Diterpenoids from Ajuga chamaepitys: Two neo-clerodane derivatives

From the whole plant of Ajuga chamaepitys two new neo-clerodane diterpenoids, ajugapitin and its dihydro derivative, have been isolated. Their     

Trypanosoma brucei: A rapid “matching” method for estimating the host's parasitemia

A new technique for estimating the absolute level of parasitemias in trypanosome infections is described. At higher levels of infection this is achieved by matching microscopic fields of a wet blood film against charts and, where fewer organisms are present, by counting the number of trypanosomes in 5, 10, or 20 such microscope fields. Good estimates of the number of organisms per milliliter of blood can be made rapidly over the whole range of microscopically patent parasitemia, i.e., above antilog 5.4 (250,000) organisms/ml.     

Bacterial periphyton of the Vltava River

Bacterial periphyton formed during 48 hours was studied by glass slide method and direct counting in Vltava River in Praha, Czechoslovakia. At water temperatures 8–11°C the numbers of rods ranged between 24,000 and 336,000 per 1 cm² and those of cocci between 30,000 and 228,000. The relation rods: cocci ranged between 0,9 and 2,4 with an average value of 1,7, whereas in a fishpond this average was 0,5. Among the periphyton 81,3% bacterial cells were active. The rods: cocci relation seems to be a good indicator of water pollution by organic matter, but numbers distinguishing the individual saprobic levels cannot be given yet.

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Zusammenfassung Es wurde der bakterielle Bewuchs von Glassplatten im Vltava-Fluss in Praha untersucht. Zweitägige Exposition erwies sich als am meisten geeignet, um den Bewuchs mikroskopisch durch direkte Zählung quantitativ zu erfassen. In Abhängigkeit von der Tiefe, Wassertemperatur, Verunreinigungsgrad, Sonnenstrahlung u.a. entwickelte sich der Bewuchs quantitativ unterschiedlich und zeigte auch eine unterschiedliche Relation von Stäbchen zu Kokken. Im beta-mesosaproben Bereich wurden im Herbst (Wassertemperaturen 8–11 °C) 24.000 bis 336.000 Stäbchen und 30.000 bis 228.000 Kokken per 1 cm² gefunden, mit den Mittelwerten 163.100 Stäbchen und 104.100 Kokken. Die Vergleichswerte von einem Fischteich in Motol lagen für Stäbchen im gleichen Bereich, während die Kokken, bis 254.000 erreichten.Die Relation Stäbchen: Kokken variierte im Vltava-Fluss zwischen 0,9 (nur einmal) und 2,4 mit dem Mittelwert 1,7, im Fischteich zwischen 0,4 ufnd 0,7 mit dem Mittelwert 0,5. Es hat sich erwiesen, dass diese Relation brauchbare Angaben über die organische Verunreinigung gibt. Leider liegen bisher zu wenige Ergebnisse vor, um eine Skale gegenüber den Saprobitätsstufen zu errichten.Unter den Bewuchsbakterien gab es in der Vltava durchschnittlich 81,3% aktive Zellen, wie durch Fluoreszenzanalyse festgestellt wurde.Fast alle Daten indizieren eine schwächere Verunreinigung des Wassers am linken Ufer als am rechten.

     

INHIBITION OF CHLORELLA (CHLOROPHYCEAE) GROWTH BY FATTY ACIDS, USING THE PAPER DISC METHOD1,2

Using the paper disc-agar plate method, a number of fatty and related acids have been tested for tested activity for inhibiting the growth of Chlorella pyrenoidosa Chick. Of the saturated acids, a peak in growth inhibiting activity wax observed in the C₇–C₁₂ range, where inhibition wax observed when solutions down to 0.02 M were applied to the discs. Most of the unsaturated acids tested showed greater inhibition than did the corresponding saturated acids. Acrylic acid showed detectable inhibition at 0.001 M concentration.     

Pericytes and perivascular microglial cells in the basal forebrain of the neonatal rabbit

Summary Three types of pericytes outline the vascular bed in Golgi preparations of the newborn rabbit brain. Elongate cells (Type I) are restricted to capillaries, elements resembling smooth muscle cells (Type II) surround vessels of intermediate size, and large flat forms (Type III) cover the surface of arterioles and venules. Electron microscopy shows all types to be located within a well defined perivascular basement membrane. It also reveals the presence of filaments in the cytoplasm of some pericytes resembling the myofilaments of smooth muscle cells. It suggests the possibility that some pericytes are capable of contraction and may participate in regulating blood flow in small vessels.Microglia cells bear no resemblance to pericytes in terms of their shape, distribution or staining characteristics. Microglia cells are located outside the vascular basement membrane (external basal lamina) in the brain parenchyma, and they vary in form according to their location and the character of the surrounding extracellular space. This study does not support the hypothesis that microglia cells arise from pericytes but indicates that they originate either by in situ division or from hematogenous elements that enter the brain by crossing the vessel wall.Support provided by N.I.H. Grants No. NS 10864 and NS 07938 from the U.S. Public Health Service.     

内切葡聚糖酶高产菌株的诱变选育

【目的】建立里氏木霉(Trichoderma reesei)高产突变菌株的快速筛选方法,选育出高产内切葡聚糖酶的突变株。【方法】对里氏木霉T306菌株的初筛培养基进行优化,建立快速筛选方法;通过紫外诱变手段选育内切葡聚糖酶高产突变菌株,并对突变菌株的产酶培养基进行优化。【结果】在初筛培养基中添加浓度为0.1%(W/V)的乳糖、蛋白胨及脱氧胆酸钠有利于菌株的筛选。诱变后筛选出菌落形态发生明显变化的内切葡聚糖酶高产突变株0516,其羧甲基纤维素酶活力(CMC酶)较出发菌株提高了38.9%。其产酶培养基经优化后,得到最适碳、氮源分别为:乳糖1.50%、硫酸铵0.14%、尿素0.05%、蛋白胨0.10%,优化后CMC酶活力达64.2 U/mL,较优化前提高了2.3倍。【结论】建立了里氏木霉高产突变菌株的快速筛选方法,通过紫外诱变育种获得了产内切葡聚糖酶能力高且遗传稳定的突变株0516。     

基于扩展耗模型的可持续发展水平区域空间差异——以中国31个省市为数据源

将区域作为一个以人类生产和消费为中心的社会-经济-自然复合生态系统,构建了一种基于生物物理视角的生态热力学方法,从整体角度对区域的可持续发展水平进行定量评价。该方法囊括了维持复合生态系统运转过程中的自然资源投入、人力资源投入和环境污染损害成本投入等三种要素,完善了可持续发展评价以及绿色GDP核算中人力资源投入和环境成本的价值体现。然后以我国为例,核算了我国31个省市2006—2015年间可持续发展水平的时间动态,并以各省为边界,计算了2015年的区域可持续发展水平差异。计算结果显示:(1)十年间,我国整体上的可持续发展水平在逐步提高,能反映出我国生产率水平的提高和资源利用效率的提高;(2)从要素投入看,自然资源投入仍然占主要,但比例在逐渐降低。环境成本投入比例呈逐步降低趋势,说明环境保护取得了成效。另外,在2010年后,人力资源投入比例增加很快,反映了我国经济发展中劳动力成本上升明显。(3)各省市的计算结果差异较大,在不考虑区域间进出口的情况下,从GDP产出角度,北京的可持续发展水平最高,西藏最低。通过将本文的评价结果与绿色发展指数的评价结果进行比较,发现具有较好的一致性。建立的方法框架是对能值分析方法的扩展和完善,在今后的研究中,还需要继续对该方法框架中没有考虑全面的因素加以考虑,以便于更全面客观地反映区域的可持续发展水平。