Density Of Nuclei Research Articles

Meningioma microstructure assessed by diffusion MRI: An investigation of the source of mean diffusivity and fractional anisotropy by quantitative histology

BackgroundMean diffusivity (MD) and fractional anisotropy (FA) from diffusion MRI (dMRI) have been associated with cell density and tissue anisotropy across tumors, but it is unknown whether these associations persist at the microscopic level. PurposeTo quantify the degree to which cell density and anisotropy, as determined from histology, account for the intra-tumor variability of MD and FA in meningioma tumors. Furthermore, to clarify whether other histological features account for additional intra-tumor variability of dMRI parameters. Materials and MethodsWe performed ex-vivo dMRI at 200 μm isotropic resolution and histological imaging of 16 excised meningioma tumor samples. Diffusion tensor imaging (DTI) was used to map MD and FA, as well as the in-plane FA (FAIP). Histology images were analyzed in terms of cell nuclei density (CD) and structure anisotropy (SA; obtained from structure tensor analysis) and were used separately in a regression analysis to predict MD and FAIP, respectively. A convolutional neural network (CNN) was also trained to predict the dMRI parameters from histology patches. The association between MRI and histology was analyzed in terms of out-of-sample (R2OS) on the intra-tumor level and within-sample R2 across tumors. Regions where the dMRI parameters were poorly predicted from histology were analyzed to identify features apart from CD and SA that could influence MD and FAIP, respectively. ResultsCell density assessed by histology poorly explained intra-tumor variability of MD at the mesoscopic level (200 μm), as median R2OS = 0.04 (interquartile range 0.01–0.26). Structure anisotropy explained more of the variation in FAIP (median R2OS = 0.31, 0.20–0.42). Samples with low R2OS for FAIP exhibited low variations throughout the samples and thus low explainable variability, however, this was not the case for MD. Across tumors, CD and SA were clearly associated with MD (R2 = 0.60) and FAIP (R2 = 0.81), respectively. In 37% of the samples (6 out of 16), cell density did not explain intra-tumor variability of MD when compared to the degree explained by the CNN. Tumor vascularization, psammoma bodies, microcysts, and tissue cohesivity were associated with bias in MD prediction based solely on CD. Our results support that FAIP is high in the presence of elongated and aligned cell structures, but low otherwise. ConclusionCell density and structure anisotropy account for variability in MD and FAIP across tumors but cell density does not explain MD variations within the tumor, which means that low or high values of MD locally may not always reflect high or low tumor cell density. Features beyond cell density need to be considered when interpreting MD.

Nucleus density based new relationship of nuclear charge radius

In this paper we predict and evaluate the value of the nuclear charge radius by analyzing the relationship between nuclear mass and nuclear charge radius.We obtain 884 nuclei (<i>Z</i>, <i>N</i> ≥ 8) with known mass and known charge radii by combining AME2020 database with CR2013 database, and calculate the mass densities <inline-formula><tex-math id="M3">\begin{document}$ \rho_\text{m} $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="11-20230126_M3.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="11-20230126_M3.png"/></alternatives></inline-formula> of the 884 nuclei. We aim to obtain an empirical formula of one constant which is useful in describing and predicting nuclear charge radius. With the empirical formula and the AME2020 database, the root-mean-square deviation (RMSD) of the nuclear charge radius of <inline-formula><tex-math id="M5">\begin{document}$ \sigma = 0.093 $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="11-20230126_M5.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="11-20230126_M5.png"/></alternatives></inline-formula> fm is successfully obtained.Considering the influence of neutron numbers on <inline-formula><tex-math id="M6">\begin{document}$\rho_{\rm{m}}$\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="11-20230126_M6.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="11-20230126_M6.png"/></alternatives></inline-formula>, we use the neutron factor <inline-formula><tex-math id="M7">\begin{document}${1}/{N} $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="11-20230126_M7.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="11-20230126_M7.png"/></alternatives></inline-formula> to correct the empirical formula, and the RMSD is reduced to <i>σ</i> = 0.047 fm (the accuracy is increased by about 50%). The second correction is shell effect of neutrons. The results show that the RMSD of nuclear charge radius is reduced to 0.034 fm based on shell effect of neutrons. We use the empirical formula with corrections to predict the nuclear charge radius (1573 nuclear charge radius with <i>Z</i>, <i>N</i> ≥ 8) which is difficult to measure experimentally. The difference between our predicted values based on AME2020 database and the experimental values measured in recent years is in the allowable range of deviation. The result shows that the new relation for nuclear charge radius is simple and reliable. In addition, the RMSD of the calculation value for 791 nuclei is reduced to σ = 0.032 fm after we have removed some nuclei with special shell effect and isotope chains. These results show that the new relation proposed in this paper can be comparable to <inline-formula><tex-math id="M8">\begin{document}$ A^{1/3} $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="11-20230126_M8.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="11-20230126_M8.png"/></alternatives></inline-formula> and <inline-formula><tex-math id="M9">\begin{document}$ Z^{1/3} $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="11-20230126_M9.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="11-20230126_M9.png"/></alternatives></inline-formula> formulas with corrections.Moreover, we study the 884 and 791 nuclear mass densities by using L-M neural network method to build description and prediction models. Comparing with CR2013, the RMSDs of nuclear charge radius are <i>σ</i> = 0.018 fm and <i>σ</i> = 0.014 fm, respectively. The RMSDs are reduced by about 50% compared with that from the empirical formula with corrections, and the predicted values are closer to the experimental values measured in recent years.

Maternal Dexamethasone Exposure Induces Sex-Specific Changes in Histomorphology and Redox Homeostasis of Rat Placenta.

As the mediator between the mother and fetus, the placenta allows the most appropriate environment and optimal fetal growth. The placenta of one sex sometimes has a greater ability over the other to respond to and protect against possible maternal insults. Here, we characterized sex differences in the placenta’s morphological features and antioxidant status following dexamethasone (Dx) exposure. Pregnant rats were exposed to Dx or saline. The placenta was histologically and stereologically analyzed. The activity of the antioxidant enzymes, lipid peroxides (TBARS), superoxide anion and nitric oxide (NO) was measured. The decrease in placental zone volumes was more pronounced (p < 0.05) in female placentas. The volume density of PCNA-immunopositive nuclei was reduced (p < 0.05) in both sexes. The reduced (p < 0.05) antioxidant enzyme activities, enhanced TBARS and NO concentration indicate that Dx exposure triggered oxidative stress in the placenta of both fetal sexes, albeit stronger in the placenta of female fetuses. In conclusion, maternal Dx treatment reduced the size and volume of placental zones, altered placental histomorphology, decreased cell proliferation and triggered oxidative stress; however, the placentas of female fetuses exerted more significant responses to the treatment effects. The reduced placental size most probably reduced the transport of nutrients and oxygen, thus resulting in the reduced weight of fetuses, similar in both sexes. The lesser ability of the male placenta to detect and react to maternal exposure to environmental challenges may lead to long-standing health effects.

Metabolic navigation during brain tumor surgery: analysis of a series of 403 patients

Introduction. Metabolic navigation with 5‑ALA is one of methods for intraoperative imaging in neuro‑oncology.Aim. To perform a comparative analysis of sensitivity of metabolic navigation with 5‑ALA during surgery of primary and secondary brain tumors of various histological nature and degree of malignancy.Materials and methods. During the period from 2013 to 2020, our group have performed surgery to 403 patients using metabolic navigation: microsurgical resections were performed in 384 people with brain tumors, 220 of them were with glial tumors, 101 were with intracranial meningiomas, 63 were with metastatic brain damage. Among patients with metastases, 39 patients had a solitary injury, 16 had a multi‑focal injury, so 72 cases of metastatic nodes were considered in this group. Stereotactic biopsies with 5‑ALA‑assistance were performed in 19 people. Metabolic navigation was performed with the drug 5‑ALA, which was taken orally at a dose of 20 mg/kg 2 hours before surgery. Intraoperative fluorescence was evaluated using microscope with a fluorescent module.Results. Metabolic navigation using microscope has a high sensitivity when employed during microsurgery (including repeated implementation of surgery) in cases of anaplastic gliomas (65 % in total, 58 % with bright glow), glioblastomas (94 % in total, 53 % with bright glow), intracranial meningiomas (94 % in total, 64 % – with bright glow). The use of 5‑ALA has significant limitations in sensitivity in cases of diffuse gliomas (46 % – in total, 27 % – with bright glow) and brain metastases (in total 87 % – for the solid part, 52 % – for the bed, with bright glow – 51 %). In diffuse gliomas, the glow areas had significantly higher proliferative index and cell nuclei density than the fluoronegative zones. Among the most important factors affecting the glow of gliomas it can be noted: the status of the IDH1 mutation, the volume of the contrasting part of the glioma according to MRI data, the methionine accumulation index according to positron emission tomography, the tumor blood flow indicators according to the arterial spin marking method – ASL perfusion.Conclusions. Implementation of 5‑ALA navigation with the use of microscope provides high sensitivity in cases of glioblastomas, anaplastic gliomas (especially for detecting of non‑contrasting part of tumor that is not visually altered in the white light of operating microscope) and brain meningiomas. The method is less effective in low‑grade gliomas and intracranial metastases.

Study of Copper Electrodeposition at a Very Low Temperature near the Freezing Point of Electrolyte

At or above room temperature, metal electrodeposits often feature coarse grains, uneven microstructure and high roughness with abnormal bulges. In this study, copper electrodeposits with abnormal properties were prepared in a sulfate bath at a low temperature near the freezing point of the electrolyte. The results showed that the average grain size of the copper featured an "increase-decrease" trend while decreasing the temperature form 5 °C to -5 °C, yielding a trend from 0.25 μm to 1 μm and then to 0.6 μm. In the early stage, the temperature does not change the three-dimensional continuous nucleation mode of deposited copper. When the nucleus density reaches saturation, the polarization caused by overpotential will act on the respective nucleation and crystal growth process twice, and finally exhibit a completely different trend than that at room temperature. This study may provide insights for breakthroughs in material properties from a temperature perspective.

Determinación de la energía interfacial del sistema ácido acetil salicílico-etanol aplicando la teoría de nucleación 3D y el método integral

In this work, the interfacial energy of the acetylsalicylic acid-ethanol system was evaluated using experimental results of the metastable zone width (MSZW) obtained at different operation conditions: agitation rate (230 and 400 rpm), cooing rate (6, 9 12 and 15 K/h) and saturation temperature (288.15, 293.15, 298.15, 303.15, 308.15 and 313.15 K). A nonlinear regression algorithm and a simple to implement lineal integration approach of the number density of nuclei were used to determine the interfacial energy. The results obtained with the two integral strategies were compared with the values obtained with the 3D nucleation theory. Estimations obtained with the nonlinear regression presented a difference smaller than 6.5 % but estimations determined with the lineal integration approach had an average difference of 48.6 %.

Initial Correlation Analysis of Diffusion Basis Spectrum Imaging of Alzheimer's Brain and Quantitative Histology

AbstractBackgroundDiffusion Basis Spectrum Imaging (DBSI), a novel MR imaging method, can be utilized as a biomarker in Alzheimer's disease (AD) staging and progression. By distinguishing diffusion effects from other concomitant disorders like axonal injury/loss and demyelination, it is capable of specifically evaluating cellularity and edema in AD brains. To test the hypothesis that DBSI cell fraction and mean cell apparent diffusion coefficient (ADC) correlate with measures of cell density and neuroinflammation, we employed high‐resolution ex vivo DBSI sequences and quantitative digital histology on post‐mortem human AD brain tissue.MethodA 15 × 20 × 6 mm3 sample of middle frontal gyrus (coronal plane) from a formalin‐fixed post‐mortem human AD brain (Knight ADRC) was incubated in phosphate‐buffered saline for 48 hours and then imaged with a Varian 11.7T MRI, using 2D spin‐echo sequence with 20‐direction diffusion encoding (max b = 3900 s/mm2, voxel = 0.25 × 0.25 × 1 mm). After MRI, it was precisely bisected along the plane of imaging, and processed into paraffin. Slide‐mounted 6 µm histologic sections were stained with H&amp;E and DAB immunohistochemistry (IBA‐1 antibody, hematoxylin counterstain) and digitized (20× magnification, Hamamatsu NanoZoomer). Maps of nuclei and microglia density were computed by segmenting nuclei and microglia respectively using Orbit Image Analysis and in‐house MATLAB programs. These histology maps were registered and downsampled to the corresponding DBSI maps. We generated cell fraction maps and mean cell ADC maps from MR images using in‐house DBSI software by computing the fraction and mean ADC of restricted isotropic diffusion (0 – 0.4 ×10‐3 mm2/s in each image voxel, respectively.ResultAmong 71 evenly spaced regions of interest (ROIs, 2 × 2 mm2) drawn across the entire specimen, the mean DBSI cell fraction correlated with nuclei density (R = 0.74, P &lt; 0.001). Additionally, among 42 ROIs drawn in the white matter region, the mean cell ADC in each ROI correlated with microglia density (R = 0.54, P &lt; 0.001).ConclusionOur findings demonstrated the feasibility of DBSI technique in ex vivo AD brain, which could improve our understanding of neuroinflammation in AD pathogenesis, early diagnostics and new disease‐modifying therapies targeting the immune response.

ALMA Observations of CO Emission from Luminous Lyman-break Galaxies at z = 6.0293–6.2037

We present our new Atacama Large Millimeter/submillimeter Array (ALMA) observations targeting CO(6–5) emission from three luminous Lyman-break galaxies (LBGs) at z spec = 6.0293–6.2037 found in the Subaru/Hyper Suprime-Cam survey, whose [O iii] 88 μm and [C ii] 158 μm emissions have been detected with ALMA. We find a marginal detection of the CO(6–5) line from one of our LBGs, J0235–0532, at the ≃4σ significance level and obtain upper limits for the other two LBGs, J1211–0118 and J0217–0208. Our z = 6 luminous LBGs are consistent with the previously found correlation between the CO luminosity and the infrared luminosity. The unique ensemble of the multiple far-infrared emission lines and underlying continuum fed to a photodissociation region model reveals that J0235–0532 has a relatively high density of hydrogen nuclei n H that is comparable to those of low-z (U)LIRGs, quasars, and Galactic star-forming regions with high n H values, while the other two LBGs have lower n H consistent with local star-forming galaxies. By carefully taking account of various uncertainties, we obtain constraints on total gas mass and gas surface density from their CO luminosity measurements. We find that J0235–0532 is located below the Kennicutt–Schmidt (KS) relation, comparable to the z = 5.7 LBG, HZ10, previously detected with CO(2–1). Combined with previous results for dusty starbursts at similar redshifts, the KS relation at z = 5–6 is on average consistent with the local one.

Morphological Changes of Glial Lamina Cribrosa of Rats Suffering from Chronic High Intraocular Pressure.

Deformations or remodeling of the lamina cribrosa (LC) induced by elevated intraocular pressure (IOP) are associated with optic nerve injury. The quantitative analysis of the morphology changes of the LC will provide the basis for the study of the pathogenesis of glaucoma. After the chronic high-IOP rat model was induced by cauterizing episcleral veins with 5-Fluorouracil subconjunctival injection, the optic nerve head (ONH) cross sections were immunohistochemically stained at 2 w, 4 w, 8 w, and 12 w. Then the sections were imaged by a confocal microscope, and six morphological parameters of the ONH were calculated after the images were processed using Matlab. The results showed that the morphology of the ONH changed with the duration of chronic high IOP. The glial LC pore area fraction, the ratio of glial LC pore area to the glial LC tissue area, first decreased at 2 w and 4 w and then increased to the same level as the control group at 8 w and continued to increase until 12 w. The number and density of nuclei increased significantly at 8 w in the glial LC region. The results might mean the fraction of glial LC beam increased and astrocytes proliferated at the early stage of high IOP. Combined with the images of the ONH, the results showed the glial LC was damaged with the duration of chronic elevated IOP.

A hybrid GNA instability

A semi-analytic admixed model formalism to study the stability effects of the inner crust regions against the local collective perturbations in non-rotating neutron stars is proposed. It consists of the viscoelastic heavy neutron-rich nuclei, superfluid neutrons, and degenerate quantum electrons. A normal spherical mode analysis yields a generalized linear dispersion relation multiparametrically mimicking the inner crust features of neutron stars. A hybrid gravito-nucleo-acoustic (GNA) instability mode is found to be excited. It is demonstrated that the electron density and the inner crust curvature act as its accelerating and antidispersive agents. In contrast, the heavy neutron-rich nucleus and neutron densities act as decelerating factors. The heavy nucleus density, electron density, and geometric curvature act as its destabilizers. It is only the neutron density that acts as the GNA stabilizing agent. The heavy neutron-rich nucleus and neutron densities are found to act as dispersive broadening factors to it. The high-K regions are the more unstable spectral windows indicating that the GNA mode plays a dominant role in the inner crust zone towards the local stability. Its fair reliability is indicated in light of the recent astronomic observed scenarios. It could be useful to explore acoustic mode signatures in non-rotating neutron stars and similar other compact astroobjects.

Ultra-magnifying Imaging of Thoracoscopic Biopsy Specimens Using Ex vivo Endocytoscopy in Three Patients with Mesothelioma.

We performed endocytoscopy (ECS) for the ex vivo evaluation of mesothelioma in specimens biopsied during medical thoracoscopy in three patients. We evaluated 19 biopsy specimens based on the density of nuclei and irregularity in the nuclei shape using ECS and compared them with the histopathological findings. All 10 specimens considered malignant based on ECS were diagnosed as malignant based on histopathology. The nine specimens evaluated as non-malignant based on ECS consisted of six specimens diagnosed as malignant based on histopathology and three diagnosed as non-malignant based on histopathology. ECS was feasible and had some utility for ex vivo ultra-magnifying imaging of thoracoscopic biopsy specimens from patients with mesothelioma.

Cellular Cytosolic Energy Replenishment Increases Vascularized Composite Tissue Tolerance to Extended Cold Ischemia Time.

Vascularized composite allotransplantation (VCA) is a restorative surgical procedure to treat whole or partially disfiguring craniofacial or limb injuries. The routine clinical use of this VCA surgery is limited using compromised allografts from deceased donors and by the failure of the current hypothermic preservation protocols to extend the allograft's cold ischemia time beyond 4 h. We hypothesized that the active replenishment of the cellular cytosolic adenosine-5`-triphosphate (ATP) stores by means of energy delivery vehicles (ATPv) encapsulating high-energy ATP is a better strategy to improve allograft's tolerance to extended cold ischemia times. We utilized established rat model of isolated bilateral in-situ non-cycled perfusions of both hind limbs. Ipsilateral and contralateral limbs in the anesthetized animal were randomized for simultaneous perfusions with either the University of Wisconsin (UW) solution, with/without O2 supplementation (control), or with the UW solution supplemented with the ATPv, with/without O2 supplementation (experimental). Following perfusion, the hind limbs were surgically removed and stored at 4°C for 12, 16, or 24 hours as extended cold ischemia times. At the end of each respective storage time, samples of skin, and soleus, extensor digitalis longus, and tibialis anterior muscles were recovered for assessment using tissue histology and tissue lysate studies. Control muscle sections showed remarkable microvascular and muscle damage associated with loss of myocyte transverse striation and marked decrease in myocyte nucleus density. A total of 1,496 nuclei were counted in 179 sections of UW-perfused control muscles in contrast to 1,783 counted in 130 sections of paired experimental muscles perfused with the ATPv-enhanced perfusate. This yielded 8 and 13 nuclei/field for the control and experimental muscles, respectively (P < .004). Oxygenation of the perfusion solutions before use did not improve the nucleus density of either the control or experimental muscles (n = 7 animals, P > .05). Total protein isolated from the muscle lysates was similar in magnitude regardless of muscle type, perfusion protocol, or duration of cold ischemia time. Prolonged static cold preservation of the hind limbs completely degraded the composite tissue's Ribonucleic acid (RNA). This supplementary result confirms the notion that that reverse transcription-Polymerase Chain Reaction, enzyme-linked immunosorbent assay, or the respiratory complex II enzyme activity techniques should not be used as indices of graft quality after prolonged static cold storage. In conclusion, this study demonstrates that active cellular cytosolic ATP replenishment increases hind limb composite tissue tolerance to extended cold ischemia times. Quality indicators and clinically relevant biomarkers that define composite tissue viability and function during static cold storage are warranted.

Study of the Klein–Gordon equation for a hydrogenic model of dyons

This paper presents the generalization of a zero spin hydrogen atom to a relativistic atomic model of hydrogen with dyons using the Klein–Gordon equation. The derivation of the Klein–Gordon equation for the particle of relative motion is shown. In addition, the analytical solutions of the equation are calculated in terms of Whittaker functions and Jacobi weighted polynomials. The discrete spectrum of energy and the charge density of the orbiting dyon are presented. For a system of positive magnetic and electric charges in the nucleus and negative charges for the orbiting particle, and considering the first allowed values of [Formula: see text] and [Formula: see text], it was found that the dyon atom acts with a greater force of interaction between the charges of the nucleus and the secondary particle compared to the standard atom. It was obtained by comparing the distance between the nucleus and charge density concentrations from the dyon atom with the relativistic pionic atom.

Classification of breast cancer histology images using MSMV-PFENet

Deep learning has been used extensively in histopathological image classification, but people in this field are still exploring new neural network architectures for more effective and efficient cancer diagnosis. Here, we propose multi-scale, multi-view progressive feature encoding network (MSMV-PFENet) for effective classification. With respect to the density of cell nuclei, we selected the regions potentially related to carcinogenesis at multiple scales from each view. The progressive feature encoding network then extracted the global and local features from these regions. A bidirectional long short-term memory analyzed the encoding vectors to get a category score, and finally the majority voting method integrated different views to classify the histopathological images. We tested our method on the breast cancer histology dataset from the ICIAR 2018 grand challenge. The proposed MSMV-PFENet achieved 93.0% and 94.8% accuracies at the patch and image levels, respectively. This method can potentially benefit the clinical cancer diagnosis.

(Invited) Addressing Key Process and Material Challenges to Enable 2D Transition Metal Dichalcogenide Channels in Advanced Logic Devices

Two dimensional ultrathin layers are considered promising materials to bring new functionalities in nanotechnologies and candidate to replace 3D materials in existing applications. Among this last category, transition metal dichalcogenides (TMDC) like WS2, MoS2, WSe2 are viewed as interesting alternative channels for ultra-scaled CMOS technologies, as silicon is approaching its physical limits. These semiconductor 2D monolayers could bring a decisive advantage in terms of electrostatic control at very low gate length, while maintaining decent carrier transport properties as compared to 3D materials at same dimension. In addition, TMDC should provide improved off current performance as compared to silicon, an important factor to improve the static power efficiency in multibillion transistor chips. Obviously, replacing the channel material of the main device in microelectronics, from silicon to TMDC, comes with a very long list of scientific and technological challenges to be addressed. In this paper we limit our scope to the growth of TMDC, one of the main pillar in this global effort, and share how we addressed some of the challenges related to the formation of 2D semiconductor channels, to enable the fabrication of functioning devices on lab and 300 mm flows.TMDCs thin films grown with metal oxide CVD on substrates with, in some case, the presence of NaCl salts, are demonstrating the largest grain size and the best electrical performance but these processes are hardly compatible with industrial CVD reactors. In contrast we use chemistries more compatible with manufacturing, with the target of growing TMDC on 300 mm substrates. We report on MoS2 and WS2 formed with chemistries using metal organic precursors such as Mo(CO)6 or W(CO)6 and di-hydrogen sulfide grown in customized epitaxial cross flow 200 and 300 mm reactors [1]. We report basic nucleation and growth studies over a large process domain which show the possibility to control the density of nuclei and the subsequent lateral crystal growth while minimizing secondary nucleation and metal particle defectivity.We study the deposition of MoS2 an WS2 on two basic types of substrates defining fundamentally the integration schemes. On one route, dedicated to device performance demonstration, TMDC monolayers are grown on templated substrates like sapphire following a van der Waals epitaxy mode which enables regular orientation of the crystallites and formation of large and oriented domains after grain ripening with reduced defect concentration. The 2D layer is then transferred onto the final substrate for the device formation. With this technique, average mobilities above 30 cm2/Vs have been achieved regularly on MoS2 backgated devices, and the best devices exhibit currents at transfer curve up to 420 mA/mm [2,3]. On the other flow, recent efforts have aimed at growing WS2 directly on various types of amorphous substrate layer typically deposited on 300mm wafer, acting either as bottom gate dielectric or sacrificial layer. This scheme doesn’t require subsequent transfer step. However, after integration, these materials demonstrate performance still substantially lower than with material grown on sapphire [4,5].As the device dimensions has scaled down over the last 20 years, improving the variability at different scales has emerged as major topic in microelectronics. TMDC channels are no exception to this trend despite intrinsic advantage in terms of thickness control. We will share on specific work done on sapphire surface specification and preparation. We have demonstrated that depositing MoS2 on 1° off-A axis C-plane sapphire substrate reduced the dispersion in mobility as compared to similar materials obtained on C-plane oriented on-axis substrates [6]. We have also worked-out in-situ Cl2 etch process to remove the superficial islands grown on top of the first layer MoS2 crystals as this first layer is being closed. The process enables full lateral etching of the secondary layer crystals selectively to the closed first layer. With this process, we observed substantial improvement in the electrostatic control of MoS2 scaled transistors, including threshold voltage variability and improved subthreshold swing control [7].We continue to work out the TMDC growth process to improve the material quality, impacted by the presence of defects at the grain boundaries or intra-grain, aiming to close the gap with advanced logic requirements.1-Caymax & al., SSDM, D-1-03, 20192-D Lin & al., Symposium on VLSI Technology, 1-2, 20213- Wu & al., IEDM, 7.4.1-7.4.4, 20214- Asselberghs & al., IEDM, 40.2.1- 40.2.4, 20205- Smets & al., IEDM, 34.2.1-34.2.4, 20216- Shi & al., ACS nano 15 (6), 9482-9494, 20217- Shi & al., IEDM, 37.1.1-37.1.4, 2021

Correction of postkeratoplastic ametropia in patients with cataract

BACKGROUND: Penetrating keratoplasty leads, on the one hand, in 100% of cases, to the formation of induced astigmatism of variable degree, on the other hand, to a decrease in the density of endothelial cells of the corneal graft, which can reach from 19.1 to 38.3%. Thus, today the task of safe cataract extraction with minimal loss of density of endothelial cells and maximal correction of corneal astigmatism by the aid of an implantation of a toric intraocular lens is paramount.&#x0D; AIM: The aim of the study is to conduct a clinical and functional analysis of cataract phacoemulsification with a toric intraocular lens implantation in patients after previously performed penetrating keratoplasty.&#x0D; MATERIALS AND METHODS: We performed phacoemulsification with implantation of a toric intraocular lens in 25 eyes (25 patients) having a history of penetrating keratoplasty. The 1st degree of the lens nucleus density (according to Buratto classification) was noted in 4 eyes, the 2nd degree in 17 eyes, the 3rd degree in 4 eyes. According to keratotopography, all patients had a symmetrical type of postkeratoplastic astigmatism. The average follow-up period was 1 year.&#x0D; RESULTS: Intra- and postoperative complications were noted. One month after surgery, uncorrected visual acuity increased from an average of 1.3 1.6 to 0.3 0.9 LogMAR, best corrected visual acuity increased from 1.0 1.18 to 0.1 0.9 LogMAR, refractive astigmatism decreased from 7.5 2.43 to 1.43 0.38 D, and did not change during 1 year of follow-up. The density of endothelial cells decreased by 9% 1 year after surgery.&#x0D; CONCLUSIONS: Cataract phacoemulsification with a toric intraocular lens implantation in patients after previously performed penetrating keratoplasty allows achieving high refractive results. Preoperative analysis of endothelial cell density, careful approach to the intraocular lens calculation, and standard protocol of phacoemulsification make this operation predictable and safe.

Formation of imperfect crystals in poly(ε-caprolactone) at high melt-supercooling

• Fast scanning calorimetry permits homogeneous crystal nucleation in PCL. • Crystallization of PCL near the glass transition yields non-lamellar, imperfect crystals. • Low-temperature crystallization of PCL suppresses spherulitic crystal growth. Poly(ε-caprolactone) (PCL) was crystallized at high melt-supercooling in a fast scanning chip calorimeter, with this instrumentation needed to reach the temperature range of homogenous crystal nucleation by fast cooling the melt. Subsequently, after slow heating the polymer to ambient temperature, the semicrystalline morphology and X-ray structure were evaluated. Nucleation and crystallization at low temperature yields a featureless structure at the micrometer-length scale, indicating non-spherulitic crystal growth. Images of the nanometer-scale structure suggest presence of irregular grown short lamellae or particle-like domains, and the absence of sharp peaks in the X-ray scattering pattern indicates formation of small or defective crystals. In conclusion, due to the high nuclei density, crystallization of PCL near the glass transition leads to formation of imperfect crystals, and slow heating to ambient temperature does not allow their reorganization to yield long-range orthorhombic order, typically observed on crystallization at low melt-supercooling.

A novel bistable device to study mechanosensitive cell responses to instantaneous stretch

The behavior of cells and tissues in vivo is determined by the integration of multiple biochemical and mechanical signals. Of the mechanical signals, stretch has been studied for decades and shown to contribute to pathophysiological processes. Several different stretch devices have been developed for in vitro investigations of cell stretch.In this work, we describe a new 3D-printed uniaxial stretching device for studying cell response to rapid deformation. The device is a bistable compliant mechanism holding two equilibrium states—an unstretched and stretched configuration—without the need of an external actuator. Furthermore, it allows multiple simultaneous measurements of different levels of stretch on a single substrate and is compatible with standard immunofluorescence imaging of fixed cells as well as live-cell imaging.To demonstrate the effectiveness of the device to stretch cells, a test case using aligned myotubes is presented. Leveraging material area changes associated with deformation of the substrate, changes in nuclei density provided evidence of affine deformation between cells and substrate. Furthermore, intranuclear deformations were also assessed and shown to deform non-affinely.As a proof-of-principle of the use of the device for mechanobiological studies, we uniaxially stretched aligned healthy and dystrophic myotubes that displayed different passive mechanical responses, consistent with previous literature in the field. We also identified a new feature in the mechanoresponse of dystrophic myotubes, which is of potential interest for identifying the diseased cells based on a quick mechanical readout. While some applications of the device for elucidating passive mechanical responses are demonstrated, the simplicity of the device allows it to be potentially used for other modes of deformation with little modifications.

SOFIA FEEDBACK Survey: PDR Diagnostics of Stellar Feedback in Different Regions of RCW 49

We quantified the effects of stellar feedback in RCW 49 by determining the physical conditions in different regions using the [C ii] 158 μm and [O i] 63 μm observations from SOFIA, the 12CO (3–2) observations from APEX, and the H2 line observations from Spitzer telescopes. Large maps of RCW 49 were observed with the SOFIA and APEX telescopes, while the Spitzer observations were only available toward three small areas. From our qualitative analysis, we found that the H2 0–0 S(2) emission line probes denser gas compared to the H2 0–0 S(1) line. In four regions (“northern cloud,” “pillar,” “ridge,” and “shell”), we compared our observations with the updated PDR Toolbox models and derived the integrated far-ultraviolet flux between 6 and 13.6 eV (G 0), H nucleus density (n), temperatures, and pressures. We found the ridge to have the highest G 0 (2.4 × 103 Habing units), while the northern cloud has the lowest G 0 (5 × 102 Habing units). This is a direct consequence of the location of these regions with respect to the Wd2 cluster. The ridge also has a high density (6.4 × 103 cm−3), which is consistent with its ongoing star formation. Among the Spitzer positions, we found the one closest to the Wd2 cluster to be the densest, suggesting an early phase of star formation. Furthermore, the Spitzer position that overlaps with the shell was found to have the highest G 0, and we expect this to be a result of its proximity to an O9V star.

Thermal behavior of Li electrode in all-solid-state batteries and improved performance by temperature modulation

All-solid-state lithium metal batteries (ASSLMBs) hold tremendous promise in electric vehicles and portable electronic devices owing to the remarkably improved safety and energy density. However, the uncontrollable Li dendrites seriously hinder the cycling performance of ASSLMBs, and the fickle environment urgently requires a reliable energy supply over a wide temperature range. Understanding the temperature-dependent behavior of Li metal electrode holds great significance for breaking the bottleneck. Herein, we experimentally and theoretically investigate the temperature-dependent morphological evolution of electrodeposited Li in solid electrolyte from -20 °C to 90 °C. It is found that as temperature increases, nuclei size, nuclei density, structural compactness and growth direction of electrodeposited Li are significantly altered. The thermal effect on Li nucleation and growth is further revealed by molecular dynamics simulations. Based on this, we propose a temperature modulation strategy to improve the cyclability of Li metal electrode. By charging at the optimal temperature, the cycling life and Coulomb efficiency of Li electrode can be simultaneously improved. Our investigation gives valuable insights towards temperature-dependent Li deposition in solid electrolyte and will provide rational guidance for the thermal management of ASSLMBs operated in extreme environments.