广玉兰树叶中温发酵产沼气潜力的试验研究

为探究植物落叶资源化利用的途径,以废弃的广玉兰树叶为原料,在恒温30℃的条件下进行批量式沼气发酵试验,试验设计1个对照组(120 g接种物)和4个试验组(A1:5%发酵浓度、原料未粉碎;A2:5%发酵浓度、原料粉碎;B1:74%发酵浓度、原料未粉碎;B2:74%发酵浓度、原料粉碎)。试验结果表明,试验组A1、A2、B1和B2的总固体含量产气率分别为278、290、245和253 mL/g·TS,它们的挥发性固体含量产气率分别为355、370、313和/g·VS,废弃的广玉兰叶是一种较好的沼气发酵原料。     

猪粪玉米秸沼气发酵的研究 I．发酵过程及其调控

以C：N分别为11：1,16：1,24：1,38：1和71：l的猪粪玉米秸混合原料,在TS为10％和5％的条件下观察了30℃时沼气发酵的情况。试验表明低浓度、C：N较低时易正常发酵; TS为10％和C：N为71：1 时很难起动。进而试验了鲜人尿、硫酸铵、尿素、碳酸氢铵,磷酸氢二铵等降低原料C：N促进沼气发酵正常化的效果。结果表明,鲜人尿、尿素及碳酸氢铵可促进高C：N和高TS％的原料正常沼气发酵;用无氮缓冲液控制发酵醪的pH值,高C：N高TS％的原料亦可正常进行沼气发酵,说明pH值对沼气发酵的影响可能比C：N值更重要。还试验了用“微生物菌群”控制发酵：将原料TS为5％、C：N为49：1的发酵液,在其pH开始回升时取出注入原料TS为10％,C：N为49:1、pH降至5．0的发酵液中。5天后沼气发酵正常起动,而注水作对照的则完全未起动。     

牲畜粪便与麦秆混合厌氧发酵的产气量、发酵时间及最优温度

探索牲畜粪便与作物秸秆混合发酵的产气量和发酵时间与发酵温度之间的关系,是解决农村户用沼气原料选择、确定最优发酵温度和提高农作物秸秆资源化利用效率的关键.采用可控型恒温发酵装置,以猪粪、牛粪和麦秆作为发酵原料,以常温厌氧发酵池的底物为接种物,在总固体（total solid,TS）质量分数为8%的条件下进行批量试验,研究了混合发酵的产气量、发酵时间及最优温度.结果表明：粪便与麦秆混合发酵明显提高了原料的产气效率,其中猪粪与麦秆混合发酵的累积产气量比猪粪作为单一发酵原料高24倍,而牛粪与麦杆混合发酵的累积产气量与单一牛粪无显著差异.猪粪、牛粪与麦秆混合发酵的最优温度均在30 ℃以上,发酵时间在60 d左右.厌氧发酵的发酵时间不总是随着温度的升高而缩短,单一以温度来断定厌氧发酵时间的长短是不可行的.     

滇池水葫芦固液分离后的沼气发酵研究

在常温下,分离水葫芦为水葫芦渣和水葫芦汁,水葫芦渣与猪粪结合进行批量发酵试验,研究了产气量及原料半纤维素、纤维素、木质素的降解,结果表明原料的产气率为504.04 L/g TS,甲烷含量65%,半纤维素、纤维素降低,木质素升高.对水葫芦汁厌氧发酵的产气及COD降解情况进行了研究,结果表明水葫芦汁的产气潜力为2.192 mL/g,COD降解率达到91.27%.     

酒精-沼气双发酵耦联工艺中SO42-的控制

SO2-4是"酒精-沼气双发酵耦联工艺"稳定运行的重要抑制物.在耦联工艺中,以中温厌氧出水代替自来水配料进行酒精发酵.通过无预糖化工序的"同步糖化发酵"技术研究,将酒精发酵的初始pH提高到6.0,H2SO4的消耗降低了50%,使SO2-4的质量浓度维持在3g/L的沼气发酵安全范围内.在进行高浓度酒精发酵时,糖化酶的添加量为每克木薯添加140U,发酵54h,最终酒精体积分数达14.7%.糖化酶添加量与常规酒精发酵用量相比,每克木薯增加了糖化酶20 U.     

前体及诱导子和发酵条件对烟曲霉TMS-26产紫杉醇发酵体系优化

紫杉醇是一种广谱的抗癌药物,因其具有独特的抗癌机制、良好的抗癌效果和供不应求的市场等特征而备受关注。紫杉醇具有重大经济效益,但产量受到制约,价格极为昂贵,通过内生真菌发酵法生产紫杉醇能在一定程度上缓解其来源困难的问题。在产紫杉醇内生真菌TMS-26发酵液中添加前体物质和诱导子,并通过对接种量、装液量、初始pH和发酵时间等条件进行优化研究。单因素及正交试验表明在PDB培养基中加入苯丙氨酸20mg/L、苯甲酸钠30mg/L、乙酸钠8g/L、甘氨酸15mg/L、CuSO₄ 0.05mg/L、H₂O₂ 6mmol/L、3,5-二硝基水杨酸15mg/L时能有效提高紫杉醇产量,比优化前增产46.64%,达到446.28µg/L,并且发现最适菌株TMS-26的发酵条件为pH7.5、接种量5%、装液量120mL/250mL、发酵时间为10d。     

添加厨余垃圾对剩余污泥厌氧消化产沼气过程的影响

为提高剩余污泥厌氧消化的沼气产量和甲烷含量,研究了厨余垃圾的不同添加量对剩余污泥厌氧消化性能的影响。结果表明,在35℃下,随着剩余污泥中厨余垃圾添加量的增加,厌氧消化系统中碳氮质量比（C／N）、胞外多聚物（EPS）等生理生化指标均有不同程度的改善。其中当剩余污泥与厨余垃圾质量比为2：1时,混合有机废弃物中沼气产量和甲烷含量均达到最大值,每克挥发性固体（VS）产生了156．56mL沼气,甲烷体积分数为67．52％,分别比剩余污泥单独厌氧消化时的产气量提高了5倍和1．5倍。     

萃取耦合技术对玉米秸秆水解液发酵产丁醇的影响

本研究以玉米秸秆水解液为原料,通过萃取发酵技术生产燃料丁醇,以提高丁醇产量,降低生产成本。通过对萃取剂的筛选与条件优化,确定纤维丁醇发酵的萃取剂为油醇,添加时间为发酵0 h,添加比例为1:1 (V/V)。该条件下发酵32 g/L糖浓度的玉米秸秆水解液,丁醇和总溶剂产量分别为3.28 g/L和4.72 g/L,比对照分别提高958.1%和742.9%。以D301树脂脱毒后5%总糖浓度的玉米秸秆水解液进行丁醇萃取发酵,丁醇和总溶剂产量分别达到10.34 g/L和14.72 g/L,发酵得率为0.31 g/g,与混合糖发酵结果相当。研究结果表明萃取发酵技术能够显著提高原料的利用率和丁醇产量,为纤维丁醇工业化生产提供了技术支撑。     

基因重组大肠杆菌表达HrpNEcc蛋白的发酵条件及诱导条件优化

对已构建好的表达HrpNEcc蛋白的工程菌BL21(DE3)/pET30a(+)hrpN Ecc的摇瓶发酵条件及乳糖诱导进行优化, 通过在7L发酵罐中放大发酵实验,以期提高蛋白产量并降低生产成本。在摇瓶中优化的发酵及诱导条件是：5% 的接种量,TB培养基,菌体培养至对数生长前期,添加3g/L外源诱导剂乳糖时,HrpNEcc蛋白产量可达417.60mg/L,比不添加乳糖时提高了36.73%,比用IPTG诱导时提高了16.85%。7L发酵罐中发酵,获得菌体湿重达到57.24g/L（WCW）,可溶性HrpNEcc蛋白产量占细胞总蛋白的50.2%,为3.29 g/L。     

利用发酵促进剂提高红酵母β-胡萝卜素产率

为提高红酵母生物合成β-胡萝卜素的产量,分别研究了几种添加物对发酵过程的促进效应。试验结果表明：分别添加硫胺素、核黄素、大豆油和番茄汁可以显著促进红酵母合成β-胡萝卜素。当按单因素试验确定的最优添加量联合添加硫胺素1.5mg/L、核黄素3mg/L、大豆油5mg/L、番茄汁6mg/L时,试验证实β-胡萝卜素发酵产率可比对照提高80%以上,值得进一步研究。     

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.

---

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.     

Separation of the pineal vesicle from the wall of the third ventricle during the post-hatching development of the chicken

Summary According to light- and electron-microscopic observations the pineal organ of the 3-day-old chicken consists of a prominent end vesicle and a tapering parenchymal stalk. During this stage the pineal lumen is in open communication with the third ventricle. However, in the 40-day-old chicken, which still possesses a well-developed end vesicle, the proximal portion of the pineal stalk displays regressive changes leading to local fragmentation. At this stage the pineal stalk is reduced, and the pineal lumen is missing. In 1-year-old chickens the parenchyma of the proximal portion of the stalk is further diminished, and in 3-year-old domestic fowl is completely displaced by bundles of collagenous fibers, only some nerve fibers being present. This post-hatching pineal development may reflect the sequence of changes leading from pineal sense organs to pineal glands.This work was supported by a grant-in-aid for Scientific Research from the Ministry of Education, Science and Culture of Japan     

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     

On the Dependence of the Quadratic Risk of the Classical Predictor and the Prediction-Horizon

When constructing predictors on the basis of the linear model of time series of various indicators often the question arises on the dependence of forecasting accuracy and the changing prediction horizon. The dependency of the quadratic risk of the classical predictor and the time horizon is considered.