gravity

重力
  • 文章类型: Journal Article
    有几种众所周知的医学状况,其中姿势和重力与自然史相互作用,包括怀孕。在这次审查中,我们全面概述了母亲体位与母亲生理和孕期休息时的病理生理之间的相互作用.我们对MEDLINE数据库进行了系统的文献检索,并确定了1991年至2021年的644项研究。符合我们的纳入标准。我们对由此产生的文献进行了叙述性回顾,并强调了差异,研究空白,和潜在的临床意义。我们按器官系统组织结果,从神经系统开始,通常沿颅尾方向进行我们的合成,用皮肤结束。循环系统值得我们最大和最密切的考虑-关于生理之间动态相互作用的文献(心率,每搏输出量,心输出量,血压,和全身血管阻力),病理生理学(例如,妊娠期高血压),和姿势的变化提供了一个复杂而迷人的例子,说明了这篇评论的主题的重要性。讨论的其他器官系统包括呼吸系统,肾,泌尿生殖系统,胃肠,腹部,和内分泌。除了总结有关母亲姿势-生理学相互作用的现有文献外,我们还指出了这方面进一步研究和临床发展的差距和机会。总的来说,我们的综述提供了产妇姿势-生理学相互作用的洞察力和相关性,相对于医疗保健的使命,以改善怀孕期间及以后的健康和健康。
    There are several well-known medical conditions in which posture and gravity interact with natural history, including pregnancy. In this review, we provide a comprehensive overview of interactions between maternal posture and maternal physiology and pathophysiology at rest during pregnancy. We conducted a systematic literature search of the MEDLINE database and identified 644 studies from 1991 through 2021, inclusive, that met our inclusion criteria. We present a narrative review of the resulting literature and highlight discrepancies, research gaps, and potential clinical implications. We organize the results by organ system and, commencing with the neurological system, proceed in our synthesis generally in the craniocaudal direction, concluding with the skin. The circulatory system warranted our greatest and closest consideration-literature concerning the dynamic interplay between physiology (heart rate, stroke volume, cardiac output, blood pressure, and systemic vascular resistance), pathophysiology (e.g., hypertension in pregnancy), and postural changes provide an intricate and fascinating example of the importance of the subject of this review. Other organ systems discussed include respiratory, renal, genitourinary, gastrointestinal, abdominal, and endocrine. In addition to summarizing the existing literature on maternal posture-physiology interactions, we also point out gaps and opportunities for further research and clinical developments in this area. Overall, our review provides both insight into and relevance of maternal posture-physiology interactions vis à vis healthcare\'s mission to improve health and wellness during pregnancy and beyond.
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  • 文章类型: Journal Article
    在许多医疗条件下,包括怀孕,重力和姿势相互作用,影响生理学和病理生理学。最近的调查,例如,关于孕妇在妊娠中期的睡眠姿势以及对胎儿生长和死产风险的可能影响突出了该受试者的重要性和潜在的临床意义。在这次审查中,我们提供了广泛的讨论,从怀孕到产后期间,母亲的姿势对胎儿生理的影响。我们对MEDLINE数据库进行了系统的文献检索,并确定了1991年至2021年的242项研究,符合我们的纳入标准。在这里,我们提供了所得文献的合成。在回顾的第一部分,我们通过产妇休息姿势对子宫颈的影响对结果进行分组,子宫,胎盘,脐带,羊水,还有胎儿.在审查的第二部分,我们讨论了在各种产妇活动期间产妇姿势对胎儿相关结局的影响(例如,睡眠,工作,锻炼),医疗程序(例如,生育力,成像,手术),分娩和分娩。我们介绍已发表的文献,突出差距和差异,并建议未来的研究机会和临床实践的变化。总之,我们预计,这篇综述将揭示产妇姿势对胎儿生理的影响,从而为致力于改善产妇的研究人员和临床医生提供实用性,胎儿,和儿童健康。
    In numerous medical conditions, including pregnancy, gravity and posture interact to impact physiology and pathophysiology. Recent investigations, for example, pertaining to maternal sleeping posture during the third trimester and possible impact on fetal growth and stillbirth risk highlight the importance and potential clinical implications of the subject. In this review, we provide an extensive discussion of the impact of maternal posture on fetal physiology from conception to the postpartum period in human pregnancy. We conducted a systematic literature search of the MEDLINE database and identified 242 studies from 1991 through 2021, inclusive, that met our inclusion criteria. Herein, we provide a synthesis of the resulting literature. In the first section of the review, we group the results by the impact of maternal posture at rest on the cervix, uterus, placenta, umbilical cord, amniotic fluid, and fetus. In the second section of the review, we address the impact on fetal-related outcomes of maternal posture during various maternal activities (e.g., sleep, work, exercise), medical procedures (e.g., fertility, imaging, surgery), and labor and birth. We present the published literature, highlight gaps and discrepancies, and suggest future research opportunities and clinical practice changes. In sum, we anticipate that this review will shed light on the impact of maternal posture on fetal physiology in a manner that lends utility to researchers and clinicians who are working to improve maternal, fetal, and child health.
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  • 文章类型: Journal Article
    目的:本研究考察了地球重力场对地球物理区静脉曲张患病率的影响。
    方法:我们对关注静脉曲张患病率的研究进行了系统评价(OVID和GoogleScholar),以确定地球重力场-GRACEGGM05S重力模型对疾病患病率的影响。PROSPERO:CRD42021279513。
    结果:81项研究符合纳入和质量标准。随着年龄的调整,重力较强的地区静脉曲张的患病率明显较高,性别和体重指数(BMI)(p值<0.02)。根据年龄调整,重力场+20mGal及以上地区的静脉曲张患病率比重力场小于20mGal的地区高1.37倍,p值0.005(95%CI:-12.5至-2.4):重力场的平均疾病患病率20mGal及以上-27.5%(平均年龄,40.1年;平均重力场,27.1mGal;63.9%的女性,37项研究,123,164名参与者)与重力场小于+20mGal的平均疾病患病率-20.1%(平均年龄,42.2年;平均重力场,5.7mGal;56.8%的女性,44项研究,205,925名与会者)。高龄是静脉曲张的主要危险因素(p值<0.005)。女性性别和高BMI与静脉曲张的高患病率无关(性别的p值>0.4,BMI的p值>0.2)。
    结论:较强的重力场与较高的静脉曲张危险因素患病率显著相关。这种现象的潜在机制是高重力场改变了全身静脉回流,在外周汇集血液和液体,直立人类身体的重力依赖区域不断生活在定义的地球物理区域。
    OBJECTIVE: This study examines the influence of Earth\'s gravity field on the prevalence of varicose veins in geophysical area.
    METHODS: We performed a systematic review (OVID and Google Scholar) of studies focusing on prevalence of varicose veins to determine the influence of Earth\'s gravity field-GRACE GGM05S gravity model-on the disease prevalence. PROSPERO: CRD42021279513.
    RESULTS: 81 studies met inclusion and quality criteria. Areas with stronger gravity have significantly higher prevalence of varicose veins with adjustment for age, gender and body mass index (BMI) (p-values < 0.02). Adjusted for age, prevalence of varicose veins in areas with gravity field +20 mGal and more is 1.37 time higher than in areas with gravity field less than +20 mGal, p-value 0.005 (95% CI: -12.5 to -2.4): mean disease prevalence for gravity field +20 mGal and more-27.5% (mean age, 40.1 years; mean gravity field, +27.1 mGal; 63.9% females, 37 studies, 123,164 participants) vs mean disease prevalence for gravity field less than +20 mGal - 20.1% (mean age, 42.2 years; mean gravity field, +5.7 mGal; 56.8% females, 44 studies, 205,925 participants). Older age is the main risk factor for varicose veins (p-values < 0.005). Female gender and high BMI are insignificantly associated with high prevalence of varicose veins (p-values > 0.4 for gender, p-values > 0.2 for BMI).
    CONCLUSIONS: Stronger gravity field is significantly associated with higher prevalence of varicose veins-risk factor. The potential mechanism of this phenomenon is that high gravity field alters systemic venous return, pooling blood and fluid in the peripheral, gravity-dependent regions of the body in upright humans constantly living in the defined geophysical area.
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  • 文章类型: Journal Article
    Since the Moon landing, nutritional research has been charged with the task of guaranteeing human health in space. In addition, nutrition applied to Orthopedics has developed in recent years, driven by the need to improve the efficiency of the treatment path by enhancing the recovery after surgery. As a result, nutritional sciences have specialized into two distinct fields of research: Nutritional Orthopedics and Space Nutrition. The former primarily deals with the nutritional requirements of old patients in hospitals, whereas the latter focuses on the varied food challenges of space travelers heading to deep space. Although they may seem disconnected, they both investigate similar nutritional issues. This scoping review shows what these two disciplines have in common, highlighting the mutual features between (1) pre-operative vs. pre-launch nutritional programs, (2) hospital-based vs. space station nutritional issues, and (3) post-discharge vs. deep space nutritional resilience. PubMed and Google Scholar were used to collect documents published from 1950 to 2020, from which 44 references were selected on Nutritional Orthopedics and 44 on Space Nutrition. Both the orthopedic patient and the astronaut were found to suffer from food insecurity, malnutrition, musculoskeletal involution, flavor/pleasure issues, fluid shifts, metabolic stresses, and isolation/confinement. Both fields of research aid the planning of demand-driven food systems and advanced nutritional approaches, like tailored diets with nutrients of interest (e.g., vitamin D and calcium). The nutritional features of orthopedic patients on Earth and of astronauts in space are undeniably related. Consequently, it is important to initiate close collaborations between orthopedic nutritionists and space experts, with the musculoskeletal-related dedications playing as common fuel.
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  • 文章类型: Journal Article
    静电纺丝是一种通用的纤维制造方法,应用范围从纺织到组织工程。尽管人们对静电纺丝的影响参数有充分的了解,设置方向的影响尚未得到彻底调查。随着当前对改良和专用静电纺丝设备的兴趣日益浓厚,审查这个很少考虑的参数的影响是及时的。设备配置在最终产品的形态中起主要作用。自旋设置之间的主要区别是电力和重力贡献的程度。由于与静电力相比,重力的大小要低得多,它被认为对纺丝过程没有显著影响。但是泰勒锥的形状,射流轨迹,纤维直径,纤维直径分布,整体纺丝效率都受其影响。在这篇综述论文中,我们讨论所有这些发展和更多。此外,因为许多研究小组建立了自己的静电纺丝设备,考虑这方面是谨慎的,因为特定方向更适合某些应用。
    Electrospinning is a versatile fibre fabrication method with applications from textile to tissue engineering. Despite the appearance that the influencing parameters of electrospinning are fully understood, the effect of setup orientation has not been thoroughly investigated. With current burgeoning interest in modified and specialised electrospinning apparatus, it is timely to review the impact of this seldom-considered parameter. Apparatus configuration plays a major role in the morphology of the final product. The primary difference between spinning setups is the degree to which the electrical force and gravitational force contribute. Since gravity is much lower in magnitude when compared with the electrostatic force, it is thought to have no significant effect on the spinning process. But the shape of the Taylor cone, jet trajectory, fibre diameter, fibre diameter distribution, and overall spinning efficiency are all influenced by it. In this review paper, we discuss all these developments and more. Furthermore, because many research groups build their own electrospinning apparatus, it would be prudent to consider this aspect as particular orientations are more suitable for certain applications.
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  • 文章类型: Journal Article
    背景:在飞行中,高性能飞机的飞行员的经验条件独特的专业。训练飞行,每周表演几次,可以将这些飞行员暴露在超过15公里的高度(约50,000英尺,机舱增压至海拔约20,000英尺),并且在飞行中执行的操纵会加剧飞行员感受到的G力。虽然飞行员专门训练以承受这些极端条件,生理压力很可能导致体内化学物质的分布差异,因此,危险的高暴露。不幸的是,对于战斗机飞行员经历的条件如何影响化学处置知之甚少。涵盖的领域:本评论的目的是提供有关高海拔影响的信息,G力,以及战斗机飞行员在化学处置方面所经历的其他条件。利用这些信息,将讨论化学暴露的预期变化,以异丙醇为例。专家意见:严重缺乏有关战斗机飞行员环境对化学品药代动力学和药效学影响的信息。考虑到飞行前或飞行中暴露的可能性,重要的是进一步研究这些潜在的影响。
    BACKGROUND: When in flight, pilots of high performance aircraft experience conditions unique to their profession. Training flights, performed as often as several times a week, can expose these pilots to altitudes in excess of 15 km (~50,000 ft, with a cabin pressurized to an altitude of ~20,000 ft), and the maneuvers performed in flight can exacerbate the G-forces felt by the pilot. While the pilots specifically train to withstand these extreme conditions, the physiologic stress could very likely lead to differences in the disposition of chemicals in the body, and consequently, dangerously high exposures. Unfortunately, very little is known about how the conditions experienced by fighter pilots affects chemical disposition. Areas covered: The purpose of this review is to present information about the effects of high altitude, G-forces, and other conditions experienced by fighter pilots on chemical disposition. Using this information, the expected changes in chemical exposure will be discussed, using isopropyl alcohol as an example. Expert opinion: There is a severe lack of information concerning the effects of the fighter pilot environment on the pharmacokinetics and pharmacodynamics of chemicals. Given the possibility of exposure prior to or during flight, it is important that these potential effects be investigated further.
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