2,168 research outputs found
Optimal local work extraction from bipartite quantum systems in the presence of Hamiltonian couplings
We investigate the problem of finding the local analog of the ergotropy, which is the maximum work that can be extracted from a system if we can only apply local unitary transformation acting on a given subsystem. In particular, we provide a closed formula for the local ergotropy in the special case in which the local system has only two levels, and we give analytic lower bounds and semidefinite programming upper bounds for the general case. As nontrivial examples of application, we compute the local ergotropy for an atom in an electromagnetic cavity with Jaynes-Cummings coupling and the local ergotropy for a spin site in an XXZ Heisenberg chain, showing that the amount of work that can be extracted with a unitary operation on the coupled system can be greater than the work obtainable by quenching off the coupling with the environment before the unitary transformation
Relation between growth dynamics and diffusional limitations in Saccharomyces cerevisiae cells growing as entrapped in insolubilized gel
Flow-cytometric analysis was employed to investigate growth dynamics of a yeast cell population immobilised in an insolubilised gelatin gel by means of the quantitative determination of the average protein content per cell. This analysis was carried out on both the immobilised cell population considered as a whole and the subpopulations colonising the gelatin matrix at different depths. The results show that growth of the gelatin-immobilised yeast population was affected by the existence of a gradient of nutrient concentrations through the matrix and are in agreement with the unsteady-state diffusion model employed for the description of glucose transfer in the gel
Perianal Crohn's disease and hidradenitis suppurativa: a possible common immunological scenario
Crohn's disease (CD) and Hidradenitis suppurativa (HS) are both chronic inflammatory diseases. The pathogenesis of these diseases is multifactorial, due to the interaction of genetic and environmental factors leading to a deregulated local immune response where T lymphocytes play a major role. To the best of our knowledge, no previous study has clarified whether the pathogenetic mechanism of perianal CD and HS is the same. We therefore analyzed the cellular expression pattern and the cytokine repertoire in three patients suffering from both perianal CD and HS
Management of pheochromocytoma during pregnancy from diagnosis to laparoscopic adrenalectomy. A case report and review of literature
INTRODUCTION: Pheochromocytoma is an endocrine tumour of chromaffin cells. It can be diagnosed either sporadically or in the context of hereditary syndromes (e.g. Von Hippel Lindau, Neurofibromatosis type 1 and multiple neuroendocrine neoplasia type 2). During pregnancy, its frequency is very low (about 0,007%). This tumour causes paroxysmal hypertension in 0,1-0,6% pregnant women, because of an overproduction of catecholamines. If undiagnosed and nontreated, it's associated with high maternal and fetal mortality (40-50%). We report the case of a 30-year-old female diagnosed with pheochromocytoma during pregnancy at week 31 of gestation. In a multidisciplinary team made of surgeons, gynaecologists, anaesthetists, geneticists and endocrinologists we evaluated the case and according to literature, we choose a surgical approach after childbirth: performing a laparoscopic right adrenalectomy. DISCUSSION: In pregnancy, pheochromocytoma is a rare clinical condition. Gold standard treatment is laparoscopic adrenalectomy. However, the optimum timing of surgery is a challenge. CONCLUSION: Timely diagnosis of pheochromocytoma in pregnant women with hypertension and appropriate therapeutic management can lead to improve maternal, fetal and neonatal outcomes. The multidisciplinary team is necessary to recognize the symptoms and to adopt the right pre - and post - operative treatment. Laparoscopic adrenalectomy after delivery is safe and feasible even though the surgical procedure should be performed by an experienced surgeon. KEY WORDS: Pheochromocytoma, Pregnancy, Laparoscopic adrenalectomy and pregnancy, Management of pheochromocytoma, Laparoscopic adrenalectomy, Adrenalectomy, Pregnancy and pheochromocytoma
Development of a High Oleic Cardoon Cell Culture Platform by SAD Overexpression and RNAi-Mediated FAD2.2 Silencing
The development of effective tools for the sustainable supply of phyto-ingredients and natural substances with reduced environmental footprints can help mitigate the dramatic scenario of climate change. Plant cell cultures-based biorefineries can be a technological advancement to face this challenge and offer a potentially unlimited availability of natural substances, in a standardized composition and devoid of the seasonal variability of cultivated plants. Monounsaturated (MUFA) fatty acids are attracting considerable attention as supplements for biodegradable plastics, bio-additives for the cosmetic industry, and bio-lubricants. Cardoon (Cynara cardunculus L. var. altilis) callus cultures accumulate fatty acids and polyphenols and are therefore suitable for large-scale production of biochemicals and valuable compounds, as well as biofuel precursors. With the aim of boosting their potential uses, we designed a biotechnological approach to increase oleic acid content through Agrobacterium tumefaciens-mediated metabolic engineering. Bioinformatic data mining in the C. cardunculus transcriptome allowed the selection and molecular characterization of SAD (stearic acid desaturase) and FAD2.2 (fatty acid desaturase) genes, coding for key enzymes in oleic and linoleic acid formation, as targets for metabolic engineering. A total of 22 and 27 fast-growing independent CcSAD overexpressing (OE) and CcFAD2.2 RNAi knocked out (KO) transgenic lines were obtained. Further characterization of five independent transgenic lines for each construct demonstrated that, successfully, SAD overexpression increased linoleic acid content, e.g., to 42.5%, of the relative fatty acid content, in the CcSADOE6 line compared with 30.4% in the wild type (WT), whereas FAD2.2 silencing reduced linoleic acid in favor of the accumulation of its precursor, oleic acid, e.g., to almost 57% of the relative fatty acid content in the CcFAD2.2KO2 line with respect to 17.7% in the WT. Moreover, CcSADOE6 and CcFAD2.2KO2 were also characterized by a significant increase in total polyphenolic content up to about 4.7 and 4.1 mg/g DW as compared with 2.7 mg/g DW in the WT, mainly due to the accumulation of dicaffeoyl quinic and feruloyl quinic acids. These results pose the basis for the effective creation of an engineered cardoon cells-based biorefinery accumulating high levels of valuable compounds from primary and specialized metabolism to meet the industrial demand for renewable and sustainable sources of innovative bioproducts
bivalirudin inhibits thrombin mediated tissue factor expression in human endothelial cells
Thrombosis is the main pathophysiological mechanism in Acute Coronary Syndromes (ACS), and involves the activation of platelets and of Tissue Factor (TF)-dependent extrinsic coagulation pathway. TF-mRNA and antigen are detectable in the adventitia of normal vessels. On the contrary, little TF immunoreactivity is measurable in the smooth muscle cells of uninjured vessels and unperturbed endothelial cells, being in contact with circulating blood, usually do not express TF activity. However, several stimuli are able to induce TF in endothelial cells, including thrombin. Thus in an acute "scenario", thrombin might be responsible for creating a prothombotic milieau. Bivalirudin (BIVA) is a synthetic, reversible direct thrombin inhibitor actually considered a valuable alternative to heparins in patients who need anticoagulation in the setting of ACS and percutaneous coronary intervention to avoid acute thrombotic events. In the present study we have investigated whether BIVA, by inhibiting thrombin, might have effects on TF expression and procoagulant activity in endothelial cells. Human Umbilical Endothelial Cells (HUVEC) were stimulated with thrombin or with the activated coagulation factors FVIIa/FXa for 2 hrs to evaluate TF-mRNA transcription by real-time PCR and for 6 hrs to measure TF expression/activity on cell surface by FACs analysis and procoagulant activity. In additional experiments HUVEC were pre-treated with BIVA for 1 hr before being stimulated and processed as above. Thrombin induced TF-mRNA transcription as well TF expression/activity on HUVEC shifting them to a procoagulant phenotype. On the contrary, the activated coagulation factors FVIIa/FXa did not affect TF expression/activity, indicating that thrombin plays a pivotal role in mediating this phenomenon. BIVA was able to prevent these thrombin deleterious effects. Data of the present study, although in vitro, suggest that BIVA, in the context of ACS, might significantly reduce thrombogenicity not only by acting as direct thrombin inhibitor but through its effects on TF expression/activity too. </p
Upregulation of TH/IL-17 Pathway-Related Genes in Human Coronary Endothelial Cells Stimulated with Serum of Patients with Acute Coronary Syndromes
Inflammation plays an essential role in the development and complications of atherosclerosis plaques, including acute coronary syndromes (ACS). Indeed, previous reports have shown that within the coronary circulation of ACS patients, several soluble mediators are released. Moreover, it has been demonstrated that endothelial dysfunction might play an important role in atherosclerosis as well as ACS pathophysiology. However, the mechanisms by which these soluble mediators might affect endothelial functions are still largely unknown. We have evaluated whether soluble mediators contained in serum from coronary circulation of ACS patients might promote changes of gene profile in human coronary endothelial cells (HCAECs)
Oxidized Low-Density Lipoproteins Induce Tissue Factor Expression in T-Lymphocytes via activation of Lectin-Like Oxidized Low-Density Lipoprotein Receptor-1
T-lymphocytes plays an important role in the pathophysiology of acute coronary syndromes (ACS). T-cell activation in vitro by pro-inflammatory cytokines may lead to functional Tissue Factor (TF) expression, indicating a possible contribution of immunity to thrombosis. Oxidized low-density lipoproteins (oxLDLs) are found abundantly in atherosclerotic plaques. We aimed at evaluating the effects of oxLDLs on TF expression in T-cells and the role of the lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1)
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