9 research outputs found
A comparative analysis of 21 literature search engines
Get PDFWith increasing number of bibliographic software, scientists and health professionals either make a subjective choice of tool(s) that could suit their needs or face a challenge of analyzing multiple features of a plethora of search programs. There is an urgent need for a thorough comparative analysis of the available bio-literature scanning tools, from the user’s perspective. We report results of the first time semi-quantitative comparison of 21 programs, which can search published (partial or full text) documents in life science areas. The observations can assist life science researchers and medical professionals to make an informed selection among the programs, depending on their search objectives. 
Some of the important findings are: 
1. Most of the hits obtained from Scopus, ReleMed, EBImed, CiteXplore, and HighWire Press were usually relevant (i.e. these tools show a better precision than other tools). 
2. But a very high number of relevant citations were retrieved by HighWire Press, Google Scholar, CiteXplore and Pubmed Central (they had better recall). 
3. HWP and CiteXplore seemed to have a good balance of precision and recall efficiencies. 
4. PubMed Central, PubMed and Scopus provided the most useful query systems. 
5. GoPubMed, BioAsk, EBIMed, ClusterMed could be more useful among the tools that can automatically process the retrieved citations for further scanning of bio-entities such as proteins, diseases, tissues, molecular interactions, etc. 
The authors suggest the use of PubMed, Scopus, Google Scholar and HighWire Press - for better coverage, and GoPubMed - to view the hits categorized based on the MeSH and gene ontology terms. The article is relavant to all life science subjects.

Molecular models for intrastrand DNA G-quadruplexes
Get PDF<p>Abstract</p> <p>Background</p> <p>Independent surveys of human gene promoter regions have demonstrated an overrepresentation of G<sub>3</sub>X<sub><it>n</it>1</sub>G3X<sub><it>n</it>2</sub>G<sub>3</sub>X<sub><it>n</it>3</sub>G<sub>3 </sub>motifs which are known to be capable of forming intrastrand quadruple helix structures. In spite of the widely recognized importance of G-quadruplex structures in gene regulation and growing interest around this unusual DNA structure, there are at present only few such structures available in the Nucleic Acid Database. In the present work we generate by molecular modeling feasible G-quadruplex structures which may be useful for interpretation of experimental data.</p> <p>Results</p> <p>We have used all quadruplex DNA structures deposited in the Nucleic Acid Database in order to select a list of fragments entailing a strand of three adjacent G's paired with another strand of three adjacent G's separated by a loop of one to four residues. These fragments were further clustered and representative fragments were finally selected. Further fragments were generated by assemblying the two strands of each fragment with loops from different fragments whenever the anchor G's were superimposable. The fragments were used to assemble G quadruplex based on a superimposability criterion.</p> <p>Conclusion</p> <p>Molecular models have been generated for a large number of G<sub>3</sub>X<sub><it>n</it>1</sub>G<sub>3</sub>X<sub><it>n</it>2</sub>G3X<sub><it>n</it>3</sub>G<sub>3 </sub>sequences. For a given sequence not all topologies are possible with the available repertoire of fragments due to steric hindrance and low superimposability. Since all molecular models are generated by fragments coming from observed quadruplex structures, molecular models are in principle reliable and may be used for interpretation of experimental data. Some examples of applications are given.</p
In search of the right literature search engine(s)
Get PDF*Background*
Collecting scientific publications related to a specific topic is crucial for different phases of research, health care and ‘effective text mining’. Available bio-literature search engines vary in their ability to scan different sections of articles, for the user-provided search terms and/or phrases. Since a thorough scientific analysis of all major bibliographic tools has not been done, their selection has often remained subjective. We have considered most of the existing bio-literature search engines (http://www.shodhaka.com/startbioinfo/LitSearch.html) and performed an extensive analysis of 18 literature search engines, over a period of about 3 years. Eight different topics were taken and about 50 searches were performed using the selected search engines. The relevance of retrieved citations was carefully assessed after every search, to estimate the citation retrieval efficiency. Different other features of the search tools were also compared using a semi-quantitative method.
*Results*
The study provides the first tangible comparative account of relative retrieval efficiency, input and output features, resource coverage and a few other utilities of the bio-literature search tools. The results show that using a single search tool can lead to loss of up to 75% relevant citations in some cases. Hence, use of multiple search tools is recommended. But, it would also not be practical to use all or too many search engines. The detailed observations made in the study can assist researchers and health professionals in making a more objective selection among the search engines. A corollary study revealed relative advantages and disadvantages of the full-text scanning tools.
*Conclusion*
While many studies have attempted to compare literature search engines, important questions remained unanswered till date. Following are some of those questions, along with answers provided by the current study:
a)	Which tools should be used to get the maximum number of relevant citations with a reasonable effort? ANSWER: _Using PubMed, Scopus, Google Scholar and HighWire Press individually, and then compiling the hits into a union list is the best option. Citation-Compiler (http://www.shodhaka.com/compiler) can help to compile the results from each of the recommended tool._
b)	What is the approximate percentage of relevant citations expected to be lost if only one search engine is used? ANSWER: _About 39% of the total relevant citations were lost in searches across 4 topics; 49% hits were lost while using PubMed or HighWire Press, while 37% and 20% loss was noticed while using Google Scholar and Scopus, respectively._ 
c)	Which full text search engines can be recommended in general? ANSWER: _HighWire Press and Google Scholar._
d)	Among the mostly used search engines, which one can be recommended for best precision? ANSWER: _EBIMed._
e)	Among the mostly used search engines, which one can be recommended for best recall? ANSWER: _Depending on the type of query used, best recall could be obtained by HighWire Press or Scopus.
How do you choose your literature search tool(s)?
No full textWith increasing number of bio-literature search engines, scientists and health professionals either make a subjective choice of tool(s) or face a challenge of analyzing multiple features of a plethora of bibliographic software. There is an urgent need for a thorough comparative analysis of the available literature scanning tools, from the user’s perspective. We report results of the first time semi-quantitative comparison of 21 search programs, which can search published (partial or full text) documents in life science areas. The observations can assist life science researchers and medical professionals to make an informed selection among the programs, depending on their search objectives. 
Some of the important findings are: 
1. Most of the hits obtained from Scopus, ReleMed, EBImed, CiteXplore, and HighWire Press were usually relevant (i.e., these tools showed a better precision than other tools). 
2. But a very high number of relevant citations were retrieved by HighWire Press, Google Scholar, CiteXplore and Pubmed Central (they had better recall). 
3. HWP and CiteXplore seemed to have a good balance of precision and recall efficiencies. 
4. PubMed Central, PubMed and Scopus provided the most useful query systems. 
5. GoPubMed, BioAsk, EBIMed, ClusterMed could be more useful among the tools that can automatically process the retrieved citations for further scanning of bio-entities such as proteins, diseases, tissues, molecular interactions etc). 
The authors suggest the use of PubMed, Scopus, Google Scholar and HighWire Press - for better coverage, and GoPubMed - to view the hits categorized based on the MeSH and gene ontology terms
β-Co(OH)2–Co3O4/Graphene Oxide 3D-Nanoarchitecture modified electrode for electrochemical sensing and energy storage applications
No full textCobalt-modified graphene oxide 3D-nanoarchitecture is fabricated here for its effective use as an electrode material for the sensing of rutin flavonoid and for supercapacitor applications. The graphene oxide preparation was accomplished here comparatively in a shorter period avoiding the tedious and time-consuming preparative pathways in other graphene-oxide-based systems. A sol-gel method was employed for hybridizing graphene with cobalt oxide/hydroxide. Material characterization studies revealed the coexistence of β-Co(OH)2 and spinel Co3O4 in the nanocomposite, whereas FESEM images revealed the 3D nanostructured morphology. The strong interaction between the carbon atoms of graphene sheets with the cobalt species is revealed from the XPS analysis. The synergistic effect provided a good current sensitivity of 1.68 μA/μM towards rutin sensing within a linear detection range of 0.1 μM–20 μM over Co(OH)2–Co3O4/graphene oxide (CoG) modified electrode. High selectivity is offered by the nanocomposite towards rutin and additionally, the sensor succeeded in the detection of a real sample, the rutin tablet. Repeatability and reproducibility in measurements are the added features of the CoG-modified electrode. The diffusion-controlled electrochemical behaviour over CoG was investigated using a redox probe K4[Fe(CN)6]. As a supercapacitor electrode material, the nanocomposite exhibited a maximum specific capacitance of 559.2 F/g at a scan rate of 10 mV/s and 288.4 F/g at 4 A/g current density. Also, it exhibited a high cyclic stability of 109.78% after 1800 continuous charge-discharge cycles displaying its excellence as an energy storage device. The nanocomposite exhibited a dominant contribution from EDLC towards the total capacitance with a low charge transfer resistance
Carnosine inhibits Aβ42 aggregation by perturbing the H-Bond network in and around the central Hydrophobic cluster
Full text linkAggregation of the amyloid-β peptide (Aβ) into fibrillar structures is a hallmark of Alzheimer's disease. Thus, preventing self-assembly of the Aβ peptide is an attractive therapeutic strategy. Here, we used experimental techniques and atomistic simulations to investigate the influence of carnosine, a dipeptide naturally occurring in the brain, on Aβ aggregation. Scanning force microscopy, circular dichroism and thioflavin T fluorescence experiments showed that carnosine does not modify the conformational features of Aβ42 but nonetheless inhibits amyloid growth. Molecular dynamics (MD) simulations indicated that carnosine interacts transiently with monomeric Aβ42 by salt bridges with charged side chains, and van der Waals contacts with residues in and around the central hydrophobic cluster ( LVFFA ). NMR experiments on the nonaggregative fragment Aβ12-28 did not evidence specific intermolecular interactions between the peptide and carnosine, in agreement with MD simulations. However, a close inspection of the spectra revealed that carnosine interferes with the local propensity of the peptide to form backbone hydrogen bonds close to the central hydrophobic cluster (residues E22, S26 and N27). Finally, MD simulations of aggregation-prone Aβ heptapeptide segments show that carnosine reduces the propensity to form intermolecular backbone hydrogen bonds in the region 18-24. Taken together, the experimental and simulation results (cumulative MD sampling of 0.2 ms) suggest that, despite the inability of carnosine to form stable contacts with Aβ, it might block the pathway toward toxic aggregates by perturbing the hydrogen bond network near residues with key roles in fibrillogenesis
