We present interferometric angular diameter measurements of 21 low-mass, Kand M-dwarfs made with the CHARA Array. This sample is enhanced by adding a collection of radii measurements published in the literature to form a total data set of 33 K-M dwarfs with diameters measured to better than 5%. We use these data in combination with the Hipparcos parallax and new measurements of the star's bolometric flux to compute absolute luminosities, linear radii, and effective temperatures for the stars. We develop empirical relations for ∼K0 to M4 mainsequence stars that link the stellar temperature, radius, and luminosity to thebroad-band color index and stellar metallicity [Fe/H]. These relations are valid for metallicities ranging from [Fe/H] = −0.5 to +0.1 dex, and are accurate to ∼2%, ∼5%, and ∼4% for temperature, radius, and luminosity, respectively. Our results show that it is necessary to use metallicity dependent transformations in order to properly convert colors into stellar temperatures, radii, and luminosities. Alternatively, we find no sensitivity to metallicity on relations we construct to the global properties of a star omitting color information e.g., temperature-radius and temperatureluminosity. Thus, we are able to empirically quantify to what order the star's observed color index is impacted by the stellar iron abundance. In addition to the empirical relations, we also provide a representative look-up table via stellar spectral classifications using this collection of data. Robust examinations of single star temperatures and radii compared to evolutionary model predictions on the luminosity -temperature and luminosity -radius planes reveals that models overestimate the temperatures of stars with surface temperatures < 5000 K by ∼ 3%, and underestimate the radii of stars with radii < 0.7 R ⊙ by ∼ 5%. These conclusions additionally suggest that the models over account for the effects that the stellar metallicity may have on the astrophysical properties of an object. By comparing the interferometrically measured radii for the single star population to those of eclipsing binaries, we find that for a given mass, single and binary star radii are indistinguishable. However, we also find that for a given radius, the literature temperatures for binary stars are systematically lower compared to our interferometrically derived temperatures of single stars by ∼ 200 to 300 K. The nature of this offset is dependent on the validation of binary star temperatures; where bringing all measurements to a uniform and correctly calibrated temperature scale is needed to identify any influence stellar activity may have on the physical properties of a star. Lastly, we present a empirically determined HR diagram using fundamental properties presented here in combination with those in Boyajian et al. (2012) for a total of 74 nearby, main-sequence, A-to M-type stars, and define regions of habitability for the potential existence of sub-stellar mass companions in each system.

Preoperative cleansing of the patient's skin with chlorhexidine-alcohol is superior to cleansing with povidone-iodine for preventing surgical-site infection after clean-contaminated surgery. (ClinicalTrials.gov number, NCT00290290.)

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Perineural invasion (PNI) is the process of neoplastic invasion of nerves and is an under-recognized route of metastatic spread. It is emerging as an important pathologic feature of many malignancies, including those of the pancreas, colon and rectum, prostate, head and neck, biliary tract, and stomach. For many of these malignancies, PNI is a marker of poor outcome and a harbinger of decreased survival. PNI is a distinct pathologic entity that can be observed in the absence of lymphatic or vascular invasion. It can be a source of distant tumor spread well beyond the extent of any local invasion; and, for some tumors, PNI may be the sole route of metastatic spread. Despite increasing recognition of this metastatic process, there has been little progress in the understanding of molecular mechanisms behind PNI and, to date, no targeted treatment modalities aimed at this pathologic entity. The objectives of this review were to lay out a clear definition of PNI to highlight its significance in those malignancies in which it has been studied best. The authors also summarized current theories on the molecular mediators and pathogenesis of PNI and introduced current research models that are leading to advancements in the understanding of this meta- A key feature of malignant cells is their ability to dissociate from the primary tumor and to establish metastatic deposits at distant sites. Vascular and lymphatic channels are well accepted routes of metastatic spread. They are well characterized in the literature and are the focus of much current research on tumor biology. However, another route of tumor spread that occurs in and along nerves has been described in the literature since the mid-1800s but has received relatively little research attention. Perineural invasion (PNI) is the process of neoplastic invasion of nerves. It also has been called neurotropic carcinomatous spread and perineural spread. PNI was reported first in the European literature by scientists who described head and neck cancers that exhibited a predilection for growth along nerves as they made their way toward the intracranial fossa.1,2 PNI has emerged since then as a key pathologic feature of many other malignancies, including those of the pancreas, colon and rectum, prostate, biliary tract, and stomach. For many of these malignancies, PNI is a marker of poor outcome and a harbinger of decreased survival.3-7