozonation. The results showed that higher chemical oxygen demand (COD) removal rate (40.1%) and acidification degree (27.6%) were obtained at pH 8.0 than those at pH 6.0 and pH 4.0. The concentration of extractable extracellular polymeric substance (EPS) in the sludge gradually decreased with the pH decreasing from 8.0 to 4.0. A similar change was also observed for the concentration of total volatile fatty acids (TVFA) in the effluent. The optimal detoxification efficiency by the HA process was obtained at pH 8.0, with higher removal efficiency (all higher than 90%) of the main toxic pollutants (crotonaldehyde, 5-formyl-6-methyl-4,5-dihydropyran, etc.) and higher anaerobic biodegradation rate (44.5%) in biochemical methane potential (BMP) assay. Among the predominant genera, the Acinetobacter and Pseudomonas were possibly related to biodegradation of pollutants, since their higher relative abundance also coincided with the better performance of the HA process at pH 8.0.

Performance of microaeration hydrolytic acidification process in the pretreatment of 2-butenal manufacture wastewater.

The performance of the microaeration hydrolytic acidification (MAHA) process and microbial community were investigated under different organic loading rates (OLRs) for the pretreatment of 2-butenal manufacture wastewater (2-BMW). Results indicated that OLRs had different impact on the performance of MAHA process. More than 23.7 ± 2.3% of the chemical oxygen demand (COD) removal and the highest acidification degree (20.9 ± 3.1%) were obtained when OLRs were less than 4.0 ± 0.1 kgCOD/m3 d. However, further increasing OLRs to 6.1 ± 0.1 kgCOD/m3 d subsequently led to the significant reductions of COD removal and acidification degree. In addition, it could be preliminarily inferred that 2H-pyran-2-one tetrahydro-4-(2-methyl-1-propen-3-yl), 5-formyl-6-methyl-4,5-dihydropyran and ethyl sorbate were the main refractory and toxic organics for microorganisms in the wastewater. The soluble microbial product (SMP) and extracellular polymeric substance (EPS) contents (protein, polysaccharide, nucleic acid) had obvious changes under different OLRs. With parallel factor (PARAFAC) model, four fluorescent components were identified. The Fmax of protein-like substances in SMP significantly decreased with increasing OLRs to 6.1 ± 0.1 kgCOD/m3 d, which might attribute to fluorescence quenching. Illumina MiSeq sequencing revealed that Pseudomonas, Longilinea, T78, Clostridium, WCHB1-05, Acinetobacter, SHD-231 and Oscillospira were dominant genera at different OLRs.

Influence of organic load rate (OLR) on the hydrolytic acidification of 2-butenal manufacture wastewater and analysis of bacterial community structure.

The influence of organic loading rate (OLR) on the performance of hydrolytic acidification process for treating 2-butenal manufacture wastewater was comprehensively studied, while its impact on microbial community was thoroughly investigated. The results demonstrated that over 21.0% of the average COD removal rate was observed in the range of OLR from 0.52 to 3.98g COD/L·d, whereas it reduced to 15.3% with increasing OLR to 6.09g COD/L·d. The acidification degree dramatically decreased from 17.1% to 4.7% when OLR increased from 3.98 to 6.09g COD/L·d. In addition, the removal rates of three kinds of typical matters were less than 65% at the OLR 6.09g COD/L·d. Illumina MiSeq sequencing revealed that Proteobacteria, Chloroflexi, Firmicutes, and Bacteroidetes were dominant phyla at different OLRs. Finally, multivariate analysis suggested that the genera Longilinea and T78 had a positive correlation with the degradation of three kinds of typical matters and COD removal rates.

Chronical sleep interruption-induced cognitive decline assessed by a metabolomics method.

Good sleep is necessary for optimal health, especially for mental health. Insomnia, sleep deprivation will make your ability to learn and memory impaired. Nevertheless, the underlying pathophysiological mechanism of sleep disorders-induced cognitive decline is still largely unknown. In this study, the sleep deprivation of animal model was induced by chronical sleep interruption (CSI), the behavioral tests, biochemical index determinations, and a liquid chromatography-mass spectrometry (LC-MS) based serum metabolic profiling analysis were performed to explore the effects of CSI on cognitive function and the underlying mechanisms. After 14-days CSI, the cognitive function of the mice was evaluated by new objects preference (NOP) task and temporal order judgment (TOJ) task. Serum corticosterone (CORT), and brain Malondialdehyde (MDA), Superoxide Dismutase (SOD), and Catalase (CAT) levels were determined by ELISA kits. Data were analyzed by Principal Component Analysis (PCA), Partial Least Squares project to latent structures-Discriminant Analysis (PLS-DA), and Student's t-test. We found that the cognitive function of the mice was significantly affected by CSI. Besides, levels of CORT and MDA were higher, and SOD and CAT were lower in CSI mice than those of control. Obvious body weight loss of CSI mice was also observed. Thirteen potential serum biomarkers including choline, valine, uric acid, allantoic acid, carnitines, and retinoids were identified. Affected metabolic pathways involve metabolism of purine, retinoid, lipids, and amino acid. These results showed that CSI can damage the cognitive performance notably. The cognitive decline may ascribe to excessive oxidative stress and a series of disturbed metabolic pathways.

[Classification and Analysis of Dissolved Organic Matter in 2-Buternal Manufacture Wastewater].

The dissolved organic matters from 2-buternal manufacture wastewater were fractionated into seven fractions by ultra-filtration membrane separation. The amounts and structural compositions of organic compounds in different molecular weight ranges were characterized by dissolved organic carbon (DOC), ultraviolet spectrum (UV), Fourier transform infrared spectrometer (FT-IR) and gas chromatography with mass spectrometry (GC-MS). The results showed that the fraction of molecular weight less than 1×103 had the largest proportion in the wastewater, and occupied 88.57% of the DOC. There were 27 kinds of compounds qualitatively analyzed by GC-MS, mainly including aldehyde, ketone, ester, alcohol, phenol, organic acid, alkane and other heterocyclic compounds. The proportions of compounds of peak area accounting for total peak area of organic matters were 6.9%, 5.3%, 35.4%, 13.2%, 4.6%, 0.4%, 1.7% and 16.8% respectively, adding up to 84%. The analysis of UV and FT-IR demonstrated that the spectral absorptive characteristics of organic compounds from different fractions were not significantly different. The fractions contained carbonyls, hydroxys and aromatic compounds, which was consistent with the qualitative analysis of GC-MS. The results of this study provide an important guidance for the development and optimization of 2-buternal manufacture wastewater treatment process.

[Variation characteristics and removal rate of fluorescence organic matter in the petrochemical wastewater treatment process].

Petrochemical wastewater is of huge quantity released during the production and complicated contaminants of petrochemical wastewater will have immense negative impact on ecology environment. Three-dimensional excitation-emission matrix fluorescence(3D-EEM) was used to investigate the characteristic fluorescence of influent and effluent from each processing unit of Hydrolysis-acidification +A/O+ Contact-oxidation Process in a typical petrochemical wastewater treatment plant . The results showed that there were 4 fluorescence peaks named Peak A, Peak B, Peak D, Peak E in the spectrum chart of influent, they are around lambda(ex/lambda(em) = 220/300, 225/340, 270/300, 275/340 nm, the primary source of fluorescence organic matter(FOM) is industrial wastewater. The fluorescence intensity of each fluorescence peak was decreased, while location was unchanged in the effluent of Hydrolysis-acidification. Peak C appeared from the effluent of anaerobic tank at lambda(ex)/lambda(em) = 250/425 nm, then the fluorescence intensity of Peak C was enhanced in the effluent of aerobic tank. Peak A disappeared from the effluent of secondary sedimentation tank. The spectrum chart of the wastewater had no obvious variation after secondary sedimentation tank. The removal rate of FOM was expressed with the degradation percentage of the fluorescence intensity, the total FOM was reduced by 92.0% after processing, and the removal rate of the FOM fluoresce around Peak A, Peak B, Peak D, Peak E were 100.0%, 91.2%, 80.3%, 92.0% respectively. A volatile I(Peak B)/I(Peak E) value of influent but a relatively stable value of effluent demonstrated that the wastewater treatment plant operated steadily and the process has higher capacity in resistance to shock loading.

The classification and application of toxic Chinese materia medica.

Many important drugs in the Chinese materia medica (CMM) are known to be toxic, and it has long been recognized in classical Chinese medical theory that toxicity can arise directly from the components of a single CMM or may be induced by an interaction between combined CMM. Traditional Chinese Medicine presents a unique set of pharmaceutical theories that include particular methods for processing, combining and decocting, and these techniques contribute to reducing toxicity as well as enhancing efficacy. The current classification of toxic CMM drugs, traditional methods for processing toxic CMM and the prohibited use of certain combinations, is based on traditional experience and ancient texts and monographs, but accumulating evidence increasingly supports their use to eliminate or reduce toxicity. Modern methods are now being used to evaluate the safety of CMM; however, a new system for describing the toxicity of Chinese herbal medicines may need to be established to take into account those herbs whose toxicity is delayed or otherwise hidden, and which have not been incorporated into the traditional classification. This review explains the existing classification and justifies it where appropriate, using experimental results often originally published in Chinese and previously not available outside China.

[A method for determination of trace naphthalene and phenanthrene in water using constant-wavelength synchronous fluorescence spectrometry].

In view of synchronous fluorescence possessing the character of good selectivity, high sensitivity, less interference, etc. it can be used for simultaneous determination of multi-component mixtures of polycyclic aromatic hydrocarbons (PAHs). A new method of constant-wavelength synchronous fluorescence spectrometry to determine two naphthalene and phenanthrene of PAHs was developed in this study. The effect of different experimental conditions, such as different disolvents for character of fluorescence spectra and the choose of the optimal wavelength difference were studied. Experiment showed that the simultaneous indentification and quantitative determination of the two PAHs when delta lambda = 100 was chosen. The fluorescence intensity was linearly related to naphthalene and phenanthrene concentration in the range of 0.5-25.0 microg x L(-1) with correlation coefficient 0.999 5 and 0.999 7, respectively. The detection limits were all lower than 0.03 microg x L(-1), and the relative standard deviations for naphthalene and phenanthrene were 1.19% and 180% (n=7), respectively. Results show that the compounds can be analyzed qualitatively and quantitatively by synchronous fluorescence spectrometry.

Evaluation of an Aß(1-40)-induced cognitive deficit in rat using a reward-directed instrumental learning task.

Alzheimer's disease (AD) is the most common form of dementia. It is a progressive neurodegenerative disorder that leads to gradual loss of cognitive and functional abilities, and development of behavioral disturbances. Previous studies using Aß(1-40) microinjection in animal models focused on cognitive deficits in spatial learning and avoidance conditioning. However, no attempt has been made to determine the sensitivity of an Aß(1-40)-manipulated animal model in tasks involving reward-directed instrumental learning (RDIL). Thus, the present study was designed to investigate the effects of intra hippocampal microinjection of Aß(1-40) on the acquisition and maintenance of a basic instrumental response (lever-pressing), then on the goal directed (higher response ratio) and habit (visual signal discrimination and extinction) learning, as well as on neurotransmitter changes which could potentially alter the regulatory processes involved in instrumental learning. Our present findings demonstrated that the focal hippocampal microinjection of Aß(1-40) rendered rats unable to process new cue/contextual information in the formation of causal relation, rather than affecting the operant action itself. Although the injected Aß(1-40) did not directly influence performance, it did prevent the information from being translated into action. Moreover, the neurotransmitter results indicated that multiple neural signaling might be involved in the regulation of RDIL in the Aß(1-40) injection model. In conclusion, results suggested that our series of instrumental learning tasks may have potential in dementia research as a novel method for testing cognitive behavior.