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We propose a protocol for creating a fully entangled GHZ-type state of neutral atoms in spatially separated optical atomic clocks. In our scheme, local operations make use of the strong dipole-dipole interaction between Rydberg excitations, which give rise to fast and reliable quantum operations involving all atoms in the ensemble. The necessary entanglement between distant ensembles is mediated by single-photon quantum channels and collectively enhanced light-matter couplings. These techniques can be used to create the recently proposed quantum clock network based on neutral atom optical clocks. We specifically analyze a possible realization of this scheme using neutral Yb ensembles., 13 pages, 11 figures

Mucosal melanoma (MM) is a rare type of cancer that differs significantly from cutaneous melanoma. In this study, we aimed to evaluate clinical and demographical characteristics, prognoses and factors influencing survival, treatment alternatives, and features of different subtypes of the patients. The patients were followed up with and treated in different centers due to their diagnoses of MM. We retrospectively analyzed data of 107 patients who were diagnosed with MM in 14 different institutions in Turkey. The mean age of the patients was 64.5 years. Of the patients, 47 % were female and 53 % were male. The median overall survival (OS) was 17 months, and the mean follow-up duration was 27 months. The 2-year survival rate was 42 %, and the 5-year survival rate was 23 %. The best survival rate appeared in those patients with MM in the head-neck region (median survival rate was 27 months, P = 0.034). The most common anatomical site was the head-neck region. In a univariate analysis, variables including age aeyen65 years, the anatomical site of the primary lesion other than head and neck region, the metastatic stage of the disease, high levels of lactate dehydrogenase (LDH), and an Eastern Cooperative Oncology Group Performance Status (ECOG PS) of aeyen1 were found to be associated with poor survival (P < 0.05). However, in a multivariate analysis, only advanced stage disease (HR = 2.70; 95 % CI, 1.64-4.45; P = 0.000) and high LDH levels (HR = 2.31; 95 % CI, 1.40-3.80; P = 0.001) were determined to be adverse prognostic variables. Primary MM presents a more aggressive behavior and offers a poorer prognosis compared to cutaneous melanoma. Because the disease is rarely seen, is heterogeneous, and lacks randomized studies, issues concerning optimal treatment approaches and management and clinical characteristics of the disease have not been clarified yet.

Brain metastasis in colorectal cancer is highly rare. In the present study, we aimed to determine the frequency of brain metastasis in colorectal cancer patients and to establish prognostic characteristics of colorectal cancer patients with brain metastasis. In this cross-sectional study, the medical files of colorectal cancer patients with brain metastases who were definitely diagnosed by histopathologically were retrospectively reviewed. Brain metastasis was detected in 2.7 % (n = 133) of 4,864 colorectal cancer patients. The majority of cases were male (53 %), older than 65 years (59 %), with rectum cancer (56 %), a poorly differentiated tumor (70 %); had adenocarcinoma histology (97 %), and metachronous metastasis (86 %); received chemotherapy at least once for metastatic disease before brain metastasis developed (72 %), had progression with lung metastasis before (51 %), and 26 % (n = 31) of patients with extracranial disease at time the diagnosis of brain metastasis had both lung and bone metastases. The mean follow-up duration was 51 months (range 5-92), and the mean survival was 25.8 months (95 % CI 20.4-29.3). Overall survival rates were 81 % in the first year, 42.3 % in the third year, and 15.7 % in the fifth year. In multiple variable analysis, the most important independent risk factor for overall survival was determined as the presence of lung metastasis (HR 1.43, 95 % CI 1.27-4.14; P = 0.012). Brain metastasis develops late in the period of colorectal cancer and prognosis in these patients is poor. However, early screening of brain metastases in patients with lung metastasis may improve survival outcomes with new treatment modalities.

WOS: 000325820300002, Because the commonly adopted viewpoint that the Keldysh parameter gamma determines the dynamical regime in strong field physics has long been demonstrated to be misleading, one can ask what happens as relevant physical parameters, such as laser intensity and frequency, are varied while gamma is kept fixed. We present results from our one-and fully three-dimensional quantum simulations of high-order-harmonic generation (HHG) from various bound states of hydrogen with n up to 40, where the laser intensities and the frequencies are scaled from those for n = 1 in order to maintain a fixed Keldysh parameter gamma < 1 for all n. We find that as we increase n while keeping gamma fixed, the position of the cutoff scales in a well-defined manner. Moreover, a secondary plateau forms with a new cutoff, splitting the HHG plateau into two regions. The first of these subplateaus is composed of lower harmonics, and has a higher yield than the second one. The latter extends up to the semiclassical I-p + 3.17U(p) cutoff. We find that this structure is universal, and the HHG spectra look the same for all n greater than or similar to 10 when plotted as a function of the scaled harmonic order. We investigate the n, l, and momentum distributions to elucidate the physical mechanism leading to this universal structure., BAPKO of Marmara University; Office of Basic Energy Sciences, US Department of Energy; National Science Foundation [PHY-1212482], I.Y., E. A. B., and Z.A. were supported by BAPKO of Marmara University. Z.A. would like to thank the National Energy Research Scientific Computing Center (NERSC) in Oakland, CA. T. T. was supported by the Office of Basic Energy Sciences, US Department of Energy, and by the National Science Foundation Grant No. PHY-1212482.

WOS: 000336100500010, We describe phase-dependent wavelength scaling of high-order-harmonic generation efficiency driven by ultrashort laser fields in the midinfrared. We employ both numerical solution of the time-dependent Schrodinger equation and the strong field approximation to analyze the fine-scale oscillations in the harmonic yield in the context of channel-closing effects. We show, by varying the carrier-envelope phase, that the amplitude of these oscillations depends strongly on the number of returning electron trajectories. Furthermore, the peak positions of the oscillations vary significantly as a function of the carrier-envelope phase. Owing to its practical applications, we also study the wavelength dependence of harmonic yield in the "single-cycle" limit, and observe a smooth variation in the wavelength scaling originating from the vanishing fine-scale oscillations., National Science Foundation [PHY-1212482], I.Y., E.A.B., and Z.A. are grateful to TUBITAK ULAK-BIM, High Performance and Grid Computing Center, BAPKO of Marmara University. T.T. was supported by the National Science Foundation Grant No. PHY-1212482.