In-vitro antimicrobial activity and synergistic/antagonistic effect of interactions between antibiotics and some spice essential oils

Spices and herbs have been used for many years by different cultures. The aim of the present study is (1) to investigate in-vitro antimicrobial effects of different spices and herbs (5 species: Rosmarinus officinalis (Rosemary), Coriandrum sativum (coriander), Micromeria fruticosa (L.) Druce subsp. Brachycalyx P.H. Davis (White micromeria), Cumium cyminum (cumin), Mentha piperita (Peppermint) against different bacteria and fungi species, and (2) to discuss the in-vitro possible effects between the plants and antibiotics. The microorganisms used were Micrococcus luteus LA 2971, Bacillus megaterium NRS, Bacillus brevis FMC 3, Enterococcus faecalis ATCC 15753, Pseudomonas pyocyaneus DC 127, Mycobacterium smegmatis CCM 2067, Escherichia coil DM, Aeromonas hydrophila ATCC 7966, Yersinia enterocolitica AU 19, Staphylococcus aureus Cowan 1, Streptococcus faecalis DC 74 bacteria, and Saccharomyces cerevisiae WET 136, Kluvyeromyces fragilis DC 98 fungi in this study. The results indicated that essential oils of Rosmarinus officinalis, Coriandrum sativum L., Micromeria fruticosa (L.) Druce subsp. brachycalyx P.H. Davis, Cumium cyminum L., Mentha piperita L. were shown antimicrobial activity in the range of 7-60 mm 2 microl(-1) inhibition zone to the microorganisms tested, using disc diffusion method. Standard antibiotic such as Gentamicin (10 microg), Cephalothin (30 microg), Ceftriaxone (10 microg), Nystatin (10 U) discs were used for comparison with the antimicrobial activities of essential oils of these plants. In addition, antibacterial activity of essential oils of these plants was researched by effects when it was used together with these standard antibiotics in vitro. However, antibacterial activity changed also by in vitro interactions between these standard antibiotics and essential oils of these plants. Synergic, additive or antagonist effects were observed in antibacterial activity.     

Screening the methanolic extracts of some plants for tyrosinase inhibitory activity

Melanin is responsible for pigmentation of skin and hair. It protects the skin from the harmful effects of UV radiation; however, its abnormal production may lead to different diseases such as hyper-pigmentation or vitiligo. Tyrosinase is a key enzyme in melanin production, therefore inhibitors of this enzyme should have broad application. Due to the adverse effects of synthetic inhibitors currently being used, the search for new inhibitors, especially natural ones, is needed. The methanolic extracts of 80 plants were tested for their tyrosinase inhibitory activities by spectrophotometry at 492?nm. The inhibition mode of effective plant extracts was determined using the Lineweaver-Burk plots. Among these plant extracts, Alhagi camelorum (camel thorn), Camelia sinensis (green tea), Cuminum cyminum (Cumin), Lawsonia inermis (henna), Quercus infectoria (masso), and Vaccinium arctostaphylos (Caucasian whortleberry) were identified as tyrosinase inhibitors with inhibitory effect of more than 50% at concentrations of 1.14?g?L^?1. The inhibition mode of four newly found effective plant extracts showed that A. camelorum and V. arctostaphylos inhibit the enzyme in a competitive manner whereas L. inermis and Q. infectoria have mixed inhibitory effect. To recommend these plant extracts for hyper-pigmentation disorders and other applications, further in vitro and in vivo studies are needed.     

Protective effect of kombucha mushroom (KM) tea on phenol-induced cytotoxicity in albino mice

The present study was carried out to evaluate the protective role of kombucha mushroom (KM) tea on cytotoxicity induced by phenol (PHE) in mice. We used weight gain and micronucleus (MN) frequency as indicators of cytotoxicity and supported these parameters with pathological findings. The animals were randomly divided into seven groups: (Group I) only tap water (Group II) 1000 microl kg(-1) b. wt KM-tea, (Group III) 35 mg kg(-1) body wt. PHE (Group IV) 35 mg kg(-1) body wt. PHE + 250 microl kg(-1) b. wt KM-tea (Group V) 35 mg kg(-1) b. wt PHE + 500 microl kg(-1) b. wt KM-tea (Group VI) 35 mg kg(-1) b. wt PHE + 750 microl kg(-1) b. wt KM-tea, (Group VII) 35 mg kg(-1) b. wt PHE + 1000 microl kg(-1) b. wt KM-tea, for 20 consecutive days by oral gavage. The results indicated that all KM-tea supplemented mice showed a lower MN frequency than erythrocytes in only PHE-treated group. There was an observable regression on account of lesions in tissues of mice supplemented with different doses of KM-tea in histopathological observations. In conclusion, the KM-tea supplementation decreases cytotoxicity induced by PHE and its protective role is dose-dependent.     

Growth and population structure in the infaunal bivalve Yoldia eightsi in relation to iceberg activity at Signy Island,Antarctica

Growth rates in the infaunal nuculanid bivalve mollusc Yoldia eightsi (Couthouy) were assessed for field populations in Factory Cove, Signy Island, Antarctica, between. February and April 1992. Daily increments in length (maximum shell dimension) ranged from 2.3 m d^-1 for a 30 mm individual to 5.1 m d^-1 for a 10 mm specimen. These growth rates were converted to annual increments, based on a growing season for the Signy population of around 5 mo, and ages for the largest individuals in the population (35 mm in length), were calculated to be 65 yr. Specimens of 43 mm in length have been found near this site and, if their growth rates are similar to this population, their ages would be in the order of 120 yr. Size distributions from two sites in the same Y. eightsi bed 300 m apart showed significant differences. At the more exposed site the distribution was dominated by small juveniles, with 86% of the population 10 mm in length, while 13% were >20 mm in length. At the less exposed site the values were 27% <10 mm and 56% >20 mm. Icebergs have often been seen grounded on the Y. eightsi bed in this study, especially on the exposed outer portion. This factor, in association with inhibition of larval settlement by high densities of large individuals, is proposed as an explanation of the observed population distributions and the absence of very large specimens in the Factory Cove population.     

菲胁迫下湿生植物美人蕉(Canna indica)对斜生栅藻(Scenedesmus obliquus)生长的影响

多环芳烃有机污染物的环境问题日益严重,亟待需求从群落及生态系统的角度进行毒理学复合危害效应的研究。本文采用以美人蕉(Canna indica)种植根区水培养斜生栅藻(Scenedesmus obliquus)的方式,观察菲胁迫下其生长的变化。结果表明,美人蕉种植根区水对斜生栅藻生长具有化感效应,且表现为"低促高抑"的现象。而在菲胁迫下,种植根区水比例为15%和30%时随着菲浓度的增加,生长促进作用增强,且在菲浓度为1 mg·L-1出现最高值;在100%种植根区水时随着菲浓度的增加生长抑制作用增强。说明,菲胁迫使美人蕉种植根区水对藻类的化感效应增强。进行逻辑斯谛生长拟合发现,30%、1 mg·L-1处理组种群内禀增长率最高,斜生栅藻种群出现暴发增长的生态风险最大。     

Infection and immunization trials of Asian seabass (Lates calcarifer) against fish pathogen Vibrio anguillarum

Vibriosis is one of the most prevalent fish diseases caused by bacteria belonging to the genus Vibrio sp. Fish disease will be controlled by proper vaccination trials and maintenance of fish form. Pathogenicity for Asian seabass (Lates calcarifer) against V anguillarum results in necrosis and haemorrhagic areas near the base of fins, exopthalmia and ulcers on the skin surface. Around 50, 100, 200 microl of formalin killed bacterial cells were injected (Intraperitoneal) to three different size (5-10, 20-30, 35-50 g) of seabass fishes respectively and control sere as saline were maintained separately. The Relative Percentage Survival (RPS) for vaccinated fishes was 60, 75, and 62.5 respectively and the vaccinations for 20-30 g fishes stay alive. These results stated that the vaccination for fishes with 20-30 g size may fabricate good immune response.     

Life history of the golden ring cowry Cypraea annulus (Mollusca: gastropoda) on Okinawa Island,Japan

Two mark-recapture studies, regular population censuses, field observations, and laboratory culture were used to study the life history of the tropical marine gastropod Cypraea annulus Linnaeus, 1758 from Cape Maeda, Okinawa Island, from April 1984 to March 1986. In the field, the average rate of increase in shell length of marked juvenile snails was 1.0±0.3 mm wk^-1 (N=13), with a maximum of 1.5 mm wk^-1 (initial shell length 10.6 to 17.2 mm). In the laboratory, the maximum growth rate of juveniles was 3.0 mm wk^-1 with food ad libitum. Snails with primordial teeth on the shells grew at a rate of 0.1 to 0.5 mm wk^-1 for about 2 wk. The adults continued to grow at a similar rate for an additional 3 to 6 wk, and ceased detectable growth when some females started spawning egg masses. In the littoral zone on Okinawa Island, snails reproduced throughout the year. Egg masses brooded by three females (shell length 17.4 to 21.3 mm) in the field contained 90 000 to 133 000 ova. In the laboratory, brooding periods of three females lasted 6,8, and 9 d. The estimated average frequency of spawning was 5 egg masses female^-1 yr^-1. The mean shell length of adult females (20.3 mm) was significantly larger than that of adult males (19.6 mm). The life-history strategy of C. annulus is characterized by rapid growth, high fecundity, and repeated spawning throughout the year.     

一株拮抗烟草青枯病菌的真菌的筛选与鉴定

为寻找烟草青枯病的生防微生物,研究采用平板涂布法从重庆烟田健康土壤中分离根际微生物,纯化后得到了59株真菌。用滤纸片法从中筛选出1株对青枯雷尔氏菌（Ralstonia solanacearum）有稳定拮抗效果的真菌,其抑菌圈为10.0 mm。其抑制活性优于或接近于近期发现的其他生防微生物。测定该株活性真菌的全细胞脂肪酸组成,进行菌落和分生孢子形态学观察,以及rDNA ITS区测序,结果表明：该菌株全细胞脂肪酸属性未被收录于TSBA6脂肪酸数据库,而根据形态学观察结果,以及对所获rDNA ITS区序列的分析,鉴定该株真菌为烟曲霉（Aspergillus fumigatus）。     

High-temperature tolerance of photosynthesis in the red alga Chondrus crispus

Chondrus crispus (Stackhouse) is a perennial red seaweed, common in intertidal and shallow sublittoral communities throughout the North Atlantic Ocean. In the intertidal zone, C. crispus may experience rapid temperature changes of 10 to 20C° during a single immerison-emerision cycle, and may be exposed to temperatures that exceed the thermal limits for long-term survival. C. crispus collected year-round at Long Cove Point, Chamberlain, Maine, USA, during 1989 and 1990, underwent phenotypic acclimation to growth temperature in the laboratory. This phenotypic acclimation enhanced its ability to withstand brief exposure to extreme temperature. Plants grown at summer seawater temperature (20°C) were able to maintain constant rates of lightsaturated photosynthesis at 30°C for 9 h. In contrast, light-saturated photosynthetic rates of plants grown at winter seawater temperature (5°C) declined rapidly following exposure to 30°C, reached 20 to 25% of initial values within 10 min, and then remained constant at this level for 9 h. The degree of inhibition of photosynthesis at 30°C was also dependent upon light intensity. Inhibition was greatest in plants exposed to 30°C in darkness or high light (600 mol photons m^-2s^-1) than in plants maintained under moderate light levels (70 to 100 mol photons m^-2s^-1). Photosynthesis of 20°C-acclimated plants was inhibited by exposure to 30°C in darkness or high light, but the degree of inhibition was less than that exhibited by 5°C-grown plants. Not only was light-saturated photosynthesis of 20°C plants less severely inhibited by exposure to 30°C than that of 5°C plants, but the former also recovered faster when they were returned to growth conditions. The mechanistic basis of this acclimation to growth temperature is not clear. Our results indicate that there were no differences between 5 and 20°C-grown plants in the thermal stability of respiration, electron transport associated with Photosystems I or II, Rubisco or energy transfer between the phycobilisomes and Photosystem II. Overall, our results suggest that phenotypic acclimation to seawater temperature allows plants to tolerate higher temperatures, and may play an important role in the success of C. crispus in the intertidal environment.     

寒温带兴安落叶松林土壤团聚体特征及其影响因素研究

以寒温带兴安落叶松(Larix gmelinii)林为研究对象,分析其土壤团聚体的分布及其有机碳含量特征,并探讨各土壤因子对团聚体稳定性的影响。在兴安落叶松林内设置28块30 m×30 m的样地,以0—10、10—20、20—40、40—60 cm分层取土样,测定各理化指标含量、不同粒级土壤团聚体及其有机碳含量。结果表明,兴安落叶松林土壤团聚体各粒级含量高低为(0.25—2 mm粒径)团聚体>(<0.053 mm粒径)团聚体>(0.053—0.25 mm粒径)团聚体,各粒级团聚体表层(0—10 cm)含量均显著区别于其他各层;土壤团聚体的平均质量直径(MWD)、几何平均直径(GMD)分别为0.53 mm和0.22 mm,分维数(D)为2.78,土壤团聚体稳定性较高且存在剖面差异;土壤有机碳主要分布于0.25—2 mm粒径的大团聚体中(34.51g·kg^-1),贡献率为52.10%,粒径0.053—2 mm土壤团聚体中有机碳含量最低(6.30 g·kg^-1),贡献率为16.42%;随土层深度增加,各粒级团聚体有机碳含量和0.25—2 mm团聚体有机碳贡献率逐渐减小,<0.25 mm团聚体贡献率逐渐增大,40 cm以下各粒级贡献率趋于稳定;兴安落叶松林土壤团聚体的粒径分配和稳定性受到林龄和林型的显著影响;大团聚体(0.25—2mm)含量与土壤总有机碳(SOC)呈极显著正相关关系(P<0.01),微团聚体(<0.25 mm)含量与Al、Mg等金属氧化物含量呈显著正相关关系(P<0.05);大团聚体(0.25—2 mm)含量和MWD、GMD指标与pH值呈极显著负相关关系(P<0.01),与土壤含水量、速效钾、有效磷、有机磷呈显著正相关关系(P<0.05)。综上,土壤有机质和金属氧化物分别为兴安落叶松林土壤0.25—2 mm大团聚体和<0.25 mm微团聚体的主要胶结物质,土壤水分、养分和酸碱条件对团聚体的形成和稳定产生影响。     

亚热带和温带生态条件下水稻生长速率和产量的相关性研究

在亚热带生态环境下的云南省宾川县和温带环境下的韩国水原市,2002和2003年对中国和韩国筛选出的4个水稻（Oryza sativa）高产品种进行了生长速率和产量的相关性研究,结果表明：在亚热带和温带的两种生态条件下水稻品种的叶面积指数和收获指数相近,但亚热带生态条件下实际产量和生长速率分别比温带条件下高3．06t·hm^-2和7．09g·m^-2·d^-1,产量高50．75％和生长速率高58．22％,差异达极显著水平。在亚热带条件下,移栽到移栽后20d、孕穗到抽穗的生长速率的增加能极显著提高水稻产量,以移栽到移栽后20d的生长速率影响最大,抽穗后20d生长速率的增加能增加水稻产量,但不显著。在施肥比例,基肥：分蘖肥：孕穗肥：穗肥：O％：50％：30％：20％的氮肥施用方式和稀植（30cmx14cm）条件下获得该生态区的最高产量和最大生长速率,分别为9．26t·hm^-2、19．53g·m^-2·d^-1;在温带条件下,移栽到抽穗的生长速率的增加能显著提高水稻产量,以移栽后21d到孕穗的生长速率影响最大,抽穗后20d生长速率的增加反而减低水稻产量,但不显著,氮肥施用方式基肥：分蘖肥：孕穗肥：穗肥=50％：20％：30％：0％和密植（20cm×14cm）条件下获得该生态区的最高产量和最大生长速率,分别为6．31t·hm^-2、12．00g·m^-2·d^-1。     

基于多元统计的引黄水库沉沙条渠泥沙与水质的变异分析

以济南市引黄供水鹊山水库沉沙条渠为研究对象,测定了9个断面（Y1—Y9）表层水体中的含沙量、总有机碳、总磷、总氮、叶绿素a等19个水质指标.运用主成分分析法和聚类分析法分别探讨水体的主要污染因子及监测断面的沿程归类,并通过室内模拟实验分析了泥沙对水体中N、P浓度的影响.结果表明,沉沙条渠中的水质总体特征以Ⅱ类水和Ⅲ类水为主,其中,超标水质指标为TN,达到劣Ⅴ类水标准,P为藻类生长的限制因子.19个水质指标可由6个主成分来反映,其贡献率分别为：F1（TN、NH3-N、NO3--N、NO2--N、总碱度、Br-、硫酸盐）34.41%,F2（含沙量、浊度、色度、电导率）22.78%,F3（pH和UV254）13.95%,F4（TP）6.280%,F5（CODCr）4.990%和F6（Chl-a）4.830%;9个监测断面归为4类,相应地整个沉沙条渠可划分为4个功能区：入渠布水区（Y1、Y2、Y3）、快速沉降区（Y4、Y5）、缓慢沉降区（Y6、Y7、Y8）和出水稳定区（Y9）.此外,水质与泥沙关系的室内模拟实验表明,条渠来水的P浓度随着泥沙颗粒的沉降而降低,TP在0—15 h内快速下降,而后缓慢下降,30 h内基本达到平衡;而泥沙颗粒对水中N浓度基本没有影响.     

Distribution of Juvenile,subadult and adult Scylla serrata (Crustacea: Portunidae) on tidal flats in Australia

In Deception Bay, northern Australia, during 1979–1981, a study was made of the distribution of Scylla serrata (Forskal) in an area having a broad intertidal zone. Juveniles (20 to 99 mm carapace width) were resident in the mangrove zone, remaining there during low tide. The majority of subadult crabs (100 to 149 mm) migrated into the intertidal zone to feed at high tide and retreated to subtidal waters at low tide. Adults (150 mm and larger) were caught mainly subtidally and only small numbers were captured in the intertidal at high tide. Few crabs were captured in the coolest months (May to August). Adults were captured on the flats mainly in the warmest months (January to April), but subadults could be captured over the entire summer (September to March). Juveniles were found in the upper intertidal throughout the year.     

Impact of environmental concentrations of beta-cypermethrin on the antioxidant system in the brain and liver of zebrafish (Danio rerio)

Beta-cypermethrin (beta-CYP) is a widely used pyrethroid pesticide, the extensive application of which may potentially cause damage to non-target organisms. To investigate the effect of beta-CYP on the antioxidant system of aquatic animals, adult zebrafish were exposed to environmentally relevant dosages (0.01, 0.1 and 1.0 μg/L) of beta-CYP. The activities of four antioxidant enzymes in zebrafish liver and brain tissue were tested after 7, 15 and 30 days of exposure. Our results showed that exposure of beta-CYP could induce different levels of increase in hepatic superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR) and glutathione peroxidase (GPx) activities at 7 and 15 days post exposure (dpe), but caused apparent inhibition of hepatic SOD, GR and GPx activities at 30 dpe. Unlike in liver tissue, SOD and CAT activities in zebrafish brain did not show any apparent response to beta-CYP during the whole treatment period. In addition, increased brain GPx activities were observed at 7 and 30 dpe.     

福建赤红壤旱地与红壤旱地水分特性的比较

释放80%的有效水时赤红壤旱地的t值（当释放的土壤有效水占有效水库容的比率为80%时的土壤水吸力值）较小，表明赤红壤旱地持水性较红壤旱地更差，植物更容易受到干旱的协迫。赤红壤旱地贮水库容比红壤旱地小，赤红壤旱地的比水容量达到10-2数量级（难效水）在-10kPa~-30kPa就开始出现，而红壤旱地出现在-30kPa以下，表明赤红壤旱地的失水速度快，保水供水性能弱于红壤旱地。最后，讨论了影响旱地土壤水分性质的因素。     

Effect of different irrigation methods on yield of red hot pepper and plant mortality caused by Phytophthora capsici Leon

This experiment was conducted in 1999 and 2000 in a field naturally infected by Phytophthora capsici to determine the effects of different irrigation methods, namely, basin (B), closed-end furrow (F), drip (D) and sprinkler (S) irrigation on dry yield of chili pepper (Capsium annuum L. K. Maras Type). Water use efficiency (WUE) and plant mortality were also measured. The averages of total applied water to the B, F, D and S plots for the two years were 937.7 mm, 920.6 mm, 886.5 and 913.4 mm, respectively. Thus, the mean seasonal water use by pepper varied from 1020.7 to 1109.7 mm. The highest water use was measured in B, followed by use for S, D and F methods. The highest mean potential dry yield with 1.58 t ha(-1) was obtained using D method. This was followed by S (1.36 t ha(-1)), B (1.13 t ha(-1)), and F (0.81 t ha(-1)) methods. In terms of plant mortality, crops having B irrigation had the highest (93.9%), followed by lessen amount to the S (3.2%), F (3.1%), and D methods (1.7%). Only the B irrigation method stimulated the development of P. capsici disease. On the other hand, mean WUEs varied between 0.7 and 1.7 kg ha(-1)mnm(-1) for Irrigation methods. WUE for D method was slightly higher than S method, but considerably higher than B and F methods.     

Quantification of ontogenetic discontinuities in three species of oegopsid squids using model II piecewise linear regression

Growth trajectories of morphological characters may change during ontogeny, but this change is often overlooked or, at best, is estimated visually. An objective method was developed for determining discontinuities in morphological measurements of three species of oceanic squids: Chtenopteryx sicula (Vérany, 1851), Mastigoteuthis magna Joubin, 1913, and Brachioteuthis sp. 3. The specimens were collected on the Amsterdam Mid North Atlantic Plankton Expeditions (1980-1983) along a transect from 55°N to 25°N along 30°W. Discontinuities were quantified via an iterative, model II, piecewise linear regression (PLR) analysis, whereby the regression model incorporated a fixed breakpoint that was increased in each iteration across the range of dorsal mantle lengths (DMLs). The iteration with the lowest LOSS value was selected as the best estimate of the breakpoint. In C. sicula, 7 of 10 measured characters had a single breakpoint, and 5 of these occurred at 7-9 mm DML. In M. magna, only 4 of 12 characters had breakpoints, 3 of which occurred at 4-7 mm DML. More, larger specimens would likely yield additional breakpoints. In Brachioteuthis sp. 3, 12 of 14 characters had discernable breakpoints; 3 characters had 2 breakpoints. Most breakpoints occurred at 11-12 mm DML, and all were found at larger sizes than in the other species. This clustering of breakpoints into discrete size ranges may be considered an allomorphosis, and this rapid morphological change may correlate with rapid ecological change.     

Effects of Lunatia heros predation on the population dynamics of Mya arenaria and Macoma balthica in Maine,USA

The interaction between the naticid snail predator Lunatia heros and 2 iteroparous, infaunal, intertidal bivalves was investigated in Lubec, Maine, USA. The Mya arenaria population consists primarily of young, small individuals. M. arenaria survivorship is low when young (3.5% yr^-1 for the first 5 yr), then increases. M. arenaria can attain a length of 60 mm, but it is susceptible to L. heros attack only until it is 30 mm long. It delays reproduction until it is 20 mm long (3.8 yr) and diverts its resources instead into rapid early growth (4.9 mm yr^-1 for the first 5 yr). The Macoma balthica population has a larger proportion of older individuals than does that of M. arenaria. Survivorship is higher for M. balthica than for M. arenaria (76.3% yr^-1 for the first 5 yr). Unlike M. arenaria, M. balthica attains a final length of only 25 mm and all sizes are susceptible to L. heros attack. M. balthica grows slowly (2.7 mm yr^-1 for the first 5 yr) and diverts its resources into earlier reproduction at a length of 10 mm (2.9 yr). These contrasting life-history patterns and the possible relationship between bivalve resource allocation and refuges from predation are discussed.     

三氯生对青海弧菌Q67和人乳腺癌细胞MCF-7的时间毒性

三氯生(triclosan,TCS)是一种广谱性抗菌剂,2005年欧盟水框架指令将TCS列为一种新型污染物。目前对TCS的研究局限于急性毒性实验,关于TCS毒性随时间的变化以及不同溶解状态下TCS的毒性差异的研究却鲜有报道。应用以96孔微板为暴露反应载体的微板毒性分析法,添加氢氧化钠(NaOH)或使用二甲亚砜(DMSO)作为助溶剂溶解TCS,分别测定其对青海弧菌Q67的相对发光抑制毒性(15min急性毒性和时间毒性)和对人乳腺癌细胞MCF-7在不同暴露时间(24、48和72h)内的细胞增殖抑制毒性。Q67的急性毒性实验结果表明,碱性条件下TCS的毒性(EC50=3.97(10-8mol.L-1)大于DMSO作为助溶剂时的毒性(EC50=1.68(10-4mol.L-1)。无论碱性条件还是DMSO助溶,TCS在不同暴露时间内对Q67的时间毒性没有明显差异。在不同暴露时间下MCF-7增殖抑制率实验中,DMSO作为助溶剂时,TCS的最高实验浓度为1.46(10-3mol.L-1,随着暴露时间的延长,抑制率在24、48和72h时分别为27.8%、44.2%和62.4%;碱性环境时TCS的最高实验浓度为1.39(10-6mol.L-1,随着暴露时间的延长,抑制率在24、48和72h时分别为20.2%、55.8%和73.9%。研究表明,在DMSO和NaOH作为助溶剂的条件下,TCS对MCF-7均存在时间毒性差异,并且NaOH碱性溶液中TCS对MCF-7的毒性远大于DMSO作为助溶剂时的毒性。     

Abundance and seasonal variations of phytoplankton in the creek waters of western mangrove of Kachchh-Gujarat

The phytoplankton was assessed quantitatively and qualitatively in regard to their abundance in creek waters at three sites along the western mangrove of Kachchh. In total one hundred and four species of phytoplankton were identified. Among them 82 species diatoms (Bacillariophyceae), 16 species dinoflagellates (Dinophyceae), 3 species blue greens (Cyanophyceae) and 2 species were green algae. The density in all the three sites varied from 94,166.67 to 2,44,500 cells l(-1). The salinity ranged from 36 to 44 per thousand, temperature 17 to 35 degrees C and pH ranged from 7 to 8.9 respectively. These semi arid zone mangrove creek area having high densities were recorded during monsoon and early winter season.