玻璃体切割手术致眼静脉空气栓塞的研究现状及进展

眼静脉空气栓塞(OVAE)是玻璃体切割手术中一种罕见的致命并发症。因手术部位靠近心脏且位于心脏上方,OVAE可能是所有手术中引起静脉空气栓塞(VAE)最严重的。随着玻璃体切割手术的发展,免缝合状态的灌注套管可出现向外滑动,使得灌注气体进入脉络膜上腔,导致涡静脉撕裂。玻璃体腔气体灌注时,外伤及脉络膜黑色素瘤手术导致的脉络膜血管伤口暴露于气体中,这使得加压气体可能通过撕裂的涡静脉或异常的脉络膜静脉开口进入循环系统导致OVAE。目前OVAE的定义、发病机制、临床表现及防治措施在不断完善,但多数玻璃体视网膜外科医生和麻醉医师仍不了解该医源性并发症。提高对OVAE的认识将有助于早期发现该并发症,进而做出及时处理,同时制定有效的预防策略。通过临床和实验室研究相结合,可不断优化OVAE防治原则。充分认识OVAE的发病机理和临床特点,关注OVAE继发性病变的特征以及重视多学科间的合作有助于OVAE应急处理和预防措施的建立和完善。     

维吾尔族发旋的调查

本文报告了新疆维吾尔族425名大学生的发旋调查情况。发现维吾尔族的单旋顺旋率明显高于汉族(P<0.05),极显著高于壮族和瑶族(P<0.01),而反旋率低于汉族(P<0.05),明显低于壮族及瑶族(P<0.01)。双旋顺反旋率高于壮族(P<0.05),低于瑶族(P<0.01),顺顺旋率均高于汉族、壮族及瑶族(P<0.01)。提示了发旋这一性状有着明显的民族差异。     

震荡法在纠正EDTA依赖的假性血小板减少中的应用

目的:评估震荡法纠正EDTA依赖的假性血小板减少(EDTA-dependent pseudothrombocytopenia,EDTA-PTCP)的可行性。方法:收集140例EDTA-PTCP血标本,比较震荡前后全自动血细胞分析仪血小板计数检测结果,同时进行外周血涂片以观察血小板分布情况。结果:140例EDTA-PTCP血标本中,93例外周血涂片显示震荡后血小板聚集明显减少,血小板计数中位数为184×10~9/L,与震荡前(33×10~9/L)差异有统计学意义(P0.05);另47例为未完全解聚标本血小板计数中位数为48×10~9/L,与震荡前(39×10~9/L)差异无统计学意义。140例EDTA-PTCP标本中,震荡前后其他参数差异均无统计学意义。20例正常抗凝血标本震荡前后各项参数差异均无统计学意义。结论:震荡法可纠正多数EDTA-PTCP,是一种简单、有效的方法,可以提高检测效率,减轻患者痛苦。     

INAUGURAL ARTICLE by a Recently Elected Academy Member:Helicity and singular structures in fluid dynamics

Helicity is, like energy, a quadratic invariant of the Euler equations of ideal fluid flow, although, unlike energy, it is not sign definite. In physical terms, it represents the degree of linkage of the vortex lines of a flow, conserved when conditions are such that these vortex lines are frozen in the fluid. Some basic properties of helicity are reviewed, with particular reference to (i) its crucial role in the dynamo excitation of magnetic fields in cosmic systems; (ii) its bearing on the existence of Euler flows of arbitrarily complex streamline topology; (iii) the constraining role of the analogous magnetic helicity in the determination of stable knotted minimum-energy magnetostatic structures; and (iv) its role in depleting nonlinearity in the Navier-Stokes equations, with implications for the coherent structures and energy cascade of turbulence. In a final section, some singular phenomena in low Reynolds number flows are briefly described.This inaugural article, although long delayed, is now fortuitously quite timely for various reasons. First, helicity in fluid dynamics is a measure of the knottedness and/or linkage of the vortex lines of a flow (1), invariant under ideal-fluid Euler evolution. Knotted vortices were first conceived by Lord Kelvin (then Sir William Thomson) in 1868 (2), but have only recently been unambiguously observed: a vortex in the form of a trefoil knot has been generated in a remarkable experiment by Kleckner and Irvine (3) by means of an ingenious technique that can in principle be adapted to generate vortices of arbitrarily linked or knotted form. The possible existence of knotted vortices is therefore no longer a matter of mere speculation!Second, helicity has long been known to be of crucial importance in turbulent dynamo theory—the theory of the spontaneous growth of a magnetic field in a conducting fluid in turbulent motion. The associated chirality of the flow is responsible for the α-effect (4), which is a crucial ingredient of the dynamo process in stars and planets. The von Karman sodium (VKS) experiment (5) developed in France over the last decade has at last provided convincing evidence for a turbulent dynamo mechanism that undoubtedly involves this α-effect in conjunction with differential rotation and strong diffusive processes.Third, the process of magnetic relaxation of a knotted magnetic flux tube in a perfectly conducting fluid under the topological constraint of invariant helicity leads in a natural physical way to the concept of the energy spectrum of knots and links (6). The minimum energy configurations obtained by this procedure are, with certain qualifications, essentially the same as the ideal or tight knot configurations introduced by Katritch et al. (7) which minimize the length-to-diameter ratio of knotted tubes. Tight knots have found wide application in polymer physics and molecular biology, as discussed in recent workshops of the Isaac Newton Institute for Mathematical Sciences (8, 9), and huge progress has been made in determining all tight configurations for links and knots up to 9 and 10 crossings, respectively (10). In particle physics, a striking correlation has been noted between the knot/link energies and the mass/energies of glueballs in the quark–gluon plasma (11); the subject has perhaps come full circle since the time of Kelvin!The time is therefore ripe to review some of the salient features of these and related phenomena in which helicity plays a central role, and I take this welcome opportunity to do so. I include also, at the suggestion of a referee of this article, a section on certain structures that can arise in flows that are dominated by viscosity, and that nevertheless exhibit structures of nontrivial topology.     

A 5-year molecular epidemiology survey of human enterovirus 71 before vaccine application in Yunnan Province,China

Enterovirus A71 (EV-A71) infection is known to cause hand, foot, and mouth disease (HFMD). Last year, an inactivated EV-A71 whole virus vaccine was used to prevent this disease in Yunnan, China. To obtain a viral genetic background for evaluating vaccine protection and monitor the adaptive evolution of the virus after the vaccination, a 5-year molecular epidemiology survey was performed before the vaccination. Twenty-six EV-A71 strains were separated from 561 stool specimens of patients with serious HFMD. The whole-genomic sequences of these strains were sequenced. Phylogenetic trees were constructed, and the mutation spectra were analyzed based on these viral sequences. There was no obvious mutation for the circular EV-A71 strains of the same year. Pathogenic EV-A71 strains may arise from a “subgroup” randomly each year. Whole-genomic analyses showed that a hotspot nonsynonymous substitution potentially affecting the immunogenicity of vaccines was found in the 2A gene, but not in genes of the viral capsid proteins, and the genetic diversity of whole viral genomes associated with the incidence of HFMD. Therefore, it will be valuable to monitor the genome-wide changes of EV-A71 to detect the adaptive mutations affecting immunogenicity or perform investigations using genetic diversity as a parameter.     

上肢涡流水疗法治疗上肢烧伤术后疤痕增生的回顾性研究

目的探究上肢涡流水疗法治疗上肢烧伤术后疤痕增生患者的临床疗效。方法回顾性分析于我院2016年12月~2018年12月接受治疗的98例上肢烧伤术后疤痕增生患者的临床资料,并根据其治疗方法进行分组,其中对照组48例予以压力疗法、超声波治疗等常规治疗,观察组50例在对照组基础上给予上肢涡流水疗法进行治疗。比较两组患者治疗前及治疗3个月后的瘢痕状况、上肢功能及生活质量变化情况。结果治疗3个月后,两组患者柔软度、血管分布、厚度、色泽得分及总分均较治疗前显著下降(P均<0.05),且观察组明显低于同期对照组(P<0.05);治疗3个月后,两组患者上肢FMA及MI得分均较治疗前显著提升(P均<0.05),且观察组明显高于同期对照组(P<0.05);治疗3个月后,两组患者生活质量各项评分均较治疗前显著升高(P均<0.05),且观察组明显高于对照组(P<0.05)。结论在常规治疗的基础上采用上肢涡流水疗法可有效促进上肢烧伤术后疤痕增生患者的上肢功能恢复,还可改善日常生活能力。     

Nanophthalmos: A Perspective on Identification and Therapy

Nanophthalmos is a rare and blinding disease. Diagnostic features include a small eye, small cornea, shallow anterior chamber, narrow angle, high lens/eye volume ratio, and uveal effusion. Intraocular surgery has a high rate of disastrous complications and blindness. The 32 eyes (16 patients) presented are in three categories based on angle closure and intraocular pressure levels. Treatment methods included medication, laser iridotomy and gonioplasty, peripheral iridectomy, filtration surgery, and cataract extraction. Glaucoma medication was effective, although miotics sometimes increased pupillary block. Laser iridotomy was successful in 83% of six eyes; laser gonioplasty in 91.6% of 12 eyes. Peripheral iridectomy succeeded in two of seven eyes, and filtering operations provided tension control in two of five eyes. Thirteen of 15 eyes undergoing filtration surgery suffered severe postoperative visual loss. Cataract extraction improved vision in only three of six eyes. The authors’ experience confirms that surgery in nanophthalmic eyes has an extremely high complication rate with disastrous results. Medication and laser therapy are the procedures of choice for angle-closure glaucoma in nanophthalmos.