14 research outputs found
Quantifying knowledge exchange in R&D networks: A data-driven model
We propose a model that reflects two important processes in R&D activities of
firms, the formation of R&D alliances and the exchange of knowledge as a result
of these collaborations. In a data-driven approach, we analyze two large-scale
data sets extracting unique information about 7500 R&D alliances and 5200
patent portfolios of firms. This data is used to calibrate the model parameters
for network formation and knowledge exchange. We obtain probabilities for
incumbent and newcomer firms to link to other incumbents or newcomers which are
able to reproduce the topology of the empirical R&D network. The position of
firms in a knowledge space is obtained from their patents using two different
classification schemes, IPC in 8 dimensions and ISI-OST-INPI in 35 dimensions.
Our dynamics of knowledge exchange assumes that collaborating firms approach
each other in knowledge space at a rate for an alliance duration .
Both parameters are obtained in two different ways, by comparing knowledge
distances from simulations and empirics and by analyzing the collaboration
efficiency . This is a new measure, that takes also in
account the effort of firms to maintain concurrent alliances, and is evaluated
via extensive computer simulations. We find that R&D alliances have a duration
of around two years and that the subsequent knowledge exchange occurs at a very
low rate. Hence, a firm's position in the knowledge space is rather a
determinant than a consequence of its R&D alliances. From our data-driven
approach we also find model configurations that can be both realistic and
optimized with respect to the collaboration efficiency .
Effective policies, as suggested by our model, would incentivize shorter R&D
alliances and higher knowledge exchange rates.Comment: 35 pages, 10 figure
NUTRITION, MALNUTRITION AND DIETARY INTERVENTIONS IN INFLAMMATORY BOWEL DISEASE
Inflammatory Bowel Disease (IBD), which includes both Crohn's disease (CD) and Ulcerative Colitis (UC), is a chronic idiopathic inflammatory disorder affecting the gastrointestinal tract. Diet, as a source of luminal antigens, is thought to be an important factor in the pathogenesis of IBD. often the nutritional status of patients is significantly compromised, particularly in CD. several factors, including drug-nutrient interactions, disease location, symptoms, and dietary restriction can lead to protein energy malnutrition and specific nutritional deficiencies. solid evidence regarding the accountability of certain dietary components in the etiology of IBD are lacking. With regard to malnutrition, its consequence are growth failure, weight loss, bone disease, and/or micronutrient deficiencies, although micronutrient deficiency in IBD in most cases does not tend to have any evident clinical manifestation, except with regardo of iron, folic acid, and vitamin B. Nutritional supplemantation is essential for patients with evidence of malnutrition to increase calorie, and protein intake. Nutritional supplementation can also have efficacy in the induction and maintenance of remission in adults with CD, however it does not replace other treatments. Aim of this review is to discuss the role of nutrition and nutrients' deficiencies in the clinical setting of IBD, and to analyze efficacy and safety of the dietary interventions in patients with IBD
Recurrent retroperitoneal abscess after biliary tract surgery in an elderly patient: a minimally invasive nonsurgical approach and its consequences: a case report
Abstract Introduction Hepatic abscess can be defined as an encapsulated collection of suppurative material within the liver parenchyma. Hepatic abscess can be distinguished as pyogenic, amebic, or fungal. Biliary tract disease remains the most common cause of hepatic abscess today, and the most common complications range from pleural effusion, empyema, and bronchohepatic fistula to subphrenic abscess and rupture into the peritoneal cavity, stomach, colon, vena cava, or kidney. A large abscess compressing the inferior vena cava and the hepatic veins may result in Budd-Chiari syndrome. In this report, we present a rare case of hepatic abscess with an unusual evolution that was treated with a noninvasive approach. Case presentation A 79-year-old Caucasian woman underwent endoscopic bile stone extraction and laparoscopic cholecystectomy. Six months later, a hepatic abscess in association with bilateral effusion was diagnosed. The prompt imaging-guided drainage solved the case. Three years later, she came to our attention complaining of dull, diffuse abdominal pain and high body temperature (38 °C). A retroperitoneal abscess was diagnosed that was spreading to the right lateral wall of the abdomen and extending across the muscular wall to the subcutaneous layer. The fluid collection also involved the right pleural cavity, forming an empyema. Also in this case, an imaging-guided drainage was performed, and the patient’s clinical picture resolved in a few days. The retroperitoneal abscess recurred 14 months later, and it was dealt with using the same treatment. Three months from the last follow-up, the patient came back to our attention with an evident swelling of her right lumbar region. Computed tomography revealed a right inferior lumbar hernia comprising adipose tissue and the right kidney. A surgical intervention was recommended to the patient, but, owing to her poor general health, she refused any invasive approach. Conclusions Retroperitoneal abscess is an uncommon complication of biliary tract surgery and represents a potential cause of death, especially in those patients with multiple diseases. Prompt drainage is crucial to the treatment. Failure in eliminating the primary infective focus could bring complications and, in general, a weakness of lumbar muscular wall, even resulting in a rare case of lumbar hernia
Advanced endoscopic imaging for surveillance for dysplasia and colorectal cancer in inflammatory bowel disease: Could the pathologist be further helped?
Patients with inflammatory bowel disease (IBD) have an increased risk of developing intestinal cancer. The magnitude of that increased risk as well as how best to mitigate it remain a topic of ongoing investigation in the field. It is important to quantify the risk of colorectal cancer in association with IBD. The reported risk varies widely between studies. This is partly due to the different methodologies used in the studies. Because of the limitations of surveillance strategies based on the detection of dysplasia, advanced endoscopic imaging and techniques involving the detection of alterations in mucosal antigens and genetic abnormalities are being investigated. Development of new biomarkers, predicting future occurrence of colonic neoplasia may lead to more biomarker-based surveillance. There are promising results that may lead to more efficient surveillance in IBD patients and more general acceptance of its use. A multidisciplinary approach, involving in particular endoscopists and pathologists, together with a centralized patient management, could help to optimize treatments and follow-up measures, both of which could help to reduce the IBD-associated cancer risk
Redox Modulation of Meniere Disease by Coriolus Versicolor Treatment, a Nutritional Mushroom Approach with Neuroprotective Potential
Background: Meniere's disease (MD) is a cochlear neurodegenerative disease. Hearing loss appears to be triggered by oxidative stress in the ganglion neurons of the inner ear.
Objective: Here, we confirm the variation of markers of oxidative stress and inflammation in patients with Meniere and hypothesize that chronic treatment with Coriolus mushroom helps in the response to oxidative stress and acts on α-synuclein and on NF-kB-mediated inflammatory processes.
Methods: Markers of oxidative stress and inflammation were evaluated in MD patients with or without Coriolus treatment for 3 or 6 months.
Results: MD patients had a small increase in Nrf2, HO-1, γ-GC, Hsp70, Trx and sirtuin-1, which were further increased by Coriolus treatment, especially after 6 months. Increased markers of oxidative damage, such as protein carbonyls, HNE, and ultraweak chemiluminescence, associated with a decrease in plasma GSH/GSSG ratio, were also observed in lymphocytes from MD patients. These parameters were restored to values similar to the baseline in patients treated with Coriolus for both 3 and 6 months. Furthermore, treated MD subjects showed decreased expression of α-synuclein, GFAP and Iba-1 proteins and modulation of the NF-kB pathway, which were impaired in MD patients. These changes were greatest in subjects taking the supplements for 6 months.
Conclusions: Our study suggests MD as a model of cochlear neurodegenerative disease for the identification of potent inducers of the Nrf2-vitagene pathway, able to reduce the deleterious consequences associated with neurodegenerative damage, probably by indirectly acting on α-synuclein expression and on inflammatory processes NF- kB-mediated
Probiotics, prebiotics and symbiotics in inflammatory bowel diseases: state-of-the-art and new insights
Inflammatory bowel disease (IBD) consists of two distinct clinical forms, ulcerative colitis (UC) and Crohn s disease (CD), with unknown aetiology, which nevertheless are considered to share almost identical pathophysiological backgrounds. Up to date, a full coherent mechanistic explanation for IBD is still lacking, but people start to realize that the pathogenesis of IBD involves four fundamental components: the environment, gut microbiota, the immune system and the genome. As a consequence, IBD development might be due to an altered immune response and a disrupted mechanism of host tolerance to the non-pathogenic resident microbiota, leading to an elevated inflammatory response. Considering the available data arising from the scientific literature, here reviewed, in CD, a benefit of probiotics remains unproven; in UC, a benefit of probiotics remains unproven, even if E. coli Nissle 1917seems promising in maintaining remission and it could be considered an alternative in patients intolerant or resistant to 5-ASA preparations; in pouchitis, small controlled trials suggest a benefit from VSL no. 3 in the primary and secondary prevention of pouchitis; in IBD-associated conditions, a benefit of probiotics remains unproven. However, well-designed randomized control clinical trials are necessary to understand the undoubted role of these agents in the management of gut physiology in health and disease