Determination on Biological Characteristics of Nematode Rhabditis(Oscheius)sp.

[ Objective] The study was aimed to determine the biological characteristics of Rhabditis （Oscheius） sp. isolated from a rhizosphere soil of alfalfa field in Hailar City, Hulunbuir League, Inner Mongolia Autonomous Region. [ Method] The last instar larvae of Galleria mellonella and Tenebrio molitor were used as insect hosts. The infectivity of nematode was determined, and its heat tolerance ability was measured by using water bath method. [Result] The infectivity of the nematodes was lower at the dosages of 10, 20 and 40 IJs/larva, but higher at the dosages of 80,160, 32.0 and 640 IJs/larva. The corrected mortality （CM） of G. mellonella at 96 h and T. molitor at 120 h were both above 90%. The nematode infectivity was highest at the dosage of 80 IJs/larva when the hosts＇ CM reached 100% after 120 h. About 25% nematode individuals could survive in 36℃ water bath for 2 d in the densities of 1 000 -5 000 IJ/ml, after 6 d, there were still 3% -9% individuals survived, until 9 d the nematodes died totally. A hundred percent of the nematode individuals died in 38℃ and 40 ~C water bath after 6 h and 2 h, respectively. [Conclusion] Rhabditis （ O. ） sp. has a higher potential to cause the host mortality and represents heat tolerance up to 36℃.

Research Progress and Identification Method of Apple Stress Resistance

In the research, changes of apple chemistry, and molecule, under stresses, are n terms of morphology, physiology, bio- illustrated and research and identifica- tion methods of apple resistance are explored involving drought-resistance, flood-re- sistance, salt-stress resistance, cold-hardiness and heat-resistance. In addition prospects of apple resistance research are proposed, as well.

Study on Biological Characteristics and Pupa's Cold Tolerance of Liriomyza sativae on Florists cineraria

In this study, Liriomyza sativaes was raised on Florist cinerarias in greenhouse with different temperatures at 15, 20, 25, 30 and 35 ℃, and their corresponding development duration of entire generation were 47.0, 25.0, 15.5, 12.5 and 12.0 d. The beginning growth temperatures of egg, larva, pupa and entire generation of Liriomyza sativae were 8.5, 9.8, 10.2 and 10.4 ℃, and their effective accumulated temperatures were 52.7, 75.8, 158.5 and 262.2 d ·℃, respectively. Liriomyza sativae had 7 generations on Florist cinerarias in Ningxia each year. However, it occurred in the whole year in greenhouse. The length of its development duration in greenhouse decreased in order from cucumber, Callestephus chinensis, Florist cinerarias to pea, but the eclosion rate of its pupa was in the eentrary order. Under the temperature of 10, 0, - 15 and 20 ℃ ,the longer the storage of pupa was,the higher the mortality rate would be. Liriomyza sativae couldn＇t survive in the winter in Ningxia Province in the natural environment.

Preparation and corrosion resistance of superhydrophobic coatings on AZ31 magnesium alloy

In order to improve the corrosion resistance of the Mg alloys, the superhydrophobic coatings on AZ31 Mg alloy wereprepared by a two-step process of micro-arc oxidation treatment and superhydrophobic treatment in stearic acid ethanol solution. Theeffects of voltages, frequencies and treatment time on the contact angle of the superhydrophobic treated sample were investigated.The results showed that with increasing the voltage, frequency and treatment time, all of the contact angles of the superhydrophobictreated sample increased first, and then decreased, reaching the maximum values at 350 V, 1000 Hz and 5 min, respectively. Theoptimal superhydrophobic coating was mainly composed of MgO and Mg2SiO4 phases, with the pore diameter of ～900 nm, thethickness of ～6.86 μm and the contact angle of 156.96°. The corrosion current density of the superhydrophobic AZ31 sampledecreased by three orders of magnitude, and the amount of hydrogen evolution decreased by 94.77% compared with that of the AZ31substrate sample.

Proteome of human colon cancer stem cells:A comparative analysis

AIM： To isolate and identify the biological characteristics of human colon cancer stem cells （SW1116 cells） and further study their proteome. METHODS： SW1116 cells were isolated and cultured with a serum-free medium （SFM）. Sphere formation was assayed to observe the formation of colon cancer stem cell spheres. SW1116 cells were inoculated into a serum-containing medium for observing their differentiation characteristics. Proliferation curve and cross-resistance of SWl116 cells to different drugs were detected by MTT. Percentage of SP cells in SW1116 cells was detected with Hoechst33342 staining. Telomerase activity in SW1116cells was checked by polymerase chain reaction （PCR）-enzyme linked immunosorbent assay. Expressions of stem cell relevant genes and proteins were detected by reverse transcription-PCR and Western blot, respectively. Total protein was isolated from SW1116 cells by two-dimensional gel electrophoresis （2-DE） and differentially expressed proteins were identified by tandem mass spectrometry （MALDI-TOF/TOF）. RESULTS： The isolated SW1116 cells presented as spheroid and suspension growths in SFM with a strong self-renewal, proliferation, differentiation and drug-resistance ability. The percentage of SP cells in SW1116 cells was 38.9%. The SW1116 cells co-expressed the CD133 and CD29 proteins. The telomerase activity in SW1116 cells was increased. The expressions of different stem cell relevant genes and proteins were detected. The proteomic analysis showed that the 26 protein spots were differently expressed in SW1116 cells and 10 protein spots were identified as ubiquitin fusion- degradation l-like protein, nuclear chloride channel protein, tubulin 13, Raichu404X, stratifin, F-actin cap- ping protein α-1 subunit, eukaryotic translation elongation factor 1 delta isoform 2, hypothetical protein, glyceraldehyde-3-phosphate dehydrogenase and guanine nucleotide binding protein 13 polypeptide 2-like 1, respectively. CONCLUSION： SW1116 cells are biologically characterized by self-renewal, proliferation and differentiation, and the differently expressed proteins in SW1116 cells may be essential for isolating cancer stem cells.

Influence of Mycorrhizal Inoculation on the Salt Tolerance of Artichoke Hybrid Seedlings

The role of mycorrhizal symbiosis in the alleviation of salinity stress induced by sodium chloride （NaCI） was investigated. Three artichoke hybrids, Madrigal F1, Opal FI, and Concerto FI （Nunhems company）, were grown in pot in controlled environment with two different mycorrhizal treatments （with or without Glomus viscosum）. Two months after inoculation, the fungus established well on roots of the Madrigal and Opal plants with higher colonization and dependency values, instead the Concerto plants showed lower mycorrhizal dependency and colonization rate. Mycorrhizal symbiosis generally improved plant vegetative growth and sustained plant physiology increasing stomatal conductance and SPAD values. The root systems of two months old artichoke plantlets, both inoculated and non inoculated, were placed in distilled water enriched with different salt concentrations （0, 100, 150, 200, 250 mM NaCI） to study the wilting response. A visual rating system was developed defining various wilting indexes （TO, no wilting; T1, foliar damage on less than 50% of vegetal tissues of basal leaves; T2, initial wilting and foliar damage on more than 50% of vegetal tissues of basal leaves; T3, foliar damage on the apical leaves; and T4, total wilting）. Mycorrhizal plants reached later the wilting indexes than non-mycorrhizal plants. Electrolyte leakage by leaves after salinity imposition was higher in non-mycorrhizal plants and the vegetal tissues were severely damaged especially in the basal leaves. The greater tolerance observed in the mycorrhizal plants could be in agreement with the improvement in growth stimulated by mycorrhizal symbiosis, which leads to the dilution of toxic ions.

Pharmacokinetics and bioequivalence analysis of amlodipine tablets in Chinese female and male volunteers by HPLC-MS/MS

In the present study, we determined the pharmacokinetics and bioequivalence of two amlodipine tablets in Chinese male and female volunteers using HPLC-MS/IVIS method. A randomized, two-period and crossover design was conducted in 20 healthy volunteers （14 male subjects and six female subjects）. A single dose of either the reference or test formulation was given at the start of each period. Blood samples were collected before drug administration and at 1, 2, 3, 4, 5, 6, 8, I0, 12, 24, 48, 72, 96, 120 and 144 h after drug administration. Plasma amlodipine was detected by HPLC-MS/MS method, and the pharmacokinetic parameters were analyzed using DAS 3.2.8. The developed HPLC-MS/MS method was suitable for the analysis of amlodipine in biological matrix samples. The main pharmacokinetic parameters between the trial preparation and the reference preparation met the regulatory criteria for bioequivalence, and the two preparations were both well tolerated.

The regulation and functions of transcription factor Nrf2 in cancer chemoprevention and chemoresistance

Chemotherapy and chemoprevention have been two of the most important means to control cancer incidence and mortality, and the cellular defensive machinery against oxidative/electrophilic stresses plays significant roles in both means. This defensive system is composed of cytoprotective enzymes that metabolize and eliminate oxidative/electrophitic species. The transcription factor nuclear factor erythroid 2-related factor 2 （Nrf2） controls the basal and inducible expression of many cytoprotective genes, and plays a pivotal role in coordinating cellular defensive responses. Under basal conditions, the activity of Nrf2 is inhibited by binding to Kelch-like ECH-associated protein 1 （Keap 1）, which is capable of sensing oxidative/electrophilic signals. Upon oxidative/electrophilic stresses, the binding of Nrf2 to Keapl is disrupted, leading to activation of Nrf2 and induction of cytoprotective enzymes. Thus, Nrf2 has emerged as an important target of chemopreventive drugs. However, activation of Nrf2 could lead to very different outcomes depending on the cellular context. The indiscriminative protective effects of Nrf2 lead to its undesired functions in carcinogenesis and chemoresistance of cancer cells. Activation of Nrf2 provides neoplastic cells with growth advantages and protects cancer cells from chemotherapeutic drugs, resulting in poor clinical outcomes. In this means, inhibitors of Nrf2 signaling can enhance the efficacy of chemotherapeutic drugs and deserve further development. A better understanding of the regulation and functions of Nrf2 would be helpful for researches in both chemoprevention and chemotherapy of cancer.

A STUDY OF THE CORRELATION BETWEEN ENGLISH MAJORS＇ SCORES OF TEM4 AND TOLERANCE OF AMBIGUITY

This is a study of the effect of English majors' tolerance ofambiguity on their scores of TEM4. The subjects for the surveyare 193 English major students. Statistical results of the surveyshow that the students' tolerance of ambiguity distributesnormally and their scores of listening comprehension and totalscores are significantly correlated with their tolerance ofambiguity. A weak positive correlation is also found betweentheir scores of dictation, cloze as well as reading comprehensionand tolerance of ambiguity. Students' scores in writing,structure and vocabulary are not significantly correlated withtolerance of ambiguity. The author makes some analysesassociating the results of the investigation with some scholarlyinferences and gives some suggestions on foreign languageteaching.

Klebsiella pneumoniae: epidemiology and analysis of risk factors for infections caused by resistant strains

OBJECTIVE: To analyze the epidemiology of hospital and community-acquired infections caused by Klebsiella pneumoniae (K. pneumoniae) and risk factors for infections caused by resistant strains. METHODS: A retrospective observational study was performed to analyze the relationship between antimicrobial use and bacterial resistance. RESULTS: A K. pneumoniae infection was diagnosed in 0.47% of patients (169 of 36 179) admitted to the hospital between 1 March 1999 and 31 August 2000. Of the 169 isolates, 166 (98.2%) were resistant to at least one antimicrobial and 91.1% (154/169) to two or more antibiotics. 98% were resistant to ampicillin, 77% to piperacillin, 64% to cephalothin, 60% to ampicillin/sulbactam, 59% to cefoperazone, 57% to cefazolin, 55% to cefuroxime, 51% to TMP-SMZ, 51% to tobramycin, 50% to gentamicin, 49% to aztreonam, cefetaxime and ceftriaxone respectively, 47% to ceftazidime, 47% to cefepime, 46% to ciprofloxacin, 46% to ticarcillin/clavulanate, 44% to amikacin, 38% to cefoxitin, 22% to piperacillin/tazobactam, while all strains were tested susceptible to imipenem. CONCLUSIONS: Prior receipt of amtimicrobial therapy was significantly associated with infection caused by a resistant organism and most strains were resistant to multiple antibiotics.