An Unexpected Finding

TM apparatus from Otto Hahn s lab urns used to prmiuce fission reactions. 

In 1934, the element with the most known protons was uranium, with 92. But that year, itaiian physicist Enrico Fermi thought he had synthesized eiements with higher atomic numbers. After bombarding a sampie of uranium with neutrons, Fermi and his co-workers recorded measurements that seemed to indicate that some uranium nuciei had absorbed neutrons and then undergone beta decay  

His report noted further subsequent beta decays, by which he hypothesized the existence of a whoie new series of transuranic elements, now called transuranes  

Unfortunately, Fermi and his group of scientists could not verify the existence of the transuranes because, according to Fermi, We did not know enough chemistry to separate the products of uranium disintegration from one another.  

Fermi s experiments caught the attention of a physicist in Berlin, Lise Meitner. Knowing that she could not perform the difficult task of chemically separating radionuclides either, Meitner persuaded a colleague, radiochemist Otto Hahn, to help her explain Fermi s results. Joined by expert chemical analyst Fritz Strassman, Meitner s team began investigating neutron-induced uranium decay at the end of 1934. 

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Both skin-exposed volunteers and those wearing WBDs were biomonitored for urinary clearance of trichloropyridinol. An unexpected finding was that before exposure (day 0) each 24-hr urine specimen contained measurable... 

An unexpected finding was that phosphati-dylserine synthase of E. coli is tightly bound to ribosomes.524 This enzyme, which incorporates serine into phospholipids according to step h of Fig. 21-4, is responsible for synthesis of the principal membrane... 

Swift B. Examination of insulin injection sites an unexpected finding of localized amyloidosis. Diabet Med 2002 19(10) 881-2. 

The values for the N-terminal amino acids of five different transferrins are given in Table 6. Three out of the five have been reported to have alanine. The absence of an N-terminal amino acid in human lactotrans-ferrin (95) is an unexpected finding in view of the many physical and chemical properties human lactotransferrin and other transferrins have in common (22, 137). Confirmation of this absence is highly desirable. 

This fairly straightforward concept of the stereochemical features defining the specificity of eel serum was, however, complicated by an unexpected finding extremely low concentrations (for example, 0.3 /Ag/ml) of an L-fucose-free polysaccharide from Taxus cuspidata com-... 

P-type ATPases. This is an unexpected finding as generally the cation specihcity of P-type ATPases is restricted to the amino acid composition of cation channels in transmemhrane domains (Axelsen and Palmgren, 1998 Mpller et al., 1996). It is probable that other, as yet to be identihed, intramolecular interactions may be important for the specihc cation transport by heavy metal P-type ATPases. Cysteine residues in transmembrane domain 6, which form a characteristic CPx (commonly CPC) motif, are commonly regarded as core elements of the cation channel in CuPAs. However, there is no direct evidence to date to support that assumption. 

The existence of multiple forms of the same peptide is not an unexpected finding. In Drosophila melanogaster a single gene codes for a family of Phe-Met-Arg-Phe-NH (FMRFamide) related peptides which are similar at the C terminus (21), as are the allatostatlns in D. punctata. Whether or not the different forms of allatostatlns have different functions remains to be determined. 

Interpretation of cohort studies is not always straightforward there are a number of selection effects and biases that must be considered. Cohort studies routinely report that the mortality of active workers is less than that of the population as a whole. It is not an unexpected finding since workers usually have to undergo some sort of selection process to become or remain workers. Nevertheless, this selection effect, known as the healthy worker effect, can lead to considerable arguments over the interpretation of study results, particularly if the cancer mortality is as expected but the all-cause mortality is much lower than expected. However, even an experimental science such as toxicology is not without a similar problem of interpretation, namely, the problem of distinguishing between the effects of age and treatment on tumor incidence. 

Lead exposure mcreases urinary ALA and coproporphyrin-III excretion and causes accumulation of 2n-protoporphyrin in erythrocytes. The definitive test for lead toxicity is measurement of blood lead, but occasionally lead exposure is responsible for porphyria-like symptoms and may be an unexpected finding when investigating patients for suspected porphyria. ... 

It is an unexpected finding that the N-acetylglucosamine moiety can be replaced completely (Fig. 11). However, the examples C and D show the selective fuco-... 

An unexpected finding of hydroxyurea treatment is induction of hemoglobin F (HbF) production in red blood cells. Hydroxyurea therapy results in an increase in both content and the number of red blood cells that contain HbF (known as F cells). This property of hydroxyurea has been... 

An additional means of synthesizing glycal derivatives has been established as a consequence of an unexpected finding made during (1) R. J. Ferrier, Advan. Carbohyd. Chem., 20,67 (1965). 

A qualitative conclusion could be drawn from this experiment reaction had occurred with the CO2 and from the first entry in table 9.18 it can be concluded that the carbamic-acid-terminated PDMS reaction product is essentially insoluble in CO2 at conditions of 300 bar and 60°C. This is not an unexpected finding if the polarity of the material is considered. Based on this reasoning, the reaction product would be expected to be insoluble in ethane as well. Furthermore, the material which dissolved in ethane could not be solely disiloxane (a water-white liquid) based on the appearance of the extract and on the measured solubility. Since some water-white liquid was collected using ethane, some reversion may have occurred, but white solid continued to appear in the extract after about 1 h, showing clearly that the reversion was... 

Modification of specific amino acid residues should affect the rate of proteolysis by those enzymes which have specificity for the unmodified residues. For example, modification of the lysine residues of a protein restricts the action of trypsin. Dimethylated casein undergoes a slower rate of hydrolysis by trypsin in vitro, and the extent of proteolysis is lower than that of casein (267). An unexpected finding was that the rate and extent of hydrolysis of dimethylated casein by a-chymotrypsin are also adversely affected, while hydrolysis by subtilisin is not. Peptides derived from dimethylated casein were inhibitory of a-chymotrypsin. 

An unexpected finding in the RNA Pol I field was the realization that yeast do not have factors that resemble the two essential vertebrate RNA Pol I auxiliary factors, UBF and SL1. Indeed, many attempts to clone yeast RNA Pol I factors by homology screening did not yield any results. Moreover, analysis of the yeast genomic sequence does not show any protein with obvious similarity to UBF or SL1. This was unexpected, as the RNA Pol II and Pol III machineries are rather conserved between vertebrates and yeast. Consequently, the identification of yeast factors involved in RNA Pol I transcription has evolved separately from the... 

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