195 research outputs found
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Deterministic Assembly of Arrays of Lithographically Defined WS2 and MoS2 Monolayer Features Directly from Multilayer Sources into Van der Waals Heterostructures
One of the major challenges in the van der Waals (vdW) integration of two-dimensional (2D) materials is achieving high-yield and high-throughput assembly of predefined sequences of monolayers into heterostructure arrays. Mechanical exfoliation has recently been studied as a promising technique to transfer monolayers from a multilayer source synthesized by other techniques, allowing the deposition of a wide variety of 2D materials without exposing the target substrate to harsh synthesis conditions. Although a variety of processes have been developed to exfoliate the 2D materials mechanically from the source and place them deterministically onto a target substrate, they can typically transfer only either a wafer-scale blanket or one small flake at a time with uncontrolled size and shape. Here, we present a method to assemble arrays of lithographically defined monolayer WS2 and MoS2 features from multilayer sources and directly transfer them in a deterministic manner onto target substrates. This exfoliate-align-release process - without the need of an intermediate carrier substrate - is enabled by combining a patterned, gold-mediated exfoliation technique with a new optically transparent, heat-releasable adhesive. WS2/MoS2 vdW heterostructure arrays produced by this method show the expected interlayer exciton between the monolayers. Light-emitting devices using WS2 monolayers were also demonstrated, proving the functionality of the fabricated materials. Our work demonstrates a significant step toward developing mechanical exfoliation as a scalable dry transfer technique for the manufacturing of functional, atomically thin materials
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Compliant substrate epitaxy: Au on MoS2
A theory for the epitaxial growth of Au on MoS2 is developed and analyzed. The theory combines continuum linear elasticity theory with density functional theory to analyze epitaxial growth in this system. It is demonstrated that if one accounts for interfacial energies and strains, the presence of misfit dislocations, and the compliance of the MoS2 substrate, the experimentally observed growth orientation is favored despite the fact that it represents a larger elastic mismatch than two competing structures. The stability of the experimentally preferred orientation is attributed to the formation of a large number of strong Au-S bonds, and it is noted that this strong bond may serve as a means to exfoliate and transfer large single layers sheets of MoS2, as well as to engineer strain within single layers of MoS2. The potential for using a van der Waals-bonded layered material as a compliant substrate for applications in 2D electronic devices and epitaxial thin film growth is discussed
The dimensions of the sphenoid sinuses: evaluation before the functional endoscopic sinus surgery
Background: The following study aimed to evaluate the dimensions (anteroposterior, transverse and vertical) of the sphenoid sinuses in the adult population. Materials and methods: The study was conducted as a retrospective analysis of the computed tomography (CT) scans of the paranasal sinuses of 296 patients (147 females and 149 males), who did not present any pathology in the sphenoid sinuses. The CT scans of the paranasal sinuses were done with the spiral CT scanner, without using any contrast medium. After obtaining transverse planes, frontal and sagittal planes were created using secondary reconstruction tool. Results: The anteroposterior dimension was found to be 2.65 cm on average, in the range of 0.5–4.3 cm. The transverse dimension was on average 1.98 cm, ranging from 0.5 cm to 4.9 cm. The average vertical dimension was found to be 2.1 cm, in the range of 0.7–3.7 cm. Conclusions: Due to the high incidence of the anatomical variants of the paranasal sinuses, a CT scan is recommended in all patients before a planned surgery in order to avoid the potential iatrogenic complications. Dimensions of the sphenoid sinuses might point towards more at risk variants, but there is still a substantial amount of research that needs to be done in that aspect
Sex determination based on the analysis of a contemporary Polish population’s palatine bones: a computed tomography study of 1,200 patients
Background: The aims of the present study were to assess whether the hard palate reveals any measurable sex-related differences, and to create a mathematical model which would differentiate between males and females using hard palate measurements alone. Materials and methods: The present study was conducted on 1,200 archived sinus computed tomography (CT) scans. Each cranial measurement was taken twice by the same observer, and in cases of any discrepancies, the mean of the two values was recorded. Twenty per cent of randomly chosen samples were re-measured by an observer who did not partake in assessing the samples the first time. Logistic regression was used to derivate two mathematical formulas which would calculate the probability of a skull being male. Results: The studied group comprised 1,200 head CT’s (627 female; 52.3%). The mean age of the group was 43.5 ± 17.4 years — no age difference between sexes was noted (p = 0.37). All of the performed measurements were significantly (p < 0.0001) larger in males than in females. The mathematical formula based on the “orale-spina nasalis posterior” (O-SNP) distance alone had a reliability rate of 68.35%. The equation based on the depth of the right greater palatine canal (GPC), the O-SNP distance and the anterior width of the palatal arch (AWPA) had a reliability rate of 78.37%. Conclusions: The most prominent sexually dimorphic parameters were the O-SNP, the GPC depth and the AWPA. The mathematical models presented in the current study can be used to successfully distinguish between sexes during forensic examination.
Protrusion of the carotid canal into the sphenoid sinuses: evaluation before endonasal endoscopic sinus surgery
Background: Many reports have previously indicated the vast number of anatomical variations of the sphenoid sinuses, e.g. presence of the recesses. Notwithstanding, there are a few crucial neurovascular structures directly neighbouring with the sinuses. The following research aimed to evaluate frequency prevalence of the carotid canal’s protrusion into the sphenoid sinuses in adult population.Materials and methods: Computed tomography (CT) scans of the paranasal sinuses of 296 patients (147 females, 149 males) were analysed in this retrospective study. The patients did not present any pathology in the sinuses. Spiral CT scanner Siemens Somatom Sensation 16 was used in the standard procedure in the option Siemens CARE Dose 4D.Results: Protrusion of the carotid canal was found in the majority of the patients — 55.74%, more frequently in males (65.1% of the patients) than in females (46.26% of the patients). The said variant — regardless of gender — was noted more often bilaterally (41.55% of the cases: 29.93% females, 53.02% males) than unilaterally (14.19% of the cases: 16.33% females, 12.08% males). In the unilateral type (regardless of gender), the protrusion was more common for the left sphenoid sinus — 10.81% of the patients (12.24% females, 9.4% males) than for the right — 3.38% of the patients (4.08% females, 2.68% males).Conclusions: Complicated structure of the paranasal sinuses, derived from the high prevalence of their anatomical variations, may perplex routine surgical interventions. Henceforth, referral for a CT scan is imperative in order to abate the risks associated with an invasive procedure in the said region
Effectiveness of the third wave cognitive behavior therapy for peripartum depression treatment – a systematic review
Introduction: To investigate the effectiveness of third-wave cognitive behavior therapies in the treatment of peripartum depression. Method: A systematic review of the effectiveness of psychological interventions in treating peripartum depression focus on the Third Wave has been conducted. The electronic databases MEDLINE, PsycINFO, Web of Science and Clinical Trials were searched, using a combination of different search terms. Data were independently extracted by two authors and a synthesis of the results was offered. Methodological quality was assessed by three authors, using ROBE-2 and MINORS. Search date was conducted in February 2022 and the search was re-run in November 2022 for new entries. Findings: Six papers were included and reported, focused on, the effectiveness of Third Wave approach interventions in reducing depressive symptoms. Papers included the following intervention approaches: Behavioral intervention (n = 2), Mindfulness (n = 2), Dialectical Behavior Therapy (n = 1) and Acceptance and Commitment Therapy (n = 1). All six papers were consistent in that interventions lead to a decrease in depression symptoms. However, risk of bias evaluation showed that all were critical low, but one paper was high quality. Conclusion and implications for practice and research: Systematic review showed that third-wave approaches are promising in effectiveness to reduce depression symptoms in peripartum women. However, more high-quality studies with follow-up are needed.info:eu-repo/semantics/publishedVersio
Evaluation of the role of downregulation of SNF5/INI1 core subunit of SWI/SNF complex in clear cell renal cell carcinoma development
Clear cell renal cell carcinoma (ccRCC) is characterized by stabilization of hypoxia-inducible factor (HIF1), and mutations in von Hippel-Lindau (VHL) gene. Additionally, in about 40% of ccRCC cases the mutation in PBRM1 (POLYBROMO1) gene coding for a non-core subunit of SWI/SNF chromatin remodeling complex was found suggesting potential impairment of this complex function in ccRCC. In this study we assessed the extent to which the core SWI/SNF complex subunit - INI1 (hSNF5/SMARCB1) is affected in ccRCC and whether it has any consequences on the development of this type of cancer. The evaluation of INI1 protein level in samples from 50 patients with diagnosed ccRCC, including three displaying rhabdoid features, showed the INI1 positive staining in rhabdoid cells while the conventional ccRCC cells exhibited reduced INI1 level. This indicated the rhabdoid component of ccRCC as distinct from other known rhabdoid tumors. The reduced INI1 protein level observed in all conventional ccRCC cases used in this study correlated with decreased SMARCB1 gene expression at the transcript level. Consistently, the overexpression of INI1 protein in A498 ccRCC cell line resulted in the elevation of endogenous SMARCB1 transcript level indicating that the INI1-dependent regulatory feedback loop controlling expression of this gene is affected in ccRCC Moreover, the set of INI1 target genes including i.e. CXCL12/CXCR7/CXCR4 chemokine axis was identified to be affected in ccRCC. In summary, we demonstrated that the inactivation of INI1 may be of high importance for ccRCC development and aggressiveness
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