蛇苔挥发油化学成分的研究

利用气相色谱-质谱联用技术对我国四川省峨嵋山地区蛇苔挥发油的化学成分进行了研究,共鉴定出38种成分,占挥发油成分总量的91．157％,其中单萜、倍半萜类成分较多,顺异丁子香酚的含量最高,占挥发油成分总量的14．4％,并且我们从乙醇浸膏中分离得到了化合物3,4-二甲氧基苯乙烯、β-谷甾醇和胡萝卜苷。     

贵州老鹰茶（红果黄肉楠）挥发油成分研究

利用常压水蒸气蒸馏提取贵州老鹰茶（Actinoaphne cupularis(Hembsl.)Gamble)的挥发油,挥发油得率0．21％,用气相色谱－质谱联用仪进行定性分析。结合计算机检索技术,对挥发油的化学成分进行分离鉴定,NIST化合物谱库检索,应用气相色谱峰面积归一化法测定各成分的相对含量。从Actinodaplme cupularis挥发油中检出138种成分,鉴定出66种成分,占挥发油组成的47．83％,主要成分是异丁子香烯（I*socaryophillene),含量8＝28％;其次是大根香叶烯B（Germacrene,1,2,3,4,4a,5,6,8a-octahydro-7-methyl-4-methylene-1-(1-methylethyl)-(1.α.,4a.α.,8a.α.)-),含量6．57％,其挥发油成分主要是萜类。     

福建产小鱼仙草挥发油的含量及其化学成分的研究

应用气相色谱－质谱－计算机联用系统对小鱼仙草（Mosla dianthera Maxim),挥发油的化学成分进行研究,以SE－54石英毛细管柱分离出43个峰,用GC／MS鉴定出39个成分,其主要成分为百里香酚（37．15％）,香荆芥酚（14．85％）,丁香烯（5．75％）,芳樟醇（5．40％）,檀香烯（4．12％）,律草烯（3．61％）,香桧醇（2．87％）等,占总挥发油的98．40％,又应用气相色谱归一化法计算了各化学成分含量。     

维吾尔医常用药材-芹菜籽挥发油化学成分的研究

利用水蒸气蒸馏法提取维吾尔医常用药材芹菜籽挥发油成分,运用气相色谱-质谱-计算机联用技术,结合标准谱库,从检出的12个化合物中共鉴定了10个成分。其中主要成分为γ-萜品烯、1-甲基-2-异丙基苯、2-甲基-5-异丙基苯酚、邻苯二甲酸正丁基异丁基二酯、邻苯二甲酸二酯、α-宁烯等,其中γ-萜品烯、1-甲基-2-异丙基苯、2-甲基-5-异丙基苯酚的含量较高,占挥发油成分总量的86．84％。检出成分占挥发油成分的98．7％。     

巴巴拉百合花的天然香气成分研究

采用水蒸气蒸馏法对巴巴拉百合花挥发油进行了提取．通过毛细管气相色谱-质谱联用法分离并鉴定了其化学成分．并用气相色谱面积归一化法测定了各成分的相对百分含量。共分离出62个峰,确定了其中60种化合物,所鉴定化合物的含量占全油的99．71％．主要化学成分为：萜二烯(59．43％);3,7-二甲基-1．6-辛二烯-3-醇(20．10％);(R)-4-甲基-1-(1-甲基乙基)-3-环己烯1醇(11．32％);3异丙烯基-5,5-二甲基环已烯(4．05％);2-氨基苯甲酸-3,7-二甲基-1,6-辛二烯-3-酯(3．52％);( )-α-萜品醇(p-薄荷-1-酮-8-醇)(2．22%);β-月桂烯(1．08％)。以上7种化合物占总挥发油的94．72％。     

藏药毛蕊杜鹃挥发油化学成分的GC-MS分析

目的：通过研究毛蕊杜鹃挥发油的化学成分,为毛蕊杜鹃的药用及开发利用提供依据.方法：采用水蒸气蒸馏法提取毛蕊杜鹃挥发油,用GC毛细管柱进行分离,归一化法测其相对含量,并用气相色谱-质谱法对化学成分进行鉴定.结果：共鉴定出38个化合物,鉴定出的化合物含量占总挥发油的92.96％.结论：毛蕊杜鹃挥发油主要成分为δ-杜松烯（相对含量为15.90％）;胡萝卜醇（15.09％）;α-杜松醇（15.02％）;τ-杜松醇（9.66％）;α-衣兰油烯（4.25％）;1,2,3,4,4a,5,6,8a-八氢-7-甲基-4-亚甲基-1-[1-甲基乙基]-萘（4.14％）;1,7-二甲基-4-异丙基-2,7-环癸二烯-1-羟基（3.27％）;石竹烯（2.86％）;5-甲基-9-亚甲基-2-异丙基-二环[4.4.0]癸-1-烯（2.62％）;1,4-二甲基-3-[2-甲基-1-丙烯-1-基]-4-乙烯基-1-环庚烯（2.42％）;γ-衣兰油烯（2.21％）;愈创醇（1.50％）;β-古芸烯（1.34％）.     

海南暗罗叶挥发油化学成分及其抗菌活性(英文)

本文采用水蒸气蒸馏萃取法提取海南暗罗叶挥发油化学成分,利用气相色谱-质谱(GC-MS)从中分离鉴定出40种化学成分,占挥发油总量的67.03%。其中主要成分为1-甲基-5-亚甲基-8-(1-甲基乙基)-1,6-二烯环十烷(18.305%),丁子香烯(6.256%)和γ-榄香烯(6.211%)。所得的挥发油抑菌试验表明其对大肠杆菌和枯草芽孢杆菌表现出显著的抑制活性。     

花椒挥发油的超临界CO2萃取法与水蒸气蒸馏法提取的比较

采用超临界萃取法与水蒸气蒸馏法从花椒中提取花椒挥发油,用GC—MS方法测定各种提取方法得到挥发油的化学成分及相对含量。结果表明,水蒸气提取挥发得率为3．8％（W／W）,主要成分为柠檬烯（22．75％）、沉香醇（21．70％）、罗勒烯（3,7-二甲基-1,3,7-辛三烯）（14．27％）等。超临界CO2萃取法挥发油得率为5．9％（W／W）,主要成分为柠檬烯（14．01％）、沉香醇（13．18％）、罗勒烯（3,7-二甲基-1,3,7-辛三烯）（26．23％）等。两种方法所得到的挥发进行比较,水蒸气蒸馏法分离法得到的挥发油中分离出78个峰,其中含量和相似度高的成分有31种,占86．31％。超临界CO2萃取法提取的花椒挥发油中分离出了152个峰,含量和相似度高的成分有36种,占74．72％。两种提取方法所得到的主要挥发油中有27种成分相同。     

巴戟天挥发性成分研究

目的：研究巴戟天中的挥发性成分。方法：利用水蒸气蒸馏法提取巴戟天（Radix morindae offtcinalis）挥发油,用GC—MS进行测定,结合计算机检索技术对分离的化合物进行结构鉴定,应用色谱峰面积归一化法计算各成分的相对百分含量。结果：鉴定出34个化学成分,其中相对百分含量大于2％的分别确定为L-龙脑（Bomeol L）29．28％,α-姜烯（Alpha—Zingiberene）4．88％,2-甲基-6-对甲基苯基-2-庚烯（Ar-Cureumene）4．49％,1-己醇（1-Hexanol）3．40％,β-倍半水芹烯（beta—sesquiphellandrene）3．34％,2-戊基呋喃（2-Amylfuran）3．32％,正壬醛（n—nonanal）2．17％,樟脑（L—camphor）2．07％,β-没药烯（bete—Bisabolene）2．06％。结论：34个挥发性成分均为首次从该植物中得到。     

海南木莲叶挥发油化学成分研究

目的：分析海南木莲叶的挥发油成分。方法：采用水蒸气法提取挥发油,气相色谱-质谱-计算机联用技术分析。结果：共鉴定出49种化合物,占挥发油总量的99．99％,其中主要成分是橙花叔醇（16．44％）;3,7-二甲基-2,6-辛二烯-1-醇（5.27％）;3,7-二甲基1,6-辛二烯-3-醇（5．12％）;α-丁香烯（4．97％）和丁香烯（4．48％）。     

Ectogenesis and the case against the right to the death of the foetus

Ectogenesis, or the use of an artificial womb to allow a foetus to develop, will likely become a reality within a few decades, and could significantly affect the abortion debate. We first examine the implications for Judith Jarvis Thomson’s violinist analogy, which argues for a woman’s right to withdraw life support from the foetus and so terminate her pregnancy, even if the foetus is granted full moral status. We show that on Thomson’s reasoning, there is no right to the death of the foetus, and abortion is not permissible if ectogenesis is available, provided it is safe and inexpensive. This raises the question of whether there are persuasive reasons for the right to the death of the foetus that could be exercised in the context of ectogenesis. Eric Mathison and Jeremy Davis have examined several arguments for this right, doubting that it exists, while Joona Räsänen has recently criticized their reasoning. We respond to Räsänen’s analysis, concluding that his arguments are unsuccessful, and that there is no right to the death of the foetus in these circumstances.     

On the diversity of the Cladocera in the tropics

The mythical concept of an impoverished tropical cladoceran fauna is refuted. On a planetary scale, around half of the cladoceran species presently known occur exclusively in the tropics-subtropics, often with considerable restriction to particular geographical subzones. On a regional (political) scale, the situation is often unclear because of the continued fragmentary nature of studies, and because political units are not a good basis for biogeographical comparisons. At the finest level of resolution (lake-perlake comparisons), there appears to be an upper limit of c. 50 cladoceran species per individual lake. No significant difference between lakes in the temperate zone and in the tropics could be established here. Daphnia is largely absent from the tropics, but is replaced by more Sidids, Moinids, and Bosminids, such that the average cladoceran community in the limnetic zone of a tropical lake is not characterized by less species but rather by lower population densities. This, in turn, is considered a consequence of higher prevalent predation levels in the tropics.     

Tubular networks in the terminal endings of the visual receptor cells in the human,the monkey,the cat and the dog

Summary A tubular network was found in the terminal endings of the visual receptor cells in the human, the monkey (Macaca mulatta), the cat and the dog. These tubules are arranged in close groups in the vicinity of the synaptic lamellae and the invaginated dendrites. According to the form, diameter, density of the tubules and to the consistence of the network formed by them one can distinguish at these places an initial type (type I), a transitory (type II) and a vesicular one (type III). In the the type III branching, bizarre forms are frequent. The diameter of all the tubules reaches 500–600 Å, their density and walls being the same as in the synaptic vesicles.Similar networks also occur in the axons of the visual receptor cells of the monkey.

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Zusammenfassung In den Endigungen der Photorezeptorzellen von Mensch, Affe (Macaca mulatta), Katze und Hund kommen aus Tubuli bestehende Komplexe vor. Organellenartig in geschlossenen Gruppen angeordnet, liegen sie in Nähe der synaptischen Lamellen und der invaginierten Dendriten. An diesen Stellen kann man nach Form, Durchmesser, Dichte und Konsistenz der von den Tubuli gebildeten Komplexe drei Typen unterscheiden: 1. einen initialen (Typus I), 2. einen Übergangstypus (Typus II) und 3. einen vesiculären Typus (Typus III). In letzterem kommen häufig verzweigte, bizarre Formen vor. Der Durchmesser sämtlicher Tubuli erreicht 500–600 Å. Ihre Dichte und ihre Wand gleicht denen der synaptischen Vesikel.Ähnliche Komplexe fanden wir auch in den Axonen der Photorezeptorzellen vom Affen.

     

Assessing the Physiological State of the Fucoids from the Barents Sea Littoral by the End of the Polar Night

Methods of amperometry and potentiometric titration were used to follow dark respiration (DR) and apparent photosynthesis (AP) in the fucoids Ascophyllum nodosum (L.) Le Jol, Fucus vesiculosus L., and F. serratus L. from the Barents Sea littoral by the end of the 40-day-long polar night. The macroalgae were shown to manifest species-specific low rates of photosynthesis and respiration. However, in spite of their low photosynthetic status due to the effects of subzero temperature and prolonged low or zero illumination, the macroalgae have been able to restore DR and AP to the initial level already by the day 9; the ability to restore AP depended on the level of illumination. The study of the changes in the carbonate–bicarbonate system in the light and darkness demonstrated that the macroalgae grown in darkness, in contrast to those grown in twilight, could absorb bicarbonate in darkness; however, they lost this capacity after two-day-long illumination at an irradiance of 7 mol/(m² s). Bicarbonate uptake in darkness and the capacity to restore the systems of photosynthesis and respiration in fucoid cells are discussed in the context of algal energy metabolism under the polar night conditions.     

Arranging the elements of the potassium channel: the T1 domain occludes the cytoplasmic face of the channel

The voltage-gated potassium channel is currently one of the few membrane proteins where functional roles have been mapped onto specific segments of sequence. Although high-resolution structures of the transmembrane portions of three bacterial potassium channels, the tetramerization domain and the cytoplasmic ball are available, their relative spatial arrangement in mammalian channels remains a matter of ongoing debate. Cryo-electron microscopic images of the six transmembrane voltage-gated Kv channel have been reconstructed at up to 18 Å resolution, revealing that the T1 domain tetramerizes and is suspended below the transmembrane segments. However, the resolution of these images is insufficient to reveal the location of the third piece of the puzzle, the inactivating ball domain. We have used the aberrant interactions observed in a series of chimæric channels to establish that an assembled T1 domain restricts access to the cytoplasmic face of the channel, suggesting that the N-terminal ball and chain may be confined in the space between the T1 domain and the transmembrane portion of the channel.     

Feeding the vertebrate retina from the Cambrian to the Tertiary

The retina of the vertebrate eye is metabolically active and requires nutritive support. During the last 540 million years it has evolved into forms as complicated and nutritionally demanding as those found in avian or primate eyes. Diffusion from the choroid is generally able to supply the metabolic needs of thin retinae. However, when the thickness exceeds the limits of diffusion, structures are needed to supplement the vascular supply from the choroid. These supplemental nutritive devices include the choroidal gland, the falciform process and preretinal vascular plexus of fish, the conus papillaris of lizards, the pecten oculi of birds, the intraretinal vessels of mammals and a few novel systems that remain difficult to classify. These vascular systems are among the most variable features of the vertebrate eye. Here, we review classical and recent findings regarding such retinal nutrition systems, propose a three category classification for them based on histologic origins and speculate on the evolutionary forces which drove their development.     

Observations on the permeability of the choriocapillaris of the eye

Summary The choriocapillaris is a fenestrated capillary bed located posterior to the retinal pigment epithelium. It serves as the main source of supply to the photoreceptors, retinal pigment epithelium, and other cells of the outer retina. The permeability of these capillaries to intravenously injected ferritin (MW — approx. 480,000; mol. diam. 11 nm) was examined in the mouse, rabbit, and guinea pig, each of which is characterized by a different type of retinal vascularization. In all three species, the bulk of the ferritin remained in the capillary lumina, where it appeared to be blocked at the level of the diaphragmed fenestrae. Some ferritin was present in endothelial cell vacuoles. The results confirm previous work on the rat choriocapillaris and indicate that the barrier function of the choriocapillary endothelium is present even among species in which the retinal circulation differs significantly.Supported by NIH grant EY03418