A new field method for tar quantification was used at Coal Oil Point (COP), California to study the mechanisms transporting oil/tar from the nearby COP natural marine hydrocarbon seep field. This method segregates tar pieces into six size classes and assigns them an average mass based on laboratory or direct field measurements. Tar accumulation on the 19,927m(2) survey area was well resolved sp...

HIV-1 Tat hijacks the human superelongation complex (SEC) to promote proviral transcription. Here we report the 5.9 Å structure of HIV-1 TAR in complex with HIV-1 Tat and human AFF4, CDK9, and CycT1. The TAR central loop contacts the CycT1 Tat-TAR recognition motif (TRM) and the second Tat Zn2+-binding loop. Hydrogen-deuterium exchange (HDX) shows that AFF4 helix 2 is stabilized in the TAR comp...

Coal tar is obtained by cooling the gas that is formed during the destructive distillation of coal to approximately ambient temperature. It is a black, viscous liquid composed primarily of a complex mixture of condensed-ring aromatic hydrocarbons. It may contain phenolic compounds, aromatic nitrogen bases and their alkyl derivatives, and paraffinic and olefinic hydrocarbons. Coal-tar pitch is t...

The formation of the Tat-protein/TAR-RNA complex is a crucial step in the regulation of human immunodeficiency virus (HIV)-gene expression. To obtain full-length viral transcripts the Tat/TAR complex has to recruit the positive transcription elongation factor complex (P-EFTb), which interacts with TAR through its cyclin T1 (CycT1) component. Mutational studies identified the TAR hexanucleotide ...

Pine tar is the end product of pine wood carbonisation following distillation using extreme heat. An extensive literature search was conducted back to the 1950s for this review. Pine tar has been used in medicine for more than 2000 years to treat a range of skin conditions because of its soothing and antiseptic properties. Pine tar should not be confused with coal tar, which has been produced f...

Pulse dipolar electron-spin resonance in the form of double electron electron resonance was applied to strategically placed, site-specifically attached pairs of nitroxide spin labels to monitor changes in the mini TAR DNA stem-loop structure brought on by the HIV-1 nucleocapsid protein NCp7. The biophysical structural evidence was at Ångstrom-level resolution under solution conditions not amena...

Efficient transcription from the human immunodeficiency virus (HIV) promoter depends on binding of the viral regulatory protein Tat to a cis-acting RNA regulatory element, TAR. Tat binds at a trinucleotide bulge located near the apex of the TAR stem-loop structure. An essential feature of Tat-TAR interaction is that the protein induces a conformational change in TAR that repositions the functio...

The age-adjusted risk for lung cancer among over 120,000 male current cigarette smokers in the American Cancer Society’s 1959-1972 prospective study was analyzed according to tar yield and quantity smoked per day. At each quantity level, the risk increased with increasing tar yield, and at each tar level, the risk increased with numbers of cigarettes smoked daily. The risks in smokers of cigare...

Cigarette smoke consists of tar and gas phase: the latter is toxicologically important because it can pass through lung alveolar epithelium to enter the circulation. Here we attempt to establish a standard method for preparation of gas phase extract of cigarette smoke (CSE). CSE was prepared by continuously sucking cigarette smoke through a Cambridge filter to remove tar, followed by bubbling i...