Laboratory Evaluation Of Crosslinked Polymer And Alkaline-Polymer-Surfactant Flood

The rheological and mechanical properties of crosslinked polymer gels arise from the structure of the gel network. In turn, the structure of the gel network results from: thermodynamically determined interactions between the polymer chain segments, the interactions of the crosslinking metal ion with the polymer, and the deformation history of the network. Interpretations of mechanical and rheological measurements on polymer gels invariably begin with a conceptual model of,the microstructure of the gel network derived from polymer kinetic theory. In the present work, we use freeze-etch replication TEM to image the polymer network morphology of titanium crosslinked hydroxypropyl guars in an attempt to directly relate macroscopic phenomena with network structure.

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The analysis of “Gels” in polymer films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100153786 ◽

1989 ◽

Vol 47 ◽

pp. 362-363

Author(s):

G. M. Brown ◽

D. F. Brown ◽

J. H. Butler

Keyword(s):

Molecular Weight ◽

Film Industry ◽

Local Stress ◽

Melt Index ◽

Polyethylene Films ◽

Crosslinked Polymer ◽

Polymeric Gels ◽

Mineral Particles ◽

Polymeric Species ◽

Special Concern

The term “gel”, in the jargon of the plastics film industry, may refer to any inclusion that produces a visible artifact in a polymeric film. Although they can occur in any plastic product, gels are a principle concern in films where they detract from the cosmetic appearance of the product and may compromise its mechanical strength by acting as local stress concentrators. Many film gels are small spheres or ellipsoids less than one millimeter in diameter whereas other gels are fusiform-shaped and may reach several centimeters in length. The actual composition of gel inclusions may vary from miscellaneous inorganics (i.e. glass and mineral particles) and processing additives to heavily oxidized, charred or crosslinked polymer. The most commonly observed gels contain polymer differing from the bulk of the sample in its melt viscosity, density or molecular weight.Polymeric gels are a special concern in polyethylene films. Over the years and with the examination of a variety of these samples three predominant polymeric species have been observed: density gels which have different crystallinity than the film; melt-index gels in which the molecular weight is different than the film and crosslinked gels which are comprised of crosslinked polyethylene.

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Tetracycline-resistant pneumococcal infection. Incidence, clinical presentation, and laboratory evaluation

Archives of Internal Medicine ◽

10.1001/archinte.123.4.388 ◽

1969 ◽

Vol 123 (4) ◽

pp. 388-393 ◽

Cited By ~ 1

Author(s):

O. J. Bizzozero

Keyword(s):

Clinical Presentation ◽

Pneumococcal Infection ◽

Laboratory Evaluation ◽

Infection Incidence

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Clinical features and outcome of acquired haemophilia A

Hämostaseologie ◽

10.1055/s-0037-1619050 ◽

2010 ◽

Vol 30 (03) ◽

pp. 156-161 ◽

Cited By ~ 9

Author(s):

R. Gheisari ◽

B. Bomke ◽

T. Hoffmann ◽

R. E. Scharf

Keyword(s):

Respiratory Diseases ◽

Care Center ◽

Treatment Algorithm ◽

Early Death ◽

Underlying Disease ◽

Pulmonary Sarcoidosis ◽

Relative Increase ◽

Laboratory Evaluation ◽

Haemophilia A ◽

Acquired Haemophilia

SummaryWe have performed a monocenter study on 29 consecutive patients with acquired haemophilia A who were referred for diagnosis and treatment to the Düsseldorf Haemophilia Comprehensive Care Center between March 2001 and February 2010. Patients, methods: 18 men (age: 44–86 years) and 11 women (age: 20–83 years). For laboratory evaluation, a standardized staged protocol of aPTT, FVIII : C activity and concentration, mixing studies with patient and normal plasma, and quantification of inhibitor titers (Bethesda assay) was used. Diagnostic work-up included elaborate examinations for any underlying disease. Results: In 18 (62%) of the 29 patients with acquired haemophilia A, an underlying disorder was identified, including 9 patients with respiratory diseases (31%), 7 patients with autoimmune disorders (24%), one with malignancy, and one with postpartum state, while in 11 patients (38%) acquired haemophilia A remained idiopathic. Haemotherapy of bleeding, suppression or elimination of the inhibitor, and induction of immunotolerance to endogenous FVIII:C were performed according to a treatment algorithm. Predefined clinical endpoints were control of bleeding, eradication of the inhibitor, complete or partial remission (CR, PR), relapse, or early death (≤30 days). Of the 29 patients in total, 22 individuals achieved CR (76%), three had PR, one relapsed, and three died within 30 days (one of acute myocardial infarction while on anti-haemorrhagic treatment, one of sepsis while on immunosuppression due to active acquired haemophilia A, one of lung bleeding in association with pre-existing pulmonary sarcoidosis). Conclusion: This monocenter study demonstrates that control of life-threatening bleeding, eradication of the inhibitor, and induction of tolerance to endogenous FVIII have significantly improved the clinical outcome of acquired haemophilia A. Our data also suggest a shift in underlying disorders associated with acquired haemophilia A, whereby, in comparison to published studies, a relative increase in the proportion of patients with respiratory diseases is present.

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Laboratory Evaluation and Clinical Characteristics of 2,132 Consecutive Unselected Patients with Venous Thromboembolism – Results of the Spanish Multicentric Study on Thrombophilia (EMET*-Study)

Thrombosis and Haemostasis ◽

10.1055/s-0038-1655986 ◽

1997 ◽

Vol 77 (03) ◽

pp. 444-451 ◽

Cited By ~ 163

Author(s):

José Mateo ◽

Artur Oliver ◽

Montserrat Borrell ◽

Núria Sala ◽

Jordi Fontcuberta ◽

...

Keyword(s):

Venous Thrombosis ◽

Odds Ratio ◽

Protein C ◽

Protein S ◽

Laboratory Evaluation ◽

Clinical Factors ◽

Recurrent Thrombosis ◽

Heparin Cofactor Ii ◽

Crude Odds Ratio ◽

History Of

SummaryPrevious studies on the prevalence of biological abnormalities causing venous thrombosis and the clinical characteristics of thrombotic patients are conflicting. We conducted a prospective study on 2,132 consecutive evaluable patients with venous thromboembolism to determine the prevalence of biological causes. Antithrombin, protein C, protein S, plasminogen and heparin cofactor-II deficiencies, dysfibrinoge-nemia, lupus anticoagulant and antiphospholipid antibodies were investigated. The risk of any of these alterations in patients with familial, recurrent, spontaneous or juvenile venous thrombosis was assessed. The overall prevalence of protein deficiencies was 12.85% (274/2,132) and antiphospholipid antibodies were found in 4.08% (87/2,132). Ten patients (0.47%) had antithrombin deficiency, 68 (3.19%) protein C deficiency, 155 (7.27%) protein S deficiency, 16 (0.75%) plasminogen deficiency, 8 (0.38%) heparin cofactor-II deficiency and 1 had dysfib-rinogenemia. Combined deficiencies were found in 16 cases (0.75%). A protein deficiency was found in 69 of 303 (22.8%) patients with a family history of thrombosis and in 205/1,829 (11.2%) without a history (crude odds ratio 2.34, 95% Cl 1.72-3.17); in 119/665 (17.9%) patients with thrombosis before the age of 45 and in 153/1,425 (10.7%) after the age of 45 (crude odds ratio 1.81, 95% Cl 1.40-2.35); in 103/616 (16.7%) with spontaneous thrombosis and in 171/1,516 (11.3%) with secondary thrombosis (crude odds ratio 1.58, 95% Cl 1.21-2.06); in 68/358 (19.0%) with recurrent thrombosis and in 206/1,774 (11.6%) with a single episode (crude odds ratio 1.78,95% Cl 1.32-2.41). Patients with combined clinical factors had a higher risk of carrying some deficiency. Biological causes of venous thrombosis can be identified in 16.93% of unselected patients. Family history of thrombosis, juvenile, spontaneous and recurrent thrombosis are the main clinical factors which enhance the risk of a deficiency. Laboratory evaluation of thrombotic patients is advisable, especially if some of these clinical factors are present.

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