21 research outputs found

    An intelligent liposome that may deliver drug molecules in a well controlled fashion

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    The passage of molecules, especially large ones, through the cellular membrane is a very important problem for some biotechnological applications, such as drug delivery. The appearance of pores in the lipid bilayer following some controlled mechanisms may be an adequate and interesting way. Some pores, named stochastic pores, can appear due to structural and dynamic properties of lipid bilayer, but others may be favored by mechanical tension induced by different ways. Recently, a sequence of 30-40 pores was observed in the same vesicle, a pore at a time, which can appear in vesicles stretched by optical induced mechanical tension. There are two very interesting biotechnological applications that require the increase of membrane permeability: gene therapy and targeted drug delivery. In the first one, the transport of DNA fragments through cellular and nuclear membranes is required. The second application uses drug molecules encapsulated in vesicles, which have to be transported to a target place. Having reached that point, one supposes that the liposome discharges its content by its breakdown. In this paper, we will write about how a lipid vesicle has to release the drug molecules in a well-controlled fashion. Such liposomes are named pulsatory liposomes and they induce cyclic activity. We will demonstrate that this liposome may be programmed to work a certain number of cycles, settled in advance. Also, we will calculate the amount of drug delivered during each cycle. In fact, a pulsatory liposome may be conceived as a drug dose micro device, which works according to a medical prescription established _a priori_

    Pulsatory Liposome: A Possible Biotechnological Device

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    A unilamellar liposome filled with an osmotic solution is introduced into a hypotonic aqueous environment. Because of the mechanical tension induced by the osmotic flow, the vesicle swells up to a critical size, when suddenly a transbilayer pore appears and the vesicle relaxing stage starts. A part of the intracellular material leaks out through this pore, and the liposome membrane relaxes and finally recovers. The swelling begins again and the liposome experiences a periodical process. For this reason, we have named it a pulsatory liposome. The swelling of the liposome is described by a differential equation. All the processes which contribute to the vesicle relaxing and its coming back to the initial size are described by three differential equations. The pulsatory liposome can be programmed to work a number of cycles, established before. The activity of a pulsatory liposome can be characterized by the following parameters: (a) number of cycles, the length time of each cycle, and liposome activity life; (b) the length time of the swelling stage and the relaxation stage for each cycle; (c) the amount of solute leaked out through the pore in each cycle. The pulsatory liposome may be regarded as a two-stroke engine

    First Bio-Anthropological Evidence for Yamnaya Horsemanship.

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    The origins of horseback riding remain elusive. Scientific studies show that horses were kept for their milk similar to 3500 to 3000 BCE, widely accepted as indicating domestication. However, this does not confirm them to be ridden. Equipment used by early riders is rarely preserved, and the reliability of equine dental and mandibular pathol-ogies remains contested. However, horsemanship has two interacting components: the horse as mount and the human as rider. Alterations associated with riding in human skeletons therefore possibly provide the best source of information. Here, we report five Yamnaya individuals well-dated to 3021 to 2501 calibrated BCE from kurgans in Romania, Bulgaria, and Hungary, displaying changes in bone morphology and distinct pathologies associated with horseback riding. These are the oldest humans identified as riders so far.Peer reviewe

    An intelligent liposome that may deliver drug molecules in a well controlled fashion

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    Association between antithrombotic treatment and outcomes at 1-year follow-up in patients with atrial fibrillation: the EORP-AF General Long-Term Registry

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    International audienceAims In recent years, stroke prevention in patients with atrial fibrillation (AF) has radically changed, with increasing use of non-vitamin K antagonist oral anticoagulants (NOACs). Contemporary European data on AF thromboprophylaxis are needed. Methods and results We report 1-year follow-up data from the EURObservational Research Programme in Atrial Fibrillation (EORP-AF) General Long-Term Registry. Outcomes were assessed according to antithrombotic therapy. At 1-year follow-up, 9663 (88.0%) patients had available data for analysis: 586 (6.1%) were not treated with any antithrombotic; 681 (7.0%) with antiplatelets only; 4066 (42.1%) with vitamin K antagonist (VKA) only; 3167 (32.8%) with NOACs only; and 1163 (12.0%) with antiplatelet and oral anticoagulant. At 1-year follow-up, there was a low rate of stroke (0.7%) and any thromboembolic event (TE) (1.2%), while haemorrhagic events occurred in 222 patients (2.3%). Cardiovascular (CV) death and all-cause death occurred in 3.9% and 5.2% of patients, respectively. Cumulative survival for all the three main outcomes considered was highest amongst patients treated only with NOACs (P < 0.0001). Multivariable-adjusted Cox regression analysis found that VKA or NOACs use was independently associated with a lower risk for any TE/acute coronary syndrome/CV death, while all treatments were independently associated with a lower risk for CV death and all-cause death. Conclusion The 1-year follow-up of EORP-AF General Long-Term Registry reported a low occurrence of thromboembolic and haemorrhagic events, although mortality was high. Both VKA and NOACs were associated with a lower risk of all main adverse outcomes. All treatments were associated with a lower risk for CV death and all-cause death

    Incidence of severe critical events in paediatric anaesthesia (APRICOT): a prospective multicentre observational study in 261 hospitals in Europe

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    Background Little is known about the incidence of severe critical events in children undergoing general anaesthesia in Europe. We aimed to identify the incidence, nature, and outcome of severe critical events in children undergoing anaesthesia, and the associated potential risk factors. Methods The APRICOT study was a prospective observational multicentre cohort study of children from birth to 15 years of age undergoing elective or urgent anaesthesia for diagnostic or surgical procedures. Children were eligible for inclusion during a 2-week period determined prospectively by each centre. There were 261 participating centres across 33 European countries. The primary endpoint was the occurence of perioperative severe critical events requiring immediate intervention. A severe critical event was defined as the occurrence of respiratory, cardiac, allergic, or neurological complications requiring immediate intervention and that led (or could have led) to major disability or death. This study is registered with ClinicalTrials.gov, number NCT01878760. Findings Between April 1, 2014, and Jan 31, 2015, 31â127 anaesthetic procedures in 30â874 children with a mean age of 6·35 years (SD 4·50) were included. The incidence of perioperative severe critical events was 5·2% (95% CI 5·0â5·5) with an incidence of respiratory critical events of 3·1% (2·9â3·3). Cardiovascular instability occurred in 1·9% (1·7â2·1), with an immediate poor outcome in 5·4% (3·7â7·5) of these cases. The all-cause 30-day in-hospital mortality rate was 10 in 10â000. This was independent of type of anaesthesia. Age (relative risk 0·88, 95% CI 0·86â0·90; p<0·0001), medical history, and physical condition (1·60, 1·40â1·82; p<0·0001) were the major risk factors for a serious critical event. Multivariate analysis revealed evidence for the beneficial effect of years of experience of the most senior anaesthesia team member (0·99, 0·981â0·997; p<0·0048 for respiratory critical events, and 0·98, 0·97â0·99; p=0·0039 for cardiovascular critical events), rather than the type of health institution or providers. Interpretation This study highlights a relatively high rate of severe critical events during the anaesthesia management of children for surgical or diagnostic procedures in Europe, and a large variability in the practice of paediatric anaesthesia. These findings are substantial enough to warrant attention from national, regional, and specialist societies to target education of anaesthesiologists and their teams and implement strategies for quality improvement in paediatric anaesthesia. Funding European Society of Anaesthesiology

    Incidence of severe critical events in paediatric anaesthesia (APRICOT): a prospective multicentre observational study in 261 hospitals in Europe

    No full text
    Background Little is known about the incidence of severe critical events in children undergoing general anaesthesia in Europe. We aimed to identify the incidence, nature, and outcome of severe critical events in children undergoing anaesthesia, and the associated potential risk factors. Methods The APRICOT study was a prospective observational multicentre cohort study of children from birth to 15 years of age undergoing elective or urgent anaesthesia for diagnostic or surgical procedures. Children were eligible for inclusion during a 2-week period determined prospectively by each centre. There were 261 participating centres across 33 European countries. The primary endpoint was the occurence of perioperative severe critical events requiring immediate intervention. A severe critical event was defined as the occurrence of respiratory, cardiac, allergic, or neurological complications requiring immediate intervention and that led (or could have led) to major disability or death. This study is registered with ClinicalTrials.gov, number NCT01878760. Findings Between April 1, 2014, and Jan 31, 2015, 31 127 anaesthetic procedures in 30 874 children with a mean age of 6.35 years (SD 4.50) were included. The incidence of perioperative severe critical events was 5.2% (95% CI 5.0-5.5) with an incidence of respiratory critical events of 3.1% (2.9-3.3). Cardiovascular instability occurred in 1.9% (1.7-2.1), with an immediate poor outcome in 5.4% (3.7-7.5) of these cases. The all-cause 30-day in-hospital mortality rate was 10 in 10 000. This was independent of type of anaesthesia. Age (relative risk 0.88, 95% CI 0.86-0.90; p<0.0001), medical history, and physical condition (1.60, 1.40-1.82; p<0.0001) were the major risk factors for a serious critical event. Multivariate analysis revealed evidence for the beneficial effect of years of experience of the most senior anaesthesia team member (0.99, 0.981-0.997; p<0.0048 for respiratory critical events, and 0.98, 0.97-0.99; p=0.0039 for cardiovascular critical events), rather than the type of health institution or providers. Interpretation This study highlights a relatively high rate of severe critical events during the anaesthesia management of children for surgical or diagnostic procedures in Europe, and a large variability in the practice of paediatric anaesthesia. These findings are substantial enough to warrant attention from national, regional, and specialist societies to target education of anaesthesiologists and their teams and implement strategies for quality improvement in paediatric anaesthesia

    Transverse momentum and pseudorapidity distributions of charged hadrons in pp collisions at (s)\sqrt(s) = 0.9 and 2.36 TeV

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    Measurements of inclusive charged-hadron transverse-momentum and pseudorapidity distributions are presented for proton-proton collisions at sqrt(s) = 0.9 and 2.36 TeV. The data were collected with the CMS detector during the LHC commissioning in December 2009. For non-single-diffractive interactions, the average charged-hadron transverse momentum is measured to be 0.46 +/- 0.01 (stat.) +/- 0.01 (syst.) GeV/c at 0.9 TeV and 0.50 +/- 0.01 (stat.) +/- 0.01 (syst.) GeV/c at 2.36 TeV, for pseudorapidities between -2.4 and +2.4. At these energies, the measured pseudorapidity densities in the central region, dN(charged)/d(eta) for |eta| < 0.5, are 3.48 +/- 0.02 (stat.) +/- 0.13 (syst.) and 4.47 +/- 0.04 (stat.) +/- 0.16 (syst.), respectively. The results at 0.9 TeV are in agreement with previous measurements and confirm the expectation of near equal hadron production in p-pbar and pp collisions. The results at 2.36 TeV represent the highest-energy measurements at a particle collider to date

    Transverse-momentum and pseudorapidity distributions of charged hadrons in pppp collisions at s\sqrt{s} = 7 TeV

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    Charged-hadron transverse-momentum and pseudorapidity distributions in proton-proton collisions at s=7\sqrt{s} = 7~TeV are measured with the inner tracking system of the CMS detector at the LHC. The charged-hadron yield is obtained by counting the number of reconstructed hits, hit-pairs, and fully reconstructed charged-particle tracks. The combination of the three methods gives a charged-particle multiplicity per unit of pseudorapidity \dnchdeta|_{|\eta| < 0.5} = 5.78\pm 0.01\stat\pm 0.23\syst for non-single-diffractive events, higher than predicted by commonly used models. The relative increase in charged-particle multiplicity from s=0.9\sqrt{s} = 0.9 to 7~TeV is 66.1\%\pm 1.0\%\stat\pm 4.2\%\syst. The mean transverse momentum is measured to be 0.545\pm 0.005\stat\pm 0.015\syst\GeVc. The results are compared with similar measurements at lower energies.Charged-hadron transverse-momentum and pseudorapidity distributions in proton-proton collisions at sqrt(s) = 7 TeV are measured with the inner tracking system of the CMS detector at the LHC. The charged-hadron yield is obtained by counting the number of reconstructed hits, hit-pairs, and fully reconstructed charged-particle tracks. The combination of the three methods gives a charged-particle multiplicity per unit of pseudorapidity, dN(charged)/d(eta), for |eta| < 0.5, of 5.78 +/- 0.01 (stat) +/- 0.23 (syst) for non-single-diffractive events, higher than predicted by commonly used models. The relative increase in charged-particle multiplicity from sqrt(s) = 0.9 to 7 TeV is 66.1% +/- 1.0% (stat) +/- 4.2% (syst). The mean transverse momentum is measured to be 0.545 +/- 0.005 (stat) +/- 0.015 (syst) GeV/c. The results are compared with similar measurements at lower energies
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