Ankle fracture surgery on a pregnant patient complicated by intraoperative emergency caesarian section.

We report the case of a woman in the third trimester of pregnancy who sustained an ankle fracture dislocation that could not be adequately closed reduced. After discussions with the patient, her obstetrician, and the anesthesiologists, she was indicated for surgical fixation. A heart tone monitor was used to assess fetal health during the procedure. During surgical incision, the fetus went into distress, and an emergency caesarian section was performed. After delivery of the infant and abdominal closer, surgery was completed. Due to a cohesive team effort, both the patient and her infant had excellent outcomes. There are many important considerations in the surgical management of the pregnant patient with traumatic orthopaedic injuries. Of especial importance to the orthopaedic surgeon is the impact of patient positioning on uteroplacental blood flow. This report discusses factors that should be taken into account by any orthopaedist who plans to operate on a pregnant patient

Equivalence after extension for compact operators on Banach spaces

In recent years the coincidence of the operator relations equivalence after extension and Schur coupling was settled for the Hilbert space case, by showing that equivalence after extension implies equivalence after one-sided extension. In this paper we investigate consequences of equivalence after extension for compact Banach space operators. We show that generating the same operator ideal is necessary but not sufficient for two compact operators to be equivalent after extension. In analogy with the necessary and sufficient conditions on the singular values for compact Hilbert space operators that are equivalent after extension, we prove the necessity of similar relationships between the $s$-numbers of two compact Banach space operators that are equivalent after extension, for arbitrary $s$-functions. We investigate equivalence after extension for operators on $\ell^{p}$-spaces. We show that two operators that act on different $\ell^{p}$-spaces cannot be equivalent after one-sided extension. Such operators can still be equivalent after extension, for instance all invertible operators are equivalent after extension, however, if one of the two operators is compact, then they cannot be equivalent after extension. This contrasts the Hilbert space case where equivalence after one-sided extension and equivalence after extension are, in fact, identical relations. Finally, for general Banach spaces $X$ and $Y$, we investigate consequences of an operator on $X$ being equivalent after extension to a compact operator on $Y$. We show that, in this case, a closed finite codimensional subspace of $Y$ must embed into $X$, and that certain general Banach space properties must transfer from $X$ to $Y$. We also show that no operator on $X$ can be equivalent after extension to an operator on $Y$, if $X$ and $Y$ are essentially incomparable Banach spaces

Design and finite element mode analysis of noncircular gear

The noncircular gear transmission is an important branch of the gear transmission, it is characterized by its compact structure, good dynamic equilibration and other advantages, and can be used in the automobile, engineering machine, ship, machine tool, aviation and spaceflight field etc. Studying on the dynamics feature of noncircular gear transmission can improve the ability to carry loads of, reduce the vibration and noise of, increase the life of the noncircular gear transmission machine, provides guidance for the design of the noncircular gear, and has significant theories and practical meanings. In this paper, the gear transmission technique is used to studied the design method of the noncircular gear, which contains distribution of teeth on the pitch curve, designs of the tooth tip curve and the tooth root curve, design of the tooth profile curve, the gear system dynamics principle is introduced to establish dynamics model for the noncircular gear; basic theory of finite element and mode analysis method are applied, finite element model for the noncircular gear is established, natural vibration characteristic of the noncircular gear is studied. And the oval gear is taken as an example, the mathematics software MathCAD, the 3D modeling software UG and the finite element software ABAQUS are used to realize precise 3D model of the oval gear. The finite element method is used, the natural vibration characteristic of the oval gear is studied, the main vibration types and natural frequencies of the oval gear and that of the equivalent cylindrical gears are analyzed and compared, the conclusions received reflect the dynamics performance of the oval gear, and solid foundation is laid for dynamics research and engineering application of the oval gear transmission

China's state-owned banks' lending practices, 1994-2005: Empirical tests and policy implications

More than half of the assets in China's banking system are accounted for by four huge state-owned commercial banks. This paper examines the changing factors influencing these banks' lending behavior over the post-1994 period on a province-by-province basis. Determinants include the concentration of state-owned enterprises, the level of provincial prosperity, deposit levels, and macroeconomic control variables. We confirm a downward trend in the banks' loan-todeposit ratio combined with some (mixed) evidence of more lending to richer provinces over time. SOE lending remained important for at least one of the four banks

A note on a conjecture concerning rank one perturbations of singular M-matrices

A conjecture from a paper by J. Bierkens and A.C.M. Ran concerning the location of eigenvalues of rank one perturbations of singular M-matrices is shown to be false in dimension four and higher, but true for dimension two, as well as for dimension three with an additional condition on the perturbation.Comment: 12 pages, 3 figure

The Impact of Gastrocnemius Muscle Cell Changes in Chronic Venous Insufficiency

AbstractObjectiveTo investigate the pathological and metabolic changes in the gastrocnemius muscle in patients with chronic vein insufficiency (CVI).MethodThirty-six patients with varicose veins were investigated by ambulatory venous pressure (AVP) and duplex ultrasonography. Twelve age and height-matched controls were used for comparison. Patients and controls consented to participate in this study. Twenty-one patients with primary vein varicose (group AI) and 15 patients (group AII) with primary deep venous valve incompetence (DVI) underwent biopsies of the gastrocnemius muscle during operation. Adductor biopsies obtained from the same limbs served as a control group (group B) and specimens from controls subjects without venous disease served as the second control group (group C). All the specimens were investigated by superoxide dismutase (SOD), nitric oxide (NO), Na+–K+-ATPase, Ca2+-ATPase and lactic acid (LD) determinations. Samples were subjected to light and electron microscopy following H & E staining, special ATPase, cytochrome oxidase/succinate dehydrogenase (COX/SDH) stains.ResultsNormal muscle architecture was seen following H & E, ATPase and COX/SDH staining and normal cell metabolism was observed in specimens of groups B and C. In group A, pathological changes were encountered in the gastrocnemius muscle including disseminated myofibril atrophy, cell denaturation and necrosis, inflammatory cell infiltration, proliferation and dilation of interfascicular veins. ATPase staining (pH 9.4) demonstrated grouping of atrophic fibres, especially type I myofibril grouping, accompanied by moderate to severe atrophy of type II muscle fibres. However, no patient had selective type I fibre atrophy. Enhanced enzymatic activity in single or multiple myofibrils was demonstrated by COX/SDH staining in approximately half of the specimens in group AII. In group AII, electron microscopy showed swelling, myelin figure denaturation of mitochondria, disruption of the myofibrils and increased lipid droplets in the gastrocnemius muscle. Increased concentration of LD was found in most specimens from group A patients. There were also reductions of SOD, NO, biochemical activity of Na+–K+-ATPase, Ca2+-ATPase with increasing concentration of LD in these patients, most prominently in group AII. We found correlation between AVP assessments and the biochemical measurements as well as morphological appearances of the gastrocnemius muscle.ConclusionVenous hypertension results in pathophysiological changes in the gastrocnemius muscles of patients with DVI, associated with decreased calf pump function