The Formation of Insecticidal Films on Building Materials

The success of size and gelatin as pretreatments was not confined to films of pyrethrins in oil. Pretreatment of cement with 10 % w/v size and 5 % w/v gelatin greatly prolonged the toxic life of films formed by other insecticides in oil solution.
The effects of adding different substances to size and gelatin solutions as pretreatments were investigated. 5 % w/v size or gelatin solutions containing suspended lime or distemper powder were, with the exception of gelatin containing distemper, less effective pretreatments than size or gelatin solutions alone. Magnesium silicofluoride, benzoic acid and salicylic acid, at concentrations up to 0.5 % w/v, appear suitable as preservatives for 5 % w/v gelatin. These three substances are, however, unsuitable for inclusion in size solutions, as they cause precipitates to form. Glycerin or turkey-red oil at concentrations of 0.5 % v/v, appear suitable as plasticizers for inclusion in both 5 % w/v size and 5 % w/v gelatin solutions.     

The toxicities of three petroleum oils to the grain weevils

The toxicities of three petroleum oils to Calandra granaria L. and C. oryzae L. have been determined. The oils were Shell oil P31, Odourless Distillate (O.D.), and Pool burning oil (P.B.O.). At 20 and 25° C. C. oryzae was more resistant than C. granaria to a direct spray of P31. At 20° C. C. oryzae was more resistant than C. granaria to direct sprays of O.D. and P.B.O. The relative toxicities to both species of direct sprays of the three oils could be expressed as: P.B.O. < P31 ≥ O.D. ≥ P.B.O. C. oryzae was the species more resistant to films of P31 on Whatman no. 544 filter-paper.
Films of P31 or a P31/water emulsion on brick, and films of P31 on sacking and cement, were non-toxic to C. granaria , but films of P31 on cement pretreated with gelatin were highly toxic to this species.
Beetles that received doses of P31 a little in excess of those sufficient to knock them down rarely recovered completely. P31 probably suffocates the beetles by blocking their spiracles and/or tracheae.
P31 appears to be the most useful of the three oils for the control of C. granaria. In practice it should be effective as a direct spray, though not as a film, and could therefore be used to control infestations in which beetles were exposed. Films of P31 on surfaces suitably pretreated might, however, be used for control.     

THE CONTROL OF CERTAIN PLANT DISEASES WITH SULPHONAMIDES

In in vitro tests, sulphanilamide was more toxic to plant pathogenic fungi than to bacterial plant pathogens, but sulphadiazine and other heterocyclic-ring substituted compounds were more toxic to plant pathogenic bacteria than to fungi. When tested in vivo against a number of facultative plant parasites the sulphonamides were without effect except in providing slight control of Pseudomonas coronafaciens on oats. Against a number of obligate parasites including Uromyces fabae on broad beans and Puccinia triticina on wheat, the sulphonamides gave effective control when applied either through the roots or leaves. The minimal effective concentrations in the leaves of the more active compounds varied between 100–200 μg./g. fresh weight of leaf tissue.
The sulphonamides are also toxic to higher plants and both the fungitoxic and phytotoxic effects could be reversed with p -aminobenzoic acid.
A number of sulphanilamides with acyl substituents on the p -amino-group were tested against P. triticina and were shown to control the disease with very slight phytotoxic damage. Control could be attributed to the release of 'free' sulphanilamide by hydrolysis within the plant.
Two factors appear to control the systemic action of sulphonamides: first, the movement in the plant which results in the accumulation of effective concentrations in the leaves, and secondly, the specificity of a sulphonamide for a particular host-parasite association.     

Sustainable bio-bricks prepared with synthetic urine enabled by biomineralization reactions

In this study, mineralization during brick preparation was performed with ureolytic bacterium, Lysinibacillus fusiformis that use urine as a substrate, omitting the heat that is normally required. Artificial urine for reasons of standardization was used to grow the bacterium for bio-bricks made of clay and cement, but their mineralization was enabled by biological activity instead of by heat. Scanning electron microscopy and energy dispersion X-ray spectroscopy were conducted to analyse the microstructures formed by L. fusiformis that precipitated various minerals in synthetic urine. The brick specimens were tested for compressive strength that was 59% more than control ones, whereas porosity of bio-bricks was 13% compared to 22% of control specimens. The minerals formed in the bio-bricks confirmed as struvite, apatite and calcite by Fourier-transform infrared spectroscopy and X-ray diffraction spectra, were responsible for improved strength and reduced porosity. The research provided evidence in utilizing ureolytic bacteria as a mode to mineralize clay in brick production with the use of (artificial) urine as a substrate.     

提高黄皮种子活力的途径

黄皮种子经脱水至40％左右或持续贮藏（一年以上）后种子活力迅速下降,PEG对劣变种子直接引发不但不能提高其活力,反而使其活力更为下降,甚至丧失萌发能力而引发加速了代谢物质的消耗和渗漏。在黄皮种子脱水前用ABA、Ca2 、茶多酚（抗氧化剂）预处理,明显降低了黄皮种子的脱水敏感性。结合用PEG引发技术,则能较大幅度提高黄皮种子脱水后的活力,Ca2 短时高温引发也能提高黄皮种子贮藏一年后的活力,说明预处理是提高脱水和贮藏后黄皮种子活力的必要措施。     

FACTORS AFFECTING THE TOXICITY OF SEVERAL LICHEN ACIDS: EFFECT OF PH AND LICHEN ACID CONCENTRATION

The effect of pH 5–8 and lichen acid concentration gradients (2.7 times 10⁻² - 2.7 times 10⁻⁶ m ) on the toxicity of the following lichen acids: usnic, lecanoric, evernic, vulpinic, stictic, fumarpro-tocetraric, psoromic, and atranorin, on spores of Funaria hygrometrica was tested. Percent germination and sporeling growth were used as indicators of toxicity. None of the lichen acids were significantly toxic, for either percent germination or sporeling growth at concentrations equal to or below 2.7 times 10⁻⁵ m at pH 7.0, but many of the lichen acids which increased in toxicity at values different from pH 7 may have been toxic at lower concentrations if a different pH was used for the assay. Lichen acid toxicity showed a good correlation with pH for the parameter of spore germination, or sporeling growth, or both. Some lichen acids did not inhibit germination but were effective in retarding sporeling growth, or vice versa. This observation is discussed in relation to changing fatty acids and other lipid composition as germination occurs. Two of the three O-methylated lichen acids (evernic and psoromic) were among the most effective in inhibiting growth over all, but at lower pH values these were less effective than non-O-methylated lichen acids. Stictic, which is also an O-methylated lichen acid, was the least effective inhibitor over all the pH values for both parameters, while vulpinic was the most toxic over all the pH values. The order of relative toxicity for the lichen acids is different, depending on the pH and concentration at which they are tested and depending on the parameter measured. Thus, in an ecological sense, it is difficult to evaluate the adaptive significance of a particular compound or group of compounds without knowing what factors influence the toxicity of those compounds and how these factors vary in the organism's habitat.     

THE CHEMICAL CONTROL OF WATER WEEDS IN THE GEZIRA AREA OF THE SUDAN

Chlorophenoxyacetate weed-killers have been tested for the control of aquatic weeds in the canals of the Sudan Gezira. Using water in tanks, it was shown that 10 parts per million of sodium 2-methyl-4-chlorophenoxyacetate (Methoxone) or of sodium 2:4-dichlorophenoxyacetate (Fernoxone) would kill most of the angiospermous water-weeds found in the Gezira area.
Small-scale field experiments, using channels of known water capacity, have shown that not only leaves and stems but also seeds and underground rhizomes were killed in treated stagnant water, provided that the weed-killers were applied as dusts. The water remained toxic to crop plants for approximately 7 weeks after treatment.
In a large-scale experiment in 1950, treating normal irrigation canals, temporary weed clearance was attained, re-infestation was delayed, and one major canal, 4.5 km. long, remained weed-free 12 months after treatment.     

THE REVERSAL OF THE SIGN OF THE CHARGE OF COLLODION MEMBRANES BY TRIVALENT CATIONS

1. Trivalent cations cause a collodion membrane covered with a protein film to be charged positively while they do not produce such an effect on collodion membranes not possessing a protein film. The same had been found for the reversal of the sign of charge of the membrane by acid. 2. This reversal in the sign of charge of the membrane by trivalent cations occurs on the alkaline side of the isoelectric point of the protein used; while the reversal by acid occurs on the acid side of the isoelectric point. 3. The reversal seems to be due to or to be accompanied in both cases by a chemical change in the protein. The chemical change which occurs when the hydrogen ions reverse the sign of charge of the protein film consists in the formation of a protein-acid salt whereby the H ion becomes part of a complex protein cation; while the chemical change which occurs when trivalent cations reverse the sign of charge of the protein film consists in the formation of an insoluble and therefore sparingly or non-ionizable metal proteinate.     

Effects of mycotoxin pretreatment on aflatoxin B1 post-treatment toxicity in Drosophila melanogaster (Diptera)

Two wild-type laboratory strains of Drosophila melanogaster were used in this study: strain Flordia-9, which is sensitive to aflatoxin B₁ (AFB₁)-induced toxicity, and strain Lausanne-S, which is resistant. Eggs of these strains were deposited on medium containing either low or high doses of dietary AFG₁, AFB₂, or sterigmatocystin (ST) and allowed to develop into second instar larvae. After this pretreatment, the larvae were transferred onto medium containing either high or low doses of dietary AFB₁ (post-treatment) and allowed to complete development and eclose as adults. Viability and development data were analyzed to determine the effects of the various pretreatments on the level of AFB₁-induced toxicity in the post-treatments. In no case did any of the pretreatments reduce the toxic effects of AFB₁ post-treatment responses. However, for strain Florida-9, all high-dose pretreatments resulted in enhanced post-treatment toxicity, and all low-dose pretreatments also enhanced toxicity of high-dose post-treatments. For strain Lausanne-S, high-dose AFB₂ pretreatment significantly enhanced toxicity of both high- and low-dose post-treatments. These results indicate that, in strain Florida-9, pretreatment with relatively less toxic mycotoxins (ST and AFB₂) has an enhancing effect on AFB₁-induced toxicity, whereas in strain Lausanne-S, a similar but smaller enhancing effect is seen only with AFB₂ pretratment.     

DNA液晶膜的结构与压电性研究

本文报导了在正交偏振片下观察DNA液晶膜的偏光显微图像,以及用小角激光光散射技术测定该膜的光散射,结果表明;液晶膜内聚核苷酸分子聚集形成棒状分子簇,其最大极化率方向倾斜于棒轴.在这种极化状态下,可测量到DNA膜对单轴机械应力的电压响应,压缩时,具有正的电信号,伸长时,具有负的电信号.     

THE EFFECTS OF SELECTED ANTIBIOTICS ON PURE CULTURES OF ALGAE

Hunter , E. O., Jr ., and Ilda Mc Veigh . (Vanderbilt U., Nashville, Tenn.) The effects of selected antibiotics on pure cultures of algae. Amer. Jour. Bot. 48(2): 179–185. 1961.—A determination was made of the effectiveness of various concentrations of actidione, nystatin, amphotericin-A, anisomycin, and sulfocidin, antibiotics active primarily against fungi, in inhibiting representative species of Myxophyceae, Chlorophyceae, Bacillariophyceae, Xanthophyceae, and Euglenophyceae. Similar investigations were made using polymyxin-B sulfate and bacitracin, antibiotics inhibitory to certain groups of bacteria. Concentrations of 1, 2, 20, 50, 100, and 200 p.p.m. were used. Concentrations of 200 p.p.m. or less of anisomycin, nystatin and actidione had little or no detectable effect on the Myxophyceae but were toxic to members of the Chlorophyceae and the Bacillariophyceae. Thus, these 3 antibiotics are of potential value in eliminating green algal and diatom contaminants from cultures of blue-green algae. Since bacitracin was found to be inhibitory to members of the Myxophyceae at concentrations not toxic to representatives of the other groups tested, it may prove useful in eradicating blue-green algae from cultures of other forms. Microscopic examinations indicated that the cells of cultures of species belonging to the Chlorophyceae, the Myxophyceae, and the Euglenophyceae, when exposed to antibiotics to which they were sensitive, usually underwent lysis, while those of species of Xanthophyceae and of Bacillariophyceae generally showed a loss in pigmentation.     

武汉东湖蓝藻水华毒性的研究Ⅰ．淡水蓝藻毒性的检测

用国外检测蓝藻水华毒性的血凝法和小白鼠腹腔注射藻类提取液法。对武汉东湖蓝藻水华进行检测。发现八月份到十月份其间的藻类水华有不同程度的毒性反应。     

THE EFFECT OF ULTRA-VIOLET,X-RAY,AND RADIUM RADIATION ON THE TOXICITY OF NORMAL BLOOD

While the number of experiments performed is perhaps somewhat limited the results obtained were quite definite and warrant the following conclusions. The toxicity of normal blood for living plant protoplasm as studied on the growth of Lupinus albus seedlings is definitely influenced by various radiations. Ultra-violet rays produce no effect on normal blood or may even render it slightly less toxic. Roentgen rays render normal blood more toxic. The toxicity is greater in the case of the blood plasma as compared with the blood cells and a more toxic effect is produced with the Coolidge tube as compared with the gas tube. Radium emanations in the few experiments performed produced changes very much the same as those given by the x-rays.     

STUDIES IN THE MODE OF ACTION OF INSECTICIDES

Homogenates of the thoracic nervous system of Locusta migratoria migratoriodes are able to hydrolyse acetylcholine (ACh) and o -nitrophenylacetate (NPA), and this hydrolysis can be inhibited by tetraethylpyrophosphate (TEPP) at approximately the same molar concentration for both substrates. It is possible that one acetyl-esterase is responsible for the breakdown of the two substances, and there is no reason to assume the existence of a specific acetylcholinesterase. In normal horse serum, on the other hand, the pseudocholinesterase is quite distinct from the enzyme responsible for the breakdown of NPA.
In an attempt to correlate the inhibition of the locust nerve cord acetylesterase with toxic activity to insects and mice, four chlorinated diethyl-phenylphosphates were tested as contact poisons against a number of insects and by injection against locusts and mice, and also as in vitro inhibitors of locust nerve cord acetylesterase and horse-serum pseudocholinesterase. The chemicals were the 2-chloro-, 4-chloro, 2:4-dichloro- and 2:4:5-trichloro- analogues of diethyl-phenylphosphate.
Good correlation exists between their in vitro activity against the nerve-cord acetylesterase and their contact activity to aphids, but not between the former and injection toxicity to locusts. No correlation could be established between the inhibition of horse-serum cholinesterase and injection toxicity to mice. It is thought likely that the inhibition of nerve-cord acetylesterase is of greater importance in aphids than in other insects, where the toxic action of the phosphoric esters is at least partly concerned with other vital processes, and that a detoxication mechanism in the mammal breaks down some of the phosphoric esters, but not others.     

THE EFFECT OF CERTAIN SOIL TREATMENTS ON DIDYMELLA STEM-ROT OF TOMATOES

About 93% of Didymella lycopersici spores were destroyed after 4 weeks incubation in unsterilized soil. A survey of the microflora of glasshouse soil receiving different treatments and inoculated with D. lycopersici showed no clear relation between numbers of any group of organisms and the incidence of stem rot. Sterilized soil was not made toxic to D. lycopersici by the growth of a number of soil microorganisms even after 9 months incubation, but addition of unsterilized soil or of a suspension of unsterilized soil quickly restored toxicity. Direct observations of spores in soil on slides showed that their fate varied with the treatment of the soil before inoculation. With fresh soil or air-dry soil moistened 2 or more days before inoculation, lysis of spores occurred. With air-dry soil moistened and inoculated simultaneously, some spores germinated but growth of germ tubes soon ceased. No direct connexion could be seen between the fate of the spores and soil microorganisms. Addition of glucose to unsterilized soil reduced its toxicity to D. lycopersici. Soils steamed for 1 min. or longer were not toxic to D. lycopersici , but soils steamed for very short periods were as toxic as unsterilized soils although the soil microflora was much reduced.     

Effects of Mechanical and Chemical Pretreatments of Zirconia or Fiber Posts on Resin Cement Bonding

The bonding strength between resin cement and posts is important for post and core restorations. An important method of improving the bonding strength is the use of various surface pretreatments of the post. In this study, the surfaces of zirconia (fiber) posts were treated by mechanical and/or chemical methods such as sandblasting and silanization. The bonding strength between the zirconia (fiber) post and the resin cement was measured by a push-out method after thermocycling based on the adhesion to Panavia F 2.0 resin cement. The zirconia and fiber posts exhibited different bonding strengths after sandblasting and/or silanization because of the different strengths and chemical structures. The zirconia post showed a high bonding strength of up to 17.1 MPa after a combined treatment of sandblasting and silanization because of the rough surface and covalent bonds at the interface. This effect was also enhanced by using 1,2-bis(trimethoxysilyl)ethane for the formation of a flexible layer at the interface. In contrast, a high bonding strength of 13.9 MPa was obtained for the fiber post treated by silane agents because the sandblasting treatment resulted in damage to the fiber post, as observed by scanning electron microscopy. The results indicated that the improvement in the bonding strength between the post and the resin cement could be controlled by different chemical and/or mechanical treatments. Enhanced bonding strength depended on covalent bonding and the surface roughness. A zirconia post with high bonding strength could potentially be used for the restoration of teeth in the future.     

THE EFFECT OF BODY WEIGHT ON THE RESISTANCE TO INSECTICIDES OF THE LAST-INSTAR LARVA OF DIATARAXIA OLERACEA L., THE TOMATO MOTH

At a constant temperature of 24° C. the final larval instar of Diataraxia oleracea lasts about 10 days, during which its resistance to DDT and γ-BHC as contact insecticides progressively increases up to the 5th or 6th day. It then suddenly decreases, this coinciding with cessation of feeding and the beginning of prepupal formation.
Between the 2nd and the 6th days the gross body weight of the last-instar larva increases from about 0.27 to 0.65g. Under the conditions of the experiments, the LD50 of parathion, as a stomach poison, was linearly related to body weight; on the same basis TEPP was slightly less, and lead arsenate, slightly more, toxic to the larger than to the smaller larvae. However, DDT as a stomach or contact insecticide, and γ-BHC as a stomach poison were notably less toxic to the larger larvae. For example, the increase in LD50 for an increase in larval body weight of × 2 was about × 11 for DDT as a stomach poison and about × 12 as a contact insecticide.
The order of effectiveness of the above insecticides as stomach poisons for the last-instar larva of D. oleracea was parathion > DDT > γ-BHC > TEPP = lead arsenate. Zinc fluoarsenate and rotenone were relatively non-toxic. Larvae of D. oleracea were repelled by food leaf treated with an extract of natural pyrethrins.     

虫草属真菌中虫草素的超声波提取及其毛细管电泳测定

比较了虫草素的四种提取方法,确定了超声波作用的时间、提取溶剂和样品预处理方式。利用高效毛细管电泳分离、测定了虫草属真菌虫草素的含量,首次报道了九州虫草中虫草素的存在。     

棒杆菌(Corynebacterium pekinense)1134菌株原生质体化及其再生条件的研究

Corynebacterium属中的某些菌种是生产氨基酸的重要菌株。但它对蛋清溶菌酶很不敏感,较难制备其原生质体和再生。本文对供试菌株在培养时,加入氨基苄青霉素(ampicillin)、丝氨酸(serine)或甘氨酸(glycine);在酶解前采用不同的预处理,探讨了棒杆菌1134株原生质体化及其再生的条件。经过多次试验,最后选用补加适量的氨基苄青霉素和丝氨酸的培养液培养菌体,用果胶酶(Pectinase)和巯基乙醇(mercaptoethanol)进行酶解前的予处理,使其原生质化的培养液时缩间短至2.5小时,再生率提高至21.1％。为实现该菌株的原生质体融合及工业微生物育种奠定了基础。     

The influence of proximal stem geometry and surface finish on the fixation of a double-tapered cemented femoral stem

In this study, the in vitro fixation of four otherwise identical double-tapered stem-types, varying only in surface finish (polished or matte) and proximal stem geometry (with or without flanges) were compared under two conditions. First, four specimens of each stem type were tested with initially bonded stem–cement interfaces, representing early post-operative conditions. Then, simulating conditions a few weeks to months later, stems were implanted in unused synthetic femurs, with a thin layer coating the stem to prevent stem–cement adhesion. Per-cycle motions were measured at both cement interfaces throughout loading. Overall, surface finish had the smallest relative effect on fixation compared to flanges. Flanges increased axial fixation by 22 μm per-cycle, regardless of surface finish (P=0.01). Further, all stems moved under dynamic load at the stem–cement interface during the first few cycles of loading, even without a thin film. The results indicate that flanges have a greater effect on fixation than surface finish, and therefore adverse findings about matte surfaces should not necessarily apply to all double-tapered stems. Specifically, dorsal flanges enhance the stability of a tapered cemented femoral stem, regardless of surface finish.