1,089 research outputs found

    On 33-syzygy and unexpected plane curves

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    In this note we study curves (arrangements) in the complex projective plane which can be considered as generalizations of free curves. We construct families of arrangements which are nearly free and possess interesting geometric properties. More generally, we study 33-syzygy arrangements and we present examples that admit unexpected curves.Comment: 19 pages, one figure, version after referee's remark

    Construction of free curves by adding osculating conics to a given cubic curve

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    In the present note we construct new families of free and nearly free curves starting from a plane cubic curve CC and adding some of its hyperosculating conics. Using obvious group actions, we get new insight into the geometry of the 2727 hyperosculating conics of the Fermat cubic curve.Comment: 11 pages, comments welcom

    Selected methods for the early diagnostics of oral malignant lesions – a literature review

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    Early diagnostics of oral cancerous lesions plays a crucial role in the process of treatment and evaluation of the patient's chances for recovery. The article presents new techniques of identifying and detecting abnormal lesions within oral mucosa, such as oral lumenoscopy (ViziLite), TBlue (toluidine blue marking system), VELscope screening system, OralCDx and the brush biopsy. Their application does not allow a definite diagnosis, nor does it replace biopsy or histopathologic assessment, but it permits a more accurate examination of the oral cavity, as well as oral lesion detection at the early stage of progression

    Points fattening on P^1 x P^1 and symbolic powers of bi-homogeneous ideals

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    We study symbolic powers of bi-homogeneous ideals of points in the Cartesian product of two projective lines and extend to this setting results on the effect of points fattening obtained by Bocci, Chiantini and Dumnicki, Szemberg, Tutaj-Gasi\'nska. We prove a Chudnovsky-type theorem for bi-homogeneous ideals and apply it to classification of configurations of points with minimal or no fattening effect. We hope that the ideas developed in this project will find further algebraic and geometric applications e.g. to study similar problems on arbitrary surfaces.Comment: 12 pages, notes from a workshop on linear series held in Lanckoron

    Characteristics of maxillofacial injuries resulting from road traffic accidents – a 5 year review of the case records from Department of Maxillofacial Surgery in Katowice, Poland

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    BACKGROUND: In spite of employing numerous devices improving the safety in motor vehicles, traffic accidents are still among the main reasons of maxillofacial injuries. The maxillofacial injuries remain the serious clinical problem because of the specificity of this anatomical region. The knowledge of etiologic factors and mechanisms of injuries can be helpful in a satisfactory trauma prevention. The aim of this study was to find out the incidence and the pattern of maxillofacial injuries resulting from traffic accidents in the patients treated in the Department of Maxillofacial Surgery (Silesian Medical Academy in Katowice, Poland) from January 2001 to December 2005. METHODS: The material consisted of 1024 case records of patients with maxillofacial injuries treated in the Maxillofacial Surgery Department of Silesian Medical Academy. The detailed analysis was carried out on the case records of 198 patients in the age of 3 to 68 with maxillofacial injuries resulting from traffic accidents. On the basis of data from a history, examination on admission, consultations and radiological examinations, patients' age and gender, we obtained the information on a pattern of injury and detailed description of an accident (the date and the time of an accident, the role of the patient in an accident). RESULTS: The traffic accidents were the cause of 19,93% maxillofacial injuries in the analyzed period of time. Most of the patients had injuries to the soft tissues of the face (22,21%), followed by tooth and alveolar process injuries (20,71%) and mandibular fractures (18,69%). All the types of injuries were more common in men than in women. The majority of the patients were car drivers followed by car passengers, pedestrians, cyclists and motor cyclists. The peak age of the patients was between 18 to 25 years. The prevalent number of accidents resulting in injuries to this region took place in spring, especially between noon and 4 PM. CONCLUSION: Our results exhibit that road traffic accidents remain among the main reasons of maxillofacial injuries following the traumas resulting from assaults and interpersonal violence. This succession of etiologic factors is in accordance with the data from the most developed countries. The relatively high incidence of injuries resulting from traffic accidents indicates the necessity to reinforce legislation aimed to prevent road traffic crashes and thus to reduce maxillofacial injuries among children and adults

    Composite Materials Infiltrated by Aluminium Alloys Based on Porous Skeletons from Alumina, Mullite and Titanium Produced by Powder Metallurgy Techniques

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    The infiltration technology with reinforcement in the form of porous skeletons fabricated with powder metallurgy methods has been presented in relation to the general characteristics of metal alloy matrix composite materials. The results of our own investigations are presented pertaining to four alternative technologies of fabrication of porous, sintered skeletons, and their structure and their key technological properties are presented. Porous skeletons made of Al2O3 aluminium are sintered reactively using blowing agents or are manufactured by ceramic injection moulding (CIM) from powder. Porous skeletons made of 3Al2O3⋅2SiO2 mullite are achieved by sintering a mixture of halloysite nanotubes together with agents forming an open structure of pores. Titanium porous skeletons are achieved by selective laser sintering (SLS). The structure and properties of composite materials with an aluminium alloy matrix—mainly EN AC-AlSi12 and also EN AC-AlSi7Mg0.3 alloys—reinforced with the so manufactured skeletons are also described. A unique structure of the achieved composite materials, together with good mechanical properties and abrasive wear resistance at low density, ensured by an aluminium alloy matrix, are indicating broad application possibilities of such composites

    Do guidelines influence breathlessness management in advanced lung diseases? A multinational survey of respiratory medicine and palliative care physicians

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    Background: Respiratory medicine (RM) and palliative care (PC) physicians’ management of chronic breathlessness in advanced chronic obstructive pulmonary disease (COPD), fibrotic interstitial lung disease (fILD) and lung cancer (LC), and the influence of practice guidelines was explored via an online survey. Methods: A voluntary, online survey was distributed to RM and PC physicians via society newsletter mailing lists. Results: 450 evaluable questionnaires (348 (77%) RM and 102 (23%) PC) were analysed. Significantly more PC physicians indicated routine use (often/always) of opioids across conditions (COPD: 92% vs. 39%, fILD: 83% vs. 36%, LC: 95% vs. 76%; all p < 0.001) and significantly more PC physicians indicated routine use of benzodiazepines for COPD (33% vs. 10%) and fILD (25% vs. 12%) (both p < 0.001). Significantly more RM physicians reported routine use of a breathlessness score (62% vs. 13%, p < 0.001) and prioritised exercise training/rehabilitation for COPD (49% vs. 7%) and fILD (30% vs. 18%) (both p < 0.001). Overall, 40% of all respondents reported reading non-cancer palliative care guidelines (either carefully or looked at them briefly). Respondents who reported reading these guidelines were more likely to: routinely use a breathlessness score (χ2 = 13.8; p < 0.001), use opioids (χ2 = 12.58, p < 0.001) and refer to pulmonary rehabilitation (χ2 = 6.41, p = 0.011) in COPD; use antidepressants (χ2 = 6.25; p = 0.044) and refer to PC (χ2 = 5.83; p = 0.016) in fILD; and use a handheld fan in COPD (χ2 = 8.75, p = 0.003), fILD (χ2 = 4.85, p = 0.028) and LC (χ2 = 5.63; p = 0.018). Conclusions: These findings suggest a need for improved dissemination and uptake of jointly developed breathlessness management guidelines in order to encourage appropriate use of existing, evidence-based therapies. The lack of opioid use by RM, and continued benzodiazepine use in PC, suggest that a wider range of acceptable therapies need to be developed and trialled
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