49 research outputs found

    New hybrid materials with porphyrin-ferrocene and porphyrin-pyrene covalently linked to single-walled carbon nanotubes.

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    Novel porphyrin derivatives bearing additional pyrene or ferrocene units as light harvesting antenna systems were synthesized and fully characterized. Following a covalent functionalization approach for single-walled carbon nanotubes (SWCNTs), stable SWCNT suspensions in common organic solvents 10 were produced. Subsequently, the resulting porphyrin-pyrene and porphyrin-ferrocene dyads were incorporated onto the nanotubes' backbone yielding donor-donor-acceptor hybrids. The resulting hybrid materials were soluble in common organic solvents and were characterized using micro-Raman, ATR-IR, UV-Vis and photoluminescence spectroscopy, transmission electron microscopy, thermogravimetric analysis and εlectrochemistry. Photoluminescence quenching of the porphyrin emission in both hybrid 15 materials was detected thus suggesting the potentiality of these materials in photoelectrochemical cells

    Prognostic significance of HER3 and HER4 protein expression in colorectal adenocarcinomas

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    BACKGROUND: Colorectal cancer remains a major cause of cancer mortality in the Western world. A limited number of studies has been conducted in respect of Her-3 and Her-4 expression and their correlation with clinical parameters and prognosis in colorectal carcinomas . In this study we sought to determine the pattern and the prognostic significance of HER-3 and HER-4 in colorectal adenocarcinoma. METHODS: We studied HER-3 and HER-4 protein expression in106 paraffin embedded specimens of primary colorectal tumors using immunohistochemistry. The pattern and protein expression levels of HER-3 and HER-4 were correlated with several clinical and pathological parameters. RESULTS: HER-3 staining displayed membranous and cytoplasmic expression pattern in 18 (17%) and 30 samples (28,3%), respectively. HER-4 membranous and cytoplasmic expression was found in 20 (18,9%) and 32 samples (30,2%), respectively. Specimens regarded as positive for HER-3 cytoplasmic expression were associated with moderate tumor grade (p = 0,032) and older median age (p = 0,010). Specimens regarded as positive for HER-4 membranous protein expression were associated with involved lymphnodes (p = 0,0003). Similar results were obtained when considering Her-3 and Her-4 protein expression irrespective of their cellular localization. There was no correlation between the expression of HER-3 and HER-4 and patients outcome. CONCLUSION: HER-4 membranous protein expression was found to predict for lymph nodes positivity in this cohort of patients with colorectal cancer.HER-4 expression status may identify tumors with aggressive biological behavior and increased metastatic potential

    Zinc Phthalocyanine−Graphene Hybrid Material for Energy Conversion: Synthesis, Characterization, Photophysics and Photoelectrochemical Cell Preparation

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    Graphene exfoliation upon tip sonication in o-­‐DCB was accomplished. Then, covalent grafting of (2-­‐ aminoethoxy)(tri-­‐tert-­‐butyl) zinc phthalocyanine (ZnPc), to exfoliated graphene sheets was achieved. The newly formed ZnPc-­‐graphene hybrid material was found soluble in common organic solvents without any precipitation for several weeks. Application of diverse spectroscopic techniques verified the successful formation of ZnPc-­‐graphene hybrid materi-­‐ al, while thermogravimetric analysis revealed the amount of ZnPc loading onto graphene. Microscopy analysis based on AFM and TEM was applied to probe the morphological characteristics and to investigate the exfoliation of graphene sheets. Efficient fluorescence quenching of ZnPc in the ZnPc-­‐graphene hybrid material suggested that photoinduced events occur from the photoexcited ZnPc to exfoliated graphene. The dynamics of the photoinduced electron transfer was evaluated by femtosecond transient absorption spectroscopy, thus, revealing the formation of transient species such as ZnPc+ yielding the charge-­‐separated state ZnPc•+–graphene•–. Finally, the ZnPc-­‐graphene hybrid material was integrated into a photoactive electrode of an optical transparent electrode (OTE) cast with nanostructured SnO2 films (OTE/SnO2), which exhibited sta le and reproducible photocurrent responses and the incident photon-­‐to-­‐current conversion efficien-­‐ cy was determine

    Extrahepatic right portal vein ligation allows parenchyma-sparing en bloc resection of segments 7,8 and 4a for liver tumors engaging the right and middle hepatic veins

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    Right trisectionectomy for posterior liver tumors engaging the right and middle hepatic veins may lead to post-hepatectomy liver failure if the anticipated liver remnant is small. In such patients we developed a parenchyma-sparing one-step approach, that includes extrahepatic right portal vein ligation accompanied by en bloc resection only of segments 7, 8 and 4a and resection of the right and middle hepatic veins. The technique was applied in 3 patients with normal liver function, where according to the preoperative computed tomography the volume of segments 1, 2 and 3 ranged between 17% and 20% of the total liver volume. In all patients liver biochemistry improved rapidly postoperatively and a doubling of volume of segments 1,2 and 3 was achieved by the third postoperative week, as extrahepatic right portal vein ligation ameliorated reperfusion injury of the remaining segments 5 and 6 and induced hypertrophy of segments 1, 2, 3 and 4b. There was no mortality or long-term complications. Patients are alive and free of disease 74, 50 and 17 months after the operation, respectively. We propose that the term “extended upper right sectionectomy” may be considered for the en bloc resection of segments 7,8 and 4a, in future revisions of the Brisbane 2000 terminology of hepatic anatomy and resections

    The Significance of Clinical Awareness of Anatomical Variations

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    So far, diverse congenital anatomical variations have been recognized as a consequence of failed developmental process during early embryogenesis [...

    Cutaneous involvement in angioimmunoblastic T-cell lymphoma

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    Angioimmunoblastic T-cell lymphoma (AITL) is an aggressive non-Hodgkin′s nodal peripheral T-cell lymphoma characterized by general lymphadenopathy, night sweats, fever, hepatosplenomegaly, polyclonal hypergammaglobulinemia, and cutaneous involvement. We present a rare case of AITL cutaneous involvement mimicking toxic erythema recurring with AITL relapse and suggesting a precursor of disease progression

    Subclavian artery occlusion and pseudoaneurysm caused by lung apex mucormycosis: Successful treatment with transcatheter embolization

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    Subclavian artery pseudoaneurysm and occlusion in young patients are usually post-traumatic. We report the case of a 33-year-old diabetic woman with subclavian artery occlusion and pseudoaneurysm formation caused by pulmonary mucormycosis infection. The patient presented with diabetic ketoacidosis, Horner’s syndrome, and absent left arm pulses. A cystic lesion of the left lung apex was found by imaging, was surgically resected, and was histologically diagnosed as mucormycosis infection. Magnetic resonance angiography depicted a left subclavian artery pseudoaneurysm and occlusion adjacent to the mucormycosis lesion. To protect against thromboembolic complications and rupture, the pseudoaneurysm was embolized with coils. The patient is clinically well 1 year after the intervention with no perfusion of the pseudoaneurysm

    Perforated mucinous cystadenoma of the vermiform appendix: an overview in reasoning clinical decisions.

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    Recent advances in the management of appendiceal mucinous neoplasms (AMN) such as peritonectomy combined with hyperthermic intraperitoneal chemotherapy have introduced new standards of care. However, many dilemmas are encountered in decision making as in the following patient. A 74-year-old woman was admitted with an appendiceal cystadenoma found in a preadmission CT scan. However, the tumour was not documented by the in hospital investigation due to its perforation and its reduction in size. Consequently, a series of management dilemmas were encountered that were solved by cautious evaluation of the pre and peroperative findings. She was submitted to a right hemicolectomy. A spontaneous perforation was suspected, but the accurate diagnosis was documented postoperatively by histopathology. This paradigm motivated this review which concluded that reasoning clinical decisions in the light of recent advances and appropriate care based on the disease-stage are essential for an optimal outcome in the management of AMN
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