78 research outputs found

    Endogeneity in Interlocks and Performance Analysis: A Firm Size Perspective

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    This paper contributes to the literature on interlocking directorates (ID) by providing a new solution to the two econometric issues arising in the joint analysis of interlocks and firm performance which are the endogenous nature of ID and sample selection bias due to the exclusion of isolated firms. Some key determinants of ID network formation are identified and used to check for endogeneity. We analyze the impact of the positioning in the network on firms’ performance and inspect how the impact varies across firms of different sizes drawing on information relating to 37,324 firms in the interlocking network which, to our knowledge, is the widest dataset ever used in approaching the study of ID. Our results, made robust for endogeneity and sample selection bias, suggest that eigenvector centrality and the clustering coefficient have a positive and significant impact on all the performance measures and that this effect is more pronounced for small firms

    miRNA expression is increased in serum from patients with semantic variant primary progressive aphasia

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    Primary progressive aphasia (PPA) damages the parts of the brain that control speech and language. There are three clinical PPA variants: nonfluent/agrammatic (nfvPPA), logopenic (lvPPA) and semantic (svPPA). The pathophysiology underlying PPA variants is not fully understood, including the role of micro (mi)RNAs which were previously shown to play a role in several neurodegenerative diseases. Using a two-step analysis (array and validation through real-time PCR), we investigated the miRNA expression pattern in serum from 54 PPA patients and 18 controls. In the svPPA cohort, we observed a generalized upregulation of miRNAs with miR-106b-5p and miR-133a-3p reaching statistical significance (miR-106b-5p: 2.69 ± 0.89 mean ± SD vs. 1.18 ± 0.28

    Custom made/patient specific alloplastic total temporomandibular joint replacement in immature patient: a case report and short review of literature

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    OBJECTIVE: Temporomandibular joint reconstructive surgery in a growing patient represents a challenging situation. Autogenous and alloplastic reconstructive options are being studied in literature; however, there are still some limitations. The objective of this case report is to evaluate a novel custom-made prosthetic system in a 12-year-old TMJ ankylosis patient. CASE PRESENTATION: The patient had complaints of temporomandibular joint ankylosis and hypoplasia. The patient had already been operated two times with autogenous grafts. Swelling and tumefaction were apparent on the right side of the face. Mouth opening was 1.5 centimeters, with limitations in lateral and protrusive movements of the jaws. Hypertonic muscles and pain upon palpation were registered. There were no signs of luxation, fracture, or traumatic avulsion. After examination, unilateral TMJ ankylosis was apparent on TC scans. Revision surgery was planned with the use of true plastic temporomandibular joint customized prosthesis. The patient underwent a TMJ reconstruction surgery using CADCAM custom-made patient specific prosthesis. The follow up period of this patient was 46 months and showed successful healing with no complications. CONCLUSIONS: Replacement of TMJ with custom made alloplastic material that is reported can be considered as a safe and useful option for growing young individuals in selected cases

    Solitary fibrous tumor of parotid gland: a case report and short review of literature

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    OBJECTIVE: This case report represents a solitary fibrous tumor, which is a very rare neoplasm in the parotid gland. CASE PRESENTATION: 80-year-old Caucasian female patient with palpable, immobile, painless, slow growing, semi-rigid-elastic neoplasm in the left parotid gland, that was existing for four months. There were no signs of inflammation and facial paralysis. The tumor was initially interpreted as a salivary gland neoplasm of uncertain origin. Fine needle aspiration was performed 2 times; however, the precise diagnosis was challenging. The tumor was excised, regional lymphadenectomy was performed. Morphological and immunophenotypical findings were consistent with solitary fibrous tumor of parotid gland. Currently, the patient is under regular follow-up period at 9 months with no evidence of metastasis or recurrence. CONCLUSIONS: Although very rare, solitary fibrous tumor (SFT) should be suspected in cases of slow growing, solid, well-defined nodules of the parotid gland. The SFT of the parotid gland are usually benign tumors, however there is a low risk of recurrency and malignant behavior with metastatic potential. Complete resection of the tumor should be performed since it is crucial for management without any recurrence

    Physical mechanical consolidation and protection of Miocenic limestone used on Mediterranean historical monuments: the case study of Pietra Cantone (southern Sardinia, Italy)

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    The present work aims to study the consolidating and protective chemical treatments of the Pietra Cantone, a Miocenic (lower Tortonian) limestone widely used in important monuments and historical buildings of Cagliari (southern Sardinia, Italy). Similar limestones of the same geological period have also been used in several important monuments of Mediterranean area, i.e., Malta and Gozo Islands, Matera (central Basilicata, Italy), Lecce (southern Puglia, Italy) and Balearic Islands (Spain). The Pietra Cantone limestone shows problems of chemical–physical decay, due to their petrophysical and compositional char- acteristics: high porosity (on average 28–36 vol%), low cemented muddy-carbonate matrix, presence of phyllosil- icates and sindepositional sea salts (\3%). So, after placed in the monument, this stone is easily alterable by weath- ering chemical processes (e.g., carbonate dissolution and sulfation) and also by cyclic mechanisms of crystalliza- tion/solubilization of salts and hydration/dehydration of hygroscopic phases of the clay component. To define the mineralogical-petrographic features (composition, texture) of limestone, the clay and salt crystalline phases, the optical microscope in polarized light and diffraction anal- ysis were used. To define the petrophysical characteristics (i.e., shape and size distribution of porosity, surface area(SBET), matrix microstructures, rock composition) and interactions of chemical treatments with rock, SEM–EDS analysis and N2 porosimetry with BET and BJH methods were used. To evaluate the efficacy of Na/K-silicates, ethyl silicate consolidants and protective nano-molecular silane monomer water repellent, the mechanical strengths (uni- axial compressive strength, point load and flexural resis- tance), water/helium open porosity, water absorption and vapour permeability data determined before and after the chemical treatments of the Pietra Cantone samples from monument were compared

    Apoptosis and the activity of ceramide, Bax and Bcl-2 in the lungs of neonatal rats exposed to limited and prolonged hyperoxia

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    BACKGROUND: The aim of the study is to examine the effect of limited and prolonged hyperoxia on neonatal rat lung. This is done by examining the morphologic changes of apoptosis, the expression of ceramide, an important mediator of apoptosis, the expression of inflammatory mediators represented by IL-1β and the expression of 2 proto-oncogenes that appear to modulate apoptosis (Bax and Bcl-2). METHODS: Newborn rats were placed in chambers containing room air or oxygen above 90% for 7 days. The rats were sacrificed at 3, 7 or 14 days and their lungs removed. Sections were fixed, subjected to TUNEL, Hoechst, and E-Cadherin Staining. Sections were also incubated with anti-Bcl-2 and anti-Bax antisera. Bcl-2 and Bax were quantitated by immunohistochemistry. Lipids were extracted, and ceramide measured through a modified diacylglycerol kinase assay. RT-PCR was utilized to assess IL-1β expression. RESULTS: TUNEL staining showed significant apoptosis in the hyperoxia-exposed lungs at 3 days only. Co-staining of the apoptotic cells with Hoechst, and E-Cadherin indicated that apoptotic cells were mainly epithelial cells. The expression of Bax and ceramide was significantly higher in the hyperoxia-exposed lungs at 3 and 14 days of age, but not at 7 days. Bcl-2 was significantly elevated in the hyperoxia-exposed lungs at 3 and 14 days. IL-1β expression was significantly increased at 14 days. CONCLUSION: Exposure of neonatal rat lung to hyperoxia results in early apoptosis documented by TUNEL assay. The early rise in Bax and ceramide appears to overcome the anti-apoptotic activity of Bcl-2. Further exposure did not result in late apoptotic changes. This suggests that apoptotic response to hyperoxia is time sensitive. Prolonged hyperoxia results in acute lung injury and the shifting balance of ceramide, Bax and Bcl-2 may be related to the evolution of the inflammatory process

    Antibiotic Prescriptions and Prophylaxis in Italian Children. Is It Time to Change? Data from the ARPEC Project.

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    BACKGROUND: Antimicrobials are the most commonly prescribed drugs. Many studies have evaluated antibiotic prescriptions in the paediatric outpatient but few studies describing the real antibiotic consumption in Italian children's hospitals have been published. Point-prevalence survey (PPS) has been shown to be a simple, feasible and reliable standardized method for antimicrobials surveillance in children and neonates admitted to the hospital. In this paper, we presented data from a PPS on antimicrobial prescriptions carried out in 7 large Italian paediatric institutions. METHODS: A 1-day PPS on antibiotic use in hospitalized neonates and children was performed in Italy between October and December 2012 as part of the Antibiotic Resistance and Prescribing in European Children project (ARPEC). Seven institutions in seven Italian cities were involved. The survey included all admitted patients less than 18 years of age present in the ward at 8:00 am on the day of the survey, who had at least one on-going antibiotic prescription. For all patients data about age, weight, underlying disease, antimicrobial agent, dose and indication for treatment were collected. RESULTS: The PPS was performed in 61 wards within 7 Italian institutions. A total of 899 patients were eligible and 349 (38.9%) had an on-going prescription for one or more antibiotics, with variable rates among the hospitals (25.7% - 53.8%). We describe antibiotic prescriptions separately in neonates ( = 30 days to <18 years old). In the neonatal cohort, 62.8% received antibiotics for prophylaxis and only 37.2% on those on antibiotics were treated for infection. Penicillins and aminoglycosides were the most prescribed antibiotic classes. In the paediatric cohort, 64.4% of patients were receiving antibiotics for treatment of infections and 35.5% for prophylaxis. Third generation cephalosporins and penicillin plus inhibitors were the top two antibiotic classes. The main reason for prescribing antibiotic therapy in children was lower respiratory tract infections (LRTI), followed by febrile neutropenia/fever in oncologic patients, while, in neonates, sepsis was the most common indication for treatment. Focusing on prescriptions for LRTI, 43.3% of patients were treated with 3rd generation cephalosporins, followed by macrolides (26.9%), quinolones (16.4%) and carbapenems (14.9%) and 50.1% of LRTI cases were receiving more than one antibiotic. For neutropenic fever/fever in oncologic patients, the preferred antibiotics were penicillins with inhibitors (47.8%), followed by carbapenems (34.8%), aminoglycosides (26.1%) and glycopeptides (26.1%). Overall, the 60.9% of patients were treated with a combination therapy. CONCLUSIONS: Our study provides insight on the Italian situation in terms of antibiotic prescriptions in hospitalized neonates and children. An over-use of third generation cephalosporins both for prophylaxis and treatment was the most worrisome finding. A misuse and abuse of carbapenems and quinolones was also noted. Antibiotic stewardship programs should immediately identify feasible targets to monitor and modify the prescription patterns in children's hospital, also considering the continuous and alarming emergence of MDR bacteria
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