Effects of fluoride on glycosaminoglycan of cancellous and cortical bone of rabbits

Summary The present report deals with the effect of excessive ingestion of fluoride on glycosaminoglycan (GAG). Increase in fluoride deposition in bone, and in circulating levels of fluoride in serum, are also reported. Among the 3 constituents of GAG investigated; hexosamine, uronic acid and sulphate, the content remained unaltered except for sulphate.Acknowledgment. The authors wish to acknowledge the Department of Science and Technology (DST), Government of India, for the financial aid. One of us (M.J.) acknowledges the receipt of a Junior Research Fellowship from DST, during the tenure of which the investigations were carried out.     

储层条件下砂岩岩心驱替实验方法研究

岩石电性数据是油田含油饱和度和储量评估的关键参数,实验方法对岩石电性数据测定的准确性具有很大影响.在储层条件(储层温度、压力)下,采用常规法和隔板法两种驱替方式,对玉门油田某区8块砂岩样品进行岩心驱替实验.实验结果表明,相对于常规法,隔板法能够使岩心达到更低的束缚水饱和度;常规驱替方法会产生末端效应,岩心内饱和度分布不均匀,隔板法可以避免末端效应;在同一饱和度状态下,隔板法测得的岩心电阻率、电阻率系数和饱和度指数n低于常规驱替方法测得的数据,不同驱替方式造成的流体分布形式的差别是导致实验结果不一致的原因.虽然隔板法能够得到较好的岩石电性数据,但是实验周期比较长.     

Functional genomics reveal that the serine synthesis pathway is essential in breast cancer

Cancer cells adapt their metabolic processes to drive macromolecular biosynthesis for rapid cell growth and proliferation. RNA interference (RNAi)-based loss-of-function screening has proven powerful for the identification of new and interesting cancer targets, and recent studies have used this technology in vivo to identify novel tumour suppressor genes. Here we developed a method for identifying novel cancer targets via negative-selection RNAi screening using a human breast cancer xenograft model at an orthotopic site in the mouse. Using this method, we screened a set of metabolic genes associated with aggressive breast cancer and stemness to identify those required for in vivo tumorigenesis. Among the genes identified, phosphoglycerate dehydrogenase (PHGDH) is in a genomic region of recurrent copy number gain in breast cancer and PHGDH protein levels are elevated in 70% of oestrogen receptor (ER)-negative breast cancers. PHGDH catalyses the first step in the serine biosynthesis pathway, and breast cancer cells with high PHGDH expression have increased serine synthesis flux. Suppression of PHGDH in cell lines with elevated PHGDH expression, but not in those without, causes a strong decrease in cell proliferation and a reduction in serine synthesis. We find that PHGDH suppression does not affect intracellular serine levels, but causes a drop in the levels of α-ketoglutarate, another output of the pathway and a tricarboxylic acid (TCA) cycle intermediate. In cells with high PHGDH expression, the serine synthesis pathway contributes approximately 50% of the total anaplerotic flux of glutamine into the TCA cycle. These results reveal that certain breast cancers are dependent upon increased serine pathway flux caused by PHGDH overexpression and demonstrate the utility of in vivo negative-selection RNAi screens for finding potential anticancer targets.     

Inverting generating functions with increased numerical precision �� A computational experience

In this paper, we consider the numerical inversion of a variety of generating functions (GFs) that arise in the area of engineering and non-engineering fields. Three classes of GFs are taken into account in a comprehensive manner: classes of probability generating functions (PGFs) that are given in rational and non-rational forms, and a class of GFs that are not PGFs. Among others, those PGFs that are not explicitly given but contain a number of unknowns are largely considered as they are often encountered in many interesting applied problems. For the numerical inversion of GFs, we use the methods of the discrete (fast) Fourier transform and the Taylor series expansion. Through these methods, we show that it is remarkably easy to obtain the desired sequence to any given accuracy, so long as enough numerical precision is used in computations. Since high precision is readily available in current software packages and programming languages, one can now lift, with little effort, the so-called Laplacian curtain that veils the sequence of interest. To demonstrate, we take a series of representative examples: the PGF of the number of customers in the discrete-time GeoX/Geo/c queue, the same in the continuous-time MX/D/c queue, and the GFs arising in the discrete-time renewal process.     

Wind pollination in Pinus roxburghii

Stigmatic pollen load and pollen concentration in the air were studied in the natural population of Pinus roxburghii at Ashtavakra (900 m asl), in the Pauri forest division of Garhwal Himalaya, India. The results reflect diurnal pollen occurrence in P. roxburghii , with the strong significant correlations between pollen concentrations in the air and wind speed, air temperature and relative air humidity. A significant correlation was also observed between microsporangium dehiscence and pollen occurrence in the air. The maximum concentration of pollen grains in the air and higher rates of pollen deposition onto the megasporophylls were between 12 pm and 16 pm of the day, which conforms the best time for pollination in a day in P. roxburghii. The receptivity of Ovulate strobili varied from 3 to 5 days, however, the bagged strobili remained receptive up to 6 days.     

Collagen in aging muscles.

The salt, acid and insoluble collagen fractions were estimated in red, white and cardiac muscles of 10-, 15- and 20-month-old albino rats. The total collagen level with reference to total proteins is more in red than in white and cardiac muscle. Accumulation of more of insoluble collagen and decrease in salt extractable collagen is seen in all three muscles with aging.     

Induction of female flowers on male plants ofCannabis Sativa L. by 2-chloroethanephos-phonic acid

Zusammenfassung Ethrel induziert auf männlichen Hanfpflanzen (Cannabis sativa L.) weibliche Blüten, welche nach der Bestäubung Früchte ausbilden.     

Wind pollination in Pinus roxburghii

Stigmatic pollen load and pollen concentration in the air were studied in the natural population of Pinus roxburghii at Ashtavakra (900 m asl), in the Pauri forest division of Garhwal Himalaya, India. The results reflect diurnal pollen occurrence in P. roxburghii, with the strong significant correlations between pollen concentrations in the air and wind speed, air temperature and relative air humidity. A significant correlation was also observed between microsporangium dehiscence and pollen occurrence in the air. The maximum concentration of pollen grains in the air and higher rates of pollen deposition onto the megasporophylls were between 12 pm and 16 pm of the day, which conforms the best time for pollination in a day in P. roxburghii. The receptivity of Ovulate strobili varied from 3 to 5 days, however, the bagged strobili remained receptive up to 6 days.     

取代四苯基卟啉的合成及性能研究

以吡咯、苯甲醛为主要原料,合成得到四苯基卟啉;将其经硝化、还原、磺化反应处理,又分别得到5-(4-硝基苯基)-10,15,20-三苯基卟啉、5-(4-氨基苯基)-10,15,20-三苯基卟啉、5-(4-氨基苯基)-10,15,20-三(4-磺酸钠苯基)卟啉3种不同取代四苯基卟啉化合物,借助元素分析、红外光谱和核磁共振氢谱等手段对所合成的4种化合物进行了表征.采用紫外-可见光谱法、荧光光谱法以及循环伏安法对4种化合物的光谱性质和电化学性质进行了探究,并讨论了不同取代基的影响.