Quasi-free-standing epitaxial graphene is obtained on SiC(0001) by hydrogen intercalation. The hydrogen moves between the (6 square root(3) x 6 square root(3))R30 degrees reconstructed initial carbon ...layer and the SiC substrate. The topmost Si atoms which for epitaxial graphene are covalently bound to this buffer layer, are now saturated by hydrogen bonds. The buffer layer is turned into a quasi-free-standing graphene monolayer with its typical linear pi bands. Similarly, epitaxial monolayer graphene turns into a decoupled bilayer. The intercalation is stable in air and can be reversed by annealing to around 900 degrees C.
To evaluate the breast cancer screening efficacy of mammography, ultrasound, and magnetic resonance imaging (MRI) in a high-risk population and in various population subgroups.
In a single-center, ...prospective, nonrandomized comparison study, BRCA mutation carriers and women with a high familial risk (> 20% lifetime risk) for breast cancer were offered screening with mammography, ultrasound, and MRI every 12 months. Diagnostic performance was compared between individual modalities and their combinations. Further comparisons were based on subpopulations dichotomized by screening rounds, mutation status, age, and breast density.
There were 559 women with 1,365 complete imaging rounds included in this study. The sensitivity of MRI (90.0%) was significantly higher (P < .001) than that of mammography (37.5%) and ultrasound (37.5%). Of 40 cancers, 18 (45.0%) were detected by MRI alone. Two cancers were found by mammography alone (a ductal carcinoma in situ DCIS with microinvasion and a DCIS with < 10-mm invasive areas). This did not lead to a significant increase of sensitivity compared with using MRI alone (P = .15). No cancers were detected by ultrasound alone. Similarly, of 14 DCISs, all were detected by MRI, whereas mammography and ultrasound each detected five DCISs (35.7%). Age, mutation status, and breast density had no influence on the sensitivity of MRI and did not affect the superiority of MRI over mammography and ultrasound.
MRI allows early detection of familial breast cancer regardless of patient age, breast density, or risk status. The added value of mammography is limited, and there is no added value of ultrasound in women undergoing MRI for screening.
We investigated the additional contribution of mammography to screening accuracy in BRCA1/2 mutation carriers screened with MRI at different ages using individual patient data from six high-risk ...screening trials.
Sensitivity and specificity of MRI, mammography and the combination of these tests were compared stratified for BRCA mutation and age using generalised linear mixed models with random effect for studies. Number of screens needed (NSN) for additional mammography-only detected cancer was estimated.
In BRCA1/2 mutation carriers of all ages (BRCA1 = 1,219 and BRCA2 = 732), adding mammography to MRI did not significantly increase screening sensitivity (increased by 3.9% in BRCA1 and 12.6% in BRCA2 mutation carriers, P > 0.05). However, in women with BRCA2 mutation younger than 40 years, one-third of breast cancers were detected by mammography only. Number of screens needed for mammography to detect one breast cancer not detected by MRI was much higher for BRCA1 compared with BRCA2 mutation carriers at initial and repeat screening.
Additional screening sensitivity from mammography above that from MRI is limited in BRCA1 mutation carriers, whereas mammography contributes to screening sensitivity in BRCA2 mutation carriers, especially those ⩽ 40 years. The evidence from our work highlights that a differential screening schedule by BRCA status is worth considering.
We report on the interface between graphene and 4H-SiC(0001) as investigated by scanning tunneling microscopy (STM) and low energy electron diffraction (LEED). It is characterized by the so-called ...(6{radical}(3)x6{radical}(3))R30 deg. reconstruction, whose structural properties are still controversially discussed but at the same time are crucial for the controlled growth of homogeneous high-quality large-terrace graphene surfaces. We discuss the role of three observed phases with periodicities (6{radical}(3)x6{radical}(3))R30 deg. (6x6), and (5x5). Their LEED intensity levels and spectra strongly depend on the surface preparation procedure applied. The graphitization process imprints distinct features in the STM images as well as in the LEED spectra. The latter have the potential for an easy and practicable determination of the number of graphene layers by means of LEED.
The detection of lymph node metastasis affects the management of patients with primary breast cancer significantly in terms of staging, treatment, and prognosis. The main goal for the radiologist is ...to determine and detect the presence of metastatic disease in nonpalpable axillary lymph nodes with a positive predictive value that is high enough to initially select patients for upfront axillary lymph node dissection. Features that are suggestive of axillary adenopathy may be seen with different imaging modalities, but ultrasound is the method of choice for evaluating axillary lymph nodes and for performing image‐guided lymph node interventions. This review aims to provide a comprehensive overview of the available imaging modalities for lymph node assessment in patients diagnosed with primary breast cancer.
Implications for Practice
The detection of lymph node metastasis affects the management of patients with primary breast cancer. The main goal for the radiologist is to detect lymph node metastasis in patients to allow for the selection of patients who should undergo upfront axillary lymph node dissection. Features that are suggestive of axillary adenopathy may be seen with mammography, computed tomography, and magnetic resonance imaging, but ultrasonography is the imaging modality of choice for evaluating axillary lymph nodes. A normal axillary lymph node is characterized by a reniform shape, a maximal cortical thickness of 3 mm without focal bulging, smooth margins, and, depending on size, a discernable central fatty hilum.
This review provides a comprehensive overview of the available imaging modalities for lymph node assessment in patients diagnosed with primary breast cancer.
Purpose. The aim of this study was to evaluate a micrometer-accurate analysis of the retropupillary Verisyse® intraocular lens (IOL) (Ophtec, Groningen NL; Santa Ana, USA) enclavation in the iris ...tissue. Methods. A retrospective consecutive case series was conducted at the Department of Ophthalmology, University Hospital Mainz. Patients with an optical coherence tomography (Spectralis®, Heidelberg Engineering®; Heidelberg, Germany) examination after retropupillary Verisyse® IOL implantation were included retrospectively. The enclavation geometry was measured using the Eye-Explorer® from Heidelberg Engineering® (Heidelberg, Germany). Seventeen measuring positions were determined nasally and temporally at the corresponding enclavation points. Results. 72 eyes of 67 patients after implantation of a retropupillary Verisyse® IOL were analyzed. The average age was 68 ± 17.2 years (63% female; 38% male). The analysis of the position of the Verisyse® IOL showed highly homogeneous data in all measured points. The depth of the anterior chamber showed a positive correlation with width of the posterior deflection of the iris tissue behind the enclavation (Pearson r: 0.321, p=0.041). The offset of the haptics showed greater deviations, and the lens diopter implanted was higher (r = 0.337, p=0.007). Conclusion. This is the first study that analysis the exact enclavation of retropupillary implanted Verisyse® IOL. It provides new information about the intrastromal course of the haptics in the iris tissue. It could be shown that the haptics do not run parallel in the iris tissue, but are anchored in the iris tissue with an average offset of 95 µm. This rebuts previous assumptions about the intrastromal course and provides new information.
Purpose. The Acrysof Cachet® angle-supported phakic intraocular lens (pIOL) (Alcon Laboratories, Inc., Fort Worth, TX) is designed to correct high refractive errors in human eyes. The aim of this ...study was to evaluate the outcome of AcrySof Cachet® angle-supported pIOL implantation with particular regard to efficacy and safety of the implant over a 60-month follow-up period. Design. Retrospective consecutive clinical case study. Methods. Prior to pIOL implantation, patients had a complete ophthalmologic examination including objective and subjective refraction, uncorrected visual acuity (UCVA) and corrected distance visual acuity (CDVA), endothelial cells density (ECD), slit lamp photography, optical coherence tomography (OCT), Scheimpflug digital videokeratoscopy, optical biometry, slit lamp examination, intraocular pressure (IOP) measurement, and pupillometry. Postoperatively, patients received yearly a complete eye examination. Results. Thirty-one eyes of 16 patients were included in this study. The mean age was 36.2 ± 8.1 years. UCVA (logMAR) improved from 1.33 ± 0.20 before surgery to 0.08 ± 0.14 one year after surgery and was 0.20 ± 0.20 five years after surgery. CDVA (logMAR) improved from 0.10 ± 0.10 before surgery to 0.05 ± 0.13 one year after surgery and was 0.04 ± 0.14 five years postoperatively. The mean percentage of endothelial cells loss (ECL) was 11.51% over the first year and 15.95% five years after surgery. There were no intraoperative complications in any of the eyes. Conclusions. Our results up to five years after implantation of the AcrySof Cachet® angle-supported pIOL demonstrated very good outcomes in all above shown measurements, including CDVA, UCVA, and ECD. However, since major endothelial cell loss may occur in some patients with this type of pIOL, regular follow-up visits are required.
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