1,686 research outputs found

    Preparation of heterocyclic block copolymer from perfluoroalkylene oxide alpha, omega-diamidoximes

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    Diamidoxime monomers are intermolecularly and thermally condensed to form a heat and chemical resistant polymer containing 1,2,4-oxadiazole linkages with identical bivalent organic radicals or any combination of bivalent organic radicals selected from the group consisting of -(CX(sub 2))p-, wherein P ranges from 2 to 8 when X is fluorine and 2 to 18 when X is hydrogen, chlorine, nitro or aryl; arylene; and an oligometric or polymeric radical prepared by reacting a dicarboxylic acid halide with a fluorinated epoxide and having the formula: (CFY(OCF(sub 2)CFY)sub m)O(CX(sub 2))(sub p)O(CFYCF(sub 2)O)(sub n)CFY wherein Y is flourine or tryifluoromethyl, X is nitro, aryl, hydrogen, chlorine or fluorine, preferably the latter, p ranges from 1 to 18 and m+n ranges from 2 to 7

    Adnexal Torsion in Pediatric Age: Does Bolli's Score Work? Report of Two Cases

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    Adnexal torsion is a surgical emergency requiring early diagnosis in order to avoid demolitive surgery. Adnexal torsion's diagnosis could be very difficult in pediatric patients because children cannot explain symptoms accurately. Furthermore reproductive organs lie high in abdomen, causing unclear examinations findings. For reducing diagnostic mistakes or delay clinical and hematological criteria could be useful. No radiological criteria (CT or MRI) should be taken in count because of the costs and the required time. By combining clinical presentation in patients with OT three useful diagnostic variables have been identified: age, duration of pain, vomiting. Presence of vomiting, short duration of abdominal pain and high CRP levels have great predictive value for the diagnosis of adnexal torsion. In those patients an exploratory laparoscopy should be performed without any doubt and/or delay. These data may aid physicians in the evaluation of abdominal pain in premenarchal girls

    Metastatic tumors to the stomach: clinical and endoscopic features.

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    AIM: To evaluate the clinical and endoscopic patterns in a large series of patients with metastatic tumors in the stomach. METHODS: A total of 64 patients with gastric metastases from solid malignant tumors were retrospectively examined between 1990 and 2005. The clinicopathological findings were reviewed along with tumor characteristics such as endoscopic pattern, location, size and origin of the primary sites. RESULTS: Common indications for endoscopy were anemia, bleeding and epigastric pain. Metastases presented as solitary (62.5%) or multiple (37.5%) tumors were mainly located in the middle or upper third of stomach. The main primary metastatic tumors were from breast and lung cancer and malignant melanoma. CONCLUSION: As the prognosis of cancer patients has been improving gradually, gastrointestinal (GI) metastases will be encountered more often. Endoscopic examinations should be conducted carefully in patients with malignancies, and endoscopic biopsies and information on the patient's clinical history are useful for correct diagnosis of gastric metastases

    Shape-changing Collisions of Coupled Bright Solitons in Birefringent Optical Fibers

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    Wecritically review the recent progress in understanding soliton propagation in birefringent optical fibers.By constructing the most general bright two-soliton solution of the integrable coupled nonlinear Schroedinger equation (Manakov model) we point out that solitons in birefringent fibers can in general change their shape after interaction due to a change in the intensity distribution among the modes even though the total energy is conserved. However, the standard shape-preserving collision (elastic collision) property of the (1+1)-dimensional solitons is recovered when restrictions are imposed on some of the soliton parameters. As a consequence the following further properties can be deduced using this shape-changing collision. (i) The exciting possibility of switching of solitons between orthogonally polarized modes of the birefringent fiber exists. (ii) When additional effects due to periodic rotation of birefringence axes are considered, the shape changing collision can be used as a switch to suppress or to enhance the periodic intensity exchange between the orthogonally polarized modes. (iii) For ultra short optical soliton pulse propagation in non-Kerr media, from the governing equation an integrable system of coupled nonlinear Schroedinger equation with cubic-quintic terms is identified. It admits a nonlocal Poisson bracket structure. (iv) If we take the higher-order terms in the coupled nonlinear Schroedinger equation into account then their effect on the shape-changing collision of solitons, during optical pulse propagation, can be studied by using a direct perturbational approach.Comment: 14 pages, ROMP31, 4 EPS figure

    Management of ascites in patients with cirrhosis: An update

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    Ascites represents a critical event in the natural history of liver cirrhosis. From a prognostic perspective, its occurrence marks the transition from the compensated to the decompensated stage of the disease, leading to an abrupt worsening of patients’ life expectancy. Moreover, ascites heralds a turbulent clinical course, characterized by acute events and further complications, frequent hospital-izations, and eventually death. The pathophysiology of ascites classically relies on hemodynamic mechanisms, with effective hypovolemia as the pivotal event. Recent discoveries, however, integrated this hypothesis, proposing systemic inflammation and immune system dysregulation as key mechanisms. The mainstays of ascites treatment are represented by anti-mineralocorticoids and loop diuretics, and large volume paracentesis. When ascites reaches the stage of refractoriness, however, diuretics administration should be cautious due to the high risk of adverse events, and patients should be treated with periodic execution of paracentesis or with the placement of a trans-jugular intra-hepatic portosystemic shunt (TIPS). TIPS reduces portal hypertension, eases ascites control, and potentially modify the clinical course of the disease. Further studies are required to expand its indica-tions and improve the management of complications. Long-term human albumin administration has been studied in two RCTs, with contradictory results, and remains a debated issue worldwide, despite a potential effectiveness both in ascites control and long-term survival. Other treatments (vaptans, vasoconstrictors, or implantable drainage systems) present some promising aspects but cannot be currently recommended outside clinical protocols or a case-by-case evaluation

    A Comparison of Framing in Two Environmental Conflicts

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    Frames can be perspectives about people, objects, events, or settings that guide action based on past experiences and values. Conflicts are created by different stakeholders “holding conflicting frames.” Researchers in the past have used framing analysis to try and better understand environmental conflicts that tend to perpetuate for extended periods of time. A set of researchers have relied on specific framing categories and typologies as a framework for analysis. They have found that the strong presence or lack thereof certain frames can tell us a lot about conflict dynamics and shed light into the undercurrents driving the complexity of the dispute. This insight can be used to make management recommendations moving forward in an effort to help resolve the conflicts. The following study looks at two natural resource based conflicts in an attempt to build upon past case study research. The first conflict takes place in South Carolina dealing with surface water withdrawal regulations. The second occurs in New Jersey involving the construction of a natural gas pipeline through the Pinelands National Reserve. Both cases are relatively new and in their early stages compared to the cases studied by past researchers. Conducting a comparative analysis is consistent with past studies and strengthens the findings and discussions within this work. The study focused on describing the presence of three initial framing categories taken from past works that are of particular importance for studying natural resource conflicts. Respectively the categories look at stakeholder’s negative perceptions of each other, how they see the conflict should be managed going forward, and their general perceptions on how decisions regarding social issues should be made. The results showed patterns of such frame usage that often further divided stakeholders and were clearly impeding conflict resolution. Although not all, several framing typologies were present in both cases and there were substantial differences as well as similarities across cases. Other framing categories emerged that did not fit a specific category and were included the analysis making for an interesting discussion. The results of this analysis provide useful insight for managers. Managers can then take steps going forward to help remedy the controversy and encourage resolution. The focus of which will be to “build common ground”, overcoming divisions created by clashing stakeholder perspectives. Past researchers have used framing analysis to look how stakeholders of the same “generically labeled group” make sense of issues within a conflict. They have raised the question of whether or not stakeholders of the same group make sense of issues in a similar way? Traditionally it has been assumed that such conflicts are driven primarily by divisions between stakeholders of different groups i.e. industry or farmer’s vs environmentalists. However, using framing analysis researchers have refuted this “assumption”. Researchers have found that at times stakeholders of the same “traditionally affiliated group” frame issues in a different way creating conflict. The results from this work support their findings. This is important for managers as they should be careful not to overlook key divisions between stakeholders of the same group. Instead of focusing on labels, scholars have contended that we should look at framing to better understand stakeholder divisions driving conflict dynamics

    Atypical ulcers: Diagnosis and management

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    Atypical ulcers show atypical clinical features, histology, localization, and resistance to standard therapies. The persistence of a chronic ulcer despite treatment with standard therapies requires a more specific diagnostic investigation. Diagnosis involves obtaining the history and performing clinical examination and additional tests. A skin biopsy is frequently used to confirm unclear diagnosis. In difficult cases, microbiological and immunohistochem-ical examinations, laboratory blood tests, or instrumental tests should be evaluated. The treatment of atypical wounds is characterized by local systemic therapy and pain control. Our results highlight the need for early diagnosis, and standardized and targeted management by a multidisciplinary wound healing center
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