Distributional Borel Summability for Vacuum Polarization by an External Electric Field

It is proved that the divergent perturbation expansion for the vacuum polarization by an external constant electric field in the pair production sector is Borel summable in the distributional sense.Comment: 14 page

Perturbation theory of PT-symmetric Hamiltonians

In the framework of perturbation theory the reality of the perturbed eigenvalues of a class of \PTsymmetric Hamiltonians is proved using stability techniques. We apply this method to \PTsymmetric unperturbed Hamiltonians perturbed by \PTsymmetric additional interactions

Single stage reconstruction of complex head and neck defects involving the skin with a single ALT flap: A ten year review

Background: Multicomponent defects of the head and neck involving the cervical skin pose a reconstructive challenge for microsurgeons and usually requires two flaps. However, many patients who undergo such surgical treatment had prior treatment with radiotherapy and the availability of recipient vessels for free flap reconstruction may be limited. The purpose of this study was to review our experience in the reconstruction of these extensive head and neck defects using a single ALT free flap. Methods: A total of 21 patients with complex defects of the head and neck involving multiple anatomical subunits, including the overlying cervical skin, underwent reconstruction with a single ALT flap. The clinical, functional, and aesthetic outcomes of these patients were reviewed. Results: The mean hospital stay was 24 days. There was one total flap loss due to pedicle thrombosis. The patient underwent a further ALT reconstruction with no postoperative complications. Cervical fistulas occurred in three patients, and all fistulas were healed by simple wound packing. Three patients with tracheal defect had a functional tracheostoma with adequate stomal patency. A modified barium swallowing study was performed on each patient, and all of them achieved total oral intake. Among them, two patients tolerated only a pureed diet. Conclusions: Complex neck reconstruction can be accomplished with a single ALT flap with good clinical and functional results, minimal morbidity and quick recovery

JJ-self-adjoint operators with C\mathcal{C}-symmetries: extension theory approach

A well known tool in conventional (von Neumann) quantum mechanics is the self-adjoint extension technique for symmetric operators. It is used, e.g., for the construction of Dirac-Hermitian Hamiltonians with point-interaction potentials. Here we reshape this technique to allow for the construction of pseudo-Hermitian ($J$-self-adjoint) Hamiltonians with complex point-interactions. We demonstrate that the resulting Hamiltonians are bijectively related with so called hypermaximal neutral subspaces of the defect Krein space of the symmetric operator. This symmetric operator is allowed to have arbitrary but equal deficiency indices . General properties of the $\cC$ operators for these Hamiltonians are derived. A detailed study of $\cC$-operator parametrizations and Krein type resolvent formulas is provided for $J$-self-adjoint extensions of symmetric operators with deficiency indices . The technique is exemplified on 1D pseudo-Hermitian Schr\"odinger and Dirac Hamiltonians with complex point-interaction potentials

Structure, Time Propagation and Dissipative Terms for Resonances

For odd anharmonic oscillators, it is well known that complex scaling can be used to determine resonance energy eigenvalues and the corresponding eigenvectors in complex rotated space. We briefly review and discuss various methods for the numerical determination of such eigenvalues, and also discuss the connection to the case of purely imaginary coupling, which is PT-symmetric. Moreover, we show that a suitable generalization of the complex scaling method leads to an algorithm for the time propagation of wave packets in potentials which give rise to unstable resonances. This leads to a certain unification of the structure and the dynamics. Our time propagation results agree with known quantum dynamics solvers and allow for a natural incorporation of structural perturbations (e.g., due to dissipative processes) into the quantum dynamics.Comment: 14 pages; LaTeX; minor change

Crypto-unitary forms of quantum evolution operators

For the description of quantum evolution, the use of a manifestly time-dependent quantum Hamiltonian $\mathfrak{h}(t) =\mathfrak{h}^\dagger(t)$ is shown equivalent to the work with its simplified, time-independent alternative $G\neq G^\dagger$. A tradeoff analysis is performed recommending the latter option. The physical unitarity requirement is shown fulfilled in a suitable ad hoc representation of Hilbert space.Comment: 15 p

The size criteria in minimally invasive video-assisted thyroidectomy

BACKGROUND: Thyroid size is a very important criteria of MIVAT exclusion because the working space provided by the technique is limited. The aim of this work has been to verify the suitability of MIVAT and its applicability in clinical practice, not only in patients with a thyroid volume up to 25 ml but also in patients with a thyroid volume included from 25 to 50 ml. METHODS: From January 2003 to February 2006, 33 patients have been selected for MIVAT. A completely gasless procedure was carried out through a central 20 to 35 mm skin incision performed "high" between the cricoid and jugular notch. RESULTS: The patients were separated in 2 groups. The first group (less than 25 ml) included 23 patients, the second group (from 25 to 50 ml) included 10 patients. The skin incision performed was from 20 to 25 mm (mean 23.61 mm ± 1.83) long in the first group and from 25 to 35 mm (mean 27.8 mm ± 2.20) long in the second one; this difference is significant (t test p < 0.001). CONCLUSION: Our study suggest that the MIVAT using for thyroids bigger than 25 ml and up to 50 ml in volume is feasible and safe. This way allows more patients, excluded before, to take the advantages of minimally invasive approach

A Novel Solid-Phase Site-Specific PEGylation Enhances the In Vitro and In Vivo Biostabilty of Recombinant Human Keratinocyte Growth Factor 1

Keratinocyte growth factor 1 (KGF-1) has proven useful in the treatment of pathologies associated with dermal adnexae, liver, lung, and the gastrointestinal tract diseases. However, poor stability and short plasma half-life of the protein have restricted its therapeutic applications. While it is possible to improve the stability and extend the circulating half-life of recombinant human KGF-1 (rhKGF-1) using solution-phase PEGylation, such preparations have heterogeneous structures and often low specific activities due to multiple and/or uncontrolled PEGylation. In the present study, a novel solid-phase PEGylation strategy was employed to produce homogenous mono-PEGylated rhKGF-1. RhKGF-1 protein was immobilized on a Heparin-Sepharose column and then a site-selective PEGylation reaction was carried out by a reductive alkylation at the N-terminal amino acid of the protein. The mono-PEGylated rhKGF-1, which accounted for over 40% of the total rhKGF-1 used in the PEGylation reaction, was purified to homogeneity by SP Sepharose ion-exchange chromatography. Our biophysical and biochemical studies demonstrated that the solid-phase PEGylation significantly enhanced the in vitro and in vivo biostability without affecting the over all structure of the protein. Furthermore, pharmacokinetic analysis showed that modified rhKGF-1 had considerably longer plasma half-life than its intact counterpart. Our cell-based analysis showed that, similar to rhKGF-1, PEGylated rhKGF-1 induced proliferation in NIH 3T3 cells through the activation of MAPK/Erk pathway. Notably, PEGylated rhKGF-1 exhibited a greater hepatoprotection against CCl4-induced injury in rats compared to rhKGF-1

Patients&apos; survival after free flap reconstructive surgery of head and neck squamous cell carcinoma : a retrospective multicentre study

Head and neck squamous cell carcinoma of the (HNSCC) represents approximately 5% of malignant tumours in Italy. HNSCC are commonly treated with surgery or radiotherapy, or a combination of such therapies. The objectives of treatment are maximum cure rate balanced with organ preservation, restoration of form and function, reduction of morbidities and improvement or maintenance of the patient's quality of life. Immediate reconstructive surgery: local, regional or free flaps are now widely advised in the treatment of these patients. Microsurgical transfer requires expertise, is time and resource consuming, and as a whole requires substantial costs. These considerations introduce some concerns about the wide or indiscriminate use of free flap reconstructive surgery. When considering cost-benefit outcomes of such treatment, the main objective is undoubtedly, survival. This data is underreported in the current literature, whereas functional outcomes of free flaps have been largely diffused and accepted. This study collects data from 1178 patients treated with free flap reconstructive surgery following ablation of HNSCC in a group of Italian tertiary hospitals, all members of the Head &amp; Neck Group affiliated with the Italian Society of Microsurgery. According to many authors, free flap surgery for HNSCC seems to be a beneficial option for treatment even in terms of survival

A quantitative mass spectrometry-based approach to monitor the dynamics of endogenous chromatin-associated protein complexes.

Understanding the dynamics of endogenous protein-protein interactions in complex networks is pivotal in deciphering disease mechanisms. To enable the in-depth analysis of protein interactions in chromatin-associated protein complexes, we have previously developed a method termed RIME (Rapid Immunoprecipitation Mass spectrometry of Endogenous proteins). Here, we present a quantitative multiplexed method (qPLEX-RIME), which integrates RIME with isobaric labelling and tribrid mass spectrometry for the study of protein interactome dynamics in a quantitative fashion with increased sensitivity. Using the qPLEX-RIME method, we delineate the temporal changes of the Estrogen Receptor alpha (ERα) interactome in breast cancer cells treated with 4-hydroxytamoxifen. Furthermore, we identify endogenous ERα-associated proteins in human Patient-Derived Xenograft tumours and in primary human breast cancer clinical tissue. Our results demonstrate that the combination of RIME with isobaric labelling offers a powerful tool for the in-depth and quantitative characterisation of protein interactome dynamics, which is applicable to clinical samples