In this task, you are given an abstract of article. Your task is to generate title for this article. Preferred titles are under thirty words.

Ex Input:
BACKGROUND Hepatitis C virus (HCV) is estimated to affect 130-180 million people worldwide. Although its origin is unknown, patterns of viral diversity suggest that HCV genotype 1 probably originated from West Africa. Previous attempts to estimate the spatiotemporal parameters of the virus, both globally and regionally, have suggested that epidemic HCV transmission began in 1900 and grew steadily until the late 1980s. However, epidemiological data suggest that the expansion of HCV may have occurred after the Second World War. The aim of our study was to elucidate the timescale and route of the global spread of HCV.
METHODS AND FINDINGS We show that the rarely sequenced HCV region (E2P7NS2) is more informative for molecular epidemiology studies than the more commonly used NS5B region. We applied phylodynamic methods to a substantial set of new E2P7NS2 and NS5B sequences, together with all available global HCV sequences with information in both of these genomic regions, in order to estimate the timescale and nature of the global expansion of the most prevalent HCV subtypes, 1a and 1b. We showed that transmission of subtypes 1a and 1b "exploded" between 1940 and 1980, with the spread of 1b preceding that of 1a by at least 16 y (95% confidence interval 15-17). Phylogeographic analysis of all available NS5B sequences suggests that HCV subtypes 1a and 1b disseminated from the developed world to the developing countries.
CONCLUSIONS The evolutionary rate of HCV appears faster than previously suggested. The global spread of HCV coincided with the widespread use of transfused blood and blood products and with the expansion of intravenous drug use but slowed prior to the wide implementation of anti-HCV screening. Differences in the transmission routes associated with subtypes 1a and 1b provide an explanation of the relatively earlier expansion of 1b. Our data show that the most plausible route of the HCV dispersal was from developed countries to the developing world. Please see later in the article for the Editors' Summary.

Ex Output:
The Global Spread of Hepatitis C Virus 1a and 1b: A Phylodynamic and Phylogeographic Analysis

Ex Input:
The pH dependence of the quaternary structure of pyruvate decarboxylase from yeast was studied in the range 6.2 less than pH less than 8.4. There is an equilibrium with a midpoint around pH 7.5 between tetramers and dimers, and the catalytic activity of the enzyme depends on the volume fraction of tetramer. This equilibrium may provide an additional regulating mechanism besides substrate activation since accumulation of pyruvate would lead to a reduction in pH and hence an increase of the concentration of the catalytically active tetramer. Radiation damage during the X-ray scattering experiments results in a shift of this equilibrium and in the formation of octamers. These effects could be circumvented and analyzed using experimental and data processing methods which can be readily applied to other radiation-sensitive systems. The low-resolution shapes of the dimers and tetramers were determined from the scattering curves using spherical harmonics. The results indicate that a conformational change must occur in the dimers upon formation of the tetramers, in agreement with earlier circular dichroism measurements.

Ex Output:
Synchrotron radiation solution X-ray scattering study of the pH dependence of the quaternary structure of yeast pyruvate decarboxylase.

Ex Input:
BACKGROUND Oral squamous cell carcinoma (OSCC) is common type of human cancer, but little is known about the molecular mechanisms deciding on this malignancy. Comprehensive gene expression profiling is essential for understanding OSCC.
METHODS cDNA microarray was used to analyze expression patterns of 16 617 genes in nine OSCC patients.
RESULTS Forty-seven genes with altered expression among all cases were extracted. The ontology of these 47 genes was classified into 10 categories. To validate the microarray data, the expression of genes, including TGFBI, FADD and DUSP1 was analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR). By hierarchical clustering analysis, the nine cases were divided into two clusters.
CONCLUSIONS The 47 genes are suggested as having a functional significance in oral squamous cell carcinogenesis. It is also suggested that the gene expression patterns by hierarchical clustering analysis can represent degrees of differentiation. The postoperative recovery was uneventful and patients free from tumor after surgery. In the future, on the occasion when the time comes that the number of cases accumulated for microarray increases and each case is observed more over a long-term, these data of 5-year survival rate will be added. Thereby, it will become possible to represent the malignancy of OSCC by these gene expression patterns.

Ex Output:
Gene expression analysis by cDNA microarray in oral squamous cell carcinoma.