Some effects of sugars and sugar phosphates on carbon dioxide fixation by isolated chloroplasts

1. Carbon dioxide fixation by isolated pea chloroplasts was stimulated by the addition of intermediates of the Calvin photosynthesis cycle and by some related compounds. 2. Ribose 5-phosphate and fructose 1,6-diphosphate consistently produced the largest effects; free sugars such as erythrose and sedoheptulose and acids such as glycollate and glyoxylate were largely ineffective or even inhibitory. 3. Small effects were produced by fructose and ribose but not by their isomers, glucose and xylose. 4. Maximal rates in the presence of ribose 5-phosphate varied between 10 and 50μmoles of carbon dioxide fixed/mg. of chlorophyll/hr.     

生物学中物理学和化学成就的利用

在H.C.赫魯晓夫同志“关于1959—1965年苏联国民經济发展的控制数字”的报告提綱里、赋予科学和技术的发展前景以特殊地位。由于科学和技术在社会主义社会发展中所占的那种地位,因而这是可以理解的。     

肺脏藥理学

肺脏換气量是直接受神經中枢及間接地受化学感受性反射的影响。众所周知,任何刺激性物貭均能引起呼吸道反射而产生浅与快式的呼吸。有許多物理因素,例如在矿厂区与街道上都有粉尘,它可以增加呼吸道的阻力而引起呼吸性反射作用;其中足以引起矽肺的那种較大的粉尘,其顆粒直径在1—5微米大小,可以依靠戴口罩来避免吸入。但是     

A NEW GRAPTOLITE FAUNA FROM THE LOWER ORDOVICIAN SHALE OF TSAIDAM,CHINGHAI PROVINCE

I.Discussion on the stratigraphical position of the graptolite-bearing shale and the distinguishing features of the fauna Our country,being vast in territory and rich in natural resources,unremittingly affords usinteresting scientific materials of both theoretical and practical significance.The finding of the newgraptolite fauna from the Ordovician shale of Tsaidam is one of a thousand like instances.Thisfinding brings forward a series of scientific problems which we should resolve,and thus pointsout more definitely the direction in which we must lay stress on our study.The graptolites were discovered and collected in 1956 by Comrade Sun Tien-Ching and other     

国际学术交流 血压的平衡与高血压症之形成机制

正常休循环血压之平衡及高血压症之形成机制,在現代医学界,仍然是一极引入注意;也非常重要的問題。高血压基本上是血压生理平衡的一种偏差,为了闡明高血压症的主要原因,我們首先須探討調节血压的各种生理机制。大家知道,血压之所以能够維持在正常生理限度之內,是通过位在主动脉弓吸頸动脉竇內压力感受器的反射作用的。大家也都知道,血压是由主动脉神經(或減压神經)及頸动脉竇神經的抑制作用反射地控制着。如果将这四条神經(通常称为緩冲神經)切断,就可以引起一种急性或慢性的     

SOME UPPER CARBONIFEROUS FUSULINIDS FROM THE VICINITY OF BEIYIN OBO,INNER MONGOLIA

The fusulinids dealt with in this paper were collected in 1955 by Mr.L.S.Wong of a field party sent by the Ministry of Geology in the vicinity of BeiyinObo,Inner Mongolia(formerly province Suiyuan).The fusulinid-bearing bedof this area was named by Mr.Wong the Lalaotu limestone.No data of stra-tigraphical sequence of this region are readily available.Since no informationof the fusulines in this region has been hitherto known,the present discoveryaffords therefore some interest.     

LUDLOVIAN GRAPTOLITE FAUNAS OF THE YANGTZE GORGES DISTRICT AND THEIR STRATIGRAPHICAL SIGNIFICANCE

Ⅰ.INTRODUCTIONThe Silurian stratigraphy of the Yangtze Gorges district has been reportedby various authors since this century.Early in 1924 J.S.Lee and Y.T.Chao subdivided the Silurian of Sintandistrict into two parts—the lower Lungma shale and the upper Sintan forma-tion,thus laying down the fundation of the silurian stratigraphy of China.Inthe following year C.Y.Hsieh and Y.T.Chao went to Lojoping area of I-Chang district and again subdivided the Silurian of that area into three sub-     

Partition of porphyrins between cyclohexanone and aqueous sodium acetate as a function of pH. Determination of uroporphyrin and of hydrophilic porphyrin conjugates

1. The partition of uroporphyrins I and III, coproporphyrins I and III, haematoporphyrin IX, porphyrin c and a hydrophilic porphyrin–peptide fraction from variegate-porphyria faeces has been studied in systems of equal volumes of cyclohexanone and sodium acetate buffers of varying pH and concentration. 2. The concentration of acetate in the aqueous phase has little effect on the partition of porphyrin c, but markedly influences that of uroporphyrin. At 50% acetate saturation and pH4·5, only 5% enters the cyclohexanone phase whereas 60% of porphyrin c is extracted under similar conditions. 3. This circumstance forms the basis of a method for the determination of hydrophilic porphyrin–peptides in variegate-porphyria urine. Its reliability has been checked in model experiments. 4. At pH1·5 and an aqueous phase half-saturated with sodium acetate, an equal volume of cyclohexanone removes 95–97% of uroporphyrin and about 55% of porphyrin c. Uroporphyrin may therefore be determined as a second step in the method. 5. For the routine determination of uroporphyrin in systems free from other hydrophilic porphyrins, cyclohexanone extraction may be performed at any pH in the range 1·0–3·0.