Preperitoneal prosthetic inguinal herniorrhaphy without a relaxing incision

A consecutive series of 276 men had 317 inguinal hernias repaired by the preperitoneal approach. Of these, 162 (59 per cent) had 194 (61 per cent) "complete" repairs using Marlex prostheses. Fifty-five of 152 indirect hernias (36 per cent) were patched similarly. Seventeen of twenty-two mixed bilateral defects (77 per cent) had a prosthetic patch. Thrity-three of forty-eight repairs (68 per cent) for recurrent hernia in forty-five men also employed Marlex. Two patients died postoperatively. Four of 194 repairs using Marlex failed. These preliminary results indicate that the advantages of preperitoneal exposure can be complemented by an initially satisfactory technic of repair using a prosthesis instead of the classic relaxing incision, which is difficult to use with this posterior approach.     

Biochemistry and hematology at decompression sickness: a case report

A 24-year-old hospital corpsman, a volunteer in a series of dry chamber air dives to a simulated pressure equivalent to 188 FSWG (57.3 MSWG), developed left knee pain shortly after standard decompression. A tentative diagnosis of decompression sickness was made and recompression therapy was initiated with alleviation of pain occurring at 60 FSWG (18.3 MSWG). A U.S. Navy Treatment Table "5 (oxygen breathing) regimen was then selected and completed uneventfully. The subject had been undergoing biomedical evaluation for several days prior to diving; thus, a clinically diagnosed case of dysbarism with subsequent treatment was available for study. This individual was then monitored for a 10-d period. The acute phase of decompression sickness was characterized by a marked shortening of clotting time and a thrombocytopenia with accompanying increased platelet aggregates. The recovery phase was categorized by a variety of hematological and bio-chemical changes. Hemodilution, an elevated megathrombocyte index, and a tendency toward eosinopenia were evident for most of the 10-d observation period. Other persistent alterations detected during this period included a relative hyperglycemia, depressed urine Na+/K+, and increased ketosteroid excretion. These observations indicate that abatement of pain after treatment of dysbarism can be followed by the onset of a variety of biochemical and hematological changes. Moreover, complete recovery may require upwards of 10 d.     

Intraoperative autotransfusion: equipment, protocols, and guidelines

Blood obtained by intraoperative autotransfusion is: 1) readily available 2) sterile 3) compatible 4) normothermic 5) inexpensive and may be infused rapidly for volume support. We have made extensive modifications to commercially available equipment in order to provide a safe, effective IAT. The effects of IAT in our series of 85 patients are outlined below. Red Cell Mass is reduced after IAT because of irretrievable blood loss and hemolysis, and may be controlled by homologous transfusion when necessary. Red Cell Survival is normal after IAT. Hemolysis. Plasma free hemoglobin is consistently elevated after IAT, but clears within 24 hours. Platelets are normal for patients autotransfused less than 3,500 ml; micropore filters should not be used in cases where greater than 3,500 ml blood is expected to be reinfused; in cases where greater than 3,500 ml is reinfused, 10 units of platelets are recommended for every 3,000 ml of blood reinfused; IAT does effect platelets function; however, platelets circulating within the patient function normally. Coagulation. We use local ACD to eliminate extracorporeal surface clotting. Even with massive IAT we have never demonstrated any clinical or laboratory evidence of intravascular coagulopathy. "Dilutional coagulopathy" may be procuced when greater than 5,000 ml are reinfused, and may be controlled with fresh frozen plasma and platelet concentrates. Bilirubin levels were normal after IAT despite gross hemoglobinuria. Fat emboli were not noted after IAT. Air emboli must be a concern in IAT; HOWEVER, PROPER OPERATION AND EQUIPMENT MODIFICATION MAY ELIMINATE EMBOLI. Renal Failure was not noted after IAT. Alveolar-arterial Oxygen Difference and Blood Gases were normal after IAT. We feel IAT is not necessary if a blood loss less than 1,000 ml is expected. Also, if greater than 3,500 ml is expected additional backup (i.e. homologous transfusions, platelets, fresh frozen plasma) may be required. As banked donor blood reserves become more limited, IAT may become a routine part of general surgical procedures.     

Monitoring environmental health using SPOT-VEGETATION-derived and field-measured spectral indices in Karabash,Russia

The objective of this study was to use satellite imagery combined with field-based spectral analysis to assess the impacts of mining-related activities on vegetation around the smelter town of Karabash, South Ural Mountains of Russia. Time series analysis of normalized difference vegetation index (NDVI) and fraction of absorbed photosynthetically active radiation (FAPAR) images derived from Système Pour l’Observation de la Terre (SPOT)-VEGETATION was combined with the analysis of vegetation stress indices calculated from 140 in situ spectral measurements. Correlation analyses have revealed that vegetation stress affects vegetation density and resilience, and that it impedes a gradual increase in photosynthetic activity in the most affected areas ranging up to 10 km from the smelter. The prolongation of the growing season of healthier vegetation at greater distances, showing higher vegetation density, lower variation, and a more positive trend over time, can possibly be related to climate change. Although land cover shows a concentric pattern around Karabash, the analysis revealed that both spectral and time series-derived indices are defined more by the distance to the Karabash smelter and vegetation stress, rather than by the land cover class.     

Characterization of Nanodomains in Polymer-Derived SiCN Ceramics Employing Multiple Techniques

A combination of methods, Bragg diffraction, small-angle X-ray scattering (SAXS), and transmission electron microscopy, is applied to the characterization of nanodomains and nanocrystals in polymer-derived ceramics (PDCs). Detailed study of two materials, silicon carbonitride (SiCN) and a SiCN–zirconia nanocomposite, is presented. The first contains domains which can be measured only by SAXS. However, the nanocrystallites of zirconia in the second material can be quantatively studied by all three techniques. In both instances, we find the SAXS to be particularly useful because these data provide detailed information regarding the size distribution of the domains and the crystallites. This information can be valuable in understanding the materials science of PDCs: e,g., the change in the distribution and the average size of the nanoclusters can be modeled to understand the kinetic mechanisms of coarsening at high temperatures.     

Purtscher's retinopathy: a case of visual impairment associated with multiple trauma

This case study describes a patient with multiple trauma associated with acute visual impairment. Funduscopic examination revealed scattered and confluent cotton wool exudates bilaterally. This retinopathy was first described by Othmar Purtscher, an Austrian ophthalmologist, in 1910, which he later referred to as "angiopathia retinae traumatica."     

Posttraumatic headache: determining chronicity

In the headache literature, there exists a great deal of discrepancy regarding when posttraumatic headache (PTH) may be classified as chronic. Although chronic pain is usually described as pain persisting for longer than six months, many view chronic posttraumatic headache as persisting for more than two months, including the International Headache Society criteria. Observations made by Brenner and Friedman in 1944 have been repeatedly cited for this determination. Surprisingly, a review of this original source revealed that the term "chronic" was never used when discussing posttraumatic headache over two months duration. The authors, in fact, suggested two months as an "arbitrary" dividing line. Recent studies suggest that many patients with PTH continue to improve or change over the first six months but start to plateau after that time. We feel six months serves as a better time indicator for defining chronicity in cases of posttraumatic headache. This would be more consistent with the current literature concerning chronic pain and the international Headache Society criteria for chronic tension headache.     

Improved algorithms for optimal length resolution refutation in difference constraint systems

This paper is concerned with the design and analysis of improved algorithms for determining the optimal length resolution refutation (OLRR) of a system of difference constraints over an integral domain. The problem of finding short explanations for unsatisfiable Difference Constraint Systems (DCS) finds applications in a number of design domains including program verification, proof theory, real-time scheduling, and operations research. These explanations have also been called “certificates” and “refutations” in the literature. This problem was first studied in Subramani (J Autom Reason 43(2):121–137, 2009), wherein the first polynomial time algorithm was proposed. In this paper, we propose two new strongly polynomial algorithms which improve on the existing time bound. Our first algorithm, which we call the edge progression approach, runs in O(n ² · k + m · n · k) time, while our second algorithm, which we call the edge relaxation approach, runs in O(m · n · k) time, where m is the number of constraints in the DCS, n is the number of program variables, and k denotes the length of the shortest refutation. We conducted an extensive empirical analysis of the three OLRR algorithms discussed in this paper. Our experiments indicate that in the case of sparse graphs, the new algorithms discussed in this paper are superior to the algorithm in Subramani (J Autom Reason 43(2):121–137, 2009). Likewise, in the case of dense graphs, the approach in Subramani (J Autom Reason 43(2):121–137, 2009) is superior to the algorithms described in this paper. One surprising observation is the superiority of the edge relaxation algorithm over the edge progression algorithm in all cases, although both algorithms have the same asymptotic time complexity.     

Deblurring subject to nonnegativity constraints when knownfunctions are present with application to object-constrainedcomputerized tomography

The reconstruction of tomographic images is often treated as a linear deblurring problem. When a high-density, man-made metal object is present somewhere in the image field, it is a deblurring problem in which the unknown function has a component that is known except for some location and orientation parameters. We first address general linear deblurring problems in which a known function having unknown parameters is present. We then show how the resulting iterative solution can be applied to tomographic imaging in the presence of man-made foreign objects, and we apply the result, in particular, to X-ray computed tomography imaging used in support of brachytherapy treatment of advanced cervical cancer.