Author Correction: Chemical trends of deep levels in van der Waals semiconductors.

A Correction to this paper has been published: https://doi.org/10.1038/s41467-020-20151-x.

Chemical trends of deep levels in van der Waals semiconductors.

Properties of semiconductors are largely defined by crystal imperfections including native defects. Van der Waals (vdW) semiconductors, a newly emerged class of materials, are no exception: defects exist even in the purest materials and strongly affect their electrical, optical, magnetic, catalytic and sensing properties. However, unlike conventional semiconductors where energy levels of defects are well documented, they are experimentally unknown in even the best studied vdW semiconductors, impeding the understanding and utilization of these materials.

Bandgap Restructuring of the Layered Semiconductor Gallium Telluride in Air.

A giant bandgap reduction in layered GaTe is demonstrated. Chemisorption of oxygen to the Te-terminated surfaces produces significant restructuring of the conduction band resulting in a bandgap below 0.8 eV, compared to 1.

Real-time observation of epitaxial graphene domain reorientation.

Graphene films grown by vapour deposition tend to be polycrystalline due to the nucleation and growth of islands with different in-plane orientations. Here, using low-energy electron microscopy, we find that micron-sized graphene islands on Ir(111) rotate to a preferred orientation during thermal annealing. We observe three alignment mechanisms: the simultaneous growth of aligned domains and dissolution of rotated domains, that is, 'ripening'; domain boundary motion within islands; and continuous lattice rotation of entire domains.

Orientation-dependent growth mechanisms of graphene islands on Ir(111).

Using low-energy electron microscopy, we find that the mechanisms of graphene growth on Ir(111) depend sensitively on island orientation with respect to Ir. In the temperature range of 750-900 °C, we observe that growing rotated islands are more faceted than islands aligned with the substrate. Further, the growth velocity of rotated islands depends not only on the C adatom supersaturation but also on the geometry of the island edge.

On demand shape-selective integration of individual vertical germanium nanowires on a Si(111) substrate via laser-localized heating.

Semiconductor nanowire (NW) synthesis methods by blanket furnace heating produce structures of uniform size and shape. This study overcomes this constraint by applying laser-localized synthesis on catalytic nanodots defined by electron beam lithography in order to accomplish site- and shape-selective direct integration of vertically oriented germanium nanowires (GeNWs) on a single Si(111) substrate. Since the laser-induced local temperature field drives the growth process, each NW could be synthesized with distinctly different geometric features.

Bulk electronic structure of the dilute magnetic semiconductor Ga(1-x)Mn(x)As through hard X-ray angle-resolved photoemission.

A detailed understanding of the origin of the magnetism in dilute magnetic semiconductors is crucial to their development for applications. Using hard X-ray angle-resolved photoemission (HARPES) at 3.2 keV, we investigate the bulk electronic structure of the prototypical dilute magnetic semiconductor Ga(0.

In situ TEM near-field optical probing of nanoscale silicon crystallization.

Laser-based processing enables a wide variety of device configurations comprising thin films and nanostructures on sensitive, flexible substrates that are not possible with more traditional thermal annealing schemes. In near-field optical probing, only small regions of a sample are illuminated by the laser beam at any given time. Here we report a new technique that couples the optical near-field of the laser illumination into a transmission electron microscope (TEM) for real-time observations of the laser-materials interactions.

Graphene Islands on Cu foils: the interplay between shape, orientation, and defects.

We have observed the growth of monolayer graphene on Cu foils using low-energy electron microscopy. On the (100)-textured surface of the foils, four-lobed, 4-fold-symmetric islands nucleate and grow. The graphene in each of the four lobes has a different crystallographic alignment with respect to the underlying Cu substrate.

Embedded binary eutectic alloy nanostructures: a new class of phase change materials.

Phase change materials are essential to a number of technologies ranging from optical data storage to energy storage and transport applications. This widespread interest has given rise to a substantial effort to develop bulk phase change materials well suited for desired applications. Here, we suggest a novel and complementary approach, the use of binary eutectic alloy nanoparticles embedded within a matrix.

Electronic structure of ferromagnetic semiconductor Ga_{1-x}Mn_{x}As probed by subgap magneto-optical spectroscopy.

We employ Faraday and Kerr effect spectroscopy in the infrared range to investigate the electronic structure of Ga_{1-x}Mn_{x}As near the Fermi energy. The band structure of this archetypical dilute-moment ferromagnetic semiconductor has been a matter of controversy, fueled partly by previous measurements of the unpolarized infrared absorption and their phenomenological impurity-band interpretation. Unlike the unpolarized absorption, the infrared magneto-optical effects we study are intimately related to ferromagnetism, and their interpretation is much more microscopically constrained in terms of the orbital character of the relevant band states.

Global faceting behavior of strained Ge islands on Si.

The evolution of crystallographic facets of strained heteroepitaxial Ge islands on Si is investigated. Islands growing on Si(001), (111), (110) and (113) are bound by an equilibrium set of facets that includes only shared stable surfaces between bulk Si and Ge--{105}, {113}, {15 3 23} and {111}. The formation of a stereographic map from these indices facilitates the prediction of Ge faceted-island shapes on any Si substrate at different stages of growth.

First report of a necrotising fasciitis of the breast following a core needle biopsy.

Necrotising fasciitis (NF) is the most aggressive form of soft tissue infection. We report the first case of NF of the breast following a core needle biopsy. Aggressive management including surgical debridement and vacuum therapy allowed wound healing and breast conservation.

Metal-insulator transition by isovalent anion substitution in Ga1-xMnxAs: implications to ferromagnetism.

We have investigated the effect of partial isovalent anion substitution in Ga1-xMnxAs on electrical transport and ferromagnetism. Substitution of only 2.4% of As by P induces a metal-insulator transition at a constant Mn doping of x=0.

Ge island assembly on metal-patterned Si: truncated pyramids, nanorods, and beyond.

The organization of semiconductor nanostructures into functional macroassemblies remains a fundamental challenge in nanoscience and nanotechnology. In the context of semiconductor epitaxial growth, efforts have focused on the application of advanced substrate patterning strategies for the directed assembly quantum-dot islands. We present a comprehensive investigation on the use of simple metal patterns to control the nucleation and growth of heteroepitaxial islands.

Gold-catalyzed oxide nanopatterns for the directed assembly of Ge island arrays on Si.

The heteroepitaxial growth of Ge on Au-patterned Si(001) is investigated using in situ spectromicroscopy. Patterning of a hydrogen-terminated Si surface with a square array of Au dots followed by brief exposure to air leads to the spontaneous, local oxidation of Si. The resulting oxide nanopattern limits the surface migration of Au during annealing up to 600 degrees C, resulting in complete preservation of the Au pattern.

[Abdominal wall necrosis as expression of Munchausen's syndrome: a case report].

Münchausen's syndrome is a psychiatric disease with behaviour disorders including self-injuries. Self mutilations interest all the body, and among others the abdominal wall, who can mimic complications of surgery. We report the history of a woman consulting for an abdominal wall panniculitis two years after a caesarean.

Sculpting semiconductor heteroepitaxial islands: from dots to rods.

In the Ge on Si model heteroepitaxial system, metal patterns on the silicon surface provide unprecedented control over the morphology of highly ordered Ge islands. Island shape including nanorods and truncated pyramids is set by the metal species and substrate orientation. Analysis of island faceting elucidates the prominent role of the metal in promoting growth of preferred facet orientations while investigations of island composition and structure reveal the importance of Si-Ge intermixing in island evolution.

Comparative study of the accuracy of breast resection in oncoplastic surgery and quadrantectomy in breast cancer.

Background: The aim of this study was to determine whether oncoplastic surgery ensures accurate tumor resection and reduces the need for further surgery in comparison with standard quadrantectomies.

Methods: This was a prospective comparative study of 74 patients with breast tumor diameter >or=15 mm. The principal criterion for case selection was breast size that allowed either quadrantectomy or oncoplastic surgery to be scheduled.

Doughnut mastopexy lumpectomy versus standard lumpectomy in breast cancer surgery: a prospective study.

Aims: Doughnut mastopexy lumpectomy (DML) is a unique breast resection in which a tissue segment is removed and the breast reshaped through a periareolar incision. The present prospective investigation compares DML and standard lumpectomy (SL) in relation to surgical variables, histological parameters, postoperative morbidity and cosmetic outcome.

Methods: 127 patients with breast cancer were offered the choice between two conservative surgical approaches: doughnut mastopexy lumpectomy (DML group, n=39) or standard lumpectomy (SL group, n=88).

[Lumpectomy vs oncoplastic surgery for breast-conserving therapy of cancer. A prospective study about 99 patients].

Unlabelled: The integration of oncoplastic techniques with a concomitant contralateral symmetrization procedure is a novel surgical approach that allows wide excisions and prevents breast deformities.

Aim Of The Study: This prospective study was undertaken to compare the accuracy of breast resection, between standard narrow lumpectomy and oncoplastic surgery.

Patients And Methods: Ninety-nine consecutive women undergoing breast cancer resection were enrolled in a prospective study comparing oncoplastic surgery (42 women) and standard lumpectomy (57 women).

Ferromagnetism in Ga(1-x)Mn(x)P: evidence for inter-Mn exchange mediated by localized holes within a detached impurity band.

We report an energy gap for hole photoexcitation in ferromagnetic Ga(1-x)Mn(x)P that is tunable by Mn concentration (x < or = 0.06) and by compensation with Te donors. For x approximately 0.

Metal-induced assembly of a semiconductor island lattice: Ge truncated pyramids on Au-patterned Si.

We report the two-dimensional alignment of semiconductor islands using rudimentary metal patterning to control nucleation and growth. In the Ge on Si system, a square array of submicron Au dots on the Si (001) surface induces the assembly of deposited Ge adatoms into an extensive island lattice. Remarkably, these highly ordered Ge islands form between the patterned Au dots and are characterized by a unique truncated pyramidal shape.

Diluted II-VI oxide semiconductors with multiple band gaps.

We report the realization of a new mult-band-gap semiconductor. Zn(1-y)Mn(y)OxTe1-x alloys have been synthesized using the combination of oxygen ion implantation and pulsed laser melting. Incorporation of small quantities of isovalent oxygen leads to the formation of a narrow, oxygen-derived band of extended states located within the band gap of the Zn(1-y)Mn(y)Te host.

[Calculous renal failure and pregnancy].

Obstructive renal failure is a rare but serious complication of pregnancy. Although most cases are due to extrinsic compression, renal tract obstruction can also be due to intraluminal precipitation of sulfadiazine prescribed for maternofoetal toxoplasmosis. The diagnosis is suggested by clinical history, ultrasound (radiolucent stones situated anywhere in the renal tract) and especially analysis of the urine pellet (wheat sheaf formation of yellowish crystals).