The choice of spectral similarity algorithms influences suspected soil sample provenance.

Similarity algorithms are commonly used in soil forensic applications to help identify similar samples from an existing reference library as possible source locations of unknown target samples. These algorithms are well-suited to compare soil spectra. However, different similarity algorithms may lead to different clusters of similar samples, and thus different strengths of evidence in forensic investigations. To quantify this, we conducted a study to evaluate the influence of seven similarity algorithms on soil provenance, using as a sample set a soil spectral library consisting of 280 soil profiles from Anhui Province, China. This library includes three spatial scales of datasets: provincial (DSp), county (DSc) and field (DSf). A set of ten samples covering a wide range of spectra variations were selected from the DSf dataset as the "unknown" samples, with the remaining being used as the reference samples. This study aimed to: (1) evaluate how several commonly-used similarity algorithms, namely Euclidean distance (ED), Mahalanobis distance (MD), Spectral angle mapper (SAM), and Spectral information divergence (SID), as well as variants of several of these measured in standardized principal component space computed from the spectra (ED_PCA, MD_PCA and SAM_PCA), influence the identification of the matched similar samples; (2) determine the overlap in sample selection between different similarity algorithms; (3) propose best practices for similarity algorithms applied to soil forensic analysis using spectroscopy. The use of different similarity algorithms did influence the selection of most similar samples. The similarity algorithms calculated in PC space (ED_PCA, MD_PCA and SAM_PCA) performed slightly better than their counterparts calculated in spectral space. Due to the availability of a detailed spectral library, regardless of the different similarity algorithms used, the matched most similar samples were all located close to the unknowns, mostly within 3 km, with one exception. That is, the varied choices of different similarity algorithms hardly influenced the conclusion of soil provenance in this case. In general, MD_PCA, SAM and ED were the best similarity algorithms overall. However, since there was no single best algorithms for all cases, we recommend the joint use of MD_PCA, SAM and ED as an ensemble. Indications of possible sample provenance from these similarity measured can be useful evidence to complement evidence from other methods in a forensic investigation.

The novel gene HA117 promotes in vitro and in vivo drug resistance in mouse colon tumor cells.

In this study, we characterized the role of HA117, a novel gene we previously identified, in drug resistance in vitro and in vivo. Briefly, CT26 cells expressing HA117 were obtained by infection with a recombinant adenovirus, and tested for drug sensitivity by methyl thiazolyl tetrazolium assay. In addition, the effect of HA117 on drug sensitivity was assessed in CT26 colon tumors transplanted into nude mice. In vitro, expression of HA117 increased the resistance of CT26 cells to 5-fluorouracil 2.75 times (P<0.05). Similarly, expression of HA117 in subcutaneously xenografted CT26 colon cancer significantly lowered its sensitivity to 5-fluorouracil (P<0.05). Collectively, the results suggest that HA117 regulates the development of drug resistance in CT26 cells in vitro and in vivo.

Simultaneous effects of surface spins: rarely large coercivity, high remanence magnetization and jumps in the hysteresis loops observed in CoFe2O4 nanoparticles.

Well-dispersed uniform cobalt ferrite nanoparticles were synthesized by thermal decomposition of a metal-organic salt in organic solvent with a high boiling point. Some of the nanoparticles were diluted in a SiO2 matrix and then the undiluted and diluted samples were characterized and their magnetic behavior explored. The undiluted and diluted samples exhibited maximum coercivity Hc of 23,817 and 15,056 Oe at 10 K, respectively, which are the highest values reported to date, and the corresponding ratios of remanence (Mr) to saturation (Ms) magnetization (Mr/Ms) were as high as 0.85 and 0.76, respectively. Interestingly, the magnetic properties of the samples changed at 200 K, which was observed in magnetic hysteresis M(H) loops and zero-field cooling curves as well as the temperature dependence of Hc, Mr/Ms, anisotropy, dipolar field, and the magnetic grain size. Below 200 K, both samples have large effective anisotropy, which arises from the surface spins, resulting in large Hc and Mr/Ms. Above 200 K, the effective anisotropy decreases because there is no contribution from surface spins, while the dipolar interaction increases, resulting in small Hc and Mr/Ms. Our results indicate that strong anisotropy and weak dipolar interaction tend to increase Hc and Mr/Ms, and also clarify that the jumps around H = 0 in M(H) loops can be attributed to the reorientation of surface spins. This work exposes the underlying mechanism in nanoscale magnetic systems, which should lead to improved magnetic performance.

Protective effect of quercetin on lead-induced oxidative stress and endoplasmic reticulum stress in rat liver via the IRE1/JNK and PI3K/Akt pathway.

Lead (Pb), a well-known environmental toxin, is one of the major hazards for human health. Quercetin (QE), a natural flavonoid, has been reported to have many benefits and medicinal properties. However, its protective effects against Pb-induced endoplasmic reticulum (ER) stress in liver have not been clarified. The aim of the present study was to investigate the effects of quercetin on hepatic ER stress in rats exposed to Pb. Wistar rats were exposed to lead acetate in the drinking water with or without quercetin co-administration for 75 days. Our data showed that quercetin significantly prevented Pb-induced hepatotoxicity in a dose-dependent manner, indicated by both diagnostic indicators of liver damage and histopathological analysis. Quercetin markedly decreased Pb contents in blood and liver. Western blot analysis showed that Pb-induced ER stress in rat liver was significantly inhibited by quercetin. In exploring the underlying mechanisms of quercetin action, we found quercetin markedly suppressed Pb-induced oxidative stress. Quercetin decreased reactive oxygen species (ROS) production and increased the total antioxidant capacity in rat livers. Additionally, quercetin dramatically increased Phosphoinositide-3-kinase (PI3K) and phosphorylated protein kinase B (PKB/Akt) levels in liver rats. In the examined unfolded protein response (UPR) pathways, quercetin markedly inhibited the Pb-induced increase of the phosphorylated inositol-requiring enzyme 1 (IRE1) and c-jun N-terminal kinase (JNK) in rat liver. Taken together, these results suggested that the inhibition of Pb-induced ER stress by quercetin is due at least in part to its anti-oxidant stress activity and its ability to modulate the PI3K/Akt and IRE1/JNK signaling pathway.

Screening siRNAs targeting a novel gene (HA117) and the development of a derivative recombinant adenovirus delivery system.

A novel gene, HA117, was discovered in our previous work. Using the pSOS-HUS vector method which we designed at previous study, we screened for small interfering RNAs (siRNAs) that targeted HA117. The pSOS-HUS siRNA screening results were verified and a delivery system was developed that contained a recombinant adenovirus carrying DNA templates for the transcription of the HA117 siRNAs. Of five pairs of DNA templates, siRNA transcribed from HAi5 produced the strongest effect against HA117. A recombinant adenovirus containing HAi5 (Ad-HAi5) was successfully constructed and evaluated. This work has laid the foundation for further study of HA117 gene function using RNA interference technology and has showed the pSOS-HUS vector method was successfully utilized as a rapid and effective screen of siRNAs for a target gene.

Feasibility of 2,4,6-trichlorophenol and malonic acid as metabolic uncoupler for sludge reduction in the sequence batch reactor for treating organic wastewater.

The activated sludge process generates a large amount of excess sludge as a byproduct, which is one of the most serious challenges in biological wastewater treatment. In the present study, the feasibility of 2,4,6-trichlorophenol (TCP) and malonic acid (MA) as metabolic uncouplers to reduce sludge generation in the sequence batch reactor (SBR) for treating organic wastewater for a long period was studied. The results showed that 2 mg/L TCP could reduce sludge generation by about 47%, while chemical oxygen demand (COD) removal efficiency and sludge settlability were not obviously influenced. Although 10 mg/L MA could also reduce excess sludge production by about 30% while slightly affecting COD removal, it seriously deteriorated sludge settlability. Accordingly, TCP is a better uncoupler for sludge reduction for a longer period in the SBR for treating organic wastewater, and MA can only be used as a short-term or transitional uncoupler. Microscopic and 16S ribosomal deoxyribonucleic acid analyses showed that the microbial population of sludge varied when uncouplers were fed to the activated sludge system. Occurrence of large amounts of filament and the disappearance of protozoa may be the main reason for the aggravation of sludge settlability under uncoupled metabolic conditions caused by MA.

Effects of the COD/NO3(-)-N ratio and pH on the accumulation of denitrification intermediates with available pyridine as a sole electron donor and carbon source.

Batch experiments were conducted to investigate the effects of COD/NO3(-)-N ratio and pH on the accumulation of the denitrification intermediates - nitrite and nitrous oxide - with pyridine as the sole electron donor and carbon source. Significant transient accumulation of nitrite was observed at COD/NO3(-)-N ratios in the range of 2-13 and pH in the range of 6.5-9.5. The optimal pH was 7.5 and the minimum COD/NO3(-)-N ratio was 4 for complete denitrification. The pH had a significant effect on denitrification. At a lower pH of 6.5, the reaction was severely inhibited whereas at a higher pH of 8.5 and 9.5, nitrate was completely reduced, but a high concentration of nitrite remained in the reactors while pyridine was almost completely degraded after one hour, even at the COD/NO3(-)-N ratio of 4. While the specific nitrate reduction rate and nitrite reduction rate in the absence of nitrate remained constant at different COD/NO3(-)-N ratios, they increased with the increase in pH. The nitrite reduction was inhibited in the presence of nitrate because of the faster rate of nitrate reduction over nitrite reduction. Nitrous oxide accumulation was also observed with a COD/NO3(-)-N ratio below 3 in the pH range of 7.5-8.5. At a COD/NO3(-)-N ratio of 4 and pH of 6, the production of nitrous oxide was much higher than that at pH 7 and 8.

Treatment of municipal wastewater with the sequence batch reactor under uncoupling metabolic conditions.

The activated sludge process generates large quantities of excess sludge as by-product, which is one of the most serious challenges in biological wastewater treatment. In this study, the feasibility of 2,4,6-trichlorophenol (TCP) as metabolic uncoupler to reduce sludge generation in the Sequence Batch Reactor (SBR) for the long-term treatment of municipal wastewater was evaluated. The results of 90 days continuous treatment showed that 2 mg/L TCP reduced sludge generation by about 47%, while COD removal efficiency and sludge ability to settle were only slightly decreased. The specific substrate removal rate of sludge in the reactor with TCP exceeded the removal rate of sludge in the control reactor, indicating that the catabolism and anabolism of sludge in the reactor with TCP was uncoupled. Microscopic and 16s DNA analyses showed that the microbial population of sludge varied when TCP was fed into the SBR. The occurrence of filaments and the disappearance of some protozoa in the sludge system might be reasons for the slight variation of sludge ability to settle under uncoupled metabolic conditions.

Comprehensive analysis of the factors for propionic acid accumulation in acidogenic phase of anaerobic process.

The accumulation of propionic acid in the anaerobic process often leads to a low efficiency of the methanogenic phase due to the low acetogenic rate of propionic acid, and hence the low wastewater treatment efficiency. Three acidogenic reactors were used to study the reasons for propionic acid accumulation in the acidogenic phase and its control strategy. The experimental results indicated that in the micro-aerobic circumstance (ORP>-100 mV) the accumulation of propionic acid in the acidogenic reactor always occurred at any pH value. Under strict anaerobic circumstances (ORP < -150 mV), typical propionic acid-type fermentation commonly occurred at pH about 5.5 regardless of ORP value. However, at pH about 5.0, either propionic acid-type or butyric acid-type fermentation might occur depending on whether ORP was high or low. Higher hydrogen production rate was found to have no direct relationship to the accumulation of propionic acid in the acidogenic reactors. In fact, great yield of NADH maybe the major reason for simultaneous accumulation of propionic acid and higher biohydrogen generation rate in the traditional anaerobic process. The highest biohydrogen generation rate occurred during the ethanol-type fermentation without the accumulation of propionic acid. Ethanol-type fermentation is a better choice when using an anaerobic acidogenic reactor of a two-phase separated anaerobic process to efficiently produce biohydrogen simultaneously with organic wastewater pre-treatment.

Optimizing cell preparation technique to enhance adsorption capacity of pseudomonas putida 5-x to heavy metal ions.

A heavy metal accumulation bacterium Pseudomonas putida 5-x isolated from electroplating effluent was used as biosorbent for heavy metal removal from wastewater. In order to compete with physical adsorbent, the optimization of the cell preparation technique for further improving its heavy metal adsorption capacity was conducted. Experimental results showed that the variation of medium compositions and cell growth age, and different cell pre-treating technique would result in the variation of the cell surface components and structural, hence the variation of adsorption capacity of the cell to heavy metal ions. With optimum cell culture conditions and pretreatment technique, the Cu2+ adsorption capacity of the cell was obviously increased from 51.2 mg g-1 to 89.6 mg g-1. The optimised P. putida 5-x cell could be reused at least five cycles to remove heavy metal ions from electroplating effluent with about 95% removal efficiency.

[Effects of O-(4-ethoxyl-butyl)-berbamine on isolated frog hearts].

AIM: To study the effects of O-(4-ethoxyl-butyl)-berbamine (EBB) on isolated frog heart. METHODS: The isolated frog hearts were prepared with Straub's method; heart contractions were recorded using LMS-2A recorder by tonotransducer. RESULTS: EBB 1-100 mumol.L-1 caused concentration-dependent increase in systolic and diastolic activities, but did not alter the heart rate. EBB 250-500 mumol.L-1 slowed the heart beats and caused ventricular asystole. Cimetidine 10 mumol.L-1 or prazosin 100 mumol.L-1 did not inhibit the positive inotropic action of EBB. Whereas verapamil 0.01 mumol.L-1 antagonized the positive inotropic action of EBB. EBB enhanced positive inotropic action of CaCl2. The action of EBB was slower but longer than caffeine or isoproterenol. At room temperature (21.0 +/- 0.5) degree C, however, the onset of oubain was slower, but the duration of its peak action was longer, than EBB. CONCLUSION: The positive inotropic action of EBB was, at least partially, via promoting the inward current of [Ca2+]o, rather than increasing the intracellular Ca2+ release.

[Three new serotypes of Salmonella II].

Eight cultures isolated from intestinal contents of reptiles were belonged to 3 new serotypes of Salmonella. They were all ducitol fermented, malonate utilized, but not attack lactose and salicin, no growth in KCN broth, ONPG negative. Therefore, they would be included in Salmonella II. They were all attacked by Felix phage O-I. Three represented strains were selected for antigen analysis. Their antigenic formula were identified as follows: S3194 Salmonella II 6,7:1,v:e,n,z15 S3196 Salmonella II 6, 7:y: e, n, z(1)5 S3195 Salmonella II 6, 8: e, h: 1,2 Among them, S3196 was indole positive belonging to a rare biotype. In addition, there were two other cultures as well as the formula of S3194, and three other cultures as well as the formula of S3196 (one of indole positive, two of indole negative).