Contribution of surface application of chitosan-thyme and chitosan-rosemary essential oils to the volatile composition, microbial profile, and physicochemical and sensory quality of dry-fermented sausages during storage.

The effect of chitosan (C), chitosan enriched with thyme (CT) or rosemary (CR) essential oils, and potassium sorbate (PS) against superficial fungal growth was investigated in fermented sausages during 3 months of storage at 4 °C. For control groups, distilled water (DW) and acetic acid (AA) were used. PS, C, CT and CR treatments inhibited fungal growth on casings while they resulted in lower Gram(+) catalase(+) cocci, Enterobacteriaceae, mold and yeast counts in sausages. Lower TBARS values were determined for CT and CR (p < .05). A total of 44 and 64 volatile compounds were identified in sausages and casings, respectively. Sausages coated with C, CT or CR had acceptable sensory attributes at the end of storage; however, DW and AA groups were rejected in the second and third month (p < .05), respectively, due to intense fungal growth which resulted in sensory defects.

Weak localization and Mott state in two-dimensional Sr3V5S11.

We report on the high-pressure synthesis, structural study and physical properties of a new layered compound, Sr3V5S11. Single-crystals of ~0.3 mm size were synthesized at the optimized growth conditions of 6 GPa and 1600 ° C. The refinement of x-ray diffraction data indicates that the crystal structure is monoclinic (space group C2/c), with cell parameters a = 8.7165(7) Å, b = 15.1096(13) Å, c = 23.111(2) Å, and ß = 98.734(9). The structure consists of a stacking of VS2 layers with a CdI2-type structure within the ab-plane connected by trimers of face-sharing VS6 octahedra oriented along the out-of-plane direction. Salient features are a 4 + valence of the V ions in the planes and a 3 + valence in the trimers and a large stripe-like modulation of the V-V distances in the planes leading to quasi-one-dimensional properties. The magnetic susceptibility displays a large temperature-independent contribution, χ0, in addition to a moderate Curie-Weiss term. In the 300-120 K range, the electrical resistivity is described well by a semiconducting-like behaviour with a room-temperature value of ~1.2-10 mΩ cm and a modest activation energy of ~13.5 meV. At lower temperatures, a crossover to a one-dimensional variable range hopping regime is observed, supporting a scenario of a correlated 1D system.

X-ray standing waves in a heterostructure: application to a Zn(1-x)CoxO epilayer on ZnO(00.1)-O substrate.

X-ray standing waves (XSW) in a thin epitaxic film are treated in the framework of the dynamical theory. It is demonstrated that the fluorescence yield around the main peak of the rocking curve has essentially the same characteristics as that of the usual XSW on a bulk crystal surface. Thus, XSW provide a direct method to probe the atom position in a thin film. The method was applied to an epilayer of the diluted magnetic semiconductor Zn0.94Co0.06O, in order to determine the Co-atom position. The XSW established that Co atoms occupy the substitutional Zn site in the ZnO matrix, although their coherent fraction, which measures the degree of order, is rather low. Moreover, the measurement of the Zn fluorescence in the film gives approximately the same value for the coherent fraction of the Zn atoms. Besides, by using the substrate rocking curve, it is shown that the XSW signal of the Zn atoms in the substrate can be detected through the film. This interesting approach allows the coherent fraction of an element of a substrate below an interface to be probed in situ. For the Zn fluorescence, the coherent fraction is lower near the interface than in the bulk. These results should relate to strains and defects on both sides of the interface.

Voronoï tessellation reveals the condensed matter character of folded proteins.

The packing geometry of amino acids in folded proteins is analyzed via a modified Voronoï tessellation method which distinguishes bulk and surface. From a statistical analysis of the Voronoï cells over 40 representative proteins, it appears that the packings are in average similar to random packings of hard spheres encountered in condensed matter physics, with a quite strong fivefold local symmetry. Moreover, the statistics permits one to establish a classification of amino acids in terms of increasing propensity to be buried in agreement with what is known from chemical considerations.

Kinetics of oxidation of the lipids and proteins of cod sarcoplasmic reticulum.

Lipid and protein oxidation in an NADH-Fe enzymic and an ascorbate-Fe nonenzymic system were determined simultaneously. The nonenzymic iron-reducing system gave rapid oxidation of lipid that leveled off at values much lower than those achieved in the enzymic system, which showed a continuous increase over the 1 or 2 h incubation times used. Protein sulfhydryl oxidation was more rapid in the nonenzymic system for total and accessible sulfhydryl groups, but the enzymic system oxidized the inaccessible sulfhydryl groups more rapidly. Both lipid and protein oxidations appeared to begin simultaneously. In the enzymic system, more lipid oxidation was achieved on a molar basis than oxidation of protein sulfhydryl groups, while in the nonenzymic system this was reversed. These data probably reflect the site specificity of the production of oxidizing elements in the two systems. The greater lipid oxidation in the enzymic system suggests that this may be the more important ferric iron-reducing system during storage of fish muscle.

Creutzfeldt-Jakob disease diagnosable by EEG and cerebrospinal fluid analysis without brain biopsy: a case report.

This case illustrates a classic example of CJD in its clinical presentation and course and the EEG. It also shows dramatically the utility of a newly developed protein assay in the diagnosis of this disease. This assay has the potential of eliminating the need for brain biopsy in most cases, thus providing a safer diagnostic method for both staff and patients. In addition, the case points out that anatomical structural studies such as CT and MRI do not replace the utility of EEG in the comprehensive evaluation of rapid onset dementia, but rather complement the usefulness of EEG.

Fractures of the base of the first metacarpal: current treatment options.

Fractures of the thumb metacarpal occur most frequently at the base. These fractures can be subdivided into intra-articular and extra-articular types. Intra-articular fractures present treatment challenges because they have a tendency to displace due to deforming forces acting at the base of the thumb. An understanding of the anatomy, biomechanics, and fracture pattern will aid in deciding on the best treatment option for each fracture type. Surgical treatment is recommended for unstable fractures. Anatomic restoration of the articular surface in Bennett and Rolando fractures is not essential to obtain a good functional result. However, reduction should be 1 mm or less to reduce the risk of radiographic arthritis. Malunion of these fractures may result in long-term disability. Closed reduction and percutaneous Kirschner-wire fixation is generally the appropriate treatment for a Bennett fracture. Rolando fractures can be treated with either open reduction and internal fixation or external fixation, depending on the size of the fracture fragments. In the case of severely comminuted intra-articular fractures, articular impaction has been implicated as one of the causes of posttraumatic arthritis. It is difficult to restore the articular surface in these injuries. Therefore, external fixation can be considered when the fracture fragments are small and there is significant soft-tissue injury.

Optimal position for plate fixation of complex fractures of the proximal radius: a cadaver study.

OBJECTIVE: To determine the optimal postion for plate fixation in complex fractures of the proximal radius in which head and neck dissociation occurs. DESIGN: Technical study. SETTING: Tertiary referral center, teaching hospital, U.S. military. SUBJECTS: Five preserved cadavers. MAIN OUTCOME MEASURE: Radioulnar impingement and proximity to neurovascular structures were directly measured in elbows plated in each of three positions: neutral, full pronation, and full supination. RESULTS: Application of the 2.0-millimeter T-plate to the lateral aspect of the radial head and neck with the forearm in neutral position had no impingement, whereas application in full pronation resulted in loss of the last 30 degrees of supination. Plate application in full supination resulted in the loss of the last 10 degrees of pronation. In addition, there was no impingement when the 2.7-millimeter plate was applied similarily in the neutral position. None of these positions resulted in increased risk to neurovascular structures. CONCLUSIONS: The optimal position for plate fixation of complex proximal radius fractures is with the forearm in neutral position, with the plate applied directly lateral. A larger implant, 2.7 millimeters, may be used if this technique is followed without further risk of impingement and loss of motion.

Scanning electron microscopic evaluation of the effects of an air-abrasive system on dental implants: a comparative in vitro study between machined and plasma-sprayed titanium surfaces.

An in vitro comparative study was conducted in order to evaluate the effects of an air-abrasive system on dental implant surfaces. Eight new titanium dental implants, four standard machined implants (machined group), and four standard plasma-sprayed implants (plasma-sprayed group) were selected for investigation. Both neck and body surfaces of the implants were analyzed. Each pair of implants in each group was treated as follows: the spray of the air-abrasive unit was applied to each area for 5 seconds on the first implant and 15 seconds on the second implant. A total of 24 areas were observed: 16 test implants and 8 controls. Scanning electron photomicrographs were analyzed by 3 examiners using a category rating scale (kappa = 0.594). The images were also computerized for texture analysis. The results indicate that a single air-powder abrasive treatment of the dental implants selected for this study modified their exposed surfaces. After treatment, the threaded neck surface of a machined group implant was least affected, whereas the body was the most altered. In the plasma-sprayed group, comparisons between implant surfaces showed little change. In the machined group, more change was observed in both neck and body areas. In all specimens, a 5-second exposure to the air-powder abrasive did not induce deep changes in the surfaces. A 15-second exposure modified all the specimen surfaces. Further studies are needed to evaluate the effect of these changes on the biological osseointegration process.

Digital image ratio: a new radiographic method for quantifying changes in alveolar bone. Part II: Clinical application.

As reported in a previous paper (1) we have developed a new technique, Digital Image Ratio (DIR), which theoretically avoids some of the drawbacks of quantitative digital substraction radiography. DIR allows the direct computation and visualization of bone-mass-ratio changes. This second paper describes the use of DIR analysis to examine 20 sites in 8 patients undergoing regenerative periodontal therapy. Standardized reproducible radiographs of these 20 sites were taken before and 12 months after surgery. Ten experimental sites were treated with bone graft substitutes (natural coral or natural coral+collagen), and 10 control sites by debridement alone. None of the experimental sites had a density ratio below 1, where 1 indicates no change. The error was +/- 0.07 (0.93-1.07). The experimental sites showed an 18% mean increase in bone density (1.18), which increased to 23% (1.23) for sites filled with natural coral alone. All the control sites had values close to 1.00 (1.00 +/- 0.07) except for 3 sites, which showed a 9-15% loss of bone density. It is thus possible to compare and quantify the changes in experimental and control sites in the same patient using the percentage gain or loss of bone density. This demonstrates that DIR is suitable for clinical applications, and can be used in clinical analysis when bone changes are expected.

Digital image ratio: a new radiographic method for quantifying changes in alveolar bone. Part 1: Theory and methodology.

A new world, digital image ratio (DIR), has been developed for directly measuring changes in alveolar bone. The image on the computer monitor represents the relative mass change between two radiographs. Fourier filtering is used to reduce noise artefacts. This method is validated through an experiment with a step wedge. DIR needs only a preliminary calibration of the experimental conditions of operation and avoids tedious calibrations for each measurement as in the case of digital image substraction. Low-voltage X-ray techniques are suggested for long-term quantitative studies of patients to minimize irradiation doses.

Progressive scoliosis in Dubowitz syndrome.

STUDY DESIGN: This case report describes a 17-year-old male with Dubowitz syndrome in whom a progressive left thoracic scoliosis developed that required surgical correction. OBJECTIVE: Scoliosis associated with Dubowitz syndrome had not been previously described among the orthopedic manifestations of this rare syndrome. A review of the literature and the surgical treatment of this patient is presented. SUMMARY OF BACKGROUND DATA: Dubowitz syndrome is a rare autosomal recessive disorder characterized by microcephaly, craniofacial abnormalities, eczematous skin rash, delayed skeletal maturation, and shortness of stature. The orthopedic manifestations of this condition primarily involve the hands and feet with brachyclinodactyly of the fifth finger and syndactyly of the second and third toes. Spinal deformity in these individuals is not well described in the literature. METHODS: Over a 2-year period, the patient's scoliosis progressed to 88 degrees, resulting in severe truncal imbalance without neurologic sequelae. A posterior spinal fusion with segment instrumentation alone was used to correct the deformity. RESULTS: After surgery, excellent restoration of spine sagittal and coronal plane alignment was achieved, resulting in improved sitting and standing balance. CONCLUSION: Patients with Dubowitz syndrome may be at risk of having a progressive, rigid scoliosis. These individuals may need to be observed over a prolonged period for the development of spinal deformity because of the potential for extended delay in skeletal maturation.

Closed posteromedial dislocation of the tibiotalar joint without fracture or diastasis: a case report.

Tibiotalar dislocation without fracture is an unusual injury. Seventy-three cases have been reported in the literature. Closed posteromedial dislocation of the tibiotalar joint without fracture or diastasis is a very rare phenomenon. Eight cases have been reported. A case of this unique injury is presented, along with a literature review of purely ligamentous ankle dislocations. The proposed mechanism and classification of these injuries are summarized.

Computer reconstruction of nucleolar architecture by interactive three-dimensional color display.

The first complete three dimensional ultrastructural reconstruction of pancreatic cell nucleoli, was done using EM and computer 3D-assisted reconstruction of serial sections with interactive 3D back-to-front and color display methods based on voxel representation. The purpose of the study was to depict the architecture of the nucleolar components. We obtained information about the location of the nucleolus within the nuclear volume and about the shape and polarity of the 3 main nucleolar territories.

Three-dimensional computer reconstructions from serial sections of cell nuclei.

The analysis of ultrathin serial sections as 3-dimensional (3D) information requires interpretation and display of a large amount of data. We suggest a simple way to solve this problem; it permits presentation of a series of sections as a 3D color image of good quality. It involves a picture system with specialized hardware and software written for this purpose. 3D images of cellular organelles have been drawn either by manually defining the contour of the objects or by thresholding of the volumes in the structures. These 2 methods allow rapid drawing of the image on the screen. It is possible to determine the position, shape and size of 3D structures. This interactive system allows the user to choose between several options: colors, removal of parts of the object, and cutout.

Computed tomography in global cerebral cortical ischemia of the neonate and young infant.

The authors have encountered three unique neonates with global cerebral cortical ischemia. The pathogenesis and computed tomography scans of these patients who sustained profound hypoxemia is described. Follow-up computed tomography scans in each case demonstrated generalized loss of cortical substance.

Incidence and causes of hyperbilirubinaemia in a hospital population: with particular reference to blood transfusion.

We surveyed a large hospital population of patients to establish the incidence and causes of hyperbilirubinaemia. In a review of 6890 patients, we found an overall incidence of hyperbilirubinaemia of 9%. We reviewed the case histories of 175 patients with hyperbilirubinaemia to analyse the causes and contributory factors. In 22% of patients with hyperbilirubinaemia, hepatobiliary disease was the sole cause and was a contributory cause in another 7%. Disorders of oxygen transport were the single most common cause of hyperbilirubinaemia, being the sole cause in 38% of patients and a contributing cause in a further 9%. Blood transfusion was the sole cause of elevation in bilirubin level in only three patients (1.7%), but was a very significant contributing factor in a further 18%. It is likely that Gilbert's syndrome was a contributing factor in some cases but, as there is no definitive test for diagnosis, clear identification was not possible.

Lateralization of brainstem lesions by brainstem auditory evoked potentials.

In eight patients with unilateral pontine and midbrain lesions, brainstem auditory evoked potentials (BAEPs) were studied with ipsilateral (Cz-Ai) and contralateral (Cz-Ac) recordings after monaural stimulation. In all cases, the most prominent abnormality was noted in BAEP generated by stimulating the ear ipsilateral to the lesions. The Cz-Ai and Cz-Ac patterns showed similar abnormalities in five of the patients and dissociated abnormalities in two patients. We conclude that: (1) Lateralization of BAEP is possible in unilateral pontine and midbrain lesions. (2) Monaural stimulation with Cz-Ai and Cz-Ac recordings is essential for lateralization. (3) The BAEP in monaural stimulation is predominantly generated from the auditory structures ipsilateral to the stimulated ear.