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1.
Phys Rev Lett ; 133(12): 126506, 2024 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-39373436

RESUMO

The unconventional superconductor CeRh_{2}As_{2} (critical temperature T_{c}≈0.4 K) displays an exceptionally rare magnetic-field-induced transition between two distinct superconducting (SC) phases, proposed to be states of even and odd parity of the SC order parameter, which are enabled by a locally noncentrosymmetric structure. The superconductivity is preceded by a phase transition of unknown origin at T_{0}=0.5 K. Electronic low-temperature properties of CeRh_{2}As_{2} show pronounced non-Fermi-liquid behavior, indicative of a proximity to a quantum critical point (QCP). The role of quantum fluctuations and normal state orders for the superconductivity in a system with staggered Rashba interaction is currently an open question, pertinent to explaining the occurrence of the two-phase superconductivity. In this work, using measurements of resistivity and specific heat under hydrostatic pressure, we show that the T_{0} order vanishes completely at a modest pressure of P_{0}≈0.5 GPa, revealing a QCP. In line with the quantum criticality picture, the linear temperature dependence of the resistivity at P_{0} evolves into a Fermi-liquid quadratic dependence as quantum critical fluctuations are suppressed by increasing pressure. Furthermore, the domelike behavior of T_{c} around P_{0} implies that the fluctuations of the T_{0} order are involved in the SC pairing mechanism.

2.
Sex Health ; 20(5): 475-477, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37599505

RESUMO

This study examined the impact of a pathway between a sexual assault service and a public sexual health service developed to improve rates of post-sexual assault medical follow-up. Follow-up attendances improved in the first 12months of the pathway (2014) compared with attendances in 2013 (17.8%vs 9.6%, P =0.01). Factors independently associated with attendance at follow-up were being prescribed HIV post-exposure prophylaxis and knowing the assailant. Those with physical injuries were less likely to attend. The prevalence of sexually transmissible infections in this cohort, 8% at the acute presentation and 5% at follow-up, suggests a need for alternatives to clinic-based follow-up.


Assuntos
Delitos Sexuais , Humanos , Estudos Transversais , Estudos Retrospectivos , Seguimentos , Comportamento Sexual
3.
Nature ; 497(7448): 199-204, 2013 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-23657348

RESUMO

There is strong circumstantial evidence that certain heavy, unstable atomic nuclei are 'octupole deformed', that is, distorted into a pear shape. This contrasts with the more prevalent rugby-ball shape of nuclei with reflection-symmetric, quadrupole deformations. The elusive octupole deformed nuclei are of importance for nuclear structure theory, and also in searches for physics beyond the standard model; any measurable electric-dipole moment (a signature of the latter) is expected to be amplified in such nuclei. Here we determine electric octupole transition strengths (a direct measure of octupole correlations) for short-lived isotopes of radon and radium. Coulomb excitation experiments were performed using accelerated beams of heavy, radioactive ions. Our data on (220)Rn and (224)Ra show clear evidence for stronger octupole deformation in the latter. The results enable discrimination between differing theoretical approaches to octupole correlations, and help to constrain suitable candidates for experimental studies of atomic electric-dipole moments that might reveal extensions to the standard model.

4.
Nano Lett ; 17(7): 4029-4037, 2017 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-28358214

RESUMO

We demonstrate the alignment-preserving transfer of parallel graphene nanoribbons (GNRs) onto insulating substrates. The photophysics of such samples is characterized by polarized Raman and photoluminescence (PL) spectroscopies. The Raman scattered light and the PL are polarized along the GNR axis. The Raman cross section as a function of excitation energy has distinct excitonic peaks associated with transitions between the one-dimensional parabolic subbands. We find that the PL of GNRs is intrinsically low but can be strongly enhanced by blue laser irradiation in ambient conditions or hydrogenation in ultrahigh vacuum. These functionalization routes cause the formation of sp3 defects in GNRs. We demonstrate the laser writing of luminescent patterns in GNR films for maskless lithography by the controlled generation of defects. Our findings set the stage for further exploration of the optical properties of GNRs on insulating substrates and in device geometries.

5.
Pneumologie ; 72(6): 446-457, 2018 Jun.
Artigo em Alemão | MEDLINE | ID: mdl-29466814

RESUMO

BACKGROUND: Interstitial lung diseases (ILD) encompass different heterogeneous, mainly chronic diseases of the pulmonary interstitium and/or alveoli with known and unknown reasons. The diagnostic of ILD is challenging and should be performed interdisciplinary. The medical history is of major importance and therefore, in German-speaking countries the Frankfurter Bogen (published in 1985) was utilised to scrutinise the medical history of the patient. This by now more than 30-years-old questionnaire requires a revision with regard to content and language. METHOD: Under the auspices of the clinical section of the DGP the new Interstitial Lung Disease Patient Questionnaire was developed in collaboration amongst pulmonologist, occupational medicine physicians and psychologists and supported by patient support groups. The questionnaire was finally optimised linguistically with the help of patients. RESULTS: The newly developed patient questionnaire for interstitial and rare lung diseases encompasses different domains: initial and current symptoms, medical history questions including prior drug treatments, previous pulmonary and extrapulmonary diseases, potential exposition at home, work and leisure time as well as family history and travelling. CONCLUSION: The newly developed questionnaire can facilitate the diagnosis in patients with suspicion on interstitial lung disease in clinical routine.


Assuntos
Doenças Pulmonares Intersticiais/diagnóstico , Inquéritos e Questionários , Adulto , Humanos , Pulmão
6.
J Sports Sci ; 35(3): 216-223, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26999625

RESUMO

The concept of recovery strategies includes various ways to achieve a state of well-being, prevent underrecovery syndromes from occurring and re-establish pre-performance states. A systematic application of individualised relaxation techniques is one of those. Following a counterbalanced cross-over design, 27 sport science students (age 25.22 ± 1.08 years; sports participation 8.08 ± 3.92 h/week) were randomly assigned to series of progressive muscle relaxation, systematic breathing, power nap, yoga, and a control condition. Once a week, over the course of five weeks, their repeated sprint ability was tested. Tests (6 sprints of 4 s each with 20 s breaks between them) were executed on a non-motorised treadmill twice during that day intermitted by 25 min breaks. RM-ANOVA revealed significant interaction effects between the relaxation conditions and the two sprint sessions with regard to average maximum speed over all six sprints, F(4,96) = 4.06, P = 0.004, [Formula: see text] = 0.15. Post-hoc tests indicated that after systematic breathing interventions, F(1,24) = 5.02, P = 0.033, [Formula: see text] = 0.18, participants performed significantly better compared to control sessions. As the focus of this study lied on basic mechanisms of relaxation techniques in sports, this randomised controlled trial provides us with distinct knowledge on their effects, i.e., systematic breathing led to better performances, and therefore, seems to be a suited relaxation method during high-intensity training.


Assuntos
Desempenho Atlético/fisiologia , Exercícios Respiratórios , Resistência Física , Psicofisiologia , Relaxamento/fisiologia , Corrida/fisiologia , Estresse Psicológico , Adulto , Desempenho Atlético/psicologia , Teste de Esforço , Feminino , Humanos , Masculino , Meditação , Relaxamento Muscular , Músculo Esquelético/fisiologia , Terapia de Relaxamento , Descanso , Sono , Yoga , Adulto Jovem
7.
Opt Lett ; 41(3): 452-5, 2016 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-26907395

RESUMO

High-Q silicon nitride (SiN) microresonators enable optical Kerr frequency comb generation on a photonic chip and have recently been shown to support fully coherent combs based on temporal dissipative Kerr soliton formation. For bright soliton formation, it is necessary to operate SiN waveguides in the multimode regime in order to produce waveguide induced anomalous group velocity dispersion. However, this regime can lead to local disturbances of the dispersion due to avoided crossings caused by coupling between different mode families and, therefore, prevent the soliton formation. Here, we demonstrate that a single-mode "filtering" section inside high-Q resonators enables efficiently suppression of avoided crossings, while preserving high quality factors (Q∼10(6)). We verify the approach by demonstrating single soliton formation in SiN resonators with a filtering section.

8.
Klin Monbl Augenheilkd ; 233(1): 50-3, 2016 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-26797887

RESUMO

Epicanthus is a skin fold covering the inner angle of the eyelid. This fold is typical in the Asian population. It can be observed in a great variety of degrees. In the Caucasian population, epicanthus is associated with some syndromes, such as blepharophimosis syndrome and Down's syndrome. The epicanthal fold originates from excessive tension in the skin and is caused by skin deficit and/or by bridging subcutaneous tissue. The epicanthal fold can be surgically corrected by reducing tension and fully replacing the skin defect by skin redraping or skin grafting.


Assuntos
Dacriocistorinostomia/métodos , Procedimentos Cirúrgicos Dermatológicos/métodos , Doenças do Aparelho Lacrimal/cirurgia , Aparelho Lacrimal/cirurgia , Procedimentos de Cirurgia Plástica/métodos , Transplante de Pele/métodos , Medicina Baseada em Evidências , Humanos , Resultado do Tratamento
9.
Opt Lett ; 40(20): 4723-6, 2015 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-26469604

RESUMO

We demonstrate the all-optical stabilization of a low-noise temporal soliton based microresonator based optical frequency comb in a crystalline resonator via a new technique to control the repetition rate. This is accomplished by thermally heating the microresonator with an additional probe laser coupled to an auxiliary optical resonator mode. The carrier-envelope offset frequency is controlled by stabilizing the pump laser frequency to a reference optical frequency comb. We analyze the stabilization by performing an out-of-loop comparison and measure the overlapping Allan deviation. This all-optical stabilization technique can prove useful as an actuator for self-referenced microresonator frequency combs.

10.
Phys Rev Lett ; 114(9): 091803, 2015 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-25793801

RESUMO

The Nπ^{0}π^{0} decays of positive-parity N^{*} and Δ^{*} resonances at about 2 GeV are studied at ELSA by photoproduction of two neutral pions off protons. The data reveal clear evidence for several intermediate resonances: Δ(1232), N(1520)3/2^{-}, and N(1680)5/2^{+}, with spin parities J^{P}=3/2^{+}, 3/2^{-}, and 5/2^{+}. The partial wave analysis (within the Bonn-Gatchina approach) identifies N(1440)1/2^{+} and the N(ππ)_{S wave} (abbreviated as Nσ here) as further isobars and assigns the final states to the formation of nucleon and Δ resonances and to nonresonant contributions. We observe the known Δ(1232)π decays of Δ(1910)1/2^{+}, Δ(1920)3/2^{+}, Δ(1905)5/2^{+}, Δ(1950)7/2^{+}, and of the corresponding spin-parity series in the nucleon sector, N(1880)1/2^{+}, N(1900)3/2^{+}, N(2000)5/2^{+}, and N(1990)7/2^{+}. For the nucleon resonances, these decay modes are reported here for the first time. Further new decay modes proceed via N(1440)1/2^{+}π, N(1520)3/2^{-}π, N(1680)5/2^{+}π, and Nσ. The latter decay modes are observed in the decay of N^{*} resonances and at most weakly in Δ^{*} decays. It is argued that these decay modes provide evidence for a 3-quark nature of N^{*} resonances rather than a quark-diquark structure.

11.
Int J Sports Med ; 36(7): 554-62, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25760153

RESUMO

This study compared traditional (TP) and daily undulating (DUP) periodization on muscle strength, EMG-estimated neural drive and muscle architecture of the quadriceps femoris (QF). 10 non-athletic females (24.4±3.2 years) performed 14 weeks of isometric training for the QF exercising 1 leg using TP and the contralateral leg using DUP. Intensities varied from 60% to 80% of MVC and the intensity zones and training volume were equated for each leg. Knee extension MVC, maximal voluntary QF-EMG activity and vastus lateralis (VL) muscle architecture were measured in both legs before, after 6 weeks and after 14 weeks of training using dynamometry, surface EMG and ultrasonography. Isometric MVC and maximal QF-EMG remained unaltered after 6 weeks of training, but were significantly (P<0.05) enhanced after 14 weeks in both legs (MVC: TP 24%, DUP 23%; QF-EMG: TP 45%, DUP 46%). VL-architecture remained unchanged following 6 weeks of training, but VL-muscle thickness (TP 17%, DUP 16%) and fascicle length (TP 16%, DUP 17%) displayed significant (P<0.05) enlargements after 14 weeks in both legs. Importantly, these temporal neuromuscular alterations displayed no significant differences between the training legs. Therefore, periodization may not act as a key trigger for neuromuscular adaptations.


Assuntos
Força Muscular/fisiologia , Músculo Quadríceps/fisiologia , Treinamento Resistido/métodos , Adulto , Eletromiografia , Feminino , Humanos , Contração Isométrica/fisiologia , Articulação do Joelho/fisiologia , Dinamômetro de Força Muscular , Adulto Jovem
12.
Anaesthesist ; 64(11): 814-27, 2015 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-26530399

RESUMO

Although anesthesia-associated mortality has been significantly reduced down to 0.00068-0.00082% over the last decades, recent studies have revealed a high perioperative mortality of 0.8- 4%. Apart from anesthesia and surgery-induced major complications, perioperative mortality is primarily negatively influenced by individual patient comorbidities. These risk factors predispose for acute critical incidents (e.g., myocardial infarction); however, the majority of fatal complications are a result of slowly progressing conditions, particularly infections or the sequelae of systemic inflammation. This implicates a broad window of opportunity for the detection and treatment of slow-onset complications to improve the perioperative outcome. The term "failure to rescue" (FTR), i.e., the proportion of patients who die from major complications compared to the number of all patients with complications, has been introduced as a valid indicator for the quality of perioperative care. Growing evidence has already shown that FTR is an underestimated factor in perioperative medicine accounting for or at least being involved in the development of postoperative mortality. While the incidence of severe postoperative complications amazingly does not show much variation between hospitals, FTR shows significant differences implying a major potential for improvement. With 14 million surgical procedures per year in Germany, a postoperative mortality of approximately 1% and an avoidable FTR rate of 40% mean that there are an estimated 60,000 preventable deaths per year. Hence, in the future it will be imperative to (1) identify patients at risk, (2) to prevent the development of postoperative complications with the use of adequate adjunctive therapeutic strategies, (3) to establish surveillance and monitoring systems for the early detection of postoperative complications and (4) to treat postoperative complications efficiently and in time when they arise.


Assuntos
Período Perioperatório/mortalidade , Procedimentos Cirúrgicos Operatórios/mortalidade , Anestesia/efeitos adversos , Anestesia/mortalidade , Alemanha , Humanos , Incidência , Risco , Fatores de Risco
14.
Eur Spine J ; 23(4): 762-71, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24549393

RESUMO

INTRODUCTION: A number of concepts with controversy approaches are currently discussed for interspinous stabilization (IPS). However, comparative biomechanical studies among the different systems are rare. Nevertheless, it remains unclear which biomechanical characteristics are influenced by different design features of these implants, such as implant stiffness or an additional tension band. Therefore, the aim of the present study was to compare different interspinous implants to investigate the biomechanical impact of IPS implant design on intersegmental kinematics, such as range of motion, neutral zone, center of rotation (COR), as well as load transfer like intradiscal pressure (IDP), to gain additional experience for clinical indications and limitations. MATERIAL AND METHOD: Twelve human lumbar spine specimens were tested in a spine loading apparatus. In vitro flexibility testing was performed by applying pure bending moments of 7.5 Nm without and with additional preload of 400 N in the three principal motion planes. Four interspinous implants, Coflex "COF" (Paradigm Spine, Germany), Wallis "WAL" (Abbott Laboratories, France), DIAM "DIA" (Sofamor Danek, France) and InterActiv (Aesculap AG, Germany) with two treatment options (without dorsal tensioning "IAO" and with dorsal tensioning "IAM") were consecutively tested in comparison to the native situation "NAT" and to a defect situation "DEF" of the functional spinal unit. The tested IPS devices are comprised of a compression stiffness range of 133 to 1,674 N/mm and a tensile stiffness range of 0-39 N/mm. Range of motion, neutral zone, center of rotation and intradiscal pressure were analyzed for all instrumentation steps and load cases. CONCLUSION: For the IPS, we found a correlation between compression stiffness and stabilization in extension. Here, the system with the lowest stiffness, DIA, displayed nearly no stabilization of the treated segment, whereas the system with the highest stiffness, WAL and COF, was most pronounced. This applies also for the correlation between device stiffness and IDP. In flexion only the degree of stabilization is in correlation with the tensile stiffness, whereas the IDP stays constant and is not affected by the different tensile stiffness. IPS is not able to stabilize in the frontal and transversal plane. Furthermore IPS does not substantially alter the location of the COR.


Assuntos
Vértebras Lombares/cirurgia , Procedimentos Ortopédicos/instrumentação , Próteses e Implantes , Desenho de Prótese , Idoso , Fenômenos Biomecânicos , Humanos , Vértebras Lombares/fisiologia , Pessoa de Meia-Idade , Maleabilidade , Amplitude de Movimento Articular , Suporte de Carga
15.
Klin Monbl Augenheilkd ; 231(1): 36-41, 2014 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-24443133

RESUMO

The well introduced surgical techniques of lower lid blepharoplasty can only repair aesthetic problems between the lid margin and the orbital rim. The neighbouring malar area is located outside the orbit and requires specialised procedures to reposition the sunken malar orbicularis muscle (festoon) and the malar fat pad. A small incision at the lateral canthus provides the access to combine three procedures: transconjunctival lower lid blepharoplasty, lateral canthoplasty and malar lift.


Assuntos
Blefaroplastia/métodos , Pálpebras/anormalidades , Pálpebras/cirurgia , Procedimentos de Cirurgia Plástica/métodos , Anormalidades da Pele/cirurgia , Terapia Combinada , Humanos , Masculino , Resultado do Tratamento
16.
Front Hum Neurosci ; 18: 1371631, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38957693

RESUMO

Brain-computer interfaces (BCIs) are scientifically well established, but they rarely arrive in the daily lives of potential end-users. This could be in part because electroencephalography (EEG), a prevalent method to acquire brain activity for BCI operation, is considered too impractical to be applied in daily life of end-users with physical impairment as an assistive device. Hence, miniaturized EEG systems such as the cEEGrid have been developed. While they promise to be a step toward bridging the gap between BCI development, lab demonstrations, and home use, they still require further validation. Encouragingly, the cEEGrid has already demonstrated its ability to record visually and auditorily evoked event-related potentials (ERP), which are important as input signal for many BCIs. With this study, we aimed at evaluating the cEEGrid in the context of a BCI based on tactually evoked ERPs. To compare the cEEGrid with a conventional scalp EEG, we recorded brain activity with both systems simultaneously. Forty healthy participants were recruited to perform a P300 oddball task based on vibrotactile stimulation at four different positions. This tactile paradigm has been shown to be feasible for BCI repeatedly but has never been tested with the cEEGrid. We found distinct P300 deflections in the cEEGrid data, particularly at vertical bipolar channels. With an average of 63%, the cEEGrid classification accuracy was significantly above the chance level (25%) but significantly lower than the 81% reached with the EEG cap. Likewise, the P300 amplitude was significantly lower (cEEGrid R2-R7: 1.87 µV, Cap Cz: 3.53 µV). These results indicate that a tactile BCI using the cEEGrid could potentially be operated, albeit with lower efficiency. Additionally, participants' somatosensory sensitivity was assessed, but no correlation to the accuracy of either EEG system was shown. Our research contributes to the growing amount of literature comparing the cEEGrid to conventional EEG systems and provides first evidence that the tactile P300 can be recorded behind the ear. A BCI based on a thus simplified EEG system might be more readily accepted by potential end-users, provided the accuracy can be substantially increased, e.g., by training and improved classification.

17.
Clin Exp Immunol ; 174(1): 45-52, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23701226

RESUMO

Neonates show an impaired anti-microbial host defence, but the underlying immune mechanisms are not understood fully. Myeloid-derived suppressor cells (MDSCs) represent an innate immune cell subset characterized by their capacity to suppress T cell immunity. In this study we demonstrate that a distinct MDSC subset with a neutrophilic/granulocytic phenotype (Gr-MDSCs) is highly increased in cord blood compared to peripheral blood of children and adults. Functionally, cord blood isolated Gr-MDSCs suppressed T cell proliferation efficiently as well as T helper type 1 (Th1), Th2 and Th17 cytokine secretion. Beyond T cells, cord blood Gr-MDSCs controlled natural killer (NK) cell cytotoxicity in a cell contact-dependent manner. These studies establish neutrophilic Gr-MDSCs as a novel immunosuppressive cell subset that controls innate (NK) and adaptive (T cell) immune responses in neonates. Increased MDSC activity in cord blood might serve as key fetomaternal immunosuppressive mechanism impairing neonatal host defence. Gr-MDSCs in cord blood might therefore represent a therapeutic target in neonatal infections.


Assuntos
Imunidade Adaptativa , Linfócitos T CD8-Positivos/imunologia , Sangue Fetal/imunologia , Imunidade Inata , Células Mieloides/imunologia , Neutrófilos/imunologia , Adulto , Sangue Fetal/citologia , Humanos , Tolerância Imunológica , Lactente , Recém-Nascido
18.
Osteoporos Int ; 24(8): 2325-34, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23436077

RESUMO

UNLABELLED: Indolent systemic mastocytosis (ISM) can trigger bone loss. However, the clinical relevance of different mast cell infiltration patterns for bone remains to be clarified. Here, we report increased bone turnover in individuals with ISM, and its extent is rather related to the type of mast cell distribution within the bone marrow than to the presence or absence of cutaneous manifestations. INTRODUCTION: It is well established that ISM can trigger osteopenia or osteoporosis. However, neither the clinical relevance of the infiltration pattern of mast cells within the bone marrow nor the impact of the presence or absence of cutaneous mast cell infiltration has been elucidated. METHODS: We retrospectively analysed 300 cases with histologically proven ISM of the bone marrow and performed quantitative histomorphometry for a subgroup of 159 patients that did not receive any treatment before the biopsies were taken. Most importantly, since 66 % of the patients displayed ISM without the characteristic skin lesions, we were able to compare ISM with or without cutaneous manifestation. RESULTS: We found that both forms of ISM were not only characterized by a decreased trabecular bone mass but also by an increased number of osteoclasts and osteoblasts. Interestingly, when we analysed these data in relation to mast cell distribution, we found that the bone cell numbers in cases with mast cell granulomas were significantly increased compared to cases with diffuse mast cell distribution. Moreover, evidence of increased bone turnover was also found in 16 patients displaying osteosclerosis. CONCLUSION: Based on the largest cohort of bone biopsies from patients with ISM analysed so far, we could demonstrate high bone turnover, more specifically increased osteoblast and osteoclast numbers and surface indices, as a cause of the skeletal changes. Moreover, the severity of the bone disease is presumably rather dependent on the amount of mast cells and their distribution within the bone marrow irrespective of the presence or absence of cutaneous involvement.


Assuntos
Mastocitose Sistêmica/patologia , Osteoblastos/patologia , Osteoclastos/patologia , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Biópsia , Células da Medula Óssea/patologia , Remodelação Óssea/fisiologia , Contagem de Células , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Mastócitos/patologia , Mastocitose Sistêmica/epidemiologia , Mastocitose Sistêmica/fisiopatologia , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Distribuição por Sexo
19.
Klin Monbl Augenheilkd ; 230(1): 36-42, 2013 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-23345148

RESUMO

Congenital nevi are very rare. Acquired nevi belong to the most common group of skin tumours. Eyelid nevi occur frequently in a great variety. They are treated for cosmetic reasons or due to the risk of malignant transformation. This contribution explains the differential diagnosis of various types of nevus and the surgical techniques of resection and plastic reconstruction.


Assuntos
Neoplasias Palpebrais/patologia , Neoplasias Palpebrais/cirurgia , Pálpebras/cirurgia , Nevo/patologia , Nevo/cirurgia , Procedimentos Cirúrgicos Oftalmológicos/métodos , Procedimentos de Cirurgia Plástica/métodos , Diagnóstico Diferencial , Pálpebras/lesões , Humanos
20.
Ophthalmologie ; 120(1): 36-42, 2023 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-35925343

RESUMO

BACKGROUND: Immune reaction (IR) after penetrating keratoplasty (PKP) is a serious complication with a high risk of graft failure. The aim of this study was to analyze and evaluate the risk factors for IR, in particular, the influence of graft size and centration. PATIENTS AND METHODS: A total of 2133 patients who underwent PKP between January 2009 and July 2019 were included in this retrospective study. The following endpoints were analyzed: frequency of IR, graft origin, donor and patient age, diagnosis, corneal diameter and ratio of the graft size to the recipient cornea size. In addition, the role of graft centration, with the help of distance measurements of the graft margins to the vascularized limbus at four locations, was investigated in detail. RESULTS: Overall, 8.25% of patients suffered from IR during the observational period. The frequency of IR was significantly correlated (p < 0.001) with the ratio of the graft size to the recipient cornea size. In addition, a statistically significant correlation was found between the occurrence of IR and a small distance to the limbal margins in the Y­axis (inferior and superior). In particular, the correlation coefficient was larger at the inferior limbus (p < 0.001). CONCLUSION: An IR after PKP is a not uncommon complication and is significantly related to graft size and centration. A large graft chosen in relation to the recipient cornea and the proximity of the graft to the vascularized limbus at the inferior and superior sites significantly correlate with the occurrence of IR. These are important risk factors for graft survival, which can be influenced by the corneal microsurgeon and could possibly be further optimized in the future.


Assuntos
Córnea , Ceratoplastia Penetrante , Humanos , Ceratoplastia Penetrante/efeitos adversos , Estudos Retrospectivos , Córnea/cirurgia , Fatores de Risco
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