Tungsten diselenide (WSe2) and related transition metal dichalcogenides exhibit interesting optoelectronic properties owing to their peculiar band structures originating from the valley degree of ...freedom. Although the optical generation and detection of valley polarization has been demonstrated, it has been difficult to realize active valley-dependent functions suitable for device applications. We report an electrically switchable, circularly polarized light source based on the material's valley degree of freedom. Our WSe2-based ambipolar transistors emit circularly polarized electroluminescence from p-i-n junctions electrostatically formed in transistor channels. This phenomenon can be explained qualitatively by the electron-hole overlap controlled by the in-plane electric field. Our device demonstrates a route to exploit the valley degree of freedom and the possibility to develop a valley-optoelectronics technology.
Superconducting Dome in a Gate-Tuned Band Insulator Ye, J. T.; Zhang, Y. J.; Akashi, R. ...
Science (American Association for the Advancement of Science),
11/2012, Letnik:
338, Številka:
6111
Journal Article
Recenzirano
A dome-shaped superconducting region appears in the phase diagrams of many unconventional superconductors. In doped band insulators, however, reaching optimal superconductivity by the fine-tuning of ...carriers has seldom been seen. We report the observation of a superconducting dome in the temperature—carrier density phase diagram of MoS₂, an archetypal band insulator. By quasi-continuous electrostatic carrier doping achieved through a combination of liquid and solid gating, we revealed a large enhancement in the transition temperature T c occurring at optimal doping in the chemically inaccessible low-carrier density regime. This observation indicates that the superconducting dome may anse even in doped band insulators.
In Cooper pairs--pairs of electrons responsible for the exotic properties of superconductors--the two electrons' spins typically point in opposite directions. A strong-enough external magnetic field ...will destroy superconductivity by making the spins point in the same direction. Lu et al. observed a two-dimensional superconducting state in the material MoS2 that was surprisingly immune to a magnetic field applied in the plane of the sample (see the Perspective by Suderow). The band structure of MoS2 and its spin-orbit coupling conspired to create an effective magnetic field that reinforced the electron pairing, with spins aligned perpendicular to the sample. Science, this issue p. 1353; see also p. 1316 The Zeeman effect, which is usually detrimental to superconductivity, can be strongly protective when an effective Zeeman field from intrinsic spin-orbit coupling locks the spins of Cooper pairs in a direction orthogonal to an external magnetic field. We performed magnetotransport experiments with ionic-gated molybdenum disulfide transistors, in which gating prepared individual superconducting states with different carrier dopings, and measured an in-plane critical field Bc2 far beyond the Pauli paramagnetic limit, consistent with Zeeman-protected superconductivity. The gating-enhanced Bc2 is more than an order of magnitude larger than it is in the bulk superconducting phases, where the effective Zeeman field is weakened by interlayer coupling. Our study provides experimental evidence of an Ising superconductor, in which spins of the pairing electrons are strongly pinned by an effective Zeeman field.
Molybdenum disulfide (MoS2) has gained attention because of its high mobility and circular dichroism. As a crucial step to merge these advantages into a single device, we present a method that ...electronically controls and locates p–n junctions in liquid-gated ambipolar MoS2 transistors. A bias-independent p–n junction was formed, and it displayed rectifying I–V characteristics. This p–n diode could perform a crucial role in the development of optoelectronic valleytronic devices.
Malignant melanoma is an aggressive cancer known for its notorious resistance to most current therapies. The basic helix-loop-helix microphthalmia transcription factor (MITF) is the master regulator ...determining the identity and properties of the melanocyte lineage, and is regarded as a lineage-specific 'oncogene' that has a critical role in the pathogenesis of melanoma. MITF promotes melanoma cell proliferation, whereas sustained supression of MITF expression leads to senescence. By combining chromatin immunoprecipitation coupled to high throughput sequencing (ChIP-seq) and RNA sequencing analyses, we show that MITF directly regulates a set of genes required for DNA replication, repair and mitosis. Our results reveal how loss of MITF regulates mitotic fidelity, and through defective replication and repair induces DNA damage, ultimately ending in cellular senescence. These findings reveal a lineage-specific control of DNA replication and mitosis by MITF, providing new avenues for therapeutic intervention in melanoma. The identification of MITF-binding sites and gene-regulatory networks establish a framework for understanding oncogenic basic helix-loop-helix factors such as N-myc or TFE3 in other cancers.
Liquid/solid interfaces are attracting growing interest not only for applications in catalytic activities and energy storage, but also for their new electronic functions in electric double-layer ...transistors (EDLTs) exemplified by high-performance organic electronics, field-induced electronic phase transitions, as well as superconductivity in SrTiO3 (ref. 12). Broadening EDLTs to induce superconductivity within other materials is highly demanded for enriching the materials science of superconductors. However, it is severely hampered by inadequate choice of materials and processing techniques. Here we introduce an easy method using ionic liquids as gate dielectrics, mechanical micro-cleavage techniques for surface preparation, and report the observation of field-induced superconductivity showing a transition temperature Tc=15.2 K on an atomically flat film of layered nitride compound, ZrNCl. The present result reveals that the EDLT is an extremely versatile tool to induce electronic phase transitions by electrostatic charge accumulation and provides new routes in the search for superconductors beyond those synthesized by traditional chemical methods.
Humour is instrumental in drawing attention to controversial topics like gender inequality. This empirical study aims to distinguish the culture-specifics of feminist humour in the Ukrainian social ...media sector by identifying women’s main techniques to overcome gender stereotypes and prejudices. The material for the study was humour patterns sampled in the Ukrainian social media sector from November 2022 to February 2023. During this period, 1803 posts were shared in these groups. In the first stage, we selected 698 posts with humour as their conceptual content. In the second stage, 121 patterns were selected, the main distinguishing characteristic of which is the use of gender terms and/or the presence of explicit gender categorical inferences. Attention was focused on those examples where the humour was aimed at gender deconstruction, achieved by criticism of discriminatory social norms restricting women’s and girls’ rights. Discourse-analytical research methods were used in the study. Feminist humour techniques used by women in the Ukrainian social media sector to challenge gender stereotypes and prejudices are as follows: 1. Positioning oneself as an irrepressible “bad girl”. This technique aims to develop and cultivate assertiveness, i. e. the ability to withstand the psychological pressure of traditional social norms attributed to a “real lady”, to regulate one’s behaviour and take responsibility for it. 2. “Confusion” of the gender binary. Humour is a platform for creating identities that do not follow the traditional concept of men or women and cannot be described within a rigid binary scheme. An important tool that enables women to challenge stereotypes is the genre of humour, such as banter, which makes it possible for women to experiment with different social constructions of what being a woman in the image of a man means. 3. Adopting the male tradition of disparagement humour. The recipients’ acceptance of disparagement humour means that they tacitly consent to the termination of typical serious or critical ways of thinking about socially problematic topics, thus ultimately destroying gender biases and stereotypes – if stereotypes do not apply to men, they lose their validity for women as well. 4. Cultivating self-compassion for oneself. Self-compassion fosters self-awareness that rejects normative gender stereotypes as factors that impede positive aspirations for growth and change. The concept of self-compassion is closely related to the positive perception of one’s body image. The results of this study have confirmed the basic conclusions made in the earlier publications that feminist humour is designed to address several psychological problems women face, the reason for which stems from their tendency to adhere to traditional beliefs about gender roles, but feminist humour is not man-hating. By identifying typical techniques employed to challenge gender biases and stereotypes in a particular country, we can understand the national and cultural specificity of feminist humour.
Summary
Water buffalo (Bubalus bubalis) is of great economic importance as a provider of milk and meat in many countries. However, the milk yield of buffalo is much lower than that of Holstein cows. ...Selection of candidate genes related to milk production traits can be applied to improve buffalo milk performance. A systematic review of studies of these candidate genes will be greatly beneficial for researchers to timely and efficiently understand the research development of molecular markers for buffalo milk production traits. Here, we identified and classified the candidate genes associated with buffalo milk production traits. A total of 517 candidate genes have been identified as being associated with milk performance in different buffalo breeds. Nineteen candidate genes containing 47 mutation sites have been identified using the candidate gene approach. In addition, 499 candidate genes have been identified in six genome‐wide association studies (GWASes) including two studies performed with the bovine SNP chip and four studies with the buffalo SNP chip. Genes CTNND2 (catenin delta 2), APOB (apolipoprotein B), FHIT (fragile histidine triad) and ESRRG (estrogen related receptor gamma) were identified in at least two GWASes. These four genes, especially APOB, deserve further study to explore regulatory roles in buffalo milk production. With growth in the number of buffalo genomic studies, more candidate genes associated with buffalo milk production traits will be identified. Therefore, future studies, such as those investigating gene location and functional analyses, are necessary to facilitate the exploitation of genetic potential and the improvement of buffalo milk performance.
Background
The benefit and harm of three‐field lymphadenectomy for oesophageal cancer are still unknown. The aim of this study was to compare overall survival and morbidity and mortality between ...three‐ and two‐field lymphadenectomy in patients with oesophageal squamous cell carcinoma.
Methods
Between March 2013 and November 2016, patients with squamous cell carcinoma of the middle or distal oesophagus were assigned randomly to open oesophagectomy with three‐field (cervical–thoracic–abdominal) or two‐field (thoracic–abdominal) lymphadenectomy. No chemo(radio) therapy was given before surgery. This paper reports on the secondary outcomes of the study: pathology and surgical complications.
Results
Some 400 patients were randomized, 200 in each group. A median of 37 (i.q.r. 30–49) lymph nodes were dissected in the three‐field group, compared with 24 (18–30) in the two‐field group (P < 0·001). Some 43 of 200 patients (21·5 per cent) in the three‐field group had cervical lymph node metastasis. More patients in the three‐field group had pN3 disease: 21 of 200 (10·5 per cent) versus 10 of 200 (5·0 per cent) (P = 0·040). The rate and severity of postoperative complications were comparable between the two groups, except that six patients in the three‐field arm needed reintubation compared with none in the two‐field group (3·0 versus 0 per cent; P = 0·030). The 90‐day mortality rate was 0 per cent in the three‐field group and 0·5 per cent (1 patient) in the two‐field group (P = 1·000).
Conclusion
Oesophagectomy with three‐field lymphadenectomy increased the number of lymph nodes dissected and led to stage migration owing to a 21·5 per cent rate of cervical lymph node metastasis. Postoperative complications were largely comparable between two‐ and three‐field lymphadenectomy. Registration number: NCT01807936 (
https://www.clinicaltrials.gov).
Antecedentes
El beneficio y los daños potenciales de la linfadenectomía en tres campos (three‐field, 3‐FLD) en el cáncer de esófago aún se desconoce. El objetivo de este estudio fue comparar la supervivencia global y la morbilidad y mortalidad entre la linfadenectomía en tres campos (3‐FLD) y la linfadenectomía en dos campos (two‐field lymphadenectomy, 2‐FLD) en pacientes con carcinoma escamoso de esófago.
Métodos
Entre marzo de 2013 y noviembre de 2016, pacientes con carcinoma escamoso del tercio medio y distal del esófago fueron asignados de forma aleatoria a esofaguectomía abierta con linfadenectomía 3‐FLD (cervical‐torácica‐abdominal) o 2‐FLD (torácica‐abdominal). No se administró quimioterapia o quimiorradioterapia antes de la cirugía. Este estudio describe los resultados secundarios: datos de la anatomía patología y complicaciones quirúrgicas.
Resultados
Se aleatorizaron un total de 400 pacientes a linfadenectomía 3‐FLD y 2‐FLD (200 pacientes en cada grupo). En el grupo de 3‐FLD se disecaron una mediana (rango) de 37 (30‐49) ganglios linfáticos en comparación con 24 (18‐30) en el grupo de 2‐FLD (P < 0,001). Un total de 43 de 200 (21,5%) pacientes en el grupo 3‐FLD presentaron metástasis en los ganglios linfáticos (lymph node metastasis, LNM) cervicales. Más pacientes en el grupo 3‐FLD presentaron un estadio de la enfermedad pN3 en comparación con el grupo 2‐FLD: 21 de 200 (10,5%) versus 10 de 200 (5,0%), P = 0,040). La tasa y gravedad de las complicaciones postoperatorias fue comparable en ambos grupos, aparte de 6 pacientes en la rama 3‐FLD que necesitaron reintubación (3,0%) en comparación con ninguno en el grupo 2‐FLD (P = 0,030). La mortalidad a los 90 días fue del 0% en 3‐FLD y del 0,5% (1 paciente en el grupo 2‐FLD (P = 1,000).
Conclusión
La esofaguectomía con 3‐FLD aumenta el número de ganglios linfáticos y conduce a una migración del estadio debido a la tasa de LNM cervicales del 21,5%. Las complicaciones postoperatorias fueron similares entre las linfadenectomías 3‐FLD y 2‐FLD.
The optimal extent of lymphadenectomy for oesophageal squamous cell carcinoma remains unclear. This trial randomized 400 patients with middle and lower thoracic oesophageal cancer to receive oesophagectomy with two‐ or three‐field lymphadenectomy. In the present analysis based on short‐term outcomes, three‐field lymphadenectomy could also be performed safely, offering more accurate nodal staging with a 21·5 per cent incidence of unforeseen cervical lymph node metastases.
Difference in nodal yield, survival awaited for
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