176 research outputs found

    God games: An experimental study of uncertainty, superstition, and cooperation

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    This paper uses a novel lab experiment to test claims about the origins and functions of religion. We modify the standard public goods game, adding a computer-based agent that adjusts earnings in ways that might depend on players\u27 contributions. Our treatments employ three different descriptions of the adjustment process that loosely correspond to monotheistic, atheistic, and agnostic interpretations of the computer\u27s role. The adjustments neither mask players\u27 contributions nor magnify their impact. Yet players in all three adjustment treatments contribute much more than those who play the standard public goods game. Players\u27 contributions and survey responses show that adjustments induce superstitions in all treatments, with the strongest superstitions appearing in the quasi-monotheistic treatment and the weakest in the quasi-atheistic treatment. Text-based communication raises contributions and strengthens coordination. But when paired with the quasi-monotheistic description, communication also promotes counterproductive quests for winning numbers

    Clinical application of ceramics in anterior cervical discectomy and fusion: A review and update

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    Study Design: Narrative review. Objectives: Anterior cervical discectomy and fusion (ACDF) is a reliable procedure, commonly used for cervical degenerative disc disease. For interbody fusions, autograft was the gold standard for decades; however, limited availability and donor site morbidities have led to a constant search for new materials. Clinically, it has been shown that calcium phosphate ceramics, including hydroxyapatite (HA) and tricalcium phosphate (TCP), are effective as osteoconductive materials and bone grafts. In this review, we present the current findings regarding the use of ceramics in ACDF. Methods: A review of the relevant literature examining the clinical use of ceramics in anterior cervical discectomy and fusion procedures was conducted using PubMed, OVID and Cochrane. Result: HA, coralline HA, sandwiched HA, TCP, and biphasic calcium phosphate ceramics were used in combination with osteoinductive materials such as bone marrow aspirate and various cages composed of poly-ether-ether-ketone (PEEK), fiber carbon, and titanium. Stand-alone ceramic spacers have been associated with fracture and cracks. Metallic cages such as titanium endure the risk of subsidence and migration. PEEK cages in combination with ceramics were shown to be a suitable substitute for autograft. Conclusion: None of the discussed options has demonstrated clear superiority over others, although direct comparisons are often difficult due to discrepancies in data collection and study methodologies. Future randomized clinical trials are warranted before definitive conclusions can be drawn. © The Author(s) 2017

    Corticosteroid Administration to Prevent Complications of Anterior Cervical Spine Fusion: A Systematic Review.

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    Study Design: Systematic review. Objectives: Anterior cervical approach is associated with complications such as dysphagia and airway compromise. In this study, we aimed to systematically review the literature on the efficacy and safety of corticosteroid administration as a preventive measure of such complications in anterior cervical spine surgery with fusion. Methods: Following a systematic literature search of MEDLINE, Embase, and Cochrane databases in July 2016, all comparative human studies that evaluated the effect of steroids for prevention of complications in anterior cervical spine surgery with fusion were included, irrespective of number of levels and language. Risk of bias was assessed using MINORS (Methodological Index for Non-Randomized Studies) checklist and Cochrane Back and Neck group recommendations, for nonrandomized and randomized studies, respectively. Results: Our search yielded 556 articles, of which 9 studies (7 randomized controlled trials and 2 non-randomized controlled trials) were included in the final review. Dysphagia was the most commonly evaluated complication, and in most studies, its severity or incidence was significantly lower in the steroid group. Although prevertebral soft tissue swelling was less commonly assessed, the results were generally in favor of steroid use. The evidence for airway compromise and length of hospitalization was inconclusive. Steroid-related complications were rare, and in both studies that evaluated the fusion rate, it was comparable between steroid and control groups in long-term follow-up. Conclusions: Current literature supports the use of steroids for prevention of complications in anterior cervical spine surgery with fusion. However, evidence is limited by substantial risk of bias and small number of studies reporting key outcomes

    Diffusion dispersion imaging: Mapping oscillating gradient spin-echo frequency dependence in the human brain.

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    PURPOSE: Oscillating gradient spin-echo (OGSE) diffusion MRI provides information about the microstructure of biological tissues by means of the frequency dependence of the apparent diffusion coefficient (ADC). ADC dependence on OGSE frequency has been explored in numerous rodent studies, but applications in the human brain have been limited and have suffered from low contrast between different frequencies, long scan times, and a limited exploration of the nature of the ADC dependence on frequency. THEORY AND METHODS: Multiple frequency OGSE acquisitions were acquired in healthy subjects at 7T to explore the power-law frequency dependence of ADC, the diffusion dispersion. Furthermore, a method for optimizing the estimation of the ADC difference between different OGSE frequencies was developed, which enabled the design of a highly efficient protocol for mapping diffusion dispersion. RESULTS: For the first time, evidence of a linear dependence of ADC on the square root of frequency in healthy human white matter was obtained. Using the optimized protocol, high-quality, full-brain maps of apparent diffusion dispersion rate were also demonstrated at an isotropic resolution of 2 mm in a scan time of 6 min. CONCLUSIONS: This work sheds light on the nature of diffusion dispersion in the healthy human brain and introduces full-brain diffusion dispersion mapping at clinically relevant scan times. These advances may lead to new biomarkers of pathology or improved microstructural modeling

    ChatGPT and Academic Research: A Review and Recommendations Based on Practical Examples

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    In the academic world, academicians, researchers, and students have already employed Large Language Models (LLMs) such as ChatGPT to complete their various academic and non-academic tasks, including essay writing, different formal and informal speech writing, summarising literature, and generating ideas. However,  yet, it is a controversial issue to use ChatGPT in academic research. Recently, its impact on academic research and publication has been scrutinized. The fundamental objective of this study is to highlight the application of ChatGPT in academic research by demonstrating a practical example with some recommendations. Data for this study was gathered using published articles, websites, blogs, and visual and numerical artefacts. We have analyzed, synthesized, and described our gathered data using an "introductory literature review." The findings revealed that for the initial idea generation for academic scientific research, ChatGPT could be an effective tool. However, in the case of literature synthesis, citations, problem statements, research gaps, and data analysis, the researchers might encounter some challenges. Therefore, in these cases, researchers must be cautious about using ChatGPT in academic research. Considering the potential applications and consequences of ChatGPT, it is a must for the academic and scientific community to establish the necessary guidelines for the appropriate use of LLMs, especially ChatGPT,  in research and publishing

    Influence of the Ion Coordination Number on Cation Exchange Reactions with Copper Telluride Nanocrystals

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    Cu2-xTe nanocubes were used as starting seeds to access metal telluride nanocrystals by cation exchanges at room temperature. The coordination number of the entering cations was found to play an important role in dictating the reaction pathways. The exchanges with tetrahedrally coordinated cations (i.e. with coordination number 4), such as Cd2+ or Hg2+, yielded monocrystalline CdTe or HgTe nanocrystals with Cu2-xTe/CdTe or Cu2-xTe/HgTe Janus-like heterostructures as intermediates. The formation of Janus-like architectures was attributed to the high diffusion rate of the relatively small tetrahedrally coordinated cations, which could rapidly diffuse in the Cu2-xTe NCs and nucleate the CdTe (or HgTe) phase in a preferred region of the host structure. Also, with both Cd2+ and Hg2+ ions the exchange led to wurtzite CdTe and HgTe phases rather than the more stable zinc-blende ones, indicating that the anion framework of the starting Cu2- xTe particles could be more easily deformed to match the anion framework of the metastable wurtzite structures. As hexagonal HgTe had never been reported to date, this represents another case of metastable new phases that can only be accessed by cation exchange. On the other hand, the exchanges involving octahedrally coordinated ions (i.e. with coordination number 6), such as Pb2+ or Sn2+, yielded rock-salt polycrystalline PbTe or SnTe nanocrystals with Cu2-xTe@PbTe or Cu2-xTe@SnTe core@shell architectures at the early stages of the exchange process. In this case, the octahedrally coordinated ions are probably too large to diffuse easily through the Cu2-xTe structure: their limited diffusion rate restricts their initial reaction to the surface of the nanocrystals, where cation exchange is initiated unselectively, leading to core@shell architectures.Comment: 11 pages, 7 figures in J. Am. Chem. Soc, 13 May 201

    Early Feasibility of Endovascular Repair of Distal Aortic Arch Aneurysms Using Patient-Specific Single Retrograde Left Subclavian Artery Branch Stent Graft

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    OBJECTIVE: To describe the feasibility and outcomes of endovascular repair of distal aortic arch aneurysms using a patient-specific stent graft with a pre-loaded single retrograde left subclavian artery (LSA) branch stent graft. METHODS: We reviewed the clinical data and outcomes of consecutive patients enrolled in an ongoing prospective, non-randomized physician-sponsored investigational device exemption study to evaluate the outcomes of endovascular aortic arch repair using patient-specific arch branch stent grafts (William Cook Europe, Bjaeverskov, Denmark) between 2019 and 2022. All patients received a design with triple-wide scallop and a single retrograde LSA branch with a pre-loaded catheter. RESULTS: There were five male patients with median age of 77 years old (72-80) treated using the single LSA branch stent graft. Technical success was achieved in all patients. Median operating time, fluoroscopy time, and total radiation dose area product were 103 (78-134) minutes, 26 (19-39) minutes, and 123 (71-270) mGy.cm CONCLUSION: This early feasibility study demonstrates successful endovascular repair of distal aortic arch aneurysms using a patient-specific stent graft with single retrograde LSA branch without technical failures, mortality or neurological events. Larger clinical experience and longer follow-up are needed to determined effectiveness of this approach in patients who need endovascular repair with proximal extension into Zone 2

    Total Transfemoral Percutaneous Endovascular Aortic Arch Repair Using 3-Vessel Inner Branch Stent-Graft

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    Endovascular repair has been introduced to decrease the morbidity and mortality associated with open surgical repair of aortic arch pathology. We illustrate total percutaneous transfemoral approach with a 3-vessel inner branch stent-graft to treat aortic arch aneurysm. (Level of Difficulty: Advanced.)
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