Mechanically-Induced Transport Switching Effect in Graphene-based Nanojunctions

We report a theoretical study suggesting a novel type of electronic switching effect, driven by the geometrical reconstruction of nanoscale graphene-based junctions. We considered junction struc- tures which have alternative metastable configurations transformed by rotations of local carbon dimers. The use of external mechanical strain allows a control of the energy barrier heights of the potential profiles and also changes the reaction character from endothermic to exothermic or vice-versa. The reshaping of the atomic details of the junction encode binary electronic ON or OFF states, with ON/OFF transmission ratio that can reach up to 10^4-10^5. Our results suggest the possibility to design modern logical switching devices or mechanophore sensors, monitored by mechanical strain and structural rearrangements.Comment: 10 pages, 4 figure

Investors' deductions and allowances in film funds : German and South African income tax laws compared

Includes bibliographical references (leaves 138-139).By comparing the income tax allowances and deductions for private investors in film production funds in Germany and in South Africa, the author aims to show how the governments of these two countries are taxing private individuals who invest in film funds, i.e. what incentives are offered to such venturesome investors. The tax incentives examined here provide the taxpayer with a deferment of his tax payments. By making the comparison the author intends examine what role a domestic film fund can play as an instrument for financing domestic and export films and how the government can promote film production in this way

Nanoscale ear drum: Graphene based nanoscale sensors

The difficulty in determining the mass of a sample increases as its size diminishes. At the nanoscale, there are no direct methods for resolving the mass of single molecules or nanoparticles and so more sophisticated approaches based on electromechanical phenomena are required. More importantly, one demands that such nanoelectromechanical techniques could provide not only information about the mass of the target molecules but also about their geometrical properties. In this sense, we report a theoretical study that illustrates in detail how graphene membranes can operate as nanoelectromechanical mass-sensor devices. Wide graphene sheets were exposed to different types and amounts of molecules and molecular dynamic simulations were employed to treat these doping processes statistically. We demonstrate that the mass variation effect and information about the graphene-molecule interactions can be inferred through dynamical response functions. Our results confirm the potential use of graphene as mass detector devices with remarkable precision in estimating variations in mass at molecular scale and other physical properties of the dopants

Different origins of hydrocephalus lead to different shunt revision rates

Introduction Hydrocephalus (HC) occurs due to multiple origins. Time course and dynamic of HC and its therapies differ between underlying pathologies. Different revision rates due to the type of HC are expected. Though hydrocephalus is known to be a life time condition, the lack of shunt malfunction years or decades after initial shunt insertion raises the hope of a superfluous shunt. Methods We conducted a retrospective survey of our OR-database during a 10 year period. All newly inserted shunt systems and subsequent shunt revisions are recorded according to quantity and time point. All patients were subdivided according their aetiology of HC. Results 260 patients were eligible with a follow-up of 4.5 years. Subgroups were: 90 patients with NPH, 76 patients with posthaemorrhagic and 16 patients had posttraumatic HC. 22 received a shunt as a consequence of a tumour, 41 were children and 15 for other causes. Overall revision rate was 39.5%. During the first 6 months 55.6%, 57.9% and 75% of patients with NPH, posthaemorrhagic and posttraumatic HC had revisions. In contrast only 38.1% of children and 20% of tumour cases required early revision. Conclusion Two different patterns of revision are evident: mainly early revisions in morphologically stable diseases such as posthaemorrhagic, posttraumatic and NPH and predominantly late revisions in changing organisms such as children and tumour patients. The conception HC may be transient because of a lack of late revisions cannot be supported by this data

Die Verwerthung der Gesichtsfeldprüfung für die Diagnostik und Prognostik der Amblyopien

http://tartu.ester.ee/record=b2019024~S1*es

Objective evaluation of an occlusive overnight intensive patch containing onion extract and allantoin for hypertrophic scars

Background Patients suffering from hypertrophic scars often describe esthetic, functional, and psychological impairments. While current guidelines for the treatment of pathologic scarring recommend the use of onion extract containing gels and sheets, hard evidence for its efficacy remains scarce due to inconsistent data. Onion extract and allantoin containing occlusive overnight intensive patches (OIP) were introduced as a recent option for noninvasive scar management. However, objective data demonstrating their efficacy are missing. Aims This study is the first to objectively evaluate the benefit and safety of an OIP for hypertrophic scars using a three‐dimensional imaging device and a standardized scar scale. Methods Twelve patients with untreated, three to twelve months old hypertrophic scars received an OIP for 3 months. The assessment was performed using PRIMOS®pico, a three‐dimensional imaging device and POSAS, a standardized scar questionnaire at baseline, one and 3 months after the last treatment. Results Objective evaluation at three months follow‐up (FU) showed a significant decrease in scar height of 28.8% (baseline mean: 2.08 ± 0.68 mm, three months FU mean: 1.48 ± 0.52 mm) and a reduction in scar volume of 31.9% (baseline mean: 454.33 ± 265.53 mm3, 3 months FU mean: 309.58 ± 224.28 mm3). Pain and pruritus subsided under treatment. There were no negative side effects. Conclusion Overnight intensive patches is a convenient, painless, safe, affordable and effective prevention and treatment option for hypertrophic scars. Treatment should be performed at least for 3 months for visible effects

Treatment of keloids using 5‐fluorouracil in combination with crystalline triamcinolone acetonide suspension: evaluating therapeutic effects by using non‐invasive objective measures

Background Intralesional 5‐fluorouracil (5‐FU) in combination with triamcinolone acetonide (TAC) has been recommended as a promising alternative for keloids not responding to silicone‐based products, cryotherapy or intralesional corticosteroids alone. Although numerous studies support the efficacy of this regime, there is a lack of objective data. Objectives In this study, we evaluate the therapeutic effect of four courses of intralesional 5‐FU in combination with TAC (3 : 1) utilizing 3D analysis (PRIMOS®pico), ultrasound and scar scales such as the Patient and Observer Scar Assessment Scales (POSAS) and the Dermatology Life Quality Index (DLQI). Methods Twenty‐five patients with keloids were treated using 5‐FU and TAC every 4 weeks. Objective assessments were performed and the scar scales administered at baseline, as well as during consecutive visits at 1‐ and 12‐month follow‐up (FU). Routine laboratory tests were performed at baseline and at 1‐month FU. Results 3D PRIMOS and ultrasound measurements revealed highly significant and stable reductions in height (baseline mean score: 4.0 ± 1.7 mm, 1‐month FU mean score: 1.5 ± 0.8 mm, 12‐month FU mean score: 1.8 ± 0.9 mm, P = <0.0001), volume (baseline mean score: 1,105 ± 911.5 mm3, 1‐month FU mean score: 416.1 ± 218.1 mm3, 12‐month FU mean sore: 431.2 ± 253.6 mm3, P = <0.0001, respectively) and penetration depth of keloids (relative reduction between baseline and 12‐month FU of 74.4%, P = <0.0001). The POSAS and DLQI scales confirmed significant objective and subjective improvements in scar appearance in all categories. The life quality associated with keloid appearance improved from a ‘moderate effect’ to a ‘small effect’ throughout the course of the study. Conclusions Results of this study confirm the efficacy and safety of the combination of 5‐FU and TAC in keloids. Treatments were well tolerated and demonstrated stable results at 12‐month FU

Cross-Linking the TCR Complex Induces Apoptosis in CD4+8+ Thymocytes in the Presence of Cyclosporin A

Although it is generally agreed that TCR ligation is a minimal requirement for negative selection in the CD+8+ double-positive (DP) thymocyte subset, the costimulatory requirements and specific signaling events necessary to induce apoptosis are not well defined. We have explored the consequences of cross-linking CD3/TCR complexes on thymocytes from H-Y TCR transgenic (Tg) mice. In agreement with previous reports, we demonstrate that culturing DP thymocytes with plate-bound anti-TCR antibody induces downregulation of CD4 and CD8 and upregulation of CD69 expression. Nevertheless, the activated cells did not undergo apoptosis, as determined by viable cell recoveries and by quantitation of DNA fragmentation using the TUNEL assay. However, specific depletion of the DP subset occurred within 24 hr when thymocytes were incubated in the presence of both anti-TCR and the immunosuppressant cyclosporin A (CsA). CsA also induced depletion of anti-CD3 stimulated normal DP thymocytes. Using mice homozygous for the lpr or gld mutation, we also have shown that Fas/Fas ligand interactions are not involved in the CsA-induced death of TCR-stimulated DP thymocytes. These data verify that TCR cross-linking alone is insufficient to induce apoptosis of DP thymocytes and further suggest that TCR stimulation activates a CsA-sensitive protective pathway that interferes with signaling events leading to apoptosis in DP thymocytes

Modeling graphene-based nanoelectromechanical devices

We report on a theoretical study of charge transport properties of graphene nanoribbons under external mechanical stress. The influence of mechanical forces on the ribbon conductance is shown to be strongly dependent on the ribbon edge symmetry, i.e., zigzag versus armchair. In contrast to zigzag-edge nanoribbons which remain robust against high strain deformations, a stretching-induced metal-semiconductor transition is obtained for armchair-edge configurations. Our results point out that armchair edge ribbons are consequently much better suited for electromechanical applications.Fil: Poetschke, M.. Technische Universität Dresden; AlemaniaFil: Rocha, C. G.. Technische Universität Dresden; AlemaniaFil: Foa Torres, Luis Eduardo Francisco. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Roche, Serge. Technische Universität Dresden; Alemania. Universite Grenoble Alpes. Institut Nanosciences et Cryogenie - Commissariat a L´Energie Atomique et Aux Energies Alternatives. Institut Nanosciences et Cryogenie; Francia. Centro de Investigación en Nanociencia y Nanotecnología (CIN2); EspañaFil: Cuniberti, G.. Technische Universität Dresden; Alemani