Q-score

Q-score Compound quality score based on molecular weight, biological promiscuity, and other data commonly accepted to measure lead-like properties of a compound. 

The Q-score is composed of a number of components. Some of these are listed below. 

Once all of the component scores are defined and calculated, one can then compute the Q-score by forming a linear combination of the components. For example, Q-score could be computed using the formula shown in Eq. 2.5 ... 

As was done for the Q-score, the numerator sum was divided by the sum of the weights so that the B-Score ranged between 0 and 1. 

The D-score is computed using the maximum dissimilarity algorithm of Lajiness (20). This method utilizes a Tanimoto-like similarity measure defined on a 360-bit fragment descriptor used in conjunction with the Cousin/ChemLink system (21). The important feature of this method is that it starts with the selection of a seed compound with subsequent compounds selected based on the maximum diversity relative to all compounds already selected. Thus, the most obvious seed to use in the current scenario is the compound that has the best profile based on the already computed scores. Thus, one needs to compute a preliminary consensus score based on the Q-score and the B-score using weights as defined previously. To summarize this, one needs to... 

Compute the normalized and regularized component scores (B-score and Q-score)... 

Compute the preliminary consensus score (e.g., Q-score +. 5 B-score)... 

Compound Q score Bscore ConsensusO OrderO Dissim Dissim order Consensus Final Order... 

An example of a final consensus list can be seen in Fig. 6. In this figure one can see the Q-score and B-score and the computed preliminary consensus score. On the basis of the preliminary consensus, NP-103930 was chosen as the best compound and selected to be the dissimilarity seed. After the maximum dissimilarity calculation, the diversity score was input and the final consensus score was calculated. As one can see from this figure, the first compound in the preliminary run remains the best. The second compound from the preliminary run does not appear in this list as it was very similar to the NP-103930 and was de-prioritized and moved down the list accordingly. Also the 155th compound in the preliminary ranking moved up the 14th rank because it was considered as a structurally novel compound. This, we feel, illustrates the power of this approach. Compounds with the most desirable properties move up the list and compounds with less desirable properties move down the list. 

Average Quality (based on Q-score) for each of the six lists is illustrated via histograms in Fig. 11. Clearly, list 1 contains the highest quality compounds and list 6 contains the worst in terms of compound quality. 

Studies also consistently show that children who were breastfed as infants suffer less from allergies, asthma, diabetes, colitis, and rheumatoid arthritis. They also have higher I.Q. scores. Breast milk contains special substances that help guide the development of the brain after birth. 

Another scoring system also mentioned in the harmonised protocol but not recommended by the authors is the Q scoring system largely used in occupational hygiene monitoring ... 

Some form of semi-quantitation (H-score, Q score, Allred score) should be performed on all positive cases, as it is therapeutically important. 

Fig. 4.7. Illustration of the process of principal components analysis to produce a new data matrix of Q scores for P samples where Q is equal to (or less than) the smaller of /V (variables) or P (samples). The loadings matrix contains the contribution (loading) of each of the Af variables to each of the O principal components.

As a commercial company that provides analytical services for the determination of radionuclides for a wide variety of clients, AMEC required a more accurate and reliable method to be developed. It needed to use relatively low hazard chemicals, have improved accuracy and precision and utilise common radiochemical analytical laboratory equipment such as liquid scintillation counters and gravity fed chromatography columns. In addition, the process must have realistic and commercially viable batch sizes, operator time and turnaround times, so that samples can be analysed in a cost-effective manner. Ideally the whole process for a batch of samples should not exceed more than one working week. As part of the validation process both internal and external quality control (QC) samples were used along with statistical tests, such as zeta (Q scores and student t-tests , to determine the accuracy of the improved method. In addition, elution profiles for iodine and chlorine and decontamination tests for potentially interfering radionuclides were also carried out in order to further validate the process. 

Although lead has been used since ancient times for medicinal purposes, its toxic properties were also understood. Thus, lead colic was reported by Hippocrates, and about 50 A.D., poisoning of lead workers was documented by Pliny. Ramazzini observed toxicity to potters working with lead in 1700, but it was not until 1933 that Kehoe demonstrated wide exposure to lead in the environment. Lead produces adverse effects on children with respect to behavior and reduced I.Q. scores, even at very low levels (5). 

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