Quasimolecular structure in elastic O16 + O16 scattering

It is suggested that the experimentally observed intermediate structure in the cross section of elastic O16 + O16 scattering is due to quasibound molecular states of the ion-ion system while the gross structure originates from virtually bound molecular states

Relativistic Comparison Theorems

Comparison theorems are established for the Dirac and Klein--Gordon equations. We suppose that V^{(1)}(r) and V^{(2)}(r) are two real attractive central potentials in d dimensions that support discrete Dirac eigenvalues E^{(1)}_{k_d\nu} and E^{(2)}_{k_d\nu}. We prove that if V^{(1)}(r) \leq V^{(2)}(r), then each of the corresponding discrete eigenvalue pairs is ordered E^{(1)}_{k_d\nu} \leq E^{(2)}_{k_d\nu}. This result generalizes an earlier more restrictive theorem that required the wave functions to be node free. For the the Klein--Gordon equation, similar reasoning also leads to a comparison theorem provided in this case that the potentials are negative and the eigenvalues are positive.Comment: 6 page

Solutions to the 1d Klein-Gordon equation with cutoff Coulomb potentials

In a recent paper by Barton (J. Phys. A40, 1011 (2007)), the 1-dimensional Klein-Gordon equation was solved analytically for the non-singular Coulomb-like potential V_1(|x|) = -\alpha/(|x|+a). In the present paper, these results are completely confirmed by a numerical formulation that also allows a solution for an alternative cutoff Coulomb potential V_2(|x|) = -\alpha/|x|, ~|x| > a, and otherwise V_2(|x|) = -\alpha/a.Comment: 8 pages, 4 figure

Klein-Gordon lower bound to the semirelativistic ground-state energy

For the class of attractive potentials V(r) <= 0 which vanish at infinity, we prove that the ground-state energy E of the semirelativistic Hamiltonian H = \sqrt{m^2 + p^2} + V(r) is bounded below by the ground-state energy e of the corresponding Klein--Gordon problem (p^2 + m^2)\phi = (V(r) -e)^2\phi. Detailed results are presented for the exponential and Woods--Saxon potentials.Comment: 7 pages, 4 figure

Ear pain in patients with oropharynx carcinoma: how MRI contributes to the explanation of a prognostic and predictive symptom

Reflex otalgia is a predictive and prognostic parameter for local control in patients with oropharynx carcinoma. Can a morphologic correlate of this important symptom be detected by MRI? Thirty-six patients were prospectively evaluated by MRI before radical radiotherapy. Sixteen patients had reflex otalgia; 20 did not. The oropharynx and adjacent regions were analyzed. Alteration was defined as effacement of anatomical structures, signal alteration or enhancement after contrast medium administration. The χ 2-test was used to compare categorical parameters. In patients with reflex otalgia, alteration of the following structures innervated by the glossopharyngeal nerve were found significantly more often: nasopharynx, hard palate, superior constrictor pharyngis muscle, palatine tonsil, palatopharyngeus muscle, palatoglossus muscle, stylopharyngeus muscle, hyoglossus muscle and preepiglottic space. No difference was found for the muscles of mastication, levator and tensor veli palatini muscles, styloglossus muscle, genioglossus muscle, intrinsic muscles of the tongue, digastric muscles, mucosal surface of the lateral and posterior pharyngeal wall, uvula, valleculae, parapharyngeal space and larynx. An alteration of structures innervated by the glossopharyngeal nerve was visualized on MRI significantly more often when reflex otalgia was present. Involvement of structures innervated by other cranial nerves did not show the same association with ear pai

A Microcystic Adnexal Carcinoma in the Auditory Canal 15 Years after Radiotherapy of a 12-Year-Old Boy with Nasopharynx Carcinoma

Background: : Radiogenic malignancies require cure of the primary disease and a prolonged survival. The introduction of high-volt technology in the 1950s and 1960s made radical radiotherapy feasible and successful in terms of higher cure rates and longer survival. We are already in a time when a higher number of patients with radiogenic secondary malignancies must be expected. Case Report: : A 12-year-old boy is reported who suffered from an advanced nasopharynx carcinoma and was treated with radical irradiation in 1983. 15 years later he developed a rare microcystic adnexal carcinoma of the auditory canal inside the volume of the target dose. The secondary malignant neoplasm was resected and required another radiation treatment (1 Gy b.i.d.) due to involved margins. Discussion and Literature Review: : The entity of microcystic carcinoma is discussed with a review of the literature on biology, diagnosis, and treatmen

1D Bose Gases in an Optical Lattice

We report on the study of the momentum distribution of a one-dimensional Bose gas in an optical lattice. From the momentum distribution we extract the condensed fraction of the gas and thereby measure the depletion of the condensate and compare it with a theorical estimate. We have measured the coherence length of the gas for systems with average occupation $\bar{n}>1$ and $\bar{n}<1$ per lattice site.Comment: 4 pages, 3 figure

Sites of Failure in Breast Cancer Patients with Extracapsular Invasion of Axillary Lymph Node Metastases: No Need for Axillary Irradiation?!

Background and Purpose:: Extracapsular spread (ECS) is frequent, but the specific sites of relapse are seldom given in the literature. In this study it was evaluated, if ECS might be an indicator for axillary irradiation. Patients and Methods:: After a retrospective review of pathology reports, the information about ECS was available in 254 lymph node-positive patients: ECS was absent in 34% (ECS-negative; n = 87) and present in 66% (ECS-positive; n = 167). All patients were irradiated locally, 78 patients got periclavicular and 74 axillary irradiation (median total dose: 50.4 Gy). 240/254 patients (94.5%) received systemic treatment/s. Mean follow-up was 46 months. Results:: The regional relapse rate was 4.6% without ECS versus 9.6% with ECS. The 5-year axillary relapse-free survival was 100% in ECS-negative and 90% in ECS-positive patients (p = 0.01), whereas corresponding values for periclavicular relapse-free survival (with ECS: 91% ± 4%; without ECS: 94% ± 3%; p = 0.77) and local relapse-free survival (with ECS: 86% ± 4%; without ECS: 91% ± 3%; p = 0.69) were not significantly different. χ2-tests revealed a high correlation of ECS with T-stage, number of positive lymph nodes and progesterone receptor status, comparisons with estrogen receptor, grade, or age were not significant. In multivariate analysis number of positive lymph nodes was solely significant for regional failure. Dividing the patients into those with one to three and those with four or more positive lymph nodes, ECS lost its significance for axillary failure. Conclusion:: ECS was accompanied by an enhanced axillary failure rate in univariate analysis, which was no longer true after adjusting for the number of positive lymph node

Long-term survival of patients with stage IV hypopharyngeal cancer: Impact of fundus rotation gastroplasty

Stage IV circular hypopharyngeal cancer is a disease with poor long-term survival, and the only means of cure—surgery—is associated with high morbidity. All patients admitted with circular hypopharyngeal cancer and extension to the esophagus were enrolled in a multidisciplinary treatment protocol, including circular laryngopharyngoesophagectomy with tracheostomy, neck dissection, and pull-up of a fundus rotation gastric tube that was anastomosed to the oropharynx. Five weeks postoperatively high-dose radiotherapy (60 Gy) was given to the cervical region. Altogether, 18 qualifying patients were explored cervically, were found to have resectable lesions (i.e., without carotid artery infiltration), and were included in the protocol. After laryngopharyngoesophagectomy, an elongated gastric tube was pulled up to the oropharynx. The average distance bridged with the tube was 32±4 cm. No anastomotic leaks were found on postoperative Gastrografin swallow, and oral feeding was started between days 5 and 8. Patients were discharged with normal oral feeding on day 21 (±17 days). Diarrhea, postprandial fullness, and reflux resolved within 6 months postoperatively. Five patients died during the follow-up period of 42 months (range 3-63 months): three due to cardiac events 18 and 38 months postoperatively and two within 12 months with residual disease and tumor recurrence, respectively. The estimated 5-year survival was 60%. We concluded that an aggressive multidisciplinary approach including circular laryngopharyngoesophagectomy, neck dissection, and high-dose radiotherapy ascertains good long-term survival and good functional results in patients with advanced hypopharyngeal cancer when the intestinal continuity is reconstructed with a fundus rotation gastroplast

Search for production of strangelets in quark matter using particle correlations

We present a new technique for observing the strangelet production in quark matter based on unlike particle correlations. A simulation is presented with a two-phase thermodynamical model