572 research outputs found

    Towards the Formalization of Fractional Calculus in Higher-Order Logic

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    Fractional calculus is a generalization of classical theories of integration and differentiation to arbitrary order (i.e., real or complex numbers). In the last two decades, this new mathematical modeling approach has been widely used to analyze a wide class of physical systems in various fields of science and engineering. In this paper, we describe an ongoing project which aims at formalizing the basic theories of fractional calculus in the HOL Light theorem prover. Mainly, we present the motivation and application of such formalization efforts, a roadmap to achieve our goals, current status of the project and future milestones.Comment: 9 page

    Emissions of ozone-depleting halocarbons from China

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    National emission inventories of ozone-depleting substances (ODS) play a key role in the control mechanisms of the Montreal Protocol's emission reduction plans. New quasi-continuous ground-based atmospheric measurements allow us to estimate China's current emissions of the most effective ODS. This serves as an independent validation of China's ODS consumption data reported to the United Nations Environment Programme (UNEP). Emissions of most first-generation ODS have declined in recent years, suggesting compliance with the regulations of China's advanced phase-out program. In contrast the emissions of some second-generation ODS have increased. Because China is currently one of the largest consumers of first generation ODS, the country's upcoming complete phase-out will be crucial for the rate of decline of atmospheric ODS hence the eventual recovery of the stratospheric ozone. Citation: Vollmer, M. K., et al. (2009), Emissions of ozone-depleting halocarbons from China, Geophys. Res. Lett., 36, L15823, doi:10.1029/2009GL038659

    Bombesin peptide antagonist for target-selective delivery of liposomal doxorubicin on cancer cells

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    Purpose: This study addresses novel peptide modified liposomal doxorubicin to specifically target tissues overexpressing bombesin (BN) receptors. Methods: DOTA-(AEEA)2-peptides containing the [7–14]bombesin and the new BN-AA1 sequence have been synthesized to compare their binding properties and in serum stabilities. The amphiphilic peptide derivative (MonYBN- AA1) containing BN-AA1, a hydrophobic moiety, polyethylenglycole (PEG), and diethylenetriaminepentaacetate (DTPA), has been synthesized. Liposomes have been obtained by mixing of MonY-BN-AA1 with 1,2-distearoylsn-glycero-3-phosphocholine (DSPC). Results: Both 111In labeled peptide derivatives present nanomolar Kd to PC-3 cells. 177Lu labeled peptide DOTA- (AEEA)2-BN-AA1 is very stable (half-life 414.1 h), while DOTA-(AEEA)2-BN, shows a half-life of 15.5 h. In vivo studies on the therapeutic efficacy of DSPC/MonY-BN-AA1/Dox in comparison to DSPC/MonY-BN/Dox, were performed in PC-3 xenograft bearing mice. Both formulations showed similar tumor growth inhibition (TGI) compared to control animals treated with non-targeted DSPC/Dox liposomes or saline solution. For DSPC/MonY-BN-AA1/Dox the maximum effect was observed 19 days after treatment. Conclusions: DSPC/MonY-BN-AA1/Dox nanovectors confirm the ability to selectively target and provide therapeutic efficacy in mice. The lack of receptor activation and possible acute biological side effects provided by using the AA1 antagonist bombesin sequence should provide safe working conditions for further development of this class of drug delivery vehicles

    CAR T cells targeting tumor endothelial marker CLEC14A inhibit tumor growth

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    Engineering T cells to express chimeric antigen receptors (CARs) specific for antigens on hematological cancers has yielded remarkable clinical responses, but with solid tumors, benefit has been more limited. This may reflect lack of suitable target antigens, immune evasion mechanisms in malignant cells, and/or lack of T cell infiltration into tumors. An alternative approach, to circumvent these problems, is targeting the tumor vasculature rather than the malignant cells directly. CLEC14A is a glycoprotein selectively overexpressed on the vasculature of many solid human cancers and is, therefore, of considerable interest as a target antigen. Here, we generated CARs from 2 CLEC14A-specific antibodies and expressed them in T cells. In vitro studies demonstrated that, when exposed to their target antigen, these engineered T cells proliferate, release IFN-γ, and mediate cytotoxicity. Infusing CAR engineered T cells into healthy mice showed no signs of toxicity, yet these T cells targeted tumor tissue and significantly inhibited tumor growth in 3 mouse models of cancer (Rip-Tag2, mPDAC, and Lewis lung carcinoma). Reduced tumor burden also correlated with significant loss of CLEC14A expression and reduced vascular density within malignant tissues. These data suggest the tumor vasculature can be safely and effectively targeted with CLEC14A-specific CAR T cells, offering a potent and widely applicable therapy for cancer

    Changes in metabolic parameters and cardiovascular risk factors after therapeutic control of acromegaly vary with the treatment modality. Data from the Bicêtre cohort, and review of the literature

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    CONTEXT: Untreated acromegaly is associated with increased morbidity and mortality due to malignant, cardiovascular, and cerebrovascular disorders. Effective treatment of acromegaly reduces excess mortality, but its impact on cardiovascular risk factors and metabolic parameters are poorly documented. AIM: We analyzed changes in cardiovascular risk factors and metabolic parameters in patients receiving various treatment modalities. PATIENTS AND METHODS: We retrospectively studied 96 patients with acromegaly, both at diagnosis and after IGF-I normalization following surgery alone (n = 51) or medical therapy with first generation somatostatin analogues (SSA, n = 23), or pegvisomant (n = 22). Duration of follow-up was 77 (42-161) months, 75 (42-112) months, and 62 (31-93) months, in patients treated with surgery alone, SSA, and pegvisomant, respectively. In all the cases except four, patients treated medically had underwent previous unsuccessful surgery. RESULTS: IGF-I normalization was associated with increased body weight, decreased systolic blood pressure (SBP) in hypertensive patients, decreased fasting plasma glucose (FPG) and HOMA-IR and HOMA-B levels, increased HDL cholesterol (HDLc); whereas, LDL cholesterol (LDLc) was not significantly different. Plasma PCSK9 levels were unchanged in patients with available values. Cardiovascular and metabolic changes varied with the treatment modality: surgery, but not pegvisomant, had a beneficial effect on SBP; FPG decreased after surgery but increased after SSA; the decline in HOMA-IR was only significant after surgery; pegvisomant significantly increased LDLc and total cholesterol; whereas SA increased HDLc and had no effect on LDLc levels. CONCLUSION: Treatments used to normalize IGF-I levels in patients with acromegaly could have differential effects on cardiovascular risk factors and metabolic parameters

    Factorial phase III randomised trial of rofecoxib and prolonged constant infusion of gemcitabine in advanced non-small-cell lung cancer: the GEmcitabine-COxib in NSCLC (GECO) study.

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    Background. The addition of cyclo-oxygenase-2 (COX-2) inhibitors and prolonged constant infusion (PCI) of gemcitabine to treatment for advanced non-small-cell lung cancer (NSCLC) might improve treatment efficacy. We aimed to assess whether the addition of rofecoxib or PCI gemcitabine could improve overall survival compared with first-line treatment with cisplatin plus gemcitabine given by standard infusion. Methods. Patients with stage IV or IIIb (with supraclavicular nodes or pleural effusion) NSCLC who were under 70 years of age and who had performance status 0 or 1 were eligible for this multicentre, prospective, open-label, randomised phase III trial with 2×2 factorial design. Patients were randomly assigned to one of four treatment groups: group A,gemcitabine 1200 mg/m2 in a 30-min intravenous infusion on days 1 and 8 and intravenous cisplatin 80 mg/m2 on day 1, every 21 days for six cycles; group B, the same treatments as group A plus oral rofecoxib 50 mg/day until disease progression; group C, intravenous PCI gemcitabine 1200 mg/m2 in a 120-min infusion on days 1 and 8 and intravenous cisplatin 80 mg/m2 on day 1, every 21 days for six cycles; group D, the same drugs as group C plus oral rofecoxib 50 mg/day until disease progression. The primary endpoint was overall survival; secondary endpoints were progression free survival, response rate, quality of life, and toxicity. Analyses were intention-to-treat. This trial is registered on the clinical trials site of the US National Institutes of Health website http://clinicaltrials.gov/ct/show/NCT00385606. Findings. Between Jan 30, 2003, and May 3, 2005, 400 patients were enrolled. Median age was 60 years (range 29–71). PCI gemcitabine did not improve overall survival (median 47 weeks [95% CI 40–55] vs 44 [36–52], with standard gemcitabine infusion, hazard ratio (HR) of death 0·93 [0·74–1·17], p=0·41), progression-free survival, nor any other secondary endpoint. Vomiting and fatigue were significantly worse with PCI gemcitabine. The two rofecoxib groups were closed early (on Oct 1, 2004) due to withdrawal of the drug because of safety issues. With intention-to-treat statistical analyses limited to 240 patients (ie, those randomised before July 1, 2004) who had at least 3 months of treatment, rofecoxib did not prolong overall survival (median 44 weeks [CI 36–55] vs 44 [40–54] without rofecoxib, and HR of death 1·00 [0·75–1·34], p=0·85), or progression-free survival, but did improve response rate (41% vs 26%, p=0·02), global quality of life, physical, emotional and role functioning, fatigue, and sleeping. Rofecoxib significantly increased the incidence of diarrhoea and decreased constipation, fatigue, fever, weight loss, and pain, and analgesic consumption. Severe cardiac ischaemia was more frequent with rofecoxib than without; however, the diff erence was not statistically signifi cant in the primary analysis (p=0·06) and became significant when patients who were randomised between July 1, 2004, and Sept 30, 2004, were included in the analysis (p=0·03). Interpretation. Neither PCI gemcitabine nor rofecoxib prolonged survival in the patients in this study. Rofecoxib improved response rate and several quality-of-life items, including pain-related items and global quality of life. Further studies with less cardiotoxic COX-2 inhibitors are needed in NSCLC

    An analytical inversion method for determining regional and global emissions of greenhouse gases: Sensitivity studies and application to halocarbons

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    A new analytical inversion method has been developed to determine the regional and global emissions of long-lived atmospheric trace gases. It exploits in situ measurement data from three global networks and builds on backward simulations with a Lagrangian particle dispersion model. The emission information is extracted from the observed concentration increases over a baseline that is itself objectively determined by the inversion algorithm. The method was applied to two hydrofluorocarbons (HFC-134a, HFC-152a) and a hydrochlorofluorocarbon (HCFC-22) for the period January 2005 until March 2007. Detailed sensitivity studies with synthetic as well as with real measurement data were done to quantify the influence on the results of the a priori emissions and their uncertainties as well as of the observation and model errors. It was found that the global a posteriori emissions of HFC-134a, HFC-152a and HCFC-22 all increased from 2005 to 2006. Large increases (21%, 16%, 18%, respectively) from 2005 to 2006 were found for China, whereas the emission changes in North America (−9%, 23%, 17%, respectively) and Europe (11%, 11%, −4%, respectively) were mostly smaller and less systematic. For Europe, the a posteriori emissions of HFC-134a and HFC-152a were slightly higher than the a priori emissions reported to the United Nations Framework Convention on Climate Change (UNFCCC). For HCFC-22, the a posteriori emissions for Europe were substantially (by almost a factor 2) higher than the a priori emissions used, which were based on HCFC consumption data reported to the United Nations Environment Programme (UNEP). Combined with the reported strongly decreasing HCFC consumption in Europe, this suggests a substantial time lag between the reported time of the HCFC-22 consumption and the actual time of the HCFC-22 emission. Conversely, in China where HCFC consumption is increasing rapidly according to the UNEP data, the a posteriori emissions are only about 40% of the a priori emissions. This reveals a substantial storage of HCFC-22 and potential for future emissions in China. Deficiencies in the geographical distribution of stations measuring halocarbons in relation to estimating regional emissions are also discussed in the paper. Applications of the inversion algorithm to other greenhouse gases such as methane, nitrous oxide or carbon dioxide are foreseen for the future

    Effects of chronic inflammatory bowel diseases on left ventricular structure and function: a study protocol

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    BACKGROUND: Experimental evidences suggest an increased collagen deposition in inflammatory bowel diseases (IBD). In particular, large amounts of collagen type I, III and V have been described and correlated to the development of intestinal fibrotic lesions. No information has been available until now about the possible increased collagen deposition far from the main target organ. In the hypothesis that chronic inflammation and increased collagen metabolism are reflected also in the systemic circulation, we aimed this study to evaluate the effects on left ventricular wall structure by assessing splancnic and systemic collagen metabolism (procollagen III assay), deposition (ultrasonic tissue characterization), and cardiac function (echocardiography) in patients with different long standing history of IBD, before and after surgery. METHODS: Thirty patients affected by active IBD, 15 with Crohn and 15 with Ulcerative Colitis, submitted to surgery will be enrolled in the study in a double blind fashion. They will be studied before the surgical operation and 6, 12 months after surgery. A control group of 15 healthy age and gender-matched subjects will also be studied. At each interval blood samples will be collected in order to assess the collagen metabolism; a transthoracic echocardiogram will be recorded for the subsequent determination of cardiac function and collagen deposition. DISCUSSION: From this study protocol we expect additional information about the association between IBD and cardiovascular disorders; in particular to address the question if chronic inflammation, through the altered collagen metabolism, could affect left ventricular structure and function in a manner directly related to the estimated duration of the disease

    Semaphorins and their receptors: Novel features of neural guidance molecules

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    Semaphorins were originally identified as axon guidance cues involved in the development of the nervous system. In recent years, it is emerging that they also participate in various biological systems, including physiological and pathological processes. In this review, we primarily focus on our cumulative findings for the role of semaphorins and their receptors in the regulation of the immune system, while also summarizing recent progress in the context of cardiovascular system
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