小切口白内障摘除术263例疗效观察

目的评价小切口白内障摘除人工晶体植入术治疗白内障的临床疗效。方法对263只白内障患眼施行小切口白内障摘除人工晶体植入术。结果术后1天、1周、3月术眼视力≥0.8者,分别为27.38%、28.14%、28.14%;视力介于0.4～0.6者,分别为58.55%、63.12%、65.02%;视力≤0.3者,分别为14.07%、8.74%、6.84%。术后并发症主要有角膜水肿、角膜内皮皱褶、重度炎症反应、高眼压和后发障,术后1天、1周、3月发生率分别为11.79%、36.50%、2.66%、3.42%和0;3.04%、.52%、2.66%、3.04%和0;0、0、0、1.14%和8.37%。结论小切口白内障摘除人工晶体植入术手术切口和创伤小、复明快、并发症少,是治疗白内障的一种安全、有效的方法。     

Solid phase microextraction fills the gap in tissue sampling protocols

Metabolomics and biomarkers discovery are an integral part of bioanalysis. However, untargeted tissue analysis remains as the bottleneck of such studies due to the invasiveness of sample collection, as well as the laborious and time-consuming sample preparation protocols. In the current study, technology integrating in vivo sampling, sample preparation and global extraction of metabolites – solid phase microextraction was presented and evaluated during liver and lung transplantation in pig model. Sampling approaches, including selection of the probe, transportation, storage conditions and analyte coverage were discussed. The applicability of the method for metabolomics studies was demonstrated during lung transplantation experiments.     

Symptomatology of adductor spasmodic dysphonia: A physiologic model

Vocal symptomatology of adductor spasmodic dysphonia (SD) is reviewed critically from historical, epidemiologic, and clinical perspectives. A model of symptomatology of this disorder based on a large patient population, and clinical and physiologic observations is advanced. The model incorporates crucial symptomatic and asymptomatic phonatory and nonphonatory physiologic parameters of laryngeal behavior in these patients. These parameters include vocal fold contact area, vocal fold collision force, glottic compression, and subglottic air pressure. Inappropriate efferent discharges from brain-stem basal ganglia are hypothesized as causing overadduction of the vocal folds in phonation, generating the basic and fundamental vocal symptom of adductor SD—strained, strangled, overpressured voice quality. Cortical loops are implicated as accountable for compensatory vocal behavior, not as the primary site of the disorder. Symptom occurrence, variability, magnitude, effects, and failure of treatment approaches, as well as recurrence of symptoms after ablative or invasive procedures, are explained by this model. The model also predicts that symptomatology of adductor spasmodic dysphonia is unique to this disorder and that symptoms are phonotopically organized. The minimal diagnostic battery based on the model is presented, and it is shown how this battery aids in the differential diagnosis of adductor SD and other phonatory disorders that closely mimic the vocal symptoms of adductor spasmodic dysphonia, including tremor.     

The signature operator at 2

It is well known that the signature operator on a manifold defines a K-homology class which is an orientation after inverting 2. Here we address the following puzzle: What is this class localized at 2, and what special properties does it have? Our answers include the following:

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the K-homology class Δ_M of the signature operator is a bordism invariant;

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the reduction mod 8 of the K-homology class of the signature operator is an oriented homotopy invariant;

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the reduction mod 16 of the K-homology class of the signature operator is not an oriented homotopy invariant.

     

Scheduling elective surgery under uncertainty and downstream capacity constraints

The objective of this study is to generate an optimal surgery schedule of elective surgery patients with uncertain surgery operations, which includes uncertainty in surgery durations and the availability of downstream resources such as surgical intensive care unit (SICU) over multi-periods. The stochastic optimization is adapted and the sample average approximation (SAA) method is proposed for obtaining an optimal surgery schedule with respect to minimizing the total cost of patient costs and overtime costs. A computational experiment is presented to evaluate the performance of the proposed method.     

Surgery and the Spinorial τ-Invariant

We associate to a compact spin manifold M a real-valued invariant τ(M) by taking the supremum over all conformal classes of the infimum inside each conformal class of the first positive Dirac eigenvalue, when the metrics are normalized to unit volume. This invariant is a spinorial analogue of Schoen's σ-constant, also known as the smooth Yamabe invariant. We prove that if N is obtained from M by surgery of codimension at least 2 then τ(N) ≥ min{τ(M), Λ _n }, where Λ _n is a positive constant depending only on n = dim M. Various topological conclusions can be drawn, in particular that τ is a spin-bordism invariant below Λ _n . Also, below Λ _n the values of τ cannot accumulate from above when varied over all manifolds of dimension n.     

Clinical investigation of surgery for intermittent exotropia

Objective： To investigate the time and postoperative binocular vision of strabismus surgery for children with intermittent exotropia （X（T））. Methods： A retrospective investigation was conducted in 80 child patients with intermittent exotropia. Pre- and postoperative angles of deviation fixating at near （33 cm） and distant targets （6 m） were measured with the prolonged alternate cover testing. The binocular function was assessed with synoptophore. Twenty-one patients took the postoperative synoptophore exercise. Results： （1） A week after surgery, 96.2% of the 80 patients had binocular normotopia, while a year after surgery, 91.3% of the 80 patients had binocular normotopia; （2） Preoperatively, 58 patients had near stereoacuity, while postoperatively, 72 patients achieved near stereoacuity （P〈0.05）; （3） Preoperatively, 64 patients had Grade Ⅰ for the synoptophore evaluation and postoperatively, 76 patients achieved Grade Ⅰ. Meanwhile, 55 patients had Grade Ⅱ preoperatively and 72 achieved Grade Ⅱ postoperatively. For Grade Ⅲ, there were 49 patients preoperatively and 64 patients postoperatively （P〈0.05）; （4） Patients of 5-8 years old had a significantly better recovery rate of binocular vision than those of 9-18 years old （P〈0.05）; （5） Patients taking postoperative synoptophore exercise had a better binocular vision than those taking no exercise （P〈0.05）. Conclusions： （1） Strabismus surgery can help to preserve or restore the binocular vision for intermittent exotropia; （2） Receiving the surgery at young ages may develop better postoperative binocular vision; （3） The postoperative synoptophore exercise can help to restore the binocular vision.