The hypothesis that fullerenes grow in a carbon plasma by the addition of C2 units (the "fullerene road") has been widely acclaimed as the most plausible mechanism for formation of larger fullerenes including C60 and C70. Calculations suggest that the association of C2 with fullerenes proceeds through two classes of intermediates, "sticks" and "handles." Here we report the observation of these ...

Bronchoscopic phototherapy is available now for 2 distinct categories of tracheobronchial cancer: roentgenographically occult superficial squamous cell carcinoma and advanced malignancy causing significant airway obstruction. Laboratory and clinical experience show that the photodynamic effect of hematoporphyrin derivative phototherapy (HpD-PT) may be useful for treating superficial cancers tha...

Weakly bound metal ion complexes are produced in molecular beams and studied with mass-selected laser photodissociation spectroscopy. The metal ions Mg+ and Ca+ are the focus of these studies because they have a single valence electron and strong atomic resonance lines in convenient wavelength regions. Weakly bound complexes of these ions with rare-gas atoms and small molecules are prepared wit...

Cervical intraepithelial neoplasia (CIN) is commonly diagnosed in women of child-bearing age. (Castle et al., 2009) The excisional treatments of CIN include cold-knife conization, laser conization, loop electrosurgical excision procedure (LEEP), and large loop excision of the transformation zone (LLETZ). CIN is also treated by ablative procedures such as laser vaporization and cryotherapy. Rece...

The literature pertinent to various aspects of drop evaporation on a heated surface is reviewed. Both the laser shadowgraphic and direct photographic methods are employed to study thermal stability and flow structures in evaporating drops in all heating regimes. It is revealed that four flow regions exist in stable and unstable type drops at low liquid-film type vaporization regime. As the surf...

Although 6.45 micro m is not the strongest absorption band of biological tissues in the mid-infrared, a Mark-III free-electron laser (FEL) tuned to this wavelength can efficiently ablate tissue while minimizing collateral damage. A model has previously been presented that explains this wavelength dependence as a competition between two dynamic processes--explosive vaporization of saline and den...

Cavity-enhanced detection’-3 can be used as a sensitive means of monitoring laser-surface interactions. In particular, it can detect the amount of material ejected from a solidor liquid-film surface when a laser beam is focused onto it. The tiny ablation plume is monitored inside an optical cavity by a fixed frequency continuous-wave (cw) probe beam. The photovaporization signal is produced by ...

METHODS: This is a retrospective observational cohort study: one cohort includes patients who underwent endoscopic surgery, and the other patients undergoing laser therapy (vaporization). A total of 106 patients were included, divided into two cohorts. Two questionnaires were prepared for those who fulfilled inclusion criteria, the International Prostate Symptom Score (IPSS), two months before ...