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Vacuum Assisted Closure (V.A.C.) is a sound strategy to control severe post-sternotomy infection. Secondary re-wiring of the sternal bone or reconstructive surgery may be required later to achieve complete wound closure. Ten patients with severe sternal bone infection underwent initial V.A.C. therapy and delayed surgery for wound closure. Complete wound healing was achieved in all cases. As a case report we describe a patient with right-sided mastectomy and irradiation for breast cancer, who developed severe post-sternotomy infection and sternal bone necrosis following CABG. A combination of V.A.C. therapy and surgical reconstruction using a pedicled latissimus dorsi musculocutaneous flap led to complete wound closure.

The causes of vascular complications after 306 cases of free vascularized tissue transfers were examined. The technique and success of the explorative operations were determined. The results show that 22 flaps were lost because of failures in indication, technique and monitoring. A no-reflow phenomenon was not observed.

The etiology of Dupuytren's contracture is still not clear. Many theories have been proposed, but no basic data are currently available that would make it possible to treat Dupuytren's contracture by other methods than surgical intervention. The surgical technique used in our clinic is described, and a postoperative treatment is also outlined. This paper is designed to propose an acceptable technique for practicing trauma and hand surgeons.

The concept of reconstruction to regain lost function after brachial plexus lesions has to be as broad and complex as possible. We have been exploring wider and more novel clinical concepts at the Clinic of Plastic, Hand, and Reconstructive Surgery at the Medical School of Hannover. Our ideas are supported by experience in 160 patients. We have attempted to combine the use of a vascularized nerve graft and a microvascularly-transferred autologous muscle. Patients undergoing the procedures have included those with late complete root avulsions and no functional return, as well as previously operated cases with poor recovery of biceps, wrist, and forearm function. The surgery is divided into two stages. In the first stage, the ulnar nerve is prepared as a vascularized nerve graft and is sutured to intercostal nerves 3 to 5 or 6. In stage 2, when the Tinel sign reaches the distal ends of the ulnar nerve graft (about six to eight months later), the latissimus dorsi muscle is harvested. The muscle is then placed as far distally as possible in the forearm and sutured to the deep finger flexors and flexor pollicis longus. Proximally, the insertion is performed similarly to Steindler's method. The vessels are connected to the brachial artery and vein and the thoracodorsal nerve is sutured to the graft. This method provides flexion of both the fingers and the elbow.

Characteristic temperatures T* have been evaluated for the oligomeric p-oxybenzoates, C6H5CO(-OC6H4CO)n-2-OC6H5 from the transition temperatures TNI presented in the preceding paper. For n = 3, 4 and 5 they are, respectively, 343, 316 and 306 K. These parameters that measure the intensities of the orientation-dependent intermolecular interactions are correlated with the optical anisotropy Δα and the average intermolecular cohesive energy expressed by the characteristic pressure p*. The characteristic temperature T* decreases slightly with chain length. The lattice theory of nematic fluids is extended to include mixtures of rodlike molecules having different characteristic temperatures T* in order to treat binary and ternary mixtures of the p-oxybenzoate oligomers. The wide biphasic gaps predicted for the several binary systems and the concomitant pronounced partitioning of the components between the nematic and isotropic phases are not confirmed by experiments. Compositions of the coexisting phases in ternary systems were found to be identical within limits of experimental determinations. These marked departures from theory are explicable on the premise that facile rotational diffusion of the nematogens here considered, which are of comparatively low chain length, leads to rapid generation of ordered domains of large dimensions. Subsequent diffusional transport over the required distances consequently is very slow. The transition temperatures observed in binary systems are in excellent agreement with calculations carried out in the “single component” approximation using mean values of the axial ratio and of T* for the mixture, these being taken to be the same in the two phases at equal concentrations.

A procedure is demonstrated for separating the intrinsic molecular component of the depolarized Rayleigh scattering (DRS) from the transient, collision-induced contribution. It depends on the use of two interference filters of differing breadths (18 and 53 cm–1, respectively) to distinguish the narrow reorientational component of

The spacio—geotnetric characteristics of macromolecular chains are discussed from the point of view of the essential connections they provide between chemical constitution and properties. Quantities such as molecular weight, radius of gyration, degree of branching, etc., that characterize the molecule as a whole do not suffice for an understanding of the virtually endless variations in the properties that distinguish one polymer from another. For this purpose it is necessary to examine the chemical structures of the constituent units, taking into account the geometric parameters pertaining to chemical bonds, the conformations accessible to the chain skeleton and the resulting spatial configurations. The physical principles underlying the statistical mechanical treatment of conformations of long chain molecules and of their configuration—dependent properties are summarized. Correlations between bonds of the chain and the range of such correlations provide insights into the spatial characteristics of polymer chains. Persistences expressing the configurational averages of vectors spanning sequences of chain units are particularly useful in this connection. Experimental methods that provide quantitative information on conformation and the correlations between units of the chain are briefly discussed.

An improved treatment of the lattice model proposed in 1956 is presented for a system of hard rods, with axial ratio x, dispersed in a diluent. Interparticle forces, apart from repulsions on contact, are deliberately ignored within the scope of the present paper. The equilibrium distribution of orientations of the rodlike particles in a phase with nematic order is derived and explicitly taken into account. Thermodynamic properties in the asymptotic limit of high degree of order reduce approximately. to those obtained previously. Calculations carried out for equilibrium between anistropic (nematic) and isotropic phases yield ν′x/νx = 1.4653 for the ratio of volume fractions in the respective phases in the limit x → ∞. The product xνx, expressing the combined covolume of solute species in the isotropic phase at coexistence is 7.89 in the same limit. The calculated critical value of the axial ratio for coexistence of the two phases in the neat liquid is xcrit, = 6.417. Results are compared with thos...

Syntheses of the trimer (n = 3), tetramer (n = 4) and the pentamer (n = 5) of the p-oxybenzoate series C6H5CO(–OC6H4CO)n-2-OC6H5 are reported. Densities and thermal expansion coefficients of the neat liquids were measured and phase transitions in the pure compounds and their binary mixtures were investigated by differential scanning calorimetry (DSC). The nematic-isotropic transition is directly accessible only in the case of the tetramer (melting point 181°C, nematic-isotropic transition temperature TNI = 254°); the trimer melts to an isotropic liquid at 136°C and the nematic-isotropic transition of the pentamer (melting point 224°C) lies above the range of thermal stability. DSC results for the binary mixtures show the coexistence range of the nematic and the isotropic phases to be very small; it is obscured by pre- and post-transition effects. In satisfactory approximation therefore, the binary mixtures can be treated as one-component systems, and TNI may be identified with the maximum of the DSC peak. Values of TNI thus obtained are linear with respect to composition and may be extrapolated to obtain TNI = 100°C for the pure trimer and 464°C for the pure pentamer. As shown by conformational analysis, all conformers of a given homolog have virtually the same axial ratio. These compounds therefore can be treated as rigid rods.

The biliary elimination of silybin, the main component of Silymarin, was examined in 11 cholecystectomized patients with T-drainage after a 3 to 5 day-administration of 140 mg of silymarin (Legalon®, sugarcoated tablets) t. i. d. The elimination of silybin was measured in 12- or 24-h-intervals. Six of these 11 patients received in addition one day before and one day after the repeated dose-period a single dose of 140 mg silymarin, in order to test the influence of repeated application on the biliary elimination kinetic. After repeated intake the steady state of silybin elimination was reached by the second day at the latest. The daily silybin quantities lay between 10 and 40 mg and were nearly independent of bile flow, which was subject to no great intraindividual variations. Kinetic studies showed that after repeated intake of silymarin the elimination of silybin was approx. twice as high as that following the first single intake. This increased elimination, however, stopped after 12 h. 48 h after the last silymarin intake silybin excretion was very low and after 72 h silybin was no longer detectable in the bile. All these observation show, that silybin does not accumulate. The silybin concentrations lay between 20 and 70 μg/ml of the day and the night bile (collecting intervals of 12 h) and correspond to the pharmacologically effective concentrations of 10 -5 and 10 -4 mol/l obtained in animal experiments. The intraindividual differences between the silybin concentrations in the day and night bile were relatively small, so that with the recommended doses therapeutically effective silybin concentrations can always be expected in the bile.

Die Indikation zur O/C-Fusion ist gegeben bei Tumordestruktion, bei pathologischen Instabilitaten und bei bestimmten Luxationsfrakturen dieser Region. Wir bevorzugen die Verbundfusion mit Drahtzuggurtung bei palliativer Stabilisierung und das Einfalzen eines massiven cortico-spongiosen Knochenblockes bei kurativem Vorgehen. Zur occipitalen Verankerung wird eine epidurale Drahtfuhrung uber 2 Bohrlocher empfohlen, fur die cervicale Verankerung eine Drahtumschlingung der Bogenwurzeln.

Calcul de l'energie conformationnelle des oligomeres monomere et trimere du PMMA et pour les segments figes dans les chaines stereoregulieres, incluant les formes isotactiques (meso) et syndiotactique (racemique)

The effects of restrictions on the fluctuations of network junctions imposed by neighboring chains are treated by resort to a model in which these restrictions are represented by domains of constraint. Whereas in a phantom network devoid of such constraints the displacements of junctions from their mean positions are invariant with strain, involvements with neighbors in a real network render them dependent on the strain. The observed stress consequently is increased above predictions for the equivalent phantom network. On the plausible assumption that the dimensions of the domains are transformed linearly (affinely) by the macroscopic strain, the constraints become less restrictive in the direction of a principal extension λt with increase in λt. Hence, the relative enhancement of the stress diminishes with the strain. The characteristic departures of the observed tension (ƒ)-extension (α) curve for elongation from the expression ƒ α kT(α−α−2) of previous molecular theories are qualitatively reproduced by the present theory, which also accounts for the approximate constancy of ƒ/(α−α−2) observed in compression and the decrease of this ratio with dilution.

Twenty-six aortic ruptures were found in 107 autopsies of vehicular trauma victims. There were 21 ruptures discovered at the classical location. In 14 accidents aortic rupture occurred in car passengers, in 4 cases in pedestrians and in 2 cases in cyclists. The aortic rupture was always caused by a severe accident, marked by high speed collision, considerable degree of automobile destruction and severe associated injuries. Aortic rupture could be correlated to a severe compression trauma in all cases. In 14 victims the impact force ran from right ventro-caudal to left dorso-cranial. In 2 victims the impact ran from left ventro-cranial to right dorso-caudal and in one pedestrian from right ventro-cranial to left dorso-caudal. The theories proposed for explaining aortic rupture at the classical location are examined on the basis of the material presented. The importance of forces acting in a right ventro-caudal to left ventro-cranial direction in causing rupture is stressed. Language: en

The lattice theory of hard rods with anisotropic dispersion forces presented recently is extended to the case where the rods are dispersed in a diluent. Two systems are treated: (i) rods of axial ratio x diluted with solvent molecules having x=1, and (ii) rods of axial ratio xα mixed with homologs of axial ratio xβ. Treatment of the latter system can be regarded as an extension of the Flory and Abe theory for ’’athermal’’ polydisperse systems, in which dispersion forces are inconsequential. Solutions of sufficiently long (x≳20) rods subject to anisotropic dispersion forces are predicted to exhibit complex phase equilibria involving a re‐entrant nematic phase (with a critical point) and a triple point, as well as the usual nematic–isotropic coexistence. These deductions should be relevant to thermotropic solutions of rodlike synthetic polymers with phenylene groups or other groups exhibiting anisotropic interactions. Calculations for mixtures of short rods yield more prosaic phase diagrams. It is suggested...

A system of rigid, inpenetrable, rodlike molecules subject to orientation-dependent mutual attractions is treated by extension of the theory presented in the preceding paper. This energy is formulated, for a system at constant volume, by considering interactions between pairs of segments in contact, rather than in terms of interactions between entire molecules. The orientation-dependent energy between a pair of segments is taken to be proportional to cos2 Ψij, where Ψij is the angle between the principal axes of their polarizability tensors, assumed to be cylindrically symmetric with respect to the molecular axis. A characteristic temperature T∗ measures the intensity of these interactions. The orientational energy of the system as a whole is of the form derived by Maier and Saupe. The orientation distribution with respect to the domain axis and the partition function are formulated with T∗ and the axial ratio x as parameters, Steric effects of molecular shape asymmetry, embodied in x, are of for...

Expressions are derived for the osmotic pressure and turbidity of a dilute solution of two chemically dissimilar polymer species in a solvent. The relations obtained are contrasted with those derived through use of the free energy of mixing as given by the quasi‐crystalline lattice model. Use of equations based on the lattice model to evaluate polymer‐polymer interaction parameters from dilute solution data is shown to be valid only in special instances.

A partition function for a system of rigid rod-like particles with partial orientation about an axis is derived through the use of a modified lattice model. In the limit of perfect orientation the partition function reduces to the ideal mixing law ; for complete disorientation it corresponds to the polymer mixing law for rigid chains. A general expression is given for the free energy of mixing as a function of the mole numbers, the axis ratio of the solute particles, and a disorientation parameter. This function passes through a minimum followed by a maximum with increase in the disorientation parameter, provided the latter exceeds a critical value which is 2e for the pure solute and which increases with dilution. Assigning this parameter the value which minimizes the free energy, the chemical potentials display discontinuities a t the concentration a t which the minimum first appears. Separation into an isotropic phase and a some what more concentrated anisotropic phase arises because of the discontinuity, in confirmation of the theories of Onsager and Isihara, which treat only the second virial coefficient. Phase separation thus arises as a consequence of particle asymmetry, unassisted by an energy term . Whereas for a large-particle asymmetry both phases in equilibrium are predicted to be fairly dilute when mixing is athermal, a comparatively small positive energy of interaction causes the concentration in the anisotropic phase to increase sharply, while the concentration in the isotropic phase becomes vanishingly small. The theory offers a statistical mechanical basis for interpreting precipitation of rod-like colloidal particles with the formation of fibrillar structures such as are prominent in the fibrous proteins. The asymmetry of tobacco mosaic virus particles (with or without inclusion of their electric double layers) is insufficient alone to explain the well-known phase separation which occurs from their dilute solutions at very low ionic strengths. Higher-order interaction between electric double layers appears to be a major factor in bringing about dilute phase separation for these and other asymmetric colloidal particles bearing large charges, as was pointed out previously by Oster.