Rapid prototyping (RP) is a relatively new technology that produces physical models by selectively solidifying UV-sensitive liquid resin using a laser beam. The technology has gained a great amount ...of attentin, particularly in oral and maxillofacial surgery. An important issue in RP applications in this field is how to obtain RP models of the required accuracy. We investigated errors generated during the production of medical RP models, and identified the factors that caused dimensional errors in each production phase. The errors were mainly due to the volume-averaging effect, threshold value, and difficulty in the exact replication of landmark locations. We made 16 linear measurements on a dry skull, a replicated three-dimensional (3-D) visual (STL) model, and an RP model. The results showed that the absolute mean deviation between the original dry skull and the RP model over the 16 linear measurements was 0.62±0.35mm (0.56±0.39%), which is smaller than values reported in previous studies. A major emphasis is placed on the dumb-bell effect. Classifying measurements as internal and external measurements, we observed that the effect of an inadequate threshold value differs with the type of measurement.
Three-dimensional (3D) printing technology has received great attention in the past decades in both academia and industry because of its advantages such as customized fabrication, low manufacturing ...cost, unprecedented capability for complex geometry, and short fabrication period. 3D printing of metals with controllable structures represents a state-of-the-art technology that enables the development of metallic implants for biomedical applications. This review discusses currently existing 3D printing techniques and their applications in developing metallic medical implants and devices. Perspective about the current challenges and future directions for development of this technology is also presented.
To resolve frequency ambiguity of tiered polyphase code (TPC), a differential encoding method to the secondary code of the TPC is proposed. By performing differential decoding, the frequency ...ambiguity is removed and the code sequence boundary is correctly found. In addition, the correlation results at the receiver can be used as a frequency offset estimator. Analysis on the receiver operations and the simulation results show that the proposed tiered differential-PC makes the code sequence boundary detection correctly under the frequency offset of up to several hundred hertz. The root mean squared error of the frequency offset estimation is reduced to <10 Hz under operating signal-to-noise power ratio which is about −35 dB.
Using predesigned trains of femtosecond optical pulses, we have selectively excited coherent phonons of the radial breathing mode of specific-chirality single-walled carbon nanotubes within an ...ensemble sample. By analyzing the initial phase of the phonon oscillations, we prove that the tube diameter initially increases in response to ultrafast photoexcitation. Furthermore, from excitation profiles, we demonstrate that an excitonic absorption peak of carbon nanotubes periodically oscillates as a function of time when the tube diameter undergoes coherent radial breathing mode oscillations.
The FeSe nematic phase has been the focus of recent research on iron-based superconductors (IBSs) due to its unusual properties, which are distinct from those of the pnictides. A series of ...theoretical/experimental studies were performed to determine the origin of the nematic phase. However, they yielded conflicting results and caused additional controversies. Here, we report the results of angle-resolved photoemission and X-ray absorption spectroscopy studies on FeSe detwinned by a piezo stack. We fully resolved band dispersions with orbital characters near the Brillouin zone (BZ) corner, and revealed an absence of any Fermi pocket at the Y point in the 1-Fe BZ. In addition, the occupation imbalance between dxz and dyz orbitals was the opposite of that of iron pnictides, consistent with the identified band characters. These results resolve issues associated with the FeSe nematic phase and shed light on the origin of the nematic phase in IBSs.Twinning is a phenomenon which describes the intergrowth between two identical crystals, and can complicate the analysis of their intrinsic properties both from a physical and structural perspective. Here, the authors use a piezo stack to detwin FeSe crystals and then investigate the band dispersions using photoelectron and X-ray absorption spectroscopies in order to further clarify the origins of the nematic phase in FeSe.
Background
High‐resolution manometry (HRM) based on spatiotemporal plots is increasingly being used. The aim this study was to evaluate, for the first time, the influence of gender, with adjustment ...for age, body mass index (BMI), and vaginal delivery, on anorectal functions in asymptomatic adults.
Methods
Fifty‐four asymptomatic healthy subjects (M : F = 27 : 27; age = 20–67 years) who were matched by age and gender were enrolled prospectively. We evaluated anorectal pressures, rectal sensation using a HRM probe, and balloon expulsion time. Multivariate linear regression analysis was performed to identify the independent effects of each factor.
Key Results
Anal resting pressure (median IQR; 32 18 vs 46 17 mmHg, p < 0.001), anal squeeze pressure (75 28 vs 178 72 mmHg, p < 0.001), rectal pressure (33 16 vs 53 46 mmHg, p = 0.009) and anal pressure (16 17 vs 30 36 mmHg, p = 0.019) during simulated evacuation with rectal distention, and the threshold for the desire to defecate (60 20 vs 80 60 mL, p = 0.020) were significantly lower in women than in men. BMI was positively correlated with anal resting pressure (95% CI: 0.598–2.947) and negatively correlated with the threshold for first sensation (95% CI: −0.099 to −0.015). Vaginal delivery did not affect any of the anorectal HRM parameters.
Conclusions & Inferences
HRM parameters may be associated with gender and BMI. Therefore, gender and BMI should be taken into consideration when interpreting HRM results.
This study investigated, for the first time, the influences of gender and body mass index (BMI) on high‐resolution anorectal manometry (HRM) parameters in asymptomatic normal Korean men and women populations. HRM parameters may be associated with gender and BMI. Therefore, gender and BMI should be taken into consideration when interpreting HRM results.
One of the important rotational resonances in nonaxisymmetric neoclassical transport has been experimentally validated in the KSTAR tokamak by applying highly nonresonant n=1 magnetic perturbations ...to rapidly rotating plasmas. These so-called bounce-harmonic resonances are expected to occur in the presence of magnetic braking perturbations when the toroidal rotation is fast enough to resonate with periodic parallel motions of trapped particles. The predicted and observed resonant peak along with the toroidal rotation implies that the toroidal rotation in tokamaks can be controlled naturally in favorable conditions to stability, using nonaxisymmetric magnetic perturbations.
Metastasis is a life-threatening feature of cancer and is primarily responsible for cancer patient mortality. Cross talk between tumor cells and endothelium is important for tumor progression and ...metastasis. However, very little is known about the mechanisms by which endothelial cells (ECs) that are close to tumor cells, respond to the tumor cells during tumor progression and metastasis. In this study, we exploited the use of EC-specific signal transducer activator of transcription 3 (STAT3) knockout mice to investigate the role of STAT3 in ECs in tumor progression and metastasis. We found that the loss of STAT3 in ECs did not affect primary Lewis lung carcinoma (LLC) tumor growth, but it reduced in vivo LLC metastasis in experimental and spontaneous metastasis models. Mechanistically, STAT3 activation upregulated cell adhesion molecule expression, including E-selectin and P-selectin, in murine endothelial MS-1 cells treated with tumor cell-conditioned media in vitro and in pre-metastatic lungs of tumor-bearing mice in vivo. We also found that both E-selectin and P-selectin were, at least in part, responsible for STAT3-induced adhesion and invasion of LLC cells through an EC monolayer. However, tumor cell-conditioned media from B16F10 melanoma cells did not activate STAT3 in MS-1 cells. As a result, EC STAT3 knockout did not affect B16F10 melanoma cell metastasis. In addition, various human cancer cells activated STAT3 in human ECs (HUVECs), resulting in increased cell adhesion molecule expression. Collectively, our findings demonstrate that STAT3 activation in ECs promotes tumor metastasis through the induction of cell adhesion molecules, demonstrating a role for ECs in response to tumor cells during tumor metastasis.
Artificial van der Waals heterostructures with two-dimensional (2D) atomic crystals are promising as an active channel or as a buffer contact layer for next-generation devices. However, genuine 2D ...heterostructure devices remain limited because of impurity-involved transfer process and metastable and inhomogeneous heterostructure formation. We used laser-induced phase patterning, a polymorph engineering, to fabricate an ohmic heterophase homojunction between semiconducting hexagonal (2H) and metallic monoclinic (1T') molybdenum ditelluride (MoTe2) that is stable up to 300°C and increases the carrier mobility of the MoTe2 transistor by a factor of about 50, while retaining a high on/off current ratio of 106. In situ scanning transmission electron microscopy results combined with theoretical calculations reveal that the Te vacancy triggers the local phase transition in MoTe2, achieving a true 2D device with an ohmic contact.
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