本.琼生喜剧作品中的现实主义倾向

本.琼生的喜剧作品从公众视角出发,主张用讽刺的手法来揭露时代的面貌,揭露了剥削阶级无情的本质、＂上流人士＂的伪善和堕落、人们贪婪的＂金钱观＂,开创了英国批判现实主义之先河,受到英美讽刺作家所效仿。

对“真实的叙述:琼生的人生与职业生涯”一文另两点质疑

伯格在"真实的叙述:琼生的人生与职业生涯"一文中对17世纪英国诗人本.琼生的一些介绍有不实的提法,如"琼生是英国第一位以写作为生的作家",是"很重视友谊,第一位以友谊为中心主题的英国诗人"等。文章通过亨斯洛日记等文献引证,质疑这些不实提法。琼生之前有其他作家以写作为生,也有其他诗人以友谊为主题创作,且琼生的友情诗也是在张扬正气的基础上抒发的。文学研究应当和科学研究一样严谨。

对《真实的叙述:琼生的人生与职业生涯》的两点质疑

文中对伯格的《真实的叙述:琼生的人生与职业生涯》一文中不实的提法提出了质疑,并以详实的例子和引文多方面论述、证明了笔者的观点——琼生是一名古典文学功底深厚的英国文学家,受古典文学家的影响较深,不仅其抒情诗约占其诗歌总量的三分之一,其戏剧中也不乏独白的戏文。

明月·童心·情诗——英诗阅读札记

锡德尼、华滋华斯、琼生都是英国诗歌史上负有盛名的诗人。三位诗人分别移情于明月 ,渴望童心永驻 ,用秋波向恋人祝酒 。

“幽默”探源

“幽默”一词，对于今天的读者来说，已不陌生了。然而，你知道它的来历吗?

Study on extraction of agaropectin from Gelidium amansii and its anticoagulant activity

Gelidium amansii agar was fractionated on DEAE-cellulose and four fractions were obtained sequentially. The yields of 1.0 mol/L NaCl fraction and 2.5 mol/L NaCl fraction were 2.80% and 2.03%. They are highly sulfated agar, and named as agaropectin with sulfate content being 22.8% and 32.5%, respectively. The anticoagulant experiment results show that agaropectin could effectively prolong the coagulation time in a dose-dependent manner in vitro. Agaropection could be absorbed and effectively prolong the plasma coagulation time in vivo. After intragastric administration at the doses of 100, 200, and 400 mg/kg·d in rats for 15 days, TT (thrombin time), CT (coagulation time), PT (prothrombin time), and APTT (activated partial thromboplastin time) could be effectively prolonged and the plasma Fib level could be significantly lowered.

Biological activities of a neutral water-soluble agar polysaccharide prepared by agarase degradation

Depolymerization of agar was performed using agarase, which was extracted from the cell-free medium of a culture of marine bacterial Alterornonas sp. nov. SY 37-12. After ethanol fractionation and lyophilization, the water-soluble agar polysaccharide （WSAP3） was collected. The anti-tumor activity of the product was determined by using Sarcoma 180 tumor in mouse. The tumor inhibition rate of WSAP3 the product was determined by using Sarcoma 180 tumor in mouse. The tumor inhibition rate of WSAP3 reached 48.7% at a dose of 64mg kg^-1 after 15 days treatment. WSAP3 enhanced the aetivities of superoxide dismutase and catalase, which suggests that WSAP3 was effective in promoting the antioxidation ability and eliminating danger from free radicals. The result of flow cytometry showed that the WSAP3 had no activities of cell cycle inhibition or apoptosis-inducing activities. The anti-oxidation of WSAP3 was further confirmed by test in vitro, which might play an important role in anti-tumor activity. The immunological regulation of WSAP3, especially its effect on the phagocytosis ratio and phagocytosis index of rophage was also assayed in test in vivo.

Biosynthesis of Polyhydroxyalkanoate （PHA） by Hydrogenophaga sp. Isolated from Soil Environment during Batch Fermentation

In this work, sucrose utilizing microbes from soil were screened to evaluate their ability for accumulation of biopolymer of polyhydroxyalkanoate （PHA）. Among 72 isolates were transferred to mineral salt medium （MSM）, 33 strains can be grown on sucrose agar medium. However, only one strain showed a strong black color for Sudan Black and gave positive result for Nile blue A. Identification by 16S rDNA nucleotide sequence homology of the isolate showed very closely to Hydrogenophaga sp. （99% identify）. To consider PHA production, the isolate was grown in the medium containing sucrose as a sole carbon under controlled conditions of 35 ℃ and at pH 7. Maximum dry cell weight （DCW） and PHA production were obtained at 3.61 g/L and 2.41 g/L after 36 and 42 h batch fermentation. Sucrose uptake measured in term of total organic carbon （TOC） showed at 14.73 g within 48 h. The highest PHA was 68.15% （gPHA/gDCW） giving maximum PHA yield （YP/s） of 0.17 （gPHA/gs ） and a productivity of 0.057 gPHA/L.h. This highlights the potential of microbial resources in soil environment and may be an exploitable application for the industrial production of PHA.

EFFECTS OF CO-CULTURE AND SALINITY ON THE GROWTH AND AGAR YIELD OF GRACILARIA TENUISTIPITATA VAR LIUI ZHANG ET XIA

Gracilaria tenuistipitata var Liui were mono cultivated and co cultivated with Pinctada martensii under high (33) and low (21) salinity conditions in laboratory. The daily growth rate of the alga was determined. Tissue carbon and nitrogen contents, the yield and fractional composition of agar were analyzed. Results showed that: 1. Gracilaria grew better under low salinity conditions, the daily growth rate was twice that under high salinity conditions. Co cultivated algae grew faster than mono cultivated algae under low salinity conditions, the daily growth rate was about 37.6% higher. 2. Compared with mono cultivated algae, tissue nitrogen contents of co cultivated algae were higher, while the C:N ratios were much lower. 3. The agar yields of co cultivated algae were much lower than those of mono cultivated algae. Agar yield was found to be negatively correlated to the tissue nitrogen contents, and positively correlated to the C:N ratios. 4. The highest fractional yields obtained from co cultivated algae were extracted with 40% ethanol, while from mono cultivated algae, the highest fractional yields obtained were extracted with distilled water at room temperature.

Application of Pyroligneous Acid in the Prevention and Control of Brown Blotch Disease in Pleurotus ostreatus

In the present study, agar diffusion test and field trials were carried out using a mushroom （Pleurotus ostreatus） culti- var Shouyanping as the experimental material to determine the antibacterial activity of refined pyroligneous acid prepared from almond shell against Pseudomonas tolaasfi and its effects on mycelial growth of mushroom. The results revealed that 1.25%, 2.50% and 5.00% of refined pyroligneous acid obviously inhibited the occurrence of brown blotch disease in mushroom, but also greatly promoted mushroom mycelial growth. Therefore, 1.25% and 2.50% of refined pyroligneous acid can be used in fields to prevent brown blotch disease, and 5.00% refined pyroligneous acid can be used to control the incidence of brown blotch disease when it widely occurs in fields.

The Use of Str Mutations for Enhancement of Hydrogen Peroxide Formation by Lactobacillus Delbrueckii MH-IO at Refrigeration

The strains ofLactobacillus delbrueckii subsp, lactis widely used in food preservation due to ability produce high amount of hydrogen peroxide at refrigerator temperatures to inhibit food-borne pathogens and psychrophilic spoilage microorganisms. In order to improve of bio-preservation efficacy ofL. delbrueckii MH 10 mutations causing resistance to streptomycin （str） were used. Among UV-mutagenized population of L. delbruecla＇i three str mutants producing high amounts of H2O2 were selected. Sir mutants produced significant amounts of hydrogen peroxide 50-60 μg/ml in sodium phosphate buffer （0.2 M, pH 6.5） and in beef broth （BB） at 5 ℃ for 5 days submerged cultivation without of growth. Evaluation mutants antibacterialactivity at refrigeration temperatures against food-borne pathogen Escherichia coli O157：H7 revealed elimination of pathogen total number up to practically undetectable amount for 3 days. In case of solid-state cultivation on agar-based medium, disks soaked by mutant cells suspensions formed larger inhibitory zones on E. coli O157：H7 lawn for one-day cold exposition. The size of inhibition zone depends on concentration of LAB cells. Str mutants L. delbrueckii reduced initial amount 2 - 105 of E. coil O 157：H7 in ground beef up to 3 log for 3 days of solid-state cocultivation when the wild strain reduced only 2 log. The application ofL. delbrueckii mutants did not cause any changes in sensory characteristics of ground beef, moreover promotes expanding of shelf-life due to inhibition of psychrophilic spoilage microorganisms.

In Vitro Activity of Lawsonia inermis （Henna） on Some Pathogenic Fungi

The present study was conducted to investigate antifungal activity ofLawsonia inermis （Henna plant）. Leaf samples of the plants were collected from Eastern Nile of Khartoum state, Sudan. Ethanol and petroleum ether extracts in various concentrations were obtained by maceration （cold method）. The extracts were bioassay in vitro to know their bioactivity to inhibit the growth of tested fungi. The cup plate agar diffusion method was adopted to assess the antifungal activity of the extracts against tested yeasts while agar incorporated method was used for other molds. Both extracts revealed anti fungal activity against all yeast strains except Pichiafabianii which was found resistant to both ethanol and ether extracts. The results displayed antifungal activity against tested fungi. Minimum mould concentration （MMC） of the extracts was determined. The obtained results revealed antifungal activity of henna leaves extracts which support the traditional use of the Henna in therapy of fungal infections. The possibility of therapeutic use of Sudanese henna as antifungal agents is recommended.

Mycelium Growth and Yielding of Black Poplar Mushroom-Agrocybe aegerita （Brig.） Sing. on Different Substrates

Mycelial growth and yield of two strains ofA. aegerita on different substrates was investigated. Mycelial growth on agar media （PDA, standard, wheat, MEA, CYM, PCA, sawdust extracts： alder and mixture of beech and birch （1：1）） and sawdust substrates （birch, beech, oak, maple, alder） was investigated. Petri dishes （Ф 9 cm） for agar media and biological tubes （18 cm long and Ф 2.5 cm） for sawdust substrates were used. Yield and morphological features were studied on birch, beech and mixture of beech and alder （1：1） sawdust substrates. The temperature of inoculation for agar media and sawdust substrates was 25 ℃. For yielding, when mycelium has completely overgrown the substrate the temperature was decreased to 15-17 ℃ to initiate primordia formation. The cultivation was enlightened 10 h/d with daylight lamps （500 Ix）. One crop was harvested after five weeks. The carpophores of black poplar mushrooms were picked up in clusters. There was no statistically important difference between the mycelial growths of the investigated strains. The best growing agar media were PDA （7.3 cm）, MEA （7.2 cm） and wheat （7.1 cm）, both strains showed the slowest mycelium growth on CYM （5.2 cm）. The mycelial growth on sawdust was the best on the beech （7.1 cm） and birch （6.8 cm） sawdust. The best substrate for cultivation ofA. aegerita was mixture of beech and alder sawdust （39.5 g/100 substrate DM）. The dry yield of carpophores were the highest on beech and alder substrate （3.2 g/100 substrate DM）, but dry matter content was the highest on beech sawdust （15.7%）. The heaviest carpophores were harvested from birch sawdust （3.7 g）; the biggest caps from beech and alder sawdust （3.3 cm）. There were no statistically important differences between the mycelium growth and yielding between both investigated strains.

In Vitro Study on Virulence Potentials of Burkholderia pseudomallei Isolated from Immunocompromised Patients

Eighty four throat swabs were obtained from Basrah General Hospital inpatients （N = 34）： 17 were suffering from renal failure and the other 17 were diabetics; and from outpatients （N = 50）. Throat swabs were cultured first in the selective media Ashdown＇s broth then subcultured on Ashdown＇s agar to isolate Burkholderia pseudomallei which was recovered from seven cases （8.33%）. Four isolates were from renal failure patients （23.53%）, two from diabetic patients （11.76%） and the seventh isolate was from an outpatient with tonsillitis. All isolates were able to produce capsules, form filament chains, exhibit swarming motility and were arabinose non assimilators （Ara-） indicative of their virulence. Additionally, isolated B. pseudomallei were found to produce protease, lipase, hemolysin, and lecithinase and were able to produce biofilm, the root of many troublesome persistent infections that resist antibiotic treatment. Susceptibility of the seven isolates of B. pseudomallei toward 11 antibiotics was assessed, isolates were found multiply resistant to all antibiotics apart from ciproflaxin. This study confirms for the first time isolation of B. pseudomallei from immunocompromised patients in Basrah city of Iraq and describes their virulence potentials.

Carboxyl groups trigger the activity of carbon nanotube catalysts for the oxygen reduction reaction and agar conversion

Ozone treatment is a common way to functionalize commercial multi-walled carbon nanotubes （CNTs） with various oxygen functionalities like carboxyl, phenol and lactone groups, in order to enhance their textural properties and chemical activity. In order to detail the effect of each functional group, we correlated the activity with the surface density of each group, and found that the carboxyl groups play a pivotal role in two important catalytic reactions, namely the electrochemical oxygen reduction reaction （ORR） and agar conversion to 5-hydroxymethylfurfural （HMF）. During the processes, the hydrophilic surface provides a strong affinity for reaction substrates while the improved porosity allows the efficient diffusion of reactants and products. Furthermore, the activity of functionalized CNTs for agar conversion remained almost unchanged during nine cycles of reaction. This work highlights a strategy for improving the activity of CNTs for electrochemical ORR and agar conversion reactions, as well a promising application of carboxyl-rich CNTs as a solid acid catalyst to produce high-purity HMF--an important chemical intermediate.

Effect of agarose content on microstructures and mechanical properties of porous silicon nitride ceramics produced by gelcasting

Porous Si3N4 self-reinforce ceramics were prepared by gelcasting using agarose solutions. By changing the agarose content in the slurries, the porous silicon nitride ceramics with different porosities, α→β-Si3N4 phase transformation, and mechanical properties were obtained. When the agarose content changed from 0.2% to 0.8% (w/w, based on powder), the porosities increased from 10.3% to 21.4%, while the fracture strength decreased from 455 to 316 MPa and the fracture toughness decreased from 6.6 to 5.5 MPa·m1/2. Many fibrous β-Si3N4 grains grown from the internal wall of the round pores is the typical microstructure of the gelcasting porous silicon nitride ceramic. Both elongated β-Si3N4 grains and suitable interfacial bonding strength contributes to high fracture toughness by favoring crack deflection and bridging. The growth mechanisms of fibrous grains resulted from the synergy of solution-diffusion-reprecipitation and vapor-liquid-solid (VLS).

Accurate assessment of antibiotic susceptibility and screening resistant strains of a bacterial population by linear gradient plate

The dynamics of a bacterial population exposed to the minimum inhibitory concentration （MIC） of an antibiotic is an important issue in pharmacological research. Therefore, a novel antibiotic susceptibility test is urgently needed that can both precisely determine the MIC and accurately select antibiotic-resistant strains from clinical bacterial populations. For this purpose, we developed a method based on Fick＇s laws of diffusion using agar plates containing a linear gradient of antibiotic. The gradient plate contained two layers. The bottom layer consisted of 15 mL agar containing the appropriate concentration of enrofloxacin and allowed to harden in the form of a wedge with the plate slanted such that the entire bottom was just covered. The upper layer consisted of 15 mL plain nutrient agar added with the plate held in the horizontal position. After allowing vertical diffusion of the drug from the bottom agar layer for 12 h, the enrofloxacin concentration was diluted in proportion to the ratio of the agar layer thicknesses. The uniform linear concentration gradient was verified by measuring the enrofloxacin concentration on the agar surface. When heavy bacterial suspensions were spread on the agar surface and incubated for more than 12 h, only resistant cells were able to form colonies beyond the boundary of confluent growth of susceptible cells. In this way, the true MIC of enrofloxacin was determined. The MICs obtained using this linear gradient plate were consistent with those obtained using conventional antibiotic susceptibility tests. Discrete colonies were then spread onto a gradient plate with higher antibiotic concentrations; the boundary line increased significantly, and gene mutations conferring resistance were identified. This new method enables the rapid identification of resistant strains in the bacterial population. Use of the linear gradient plate can easily identify the precise MIC and reveal the dynamic differentiation of bacteria near the MIC. This method allows the study of genetic and physiological characteristics of individual strains, and may be useful for early warning of antibiotic resistance that may occur after use of certain antirnicrobial agents, and guide clinical treatment.

Metal chelate affinity to immobilize horseradish peroxidase on functionalized agarose/CNTs composites for the detection of catechol

The paper reports a novel amperometric biosensor for catechol based on immobilization of a highly sensitive horseradish peroxidase by affinity interactions on metal chelate-functionalized agarose/carbon nanotubes composites. Metal chelate affinity takes advantage of the affinity of Ni2＋ ions to bind strongly and reversibly to histidine or cysteine tails found on the surface of the horseradish peroxidase. Thus, enzymes with such residues in their molecules can be easily attached to functionalized aga- rose/carbon nanotubes composites support containing a nickel chelate. Linear sweep voltammograms and amperometry are used to study the proposed electrochemical biosensor. Catechol is determined by direct reduction of biocatalytically liberated quinone species at -0.05 V （vs. SCE）. The effect ofpH, applied electrode potential and the concentration of H2O2 on the sensitivity of the biosensor has been investigated. The performance of the proposed biosensor is tested using four different phenolic compounds, showing very high sensitivity, in particular, the linearity of cateehol is observed from 2.0 × 10-8 to 1.05×10-5 M with a detection limit of 5.0×10-9 M.