Internal Closure Research Articles

Internal Closure of Portals in Shoulder Arthroscopy

Abstract Arthroscopic cannulas may be up to 9 mm in diameter and leave a large defect in the capsule. There is concern that this may compromise the structural integrity of the capsule, and, therefore, we close our portal sites using the following method.

Discussion

Background: Vacuum-assisted closure therapy has gained widespread use since its introduction in 1997. Previous studies have attributed significant benefit to its use for treatment of sternal wounds with or without mediastinitis. Management of sternal wounds with this therapy has been shown to decrease the number of dressing changes, reduce the time between debridement and definitive closure, and reduce costs associated with a protracted course of in-hospital dressing changes. The therapy has been used both as a bridge between debridement and definitive closure and as a catalyst to secondary sternal-wound healing. Methods: The authors performed a retrospective review of 103 patients who underwent vacuum-assisted closure therapy after median stemotomy between June of 1999 and March of 2004 at a single institution. The wounds were classified as sterile wounds, superficial sternal infections, and mediastinitis. The wound closure device, consisting of a polyurethane sponge and evacuation tube with inline suction, was applied sterilely to all wounds over a layer of Acticoat. Results: Vacuum-assisted closure was utilized in the treatment of sternal wounds for 103 patients (67 male patients and 36 female patients) whose mean age was 52 years (range, 3 months to 91 years). Patient comorbidities included diabetes, chronic obstructive pulmonary disease, end-stage renal disease, immunosuppression, and others. Sixty-four percent of the patients had a diagnosis of mediastinitis; 36 percent had either superficial infections or a sterile wound. The therapy was utilized for an average period of 11 days per patient. Sixty-eight percent of the patients (70 of 103) had definitive chest closure with open reduction internal fixation and/or flap closure. The remaining 32 percent had no definitive closure method. The overall mortality rate was 28 percent (29 of 103 patients), although no deaths were directly related to use of the therapy, and only four deaths resulted from sepsis as a consequence of mediastinitis. Conclusions: The authors report the largest series of patients treated with this therapy for post-sternotomy sternal wounds and believe it is safe and effective as a first-line therapy in the management of sternal wounds. The mortality rate from their study represents the patients' underlying disease process and comorbidities and is not a reflection of complications associated with the therapy. Vacuum-assisted closure therapy has been shown to decrease wound edema, decrease the time to definitive closure, and reduce wound bacterial colony counts. The authors have implemented the therapy for most patients with sternal wounds/mediastinitis at their institution, and believe it should be a standard protocol in the first-line management of these types of wounds.

A review of biomass burning emissions part III: intensive optical properties of biomass burning particles

Abstract. Because of its wide coverage over much of the globe, biomass burning has been widely studied in the context of direct radiative forcing. Such study is warranted as smoke particles scatter and at times absorb solar radiation efficiently. Further, as much of what is known about smoke transport and impacts is based on remote sensing measurements, the optical properties of smoke particles have far reaching effects into numerous aspects of biomass burning studies. Global estimates of direct forcing have been widely varying, ranging from near zero to −1 W m-2. A significant part of this difference can be traced to varying assumptions on the optical properties of smoke. This manuscript is the third part of four examining biomass-burning emissions. Here we review and discuss the literature concerning measurement and modeling of optical properties of biomass-burning particles. These include available data from published sensitivity studies, field campaigns, and inversions from the Aerosol Robotic Network (AERONET) of Sun photometer sites. As a whole, optical properties reported in the literature are varied, reflecting both the dynamic nature of fires, variations in smoke aging processes and differences in measurement technique. We find that forward modeling or ''internal closure'' studies ultimately are of little help in resolving outstanding measurement issues due to the high degree of degeneracy in solutions when using ''reasonable'' input parameters. This is particularly notable with respect to index of refraction and the treatment of black carbon. Consequently, previous claims of column closure may in fact be more ambiguous. Differences between in situ and retrieved ωo values have implications for estimates of mass scattering and mass absorption efficiencies. In this manuscript we review and discuss this community dataset. Strengths and lapses are pointed out, future research topics are prioritized, and best estimates and uncertainties of key smoke particle parameters are provided.

CVD Growth of Boron Nitride Nanotubes

Multiwalled BN nanotubes are grown from nickel boride catalyst particles by chemical vapor deposition at 1000−1100 °C using borazine, B3N3H6, as the precursor. This precursor is generated in situ from molten salt that forms from mixtures of (NH4)2SO4, NaBH4, and Co3O4 at 300−400 °C. The BN nanotubes have concentric-tube structures, are free of internal closures, have crystalline walls, and exhibit lengths of up to ∼5 μm. The nanotubes often possess bulbous, flag-like, or club-like tip closures. A root-growth mechanism is proposed for the catalyzed process.

Complementarity and closure

This paper compares two different accounts of closure to explain biological organization: as an organization enabled by an informational control on dynamics (Pattee) and as an internal closure of a dynamic nature (Varela). The two of them adopt different versions of a principle of complementarity to relate symbolic and dynamic explanations.

Aerosol measurements in the Arctic relevant to direct and indirect radiative forcing

Airborne measurements in the Arctic in June permit calculation of some of the parameters needed to assess both the direct and indirect radiative forcing by aerosols in the region. Values for the single‐scattering albedo of the aerosols suggest that in June the direct effect will produce a net cooling, in contrast to winter arctic hazes. Internal closure calculations comparing aerosol size distribution measurements with directly measured light scattering by aerosols over the first 4 km of the atmosphere show good agreement. Measurements of cloud condensation nucleus (CCN) activation spectra show steeper slopes than previous measurements in the Arctic in winter and early spring. Based on the CCN and collated cloud microphysical measurements, the susceptibility of the clouds encountered in this project to aerosol‐induced albedo modification appears quite high.

Internal Closure of an Aspergilloma Cavity

We have described a case in which closure of an aspergilloma cavity was done internally when it was determined that pulmonary resection was too hazardous. There was an intense inflammatory reaction surrounding the aorta and pulmonary artery. In the absence of gross purulence and underlying parenchymal infection, this technique may be used to avoid the prolonged hospitalization and bronchopleural fistulas associated with external drainage procedures.

腎移植後の内シャントの閉鎖について

腎移植後の内シャントの閉鎖について

Domain structure and magnetization processes in permalloy propagation elements

A review of domain structures and magnetization processes in permalloy overlays is given, together with some new results. The simplest domain structure for a given element consists of a loop of magnetic flux, but in elements with irregular geometry the circulating flux is not constant. More complex structures arise when an element contains internal closure domains. In-plane anisotropy in permalloy affects the distribution of closure domains but with decreasing bar width the influence of anisotropy is reduced. Reversible wall motion in weak fields gives way to hysteresis effects when the applied field exceeds a certain level, H s. In particular magnetization buckling may occur. Some details of buckling in asymmetric chevrons and half-discs are given and compared with the behaviour in an I-bar. The proximity of a bubble medium containing stripe domains is shown to reduce considerably the applied fields needed for buckling in overlay components. Following saturation, changes in the demagnetized state are usually apparent. On a simple level, the spin structure and polarity of Bloch walls is altered. More noticeably the wall pattern itself can change when closure domains are created or annihilated in pairs. The significance of these fluctuations for bubble propagation is assessed by considering the intrinsic stray field profile of a Bloch wall segment. A simple wall model is employed. It is demonstrated that a curved domain wall provides a reasonable basis for modelling the field of a magnetized bar up to saturation. Calculated values of H s agree qualitatively with experiment. The external field of the bar is rather insensitive to the exact distribution of free-pole density. Together with the observed complexities of domain behabiour this reaffirms the validity of the continuum approach to modelling.

ACQUISITION OF KNOWLEDGE WITHOUT TRANSCENDENTAL ASSISTANCE: AN EXTENDED PIAGETIAN APPROACH

Piaget's basic objective is seen as an attempt to explain how the individual and his evolutionary forbears can collectively gain practical mental‐models of the “real world”—starting ultimately from nothing, and without independent assistance. This paper firstly sets out to clarify Piaget's rather abstract views on this matter by postulating a more detailed mechanistic basis for them, and then interpreting various observations in terms of the hypothetical mechanisms. (This analytical approach is thus primarily intended as a heuristic aid; though it is also shown to be prima facie compatible with some other, non‐Piagetian paradigms.) It is concluded that a useful way of summarizing the process is in terms of the combined operations of preference for “internal closure” within the brain (Internal Coherence or consistency), and preference for “external closure” during interaction with the environment (Pragmatism or experimentation). In the light of this, Part II briefly discusses the views of Tarski, Popper and the Operationalists/Behaviourists concerning the nature of truth and the legitimacy of reductionism into unobservable domains.

Head and neck operations after radiation therapy

Postirradiation operations require that the surgeon have a healthy respect for postoperative complications and know how to prevent them as well as to treat them when they do occur. By the selection of appropriate neck incisions and the liberal use of flaps for the internal closure, postoperative complications are minimized and function is maximized. Surgeons should not be satisfied with adequate excision of the tumor and its metastases alone, although this is the most important part of the therapy. Rehabilitation of cosmesis, speech, and swallowing is most important and should begin at the time of the primary operation.

The behavior of the domain structure of polycrystalline magnetite at the margins of the crystallites

Domain structure studies on a polycrystalline massive magnetite ore show that a strong magnetic interaction between the crystals must be assumed, as the domain configuration continues in most cases across the crystal boundaries. The occurrence of internal closure domains is occasionally also observed but no apparent difference could be found between grain boundaries with and without internal closure domains.

A new operation of internal closure of the larynx for separation of the air and food passages.

Indications for internal closure of the larynx are the same as those set out by Smith, Spalding, Ardran, and Livingstone (1965) for laryngectomy in non-malignant conditions. There should be no prospect of recovery from the pharyngeal palsy which endangers the life of the patient from inhalation pneumonia. The advantage of closure of the larynx over laryngectomy is that it is only a mildly traumatic procedure, being less disturbing generally and likely to avoid complications at the operation site. This simple procedure could play an important part in hastening the rehabilitation of patients with permanent pharyngeal dysphagia, allowing early removal of the tracheotomy tube. Rather than adding to the difficulties in swallowing, as a laryngectomy may do, simple closure of the larynx can increase the patient's confidence in swallowing, with early resumption of normal feeding.