227 research outputs found

    Emergence of autopoietic vesicles able to grow, repair and reproduce in a minimalist particle system

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    This paper describes a 2D particle system in which autopoietic vesicles that are able to grow, repair, and reproduce can emerge from an initial random distribution of individual components. The reproduction process also exhibits inheritance of the vesicle content that could in principle change from one generation to the next and influence fitness, making those autopoietic vesicles eligible to be acted upon by natural selection. Video abstract: https://www.youtube.com/watch?v=JmCN_4jTwf

    Assessing a treatment on the basis of an individual or a group. An example: the homeopathic treatment of digestive-tract strongyles in sheep

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    Homeopathic treatments, widely used in organic farming, remain unevaluated. Assessment is difficult since the individuals that respond to treatment are not identified, although it is central to the concept of homeopathic treatment. Classifying lambs into those to be treated (since they have high parasitic infection rate or poor production performances) or that should remain untreated (in other words, even when treated, they will not benefit from treatment) is not simple. The identification of lambs to be treated can be based on parasitological examinations (eggs per gram of faeces), clinical (anaemia or diarrhoea)or production-related (weight gain) results. The classification of lambs was a posteriori and based on dendrograms using UPGMA (unweighted pairwise grouping on arithmetic average) and Gower’s similarity index. Parasitological, clinical and production identifiers were used for assessing the efficacy of Teucrium marum (9 CH) on digestive-tract strongyles. There was no reduction in gastro-intestinal infection in lambs with high infection rates or poor live weight gain

    Perception of spatialized vibrotactile impacts in a hand-held tangible for Virtual Reality

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    International audienceInformative and realistic haptic feedback significantly enhances virtual reality (VR) manipulation. In particular, vibrotactile feedback (VF) can deliver diverse haptic sensations while remaining relatively simple. This has made it a go-to solution for haptics within hand-held controllers and tangible props for VR. However, VF in hand-helds has solely focused on monolithic vibration of the entire hand-held device. Thus, it is not clear to what extent such hand-held devices could support the delivery of spatialized information within the hand. In this paper, we consider a tangible cylindrical handle that allows interaction with virtual objects extending beyond it. This handle is fitted with a pair of vibrotactile actuators with the objective of providing in-hand spatialized cues indicating direction and distance of impacts. We evaluated its capability for rendering spatialized impacts with external virtual objects. Results show that it performs very well for conveying an impact's direction and moderately well for conveying an impact's distance to the user

    First g(2+) measurement on neutron-rich 72 Zn, and the high-velocity transient field technique for radioactive heavy-ion beams

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    The high-velocity transient-field (HVTF) technique was used to measure the g factor of the 2+ state of 72Zn produced as a radioactive beam. The transient-field strength was probed at high velocity in ferromagnetic iron and gadolinium hosts using 76Ge beams. The potential of the HVTF method is demonstrated and the difficulties that need to be overcome for a reliable use of the TF technique with high-Z, high-velocity radioactive beams are revealed. The polarization of K-shell vacancies at high velocity, which shows more than an order of magnitude difference between Z = 20 and Z = 30 is discussed. The g-factor measurement hints at the theoretically predicted transition in the structure of the Zn isotopes near N = 40

    Calcium Complexes Having Different Amidinate Ligands - Synthesis and Structural Diversity

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    A one-pot reaction of α-diimine ligand 1,4-disubstituted diazabutadienes (DAD) with potassium benzyl and anhydrous calcium iodide in 1:1:1 molar ratio afforded unprecedented 3-phenylprop-2-ene-di-amido calcium compound [κ2-(THF)4Ca{DippNC(=CHPh)CH2NDipp}] (1) (Dipp = 2,6-diisopropylphenyl) in good yield. The solid-state structure of the compound 1 revealed the formation of dianionic 3-phenylprop-2-ene-di-amido ligand having an exocyclic olefinic bond derived from neutral α-diimine fragment. However, analogous reactions with three different carbodiimides (RN=C=NR; R=Cy, iPr and tBu) with alkyl potassium and anhydrous calcium diiodide yielded corresponding homoleptic calcium compounds with amidinato ligand [κ2-(THF)2Ca{RN=C(CH2Ph)NR}2] [R=Cy (2), iPr (3) and tBu (4)]. A separate reaction of DAD ligand, LiCH2SiMe3 and anhydrous ZnCl2 in diethylether solvent produced tri-coordinated zinc compound [κ2- {DippN=C(CH2SiMe3)CH2NDipp}Zn[κ1-{DippN=C(CH2SiMe3)CH2N-Dipp}] (5) having amidinato moieties in the zinc coordination sphere in high yield. Molecular structures of compounds 2–5 in their solid states were also established

    Epidural Interventions in the Management of Chronic Spinal Pain: American Society of Interventional Pain Physicians (ASIPP) Comprehensive Evidence-Based Guidelines.

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    BACKGROUND: Chronic spinal pain is the most prevalent chronic disease with employment of multiple modes of interventional techniques including epidural interventions. Multiple randomized controlled trials (RCTs), observational studies, systematic reviews, and guidelines have been published. The recent review of the utilization patterns and expenditures show that there has been a decline in utilization of epidural injections with decrease in inflation adjusted costs from 2009 to 2018. The American Society of Interventional Pain Physicians (ASIPP) published guidelines for interventional techniques in 2013, and guidelines for facet joint interventions in 2020. Consequently, these guidelines have been prepared to update previously existing guidelines. OBJECTIVE: To provide evidence-based guidance in performing therapeutic epidural procedures, including caudal, interlaminar in lumbar, cervical, and thoracic spinal regions, transforaminal in lumbar spine, and percutaneous adhesiolysis in the lumbar spine. METHODS: The methodology utilized included the development of objective and key questions with utilization of trustworthy standards. The literature pertaining to all aspects of epidural interventions was viewed with best evidence synthesis of available literature and recommendations were provided. RESULTS: In preparation of the guidelines, extensive literature review was performed. In addition to review of multiple manuscripts in reference to utilization, expenditures, anatomical and pathophysiological considerations, pharmacological and harmful effects of drugs and procedures, for evidence synthesis we have included 47 systematic reviews and 43 RCTs covering all epidural interventions to meet the objectives.The evidence recommendations are as follows: Disc herniation: Based on relevant, high-quality fluoroscopically guided epidural injections, with or without steroids, and results of previous systematic reviews, the evidence is Level I for caudal epidural injections, lumbar interlaminar epidural injections, lumbar transforaminal epidural injections, and cervical interlaminar epidural injections with strong recommendation for long-term effectiveness.The evidence for percutaneous adhesiolysis in managing disc herniation based on one high-quality, placebo-controlled RCT is Level II with moderate to strong recommendation for long-term improvement in patients nonresponsive to conservative management and fluoroscopically guided epidural injections. For thoracic disc herniation, based on one relevant, high-quality RCT of thoracic epidural with fluoroscopic guidance, with or without steroids, the evidence is Level II with moderate to strong recommendation for long-term effectiveness.Spinal stenosis: The evidence based on one high-quality RCT in each category the evidence is Level III to II for fluoroscopically guided caudal epidural injections with moderate to strong recommendation and Level II for fluoroscopically guided lumbar and cervical interlaminar epidural injections with moderate to strong recommendation for long-term effectiveness.The evidence for lumbar transforaminal epidural injections is Level IV to III with moderate recommendation with fluoroscopically guided lumbar transforaminal epidural injections for long-term improvement. The evidence for percutaneous adhesiolysis in lumbar stenosis based on relevant, moderate to high quality RCTs, observational studies, and systematic reviews is Level II with moderate to strong recommendation for long-term improvement after failure of conservative management and fluoroscopically guided epidural injections. Axial discogenic pain: The evidence for axial discogenic pain without facet joint pain or sacroiliac joint pain in the lumbar and cervical spine with fluoroscopically guided caudal, lumbar and cervical interlaminar epidural injections, based on one relevant high quality RCT in each category is Level II with moderate to strong recommendation for long-term improvement, with or without steroids. Post-surgery syndrome: The evidence for lumbar and cervical post-surgery syndrome based on one relevant, high-quality RCT with fluoroscopic guidance for caudal and cervical interlaminar epidural injections, with or without steroids, is Level II with moderate to strong recommendation for long-term improvement. For percutaneous adhesiolysis, based on multiple moderate to high-quality RCTs and systematic reviews, the evidence is Level I with strong recommendation for long-term improvement after failure of conservative management and fluoroscopically guided epidural injections. LIMITATIONS: The limitations of these guidelines include a continued paucity of high-quality studies for some techniques and various conditions including spinal stenosis, post-surgery syndrome, and discogenic pain. CONCLUSIONS: These epidural intervention guidelines including percutaneous adhesiolysis were prepared with a comprehensive review of the literature with methodologic quality assessment and determination of level of evidence with strength of recommendations

    Aluminum salen and salan complexes in the ring-opening polymerization of cyclic esters: Controlled immortal and copolymerization of <em>rac</em>-β-butyrolactone and <em>rac</em>-lactide

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    Aluminum-based salen and salan complexes mediate the ring-opening polymerization (ROP) of rac-β-butyrolactone (β-BL), rac-lactide, and ε-caprolactone. Al-salen and Al-salan complexes exhibit excellent control over the ROP of rac-β-butyrolactone, yielding atactic poly(3-hydroxybutyrate) (PHB) with narrow PDIs of <1.15 for Al-salen and <1.05 for Al-salan. Kinetic studies reveal pseudo-first-order polymerization kinetics and a linear relationship between molecular weight and percent conversion. These complexes also mediate the immortal ROP of rac-β-BL and rac-lactide, through the addition of excess benzyl alcohol of up to 50 mol eq., with excellent control observed. A novel methyl/adamantyl-substituted Al-salen system further improves control over the ROP of rac-lactide and rac-β-BL, yielding atactic PHB and highly isotactic poly(lactic acid) (Pm = 0.88). Control over the copolymerization of rac-lactide and rac-β-BL was also achieved, yielding poly(lactic acid)-co-poly(3-hydroxybutyrate) with narrow PDIs of <1.10. 1H NMR spectra of the copolymers indicate a strong bias for the insertion of rac-lactide over rac-β-BL

    Advances in heterometallic ring-opening (co)polymerisation catalysis

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    Truly sustainable plastics require renewable feedstocks coupled with efficient production and end-of-life degradation/recycling processes. Some of the most useful degradable materials are aliphatic polyesters, polycarbonates and polyamides, which are often prepared via ring-opening (co)polymerisation (RO(CO)P) using an organometallic catalyst. While there has been extensive research into ligand development, heterometallic cooperativity offers an equally promising yet underexplored strategy to improve catalyst performance, as heterometallic catalysts often exhibit significant activity and selectivity enhancements compared to their homometallic counterparts. This review describes advances in heterometallic RO(CO)P catalyst design, highlighting the overarching structure-activity trends and reactivity patterns to inform future catalyst design

    EFSA BIOHAZ Panel (EFSA Panel on Biological Hazards), 2013. Scientific Opinion on the public health hazards to be covered by inspection of meat (bovine animals).

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    A risk ranking process identified Salmonella spp. and pathogenic verocytotoxin-producing Escherichia coli (VTEC) as current high-priority biological hazards for meat inspection of bovine animals. As these hazards are not detected by traditional meat inspection, a meat safety assurance system for the farm-to-chilled carcass continuum using a risk-based approach was proposed. Key elements of the system are risk-categorisation of slaughter animals for high-priority biological hazards based on improved food chain information, as well as risk-categorisation of slaughterhouses according to their capability to control those hazards. Omission of palpation and incision during post-mortem inspection for animals subjected to routine slaughter may decrease spreading and cross-contamination with the high-priority biological hazards. For chemical hazards, dioxins and dioxin-like polychlorinated biphenyls were ranked as being of high potential concern; all other substances were ranked as of medium or lower concern. Monitoring programmes for chemical hazards should be more flexible and based on the risk of occurrence, taking into account the completeness and quality of the food chain information supplied and the ranking of chemical substances, which should be regularly updated to include new hazards. Control programmes across the food chain, national residue control programmes, feed control and monitoring of environmental contaminants should be better integrated. Meat inspection is a valuable tool for surveillance and monitoring of animal health and welfare conditions. Omission of palpation and incision would reduce detection effectiveness for bovine tuberculosis and would have a negative impact on the overall surveillance system especially in officially tuberculosis free countries. The detection effectiveness for bovine cysticercosis, already low with the current meat inspection system, would result in a further decrease, if palpation and incision are removed. Extended use of food chain information could compensate for some, but not all, the information on animal health and welfare lost if only visual post-mortem inspection is applied
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