Expected and unexpected behavior of the orientational order and dynamics induced by azobenzene solutes in a nematic

We have explored the changes in the phase stability, orientational order, and dynamics of the nematic 4-cyano-4¢-n-pentylbiphenyl (5CB) doped with either the trans or the cis form of different p-azobenzene derivatives using the ESR spin-probe technique. In particular, we have studied the effects induced by each of the seven nonmesogenic 4-R-phenylazobenzenes (R = H, F, Br, CH3, CF3, On-Bu, Ot-Bu) at 1% and 7% mole fraction on the order parameter and on the shift of the nematic-isotropic transition temperature (TNI), as reported by a nitroxide spin probe, and we have tried to relate them to the solute shape and charge distribution. In all the cases the presence of the azo-derivative causes a depression of TNI, more pronounced for the cis isomers. The dependence of on the reduced temperature T*=T/TNI remains the same as that of pure 5CB in all trans-doped samples at 1% and 7% and decreases only slightly in the cis at 1%. However, we observe different and in some cases large variations (up to 25%) in for the cis at 7%, showing solute effects that go beyond the shift in TNI. Surprisingly enough, even at the highest concentration, the probe dynamics appears to be essentially independent of the nature, the configuration, and the concentration of the different solutes and very similar to that observed in the pure 5CB

Metachronous hepatic metastases from gastric carcinoma: a multicentric survey

BACKGROUND: The treatment of hepatic metastases from gastric cancer is controversial, due to biologic aggressiveness of the disease. OBJECTIVE: To survey the clinical approach to the subset of atients presenting with metachronous hepatic metastases as sole site of recurrence after curative resection of gastric cancer, focusing on the results achieved by different therapies and to investigate the prognostic factors of major clinical relevance. METHODS: Retrospective multi-center chart review evaluating 73 patients, previously submitted to D >or= 2 gastrectomy for gastric cancer, who developed exclusive hepatic recurrence. Prognostic factors related to the patient, to the gastric malignancy and its treatment, and to the metastatic disease and its therapy were evaluated. RESULTS: Forty-five patients received supportive care, 17 were submitted to chemotherapy, and 11 to hepatic resection. Survival was independently influenced by the variables T (p=0.019), N (p=0.05) and G (p=0.018) of the gastric primary and by the therapeutic approach to the metastases (p<0.005). In particular, T4 gastric cancer, presence of lymph-node metastases and G3 tumor displayed a negative prognostic value. Therapeutic approach to the metastases was the principal prognostic variable: 1, 2, and 3 years survival rates were 22.2%, 4.4% and 2.2%, respectively, for patients without specific treatment; 44.9%, 12.8% and 6.4% after chemotherapy (p=0.08) and 80.8%, 30.3% and 20.2% after surgical resection (p<0.001). CONCLUSIONS: Our data suggest some clinical criteria that may facilitate selection of therapy for patients with hepatic recurrence after primary gastric cancer resection. The best survival rates are associated with surgical treatment, which should be chosen whenever possible

Increased risk of second malignancy in pancreatic intraductal papillary mucinous tumors: Review of the literature.

AIM: To analyze the available evidence about the risk of extrapancreatic malignancies and pancreatic ductal adenocarcinoma associated to pancreatic intraductal papillary mucinous tumors (IPMNs). METHODS: A systematic search of literature was undertaken using MEDLINE, EMBASE, Cochrane and Web-of-Science libraries. No limitations for year of publication were considered; preference was given to English papers. All references in selected articles were further screened for additional publications. Both clinical series and Literature reviews were selected. For all eligible studies, a standard data extraction form was filled in and the following data were extracted: study design, number of patients, prevalence of pancreatic cancer and extrapancreatic malignancies in IPMN patients and control groups, if available. RESULTS: A total of 805 abstracts were selected and read; 25 articles were considered pertinent and 17 were chosen for the present systematic review. Eleven monocentric series, 1 multicentric series, 1 case-control study, 1 population-based study and 3 case report were included. A total of 2881 patients were globally analyzed as study group, and the incidence of pancreatic cancer and/or extrapancreatic malignancies ranged from 5% to 52%, with a mean of 28.71%. When a control group was analyzed (6 papers), the same incidence was as low as 9.4%. CONCLUSION: The available Literature is unanimous in claiming IPMNs to be strongly associated with pancreatic and extrapancreatic malignancies. The consequences in IPMNs management are herein discussed

In situ real-time characterization of block copolymer self-assembly processes by GISAXS

E-MRS Spring Meeting and Exhibit will be held in the Convention Centre of Strasbourg (France), from June 18 to 22 (2018). .--https://www.european-mrs.com/block-copolymer-self-assembly-fundamentals-and-applications-emr

A separation of electrons and protons in the GAMMA-400 gamma-ray telescope

The GAMMA-400 gamma-ray telescope is intended to measure the fluxes of gamma rays and cosmic-ray electrons and positrons in the energy range from 100 MeV to several TeV. Such measurements concern with the following scientific goals: search for signatures of dark matter, investigation of gamma-ray point and extended sources, studies of the energy spectra of Galactic and extragalactic diffuse emission, studies of gamma-ray bursts and gamma-ray emission from the active Sun, as well as high-precision measurements of spectra of high-energy electrons and positrons, protons, and nuclei up to the knee. The main components of cosmic rays are protons and helium nuclei, whereas the part of lepton component in the total flux is ~10E-3 for high energies. In present paper, the capability of the GAMMA-400 gamma-ray telescope to distinguish electrons and positrons from protons in cosmic rays is investigated. The individual contribution to the proton rejection is studied for each detector system of the GAMMA-400 gamma-ray telescope. Using combined information from all detector systems allow us to provide the proton rejection from electrons with a factor of ~4x10E5 for vertical incident particles and ~3x10E5 for particles with initial inclination of 30 degrees. The calculations were performed for the electron energy range from 50 GeV to 1 TeV.Comment: 19 pages, 10 figures, submitted to Advances and Space Researc

The GAMMA-400 space observatory: status and perspectives

The present design of the new space observatory GAMMA-400 is presented in this paper. The instrument has been designed for the optimal detection of gamma rays in a broad energy range (from ~100 MeV up to 3 TeV), with excellent angular and energy resolution. The observatory will also allow precise and high statistic studies of the electron component in the cosmic rays up to the multi TeV region, as well as protons and nuclei spectra up to the knee region. The GAMMA-400 observatory will allow to address a broad range of science topics, like search for signatures of dark matter, studies of Galactic and extragalactic gamma-ray sources, Galactic and extragalactic diffuse emission, gamma-ray bursts and charged cosmic rays acceleration and diffusion mechanism up to the knee

Personalized bone reconstruction and regeneration in the treatment of craniosynostosis

Craniosynostosis (CS) is the second most prevalent craniofacial congenital malformation due to the premature fusion of skull sutures. CS care requires surgical treatment of variable complexity, aimed at resolving functional and cosmetic defects resulting from the skull growth constrain. Despite significant innovation in the management of CS, morbidity and mortality still exist. Residual cranial defects represent a potential complication and needdedicated management to drive a targeted bone regeneration while modulating suture ossification. To this aim, existing techniques are rapidly evolving and include the implementation of novel biomaterials, 3D printing and additive manufacturing techniques, and advanced therapies based on tissue engineering. This review aims at providing an exhaustive and up\u2010to\u2010date overview of the strategies in use to correct these congenital defects, focusing on the technological advances in the fields of biomaterials and tissue engineering implemented in pediatric surgical skull reconstruction, i.e., biodegradable bone fixation systems, biomimetic scaffolds, drug delivery systems, and cell\u2010based approaches

CRT-700.1 Multi-Center Compassionate use Early Feasibility Evaluation of J-Valve Transcatheter Treatment for Severe Aortic Valve Regurgitation: Preliminary Results

Background: Although transcatheter aortic valve replacement (TAVR) is accepted therapy for treatment of symptomatic severe aortic valve stenosis (AS), current devices are associated with increased procedural complications and sub-optimal outcomes when used to treat of aortic valve regurgitation (AR). Severe AR is the indication for 20-30% of surgical aortic valve replacements and is associated with increased morbidity and mortality. J-valve is a short frame, self-expanding TAVR device. (Figure) specifically designed for treatment of severe AR. Anchor rings facilitate commissural alignment and secure attachment to non-calcified native valves. Methods: From Sept 2019 through Oct 2022, patients with symptomatic severe AR who were not surgical candidates or excluded from the ALIGN-AR trial were enrolled into a compassionate use early feasibility study at 5 North American centers. All patients signed informed consent for protocol approved by respective institutional review boards. Results: Data from 13/28 patients (mean age 80 yrs; 38.5% male) with symptomatic (92.3% NYHA class III/IV; mean LVEF 48% [range 23-64%]) severe (92% grade III/IV) AR, atrial fibrillation (53.8%), and pacemaker/ICD (15.4%), had J-valve TAVR (15.4% alternative access). There were no deaths to 30 days and post-procedural AR grade was none/trivial in all patients. In follow-up (mean 333 days) there are 0 cardiac deaths (total mortality 30.7%; 3 malignancies, 1 sepsis). Serial echocardiograms demonstrate AR grade none/mild in 89%, and 100% at 30 days and 1 year respectively). Conclusion: Despite high risk profile, preliminary analysis of this multi-center compassionate use study suggests that J-valve is safe with durable effectiveness for the treatment of symptomatic severe AR. Full data set on all patients will be presented