141 research outputs found

    Energy preserving methods for volterra lattice equation

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    We investigate linear energy preserving methods for the Volterra lattice equation as non-canonical Hamiltonian system. The averaged vector field method was applied to the Volterra lattice equation in bi-Hamiltonian form with quadratic and cubic Poisson brackets. Numerical results confirm the excellent long time preservation of the Hamiltonians and the polynomial integrals.Publisher's Versio

    Antimicrobial activity of leaf extracts of Bituminaria sp. genotypes at different growth stages

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    302-309Plants have secondary metabolites that play a role in defense mechanism are known to have effects on microorganisms. These metabolites and their amounts vary depending upon various factors. Here, we studied the antimicrobial effect of secondary metabolites of Bituminaria sp. genotypes and explored whether this effect changes with different growing stages of the plant. The results show that extracts obtained from 12 B. bituminosa genotypes were not significantly effective on Gram-negative bacteria but highly effective on Gram-positive bacteria and eukaryotic yeast. Of these genotypes, 9 and 12 genotype were more effective than the rest. Observations suggest that the extracts from the plants are more effective during the beginning of flowering stage than the growth and budding stages for the bacteria studied. It could be due to the differences in the nature of the metabolites and their quantity

    Antimicrobial activity of leaf extracts of Bituminaria sp. genotypes at different growth stages

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    Plants have secondary metabolites that play a role in defense mechanism are known to have effects on microorganisms. These metabolites and their amounts vary depending upon various factors. Here, we studied the antimicrobial effect of secondary metabolites of Bituminaria sp. genotypes and explored whether this effect changes with different growing stages of the plant. The results show that extracts obtained from 12 B. bituminosa genotypes were not significantly effective on Gram-negative bacteria but highly effective on Gram-positive bacteria and eukaryotic yeast. Of these genotypes, 9 and 12 genotype were more effective than the rest. Observations suggest that the extracts from the plants are more effective during the beginning of flowering stage than the growth and budding stages for the bacteria studied. It could be due to the differences in the nature of the metabolites and their quantity

    COVID-19 infection, vaccine status, and avoidance behaviors in adults with attention deficit and hyperactivity disorder: A cross-sectional study

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    Objective: We aim to examine infection risk and vaccine status of COVID-19 in attention deficit and hyperactivity disorder and evaluate the impact of demographic, clinical, and COVID-19-related factors on the infection status and behavioral avoidance of COVID-19. Methods: This cross-sectional study assessed adults with attention deficit and hyperactivity disorder recruited from an outpatient psychiatry clinic. Patients and healthy controls completed a survey on sociodemographic data, COVID-19 infection status, and vaccine status. COVID-19 Disease Perception Scale, COVID-19 Avoidance Attitudes Scale, Attitudes toward COVID-19 Vaccine Scale, Adult Attention Deficit and Hyperactivity Disorder Self-report Screening Scale for DSM-5, Adult Attention Deficit and Hyperactivity Disorder Self-Report Scale Symptoms Checklist, Patient Health Questionnaire-9, and State-Trait Anxiety Inventory were applied. Results: Ninety patients and 40 healthy controls participated. Patients did not differ from controls in COVID-19 infection and vaccine status, and behavioral avoidance of COVID-19. No demographic and clinical factor significantly affected the COVID-19 infection status. Patients scored higher than controls in the perception of COVID-19 as contagious (p = 0.038), cognitive avoidance of COVID-19 (p = 0.008), and positive attitudes toward the COVID-19 vaccine (p = 0.024). After adjustment of possible factors, a positive perception of the COVID-19 vaccine and a perception of COVID-19 as dangerous were the two factors significantly affecting behavioral avoidance of COVID-19 [R2 = 0. 17, F(2) = 13.189, p < 0.0001]. Conclusion: Infection and vaccine status of COVID-19 in patients did not significantly differ from controls. No demographic and clinical factor significantly affected the COVID-19 infection status. Approximately four-fifths of the patients were fully vaccinated as recommended by national and global health organizations. This has increased the knowledge base showing that the COVID-19 vaccine is acceptable and receiving the vaccine is endorsed by ADHD patients. Attention deficit and hyperactivity disorder itself may provoke no kind of mental disturbance in sense of perception of the danger of this disease. Our findings have increased the knowledge base showing that the COVID-19 vaccine is acceptable and the actual practice of receiving the vaccine is endorsed in this population. Our message for practice would be to take into account not only the core symptoms and the comorbidities of the disorder but also the perception of the disease while exploring its link with COVID-19

    THE EVALUATION OF ETIOLOGICAL FACTORS IN URTICARIA

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    Amaç: Urtikarya sık görülen, tanısı kolay konulabilen ancak oldukça değişken etyolojik faktörlerin saptanmasının zor olduğu bir dermatozdur. Bu çalışmada kliniğimizde urtikarya tanısıyla izlenmiş olan hastalarda saptanan etyolojik faktörlerin değerlendirilmesi amaçlanmıştır. Gereç ve yöntem: Bu retrospektif çalışmada 2000-2007 yılları arasında Dokuz Eylül Üniversitesi Tıp Fakültesi Dermatoloji Kliniği'nde yatarak tedavi gören urtikarya tanısı almış 127 olguda saptanan etyolojik etmenler araştırılmıştır. Bulgular: Ayrıntılı anamnez ve etyolojiye yönelik yapılan tetkikler sonucunda özellikle gıdalar, ilaçlar ve infeksiyonlar olmak üzere 92 (%72,4) hastada en az 1 veya daha fazla olası tetikleyici etken saptanırken, 35 (%27,6) hastada tetikleyici etken saptanamamıştır. Sonuç: Çalışmada elde edilen bulgular ışığında; urtikaryalı olguların değerlendirilmesinde infeksiyonlar, ilaçlar ve gıdalar başta olmak üzere olası tetikleyici faktörlerin alınacak ayrıntılı anamnezde yer almasının önemi vurgulanmıştır. Objective: Urticaria is a common skin disease which is easily diagnosed. In contrast to the ease of its diagnosis, the underlying etiologic factors are often difficult to determine. In the present study, we aimed to evaluate the etiologic factors in patients with urticaria who were followed-up by our clinic. Material and method: In this retrospective study; 127 in-patients with urticaria who were followed up in Dokuz Eylül University Medical School Department of Dermatology between the years 2000-2007 were re-evaluated to outline the established etiologic factors. Results: Detailed anamnesis and laboratory investigations revealed at least one etiological factor in 92 (72.4%) patients, especially foods, drugs and infections. On the other hand 35 (27.6%) patients had no associating triggering factors. Conclusion: In this study, the importance of a detailed history regarding triggering factors such as infections, drugs and foods in the evaluation of patients with urticaria was emphasized

    Assessing the microcirculation with handheld vital microscopy in critically ill neonates and children: Evolution of the technique and its potential for critical care

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    Assuring adequate tissue oxygenation in the critically ill, but still developing child is challenging. Conventional hemodynamic monitoring techniques fall short in assessing tissue oxygenation as these are directed at the macrocirculation and indirect surrogates of tissue oxygenation. The introduction of handheld vital microscopy (HVM) has allowed for the direct visualization of the microcirculation and with this has offered insight into tissue oxygenation on a microcirculatory level. Since its introduction, technical improvements have been made to HVM, to both hardware and software, and guidelines have been developed through expert consensus on image assessment and analysis. Using HVM, the microcirculation of the skin, the buccal mucosa, and the sublingual mucosa of healthy and (critically) ill neonates and children have been visualized and investigated. Yet, integration of HVM in hemodynamic monitoring has been limited due to technical shortcomings. Only superficial microcirculatory beds can be visualized, inter-observer and intra-observer variabilities are not accounted for and image analysis happens offline and is semi-automated and time-consuming. More importantly, patients need to be cooperative or fully sedated to prevent pressure and movement artifacts, which is often not the case in children. Despite these shortcomings, observational research with HVM in neonates and children has revealed the following: (1) age-related developmental changes in the microcirculation, (2) loss of hemodynamic coherence, i.e., microcirculatory disturbances in the presence of a normal macrocirculation and, (3) microcirculatory disturbances which were independently associated with increased mortality risk. Although these observations underline the importance of microcirculatory monitoring, several steps have to be taken before integration in the decision process during critical care can happen. These steps include technological innovations to ease the use of HVM in the pediatric age group, measuring additional functional parameters of microvascular blood flow and integrated automated analysis software. As a next step, reference values for microcirculatory parameters need to be established, while also accounting for developmental changes. Finally, studies on microcirculatory guided therapies are necessary to assess whether the integration of microcirculatory monitoring will actually improve patient outcome. Nevertheless, HVM remains a promising, noninvasive tool to help physicians assure tissue oxygenation in the critically ill child

    Microcirculatory Monitoring in Children with Congenital Heart Disease Before and After Cardiac Surgery

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    In this prospective observational study, we investigated whether congenital heart disease (CHD) affects the microcirculation and whether the microcirculation is altered following cardiac surgery with cardiopulmonary bypass (CPB). Thirty-eight children with CHD undergoing cardiac surgery with CPB and 35 children undergoing elective, non-cardiac surgery were included. Repeated non-invasive sublingual microcirculatory measurements were performed with handheld vital microscopy. Before surgery, children with CHD showed similar perfused vessel densities and red blood cell velocities (RBCv) but less perfused vessels (p < 0.001), lower perfusion quality (p < 0.001), and higher small vessel densities (p = 0.039) than children without CHD. After cardiac surgery, perfused vessel densities and perfusion quality of small vessels declined (p = 0.025 and p = 0.032), while RBCv increased (p = 0.032). We demonstrated that CHD was associated with decreased microcirculatory perfusion and increased capillary recruitment. The microcirculation was further impaired after cardiac surgery. Decreased microcirculatory perfusion could be a warning sign for altered tissue oxygenation and requires further exploration

    Microcirculatory Monitoring in Children with Congenital Heart Disease Before and After Cardiac Surgery

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    In this prospective observational study, we investigated whether congenital heart disease (CHD) affects the microcirculation and whether the microcirculation is altered following cardiac surgery with cardiopulmonary bypass (CPB). Thirty-eight children with CHD undergoing cardiac surgery with CPB and 35 children undergoing elective, non-cardiac surgery were included. Repeated non-invasive sublingual microcirculatory measurements were performed with handheld vital microscopy. Before surgery, children with CHD showed similar perfused vessel densities and red blood cell velocities (RBCv) but less perfused vessels (p &lt; 0.001), lower perfusion quality (p &lt; 0.001), and higher small vessel densities (p = 0.039) than children without CHD. After cardiac surgery, perfused vessel densities and perfusion quality of small vessels declined (p = 0.025 and p = 0.032), while RBCv increased (p = 0.032). We demonstrated that CHD was associated with decreased microcirculatory perfusion and increased capillary recruitment. The microcirculation was further impaired after cardiac surgery. Decreased microcirculatory perfusion could be a warning sign for altered tissue oxygenation and requires further exploration. Graphical abstract: [Figure not available: see fulltext.].</p

    Systems-level analysis reveals multiple modulators of epithelial-mesenchymal transition and identifies DNAJB4 and CD81 as novel metastasis inducers in breast cancer

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    Epithelial-mesenchymal transition (EMT) is driven by complex signaling events that induce dramatic biochemical and morphological changes whereby epithelial cells are converted into cancer cells. However, the underlying molecular mechanisms remain elusive. Here, we used mass spectrometry based quantitative proteomics approach to systematically analyze the post-translational biochemical changes that drive differentiation of human mammary epithelial (HMLE) cells into mesenchymal. We identified 314 proteins out of more than 6,000 unique proteins and 871 phosphopeptides out of more than 7,000 unique phosphopeptides as differentially regulated. We found that phosphoproteome is more unstable and prone to changes during EMT compared with the proteome and multiple alterations at proteome level are not thoroughly represented by transcriptional data highlighting the necessity of proteome level analysis. We discovered cell state specific signaling pathways, such as Hippo, sphingolipid signaling, and unfolded protein response (UPR) by modeling the networks of regulated proteins and potential kinase-substrate groups. We identified two novel factors for EMT whose expression increased on EMT induction: DnaJ heat shock protein family (Hsp40) member B4 (DNAJB4) and cluster of differentiation 81 (CD81). Suppression of DNAJB4 or CD81 in mesenchymal breast cancer cells resulted in decreased cell migration in vitro and led to reduced primary tumor growth, extravasation, and lung metastasis in vivo. Overall, we performed the global proteomic and phosphoproteomic analyses of EMT, identified and validated new mRNA and/ or protein level modulators of EMT. This work also provides a unique platform and resource for future studies focusing on metastasis and drug resistanceTurkiye Cumhuriyeti Kalkinma Bakanlig
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