Apparent Enhancement Research Articles

Tolerance of Tetraselmis tetrathele to High Ammonium Nitrogen and Its Effect on Growth Rate, Carotenoid, and Fatty Acids Productivity.

Microalgae can use either ammonium or nitrate for its growth and vitality. However, at a certain level of concentration, ammonium nitrogen exhibits toxicity which consequently can inhibit microalgae productivity. Therefore, this study is aimed to investigate the tolerance of Tetraselmis tetrathele to high ammonium nitrogen concentrations and its effects on growth rate, photosynthetic efficiency (Fv/Fm), pigment contents (chlorophyll a, lutein, neoxanthin, and β-carotene), and fatty acids production. Experiments were performed at different ammonium nitrogen concentrations (0.31–0.87 gL−1) for 6 days under a light source with an intensity of 300 μmol photons m−2 s−1 and nitrate-nitrogen source as the experimental control. The findings indicated no apparent enhancement of photosynthetic efficiency (Fv/Fm) at high levels of ammonium nitrogen (-N) for T. tetrathele within 24 h. However, after 24 h, the photosynthetic efficiency of T. tetrathele increased significantly (p < 0.05) in high concentration of -N. Chlorophyll a content in T. tetrathele grown in all of the different -N levels increased significantly compared to nitrate-nitrogen (NO3-N) treatment (p < 0.05); which supported that this microalgal could grow even in high level of -N concentrations. The findings also indicated that T. tetrathele is highly resistant to high ammonium nitrogen which suggests T. tetrathele to be used in the aquaculture industry for bioremediation purpose to remove ammonium nitrogen, thus reducing the production cost while improving the water quality.

Hydrodynamics in lattice models with continuous non-Abelian symmetries

We develop a systematic effective field theory of hydrodynamics for many-body systems on the lattice with global continuous non-Abelian symmetries. Models with continuous non-Abelian symmetries are ubiquitous in physics, arising in diverse settings ranging from hot nuclear matter to cold atomic gases and quantum spin chains. In every dimension and for every flavor symmetry group, the low energy theory is a set of coupled noisy diffusion equations. Independence of the physics on the choice of canonical or microcanonical ensemble is manifest in our hydrodynamic expansion, even though the ensemble choice causes an apparent shift in quasinormal mode spectra. We use our formalism to explain why flavor symmetry is qualitatively different from hydrodynamics with other non-Abelian conservation laws, including angular momentum and charge multipoles.As a significant application of our framework, we study spin and energy diffusion in classical one-dimensional SU(2)-invariant spin chains, including the Heisenberg model along with multiple generalizations. We argue based on both numerical simulations and our effective field theory framework that non-integrable spin chains on a lattice exhibit conventional spin diffusion, in contrast to some recent predictions that diffusion constants grow logarithmically at late times. We show that the apparent enhancement of diffusion is due to slow equilibration caused by (non-Abelian) hydrodynamic fluctuations.

A new lightweight cryptographic algorithm for enhancing data security in cloud computing

Data has been pivotal to all facets of human life in the last decades. In recent years, the massive growth of data as a result of the development of various applications. This data needs to be secured and stored in secure sites. Cloud computing is the technology can be used to store those massive amounts of data. . The rapid development of this technology makes it more critical. Therefore, it has become urgent to secure data from attackers to preserve its integrity, confidentiality, protection, privacy and procedures required for handling it. This paper proposed a New Lightweight Cryptographic Algorithm for Enhancing Data Security that can be used to secure applications on cloud computing. The algorithm is a 16 bytes (128-bit) block cipher and wants 16 bytes (128-bit) key to encrypt the data. It is inspired by feistal and substitution permutation architectural methods to improve the complexity of the encryption. The algorithm achieves Shannon's theory of diffusion and confusion by the involvement of logical operations, such as (XOR, XNOR, shifting, swapping). It also features flexibility in the length of the secret key and the number of turns. The experimental results of the proposed algorithm presented a strong security level and an apparent enhancement in measures of cipher execution time and security forces compared to the cryptographic systems widely used in cloud computing.

Enhancement of the molecular orientation of TPBi in coevaporated films of UGH‐2 host molecules

In this study, we investigated the spontaneous orientation polarization (SOP) in coevaporated films of polar and nonpolar molecules. SOP has been commonly observed in the evaporated films of organic light‐emitting diode materials, and it influences the device performances. However, the mechanism of the SOP formation is yet to be clarified. Herein, we characterized the molecular orientation of polar molecules of 1,3,5‐tris (1phenyl‐1H‐benzimidazol‐2‐yl) benzene (TPBi) in coevaporated films with nonpolar molecules of 1,4‐bis‐(triphenylsilyl) benzene (UGH‐2) or 4,4′‐bis (N‐carbazolyl)‐1,1′‐biphenyl (CBP). We measured the surface potential characteristics of the coevaporated films. We found that the molecular orientation of TPBi in both UGH‐2 and CBP hosts was enhanced, though the apparent enhancement factor was small in the UGH‐2 host. The enhancement of the molecular orientation is attributed to the reduction of the electrostatic interaction between polar molecules (TPBi), which deteriorates SOP as previously reported. In addition, our results suggest that the SOP of TPBi is robust even in the UGH‐2 host, in contrast to the random orientation of Ir complexes in the UGH‐2 host. Considering a polyhedral shape of Ir complexes, the robust SOP of TPBi in the host molecules with a weak van der Waals interaction, such as UGH‐2, is possibly due to its disk‐like molecular shape.

Combinatorial Passivation Study in the Aluminium-Samarium System for Basic Property Mapping and Identification of Secondary Phase Influence

An aluminium-samarium binary library with a varying Sm concentration between 4 to 14 at.% was produced using a thermal co-evaporation technique. Morphological and crystallographic characterization of the parent metal alloys revealed compositionally dependent surface structure and atomic arrangements. Grains resembling pure Al on the surface slowly disappeared with increasing Sm content and above 8 at.% Sm nucleation of the AlSm2 intermetallic phase was observed. Scanning droplet cell microscopy was used for a comprehensive electrochemical characterization along the Al-Sm compositional gradient. Anodic oxide formation under high field conditions was discussed for alloys below the compositional threshold of 8 at.% Sm. Above this threshold a continuous increase of Sm dissolution during anodization with increasing Sm concentration was proven by inductively coupled plasma optical emission spectroscopy. Coulometry followed by EIS allowed mapping of the oxide formation factors and oxide electrical permittivity as material constants for single Al-Sm alloys. A small increase of both material constants for alloys below the compositional threshold described the Sm contribution to the anodization process. An apparent enhancement of their values at alloys above the threshold was directly attributed to the increased Sm dissolution rates reaching values of 2 ng cm−2 s–1 at 12 at.% Sm.

A new data security algorithm for the cloud computing based on genetics techniques and logical-mathematical functions

With the rapid development of distributed system technologies, one of the biggest challenges facing the digital world is ensuring the security of sensitive and confidential data during transport and storage, which are considered the most critical challenges facing cloud computing. There are many techniques to enhance data security on cloud computing storage environment. Encryption is the most significant method for data protection. Therefore, many available encryption algorithms are used to provide security, integrity, and authorized access using many methods such as DNA. However, they still have some limitations. In this paper, a novel variant of cryptography techniques is designed to improve cloud computing security by using two layers of encryption. The first layer is inspired by Shannon’s theory of diffusion and confusion by the involvement of logical operations, such as (XOR, XNOR, shifting) with split the original plaintext and key into equal parts. The second layer is inspired from structures of genetics based on the Central Dogma of Molecular Biology for cryptographic purpose through simulation of the natural processes of genetic cryptography (translation from binary to DNA bases), transcription (regeneration from DNA to mRNA), and translation (regeneration from mRNA to protein). The experimental results enhanced data security that can be used to secure applications on cloud computing. The proposed algorithm’s experimental results presented a strong security level, an apparent enhancement of cipher size and execution time compared to existing techniques widely used in cloud computing.

Isotopic equilibrium constants for very low-density and low-temperature nuclear matter

Yields of equatorially emitted light isotopes, $1\le Z\le 14$, observed in ternary fission in the reaction $^{241}$Pu($n_{\rm th}$,f) are employed to determine apparent chemical equilibrium constants for low-temperature and low-density nuclear matter. The degree of liberation and role of medium modifications are probed through a comparison of experimentally derived reaction quotients with equilibrium constants calculated using a relativistic mean-field model employing a universal medium modification correction for the attractive $\sigma$ meson coupling. The results of these comparisons indicate that equilibrium is achieved for the lighter ternary fission isotopes. For the heavier isotopes experimental reaction quotients are well below calculated equilibrium constants. This is attributed to a dynamical limitation reflecting insufficient time for full equilibrium to develop. The role of medium effects leading to yield reductions is discussed as is the apparent enhancement of yields for $^8$He and other very neutron rich exotic nuclei.

Rational Design of Pillared SnS/Ti3C2Tx MXene for Superior Lithium-Ion Storage.

MXenes have been widely explored in energy storage because of their extraordinary properties; however, the majority of research on their application was staged at multilayered MXenes or assisted by carbon materials. Scientifically speaking, the two most distinctive properties of MXenes are usually neglected, composed of large interlayer spacing and abundant surface chemistry, which distinguish MXenes from other two-dimensional materials. Herein, few-layered MXene (f-MXene) nanosheet powders can be easily prepared according to the modified solution-phase flocculation method, completely avoiding the restacking phenomenon of f-MXene nanosheets in preparation and oxidation issues during the storage process. Via further employing the solvothermal reaction and annealing treatment, we successfully constructed pillared SnS/Ti3C2Tx composites decorated with in situ formed TiO2 nanoparticles. In the composites, MXenes can play the role of a conductive network, a buffer matrix for volume expansion of SnS, while the active SnS nanoplates can fully deliver the advantage of high capacity and further induce interlayer engineering of Ti3C2Tx during cycling. As a result, the pillared SnS/Ti3C2Tx MXene composites exhibit obvious improvement in electrochemical performance. Interestingly, there is an apparent enhancement of capacity at succedent cycling, which can be ascribed to the "pillar effect" of Ti3C2Tx MXenes. The efforts and attempts made in this work can further broaden the development of pillared MXene composites.

Bubble nucleation on grooved surfaces with hybrid wettability: Molecular dynamics study under a transient temperature boundary condition

Mechanisms of bubble nucleation need a better understanding, especially for heterogeneous surfaces with different wettability. In this study, the bubble nucleation and the heat transfer performance on grooved surfaces with different hybrid wettability under a transient temperature boundary condition was investigated by characterizing the contact-line movement using molecular dynamics simulation. The bubble growth rate on the all-hydrophilic groove is faster than the other grooved surfaces. The grooved surfaces with patterned wettability, especially the BphoSphi (hydrophobic bottom wall and hydrophilic sidewall) surface, can facilitate the nucleation of the bubble. Meanwhile, an apparent enhancement of the maximum heat flux was found for the BphiSpho (hydrophilic bottom wall and hydrophobic sidewall) surface. This work provides insights into the mechanisms of enhancing the boiling heat transfer under irradiation condition by the contact line movement during bubble nucleation on structured surfaces.

Analysis of the rate of combustion of biomass char in a fluidised bed of CLOU particles

This research concerns the combustion of biomass char in a fluidised bed using Chemical Looping Combustion with Oxygen Uncoupling (CLOU). To evaluate the influence of the CLOU material on the rate of combustion, an analytical model has been developed, based on a simplified scenario, i.e. gaseous mass transfer external to the fuel particle was taken as a stagnant system, ignoring advective flow. The combustion of a char particle was modelled as a shrinking particle. Results from the model were compared with experiments performed by combusting char from birch-wood in a fluidised bed (i.d. 30 mm) of an active oxygen carrier (CuO supported on mayenite) or inert SiO2 sand. The experiments were undertaken with a partial pressure of oxygen, pO2, close to the equilibrium pressure of O2 of the Cu-based oxygen carrier. Despite the same pO2 for both experiments, the presence of the reaction of oxygen uncoupling from the oxygen carrier resulted in a significant increase in the combustion rate of char. As a result, at 1173 K, the burn-out time of 0.1 g of char particles with the oxygen carrier was around five times faster than with SiO2. The results from the analytical model of CLOU agreed with the experimental observations despite the simplified assumption of a stagnant system, viz. a system in which the mass transfer boundary layer, δ, is infinite. This is because the char combustion in CLOU depends, in fact, on gaseous mass transfer across an effective boundary thickness, δe, rather than a conventional boundary thickness for the system, δ. At 1023 K when the oxygen uncoupling did not occur, the enhancement in the rate of reaction due to the presence of the CLOU particle was less significant. The model was used to investigate the apparent enhancement of the combustion rate in CLOU, and possible explanations, including improved mass transfer, are discussed.

Sulfonate substituted rhodamine hydrophilic fluorescent probes: Application to specific detection of Fe3+ and imaging in living fish

Two Sulfonate substituted rhodamine hydrophilic fluorescent probes RbS1 and RbS2 were designed and synthesized for specific detection of Fe3+. It was found that the probe RbS2 was stronger than RbS1 in the water solubility test. Both of them displayed responses to Fe3+ with a apparent fluorescence enhancement at 585 nm, accompanied with a distinct fluorescence change to pink. Upon addition of Fe3+ ions (0–16 μM), the emission intensity of RbS1 and RbS2 increased to 40 and 70 fold, which exhibited a good linear relationship with the concentration of Fe3+. The detection limits of RbS1 and RbS2 for sensing Fe3+ were 0.64 μM and 0.56 μM, respectively. The binding ratios of the RbS1 and RbS2 to Fe3+ were 1:1 and the recycling ability for Fe3+ was reasonable. RbS1 and RbS2 have been successfully applied to the determination of Fe3+ in real water samples with satisfactory recovery and accuracy. In further living fish imaging test, the probe RbS2 was distributed into abdomen, which exhibited better fluorescence imaging ability than that of RbS1.

Comparison of Skin Dose for Brain Cancer Patients Between a 1.5 T MR-Linac and a Conventional Linac

The MR-Linac (MRL) is a new technology, and due to the presence of the electron return effect (ERE) elicited by the strong magnetic field, there is concern about there being elevated surface dose due to the ERE. The hypothesis is that the skin doses for the MRL is greater than for the conventional Linac. Six brain cancer patients being treated on our MRL were included in the present study and were planned with an IMRT technique using the MRL’s Monte Carlo based treatment planning system (TPS-MRL). Each patient had a back-up IMRT 6 MV plan for a conventional (no magnetic field) Linac generated on our standard TPS, which used a collapsed cone-based dose engine (TPS-conventional). These back-up plans were clinically delivered during an MRL preventative maintenance day, which provided an opportunity to compare skin dose measurements between MRL and conventional Linac. For one fraction on each Linac, an optically stimulated luminescence dosimeter (OSLD) was placed at the same location on the skin proximal to the target. Within TPS-MRL and TPS-conventional, a dose point was created at the OSLD location and at a skin depth equivalent to the water equivalent thickness of the OSLD (0.6 mm). Five of six patients had higher OSLD readings on the MRL than for the conventional Linac, ranging from 11.5%-24.8% higher (the one exception had the MRL 7.5% less than the conventional Linac). The OSLD measurement for the MRL ranged from 11.8-45.7 Gy; the OSLD doses for the conventional Linac ranged from 10.0-39.4 Gy. The root mean square error between measurement and TPS was 7.3% and 17.4% for MRL and conventional, respectively. This may be explained because the conventional Linac TPS uses a superposition-convolution algorithm, and the MRL TPS uses a theoretically more accurate Monte Carlo algorithm. Skin dose, as determined in the present study with in vivo OSLD measurements, were higher on the MRL than a conventional Linac for brain patients. Furthermore, the skin dose as estimated by the TPS-MRL is more accurately modeled compared to the TPS-conventional. Although the exact cause(s) of the apparent skin dose enhancement can only be speculated, the potential implications of the measurements in the present study include enhanced adverse skin reactions on the MRL compared to conventional Linac. However, the fact that the MRL-TPS models the surface dose with a Monte Carlo dose engine can enable clinicians to incorporate strategies for reducing surface dose at the planning stage.

Improving the performances of CsPbBr3 solar cells fabricated in ambient condition

Inorganic perovskite cesium lead bromide (CsPbBr3) gets extensive attention due to its superb stability and moisture-tolerance feature. Here, solution-processed CsPbBr3 perovskite films and their based solar cells were fabricated in ambient condition. The effect of post-annealing on the properties of the CsPbBr3 film grown and the photoelectric performance of perovskite solar cells (PSCs) have been systematically investigated, which enhances the device power conversion efficiency (PCE) from 2.67 to 5.20%. Moreover, by doping mesoporous TiO2 (m-TiO2) with reduced graphene oxide (RGO), the PCE of solar cells attained an apparent enhancement and finally improved to 7.08%. Not only high-quality CsPbBr3 perovskite films but also high-performance mesoporous PSCs were obtained by film post-annealing and electron transport layer (ETL) doping, which were all fabricated in ambient conditions.

N−nH complexes in GaAs studied at the atomic scale by cross-sectional scanning tunneling microscopy

Hydrogenation of nitrogen (N) doped GaAs allows for reversible tuning of the bandgap and the creation of site controlled quantum dots through the manipulation of N-nH complexes, N-nH complexes, wherein a nitrogen atom is surrounded by n hydrogen (H) atoms. Here we employ cross-sectional scanning tunneling microscopy (X-STM) to study these complexes in the GaAs (110) surface at the atomic scale. In addition to that we performed density functional theory (DFT) calculations to determine the atomic properties of the N-nH complexes. We argue that at or near the (110) GaAs surface two H atoms from N-nH complexes dissociate as an H$_2$ molecule. We observe multiple features related to the hydrogenation process, of which a subset is classified as N-1H complexes. These N-1H related features show an apparent reduction of the local density of states (LDOS), characteristic to N atoms in the GaAs (110) surface with an additional apparent localized enhancement of the LDOS located in one of three crystal directions. N-nH features can be manipulated with the STM tip. Showing in one case a switching behavior between two mirror-symmetric states and in another case a removal of the localized enhancement of the LDOS. The disappearance of the bright contrast is most likely a signature of the removal of an H atom from the N-nH complex.

Single-molecule diffusometry reveals no catalysis-induced diffusion enhancement of alkaline phosphatase as proposed by FCS experiments

Theoretical and experimental observations that catalysis enhances the diffusion of enzymes have generated exciting implications about nanoscale energy flow, molecular chemotaxis, and self-powered nanomachines. However, contradictory claims on the origin, magnitude, and consequence of this phenomenon continue to arise. To date, experimental observations of catalysis-enhanced enzyme diffusion have relied almost exclusively on fluorescence correlation spectroscopy (FCS), a technique that provides only indirect, ensemble-averaged measurements of diffusion behavior. Here, using an anti-Brownian electrokinetic (ABEL) trap and in-solution single-particle tracking, we show that catalysis does not increase the diffusion of alkaline phosphatase (ALP) at the single-molecule level, in sharp contrast to the ∼20% enhancement seen in parallel FCS experiments using p-nitrophenyl phosphate (pNPP) as substrate. Combining comprehensive FCS controls, ABEL trap, surface-based single-molecule fluorescence, and Monte Carlo simulations, we establish that pNPP-induced dye blinking at the ∼10-ms timescale is responsible for the apparent diffusion enhancement seen in FCS. Our observations urge a crucial revisit of various experimental findings and theoretical models--including those of our own--in the field, and indicate that in-solution single-particle tracking and ABEL trap are more reliable means to investigate diffusion phenomena at the nanoscale.

An unusual case of melanoma metastasis in the buccal space: learning by mistakes to distinguish it from salivary neoplasms

BackgroundThe buccal space is an unusual location of malignancies. We report here the case of a woman with a melanoma metastasis in buccal fat pad, to evaluate the imaging features which might lead to the correct, although uncommon, diagnosis.Case presentationA 71-year-old woman presented with a painless visible swelling of the left cheek. MRI revealed the presence of a solid lesion located in the buccal fat pad with features suggestive of malignancy. It showed T1 hyperintensity and T2 hypointensity, and restriction of diffusion. Histological examination showed neoplastic cells compatible with melanoma.DiscussionThe lesion features (T1 hyperintensity and T2 hypointensity) initially lead our team to believe that there was a hemorrhagic component, possibly a residue of the biopsy. However, when associated with other malignancy features, such as low apparent diffusion coefficient (ADC) values and contrast enhancement, they should evoke the suspect of melanoma, provided that no biopsy was performed and no trauma occurred in the 3–7 days before.

Synthesis of NaGdF4:Er3+/Yb3+ Upconversion Particles as Exogenous Contrast Agent for Swept-Source Optical Coherence Tomography: In Vitro Animal Tissue Imaging

Swept-source optical coherence tomography (SSOCT) is a noncontact, noninvasive bioimaging tool that uses various probes to obtain high contrast images. Rare-earth based upconversion particles (UCPs) provide a unique platform to enhance the capabilities of bioimaging techniques. The UCPs can act as contrast enhancers for the SSOCT with additional optical functionality, and hence in this work upconversion emission optimized polyvinylpyrrolidone (PVP)/NaGdF4:Er3+/Yb3+ UCPs were synthesized and then injected into chicken breast tissues to enhance the SSOCT images. As-synthesized samples have shown good biocompatibility toward HEK293, HeLa cell lines and showed apparent enhancement in contrast to SSOCT images. Additionally, compared to the bare NaGdF4:Er3+/Yb3+ UCPs the polyvinylpyrrolidone-stabilized UCPs have shown 3-fold enhancement in the frequency of upconverted green and red light intensity under 976 nm diode laser excitation (26 W/cm2).

Outcomes assessment in intrahepatic cholangiocarcinoma using qualitative and quantitative imaging features

BackgroundTo assess the performance of imaging features, including radiomics texture features, in predicting histopathologic tumor grade, AJCC stage, and outcomes [time to recurrence (TTR) and overall survival (OS)] in patients with intrahepatic cholangiocarcinoma (ICC).MethodsSeventy-three patients (26 M/47F, mean age 63y) with pre-operative imaging (CT, n = 37; MRI, n = 21; CT and MRI, n = 15] within 6 months of resection were included in this retrospective study. Qualitative imaging traits were assessed by 2 observers. A 3rd observer measured tumor apparent diffusion coefficient (ADC), enhancement ratios (ERs), and Haralick texture features. Blood biomarkers and imaging features were compared with histopathology (tumor grade and AJCC stage) and outcomes (TTR and OS) using log-rank, generalized Wilcoxon, Cox proportional hazards regression, and Fisher exact tests.ResultsMedian TTR and OS were 53.9 and 79.7 months. ICC recurred in 64.4% (47/73) of patients and 46.6% (34/73) of patients died. There was fair accuracy for some qualitative imaging features in the prediction of worse tumor grade (maximal AUC of 0.68 for biliary obstruction on MRI, p = 0.032, observer 1) and higher AJCC stage (maximal AUC of 0.73 for biliary obstruction on CT, p = 0.002, observer 2; and AUC of 0.73 for vascular involvement on MRI, p = 0.01, observer 2). Cox proportional hazards regression analysis showed that CA 19–9 [hazard ratio (HR) 2.44/95% confidence interval (CI) 1.31–4.57/p = 0.005)] and tumor size on imaging (HR 1.13/95% CI 1.04–1.22/p = 0.003) were significant predictors of TTR, while CA 19–9 (HR 4.08/95% CI 1.75–9.56, p = 0.001) and presence of metastatic lymph nodes at histopathology (HR 2.86/95% CI 1.35–6.07/p = 0.006) were significant predictors of OS. On multivariable analysis, satellite lesions on CT (HR 2.79/95%CI 1.01–7.15/p = 0.032, observer 2), vascular involvement on MRI (HR 0.10/95% CI 0.01–0.85/p = 0.032, observer 1), and texture feature MRI variance (HR 0.55/95% CI 0.31–0.97, p = 0.040) predicted TTR once adjusted for the independent predictors CA 19–9 and tumor size on imaging. Several qualitative and quantitative features demonstrated associations with TTR, OS, and AJCC stage at univariable analysis (range: HR 0.35–19; p < 0.001–0.045), however none were predictive of OS at multivariable analysis when adjusted for CA 19–9 and metastatic lymph nodes (p > 0.088).ConclusionsThere was reasonable accuracy in predicting tumor grade and higher AJCC stage in ICC utilizing certain qualitative and quantitative imaging traits. Serum CA 19–9, tumor size, presence of metastatic lymph nodes, and qualitative imaging traits of satellite lesions and vascular involvement are predictors of patient outcomes, along with a promising predictive ability of certain quantitative texture features.

Diagnostic performance of multi-parametric MRI to differentiate benign sex cord stromal tumors from malignant (non-stromal and stromal) testicular neoplasms.

Testicular stromal tumors are uncommon, although mostly benign. The purpose of this study is to assess the role of multi-parametric MRI in differentiating benign testicular stromal tumors from malignant testicular neoplasms (non-stromal and stromal). A single-center retrospective study comparing benign stromal tumors (STs) to malignant testicular neoplasms (MTNs) was conducted. MR imaging assessment included tumor size, T2- and T1-weighted signal intensity, T2- and T1-weighted texture pattern, diffusion restriction, presence of hemorrhage and/or necrosis, and measurement of apparent diffusion coefficient and dynamic contrast enhancement (DCE). Inter-observer agreement was assessed using Cohen's kappa and Bland-Altman and data were compared using independent t-tests or χ2. Receiver operating characteristic curve analysis was used to test models incorporating various imaging features. Radical orchiectomy and histopathology revealed 20 testicular neoplasms: seven STs (35%) and thirteen MTNs (65%). MTNs were significantly larger in size than STs (5.1 ± 2.36cm vs. 1.27 ± 0.56cm; p-value < 0.001). STs demonstrated more hypointense T2W signal (85.7% vs. 46.2%; p-value < 0.09), less T2W heterogeneous texture (14.3% vs. 61.5%; p-value < 0.04), and less diffusion restriction (16.7% vs. 83.3%; p-value < 0.01) in comparison to MTNs. STs demonstrated mainly homogenous post-contrast enhancement pattern (71.4% vs. 7.7%; p-value < 0.004), while MTNs showed primarily heterogeneous enhancement pattern (77% vs. 14.3%; p-value < 0.02). STs revealed greater corrected venous phase enhancement (STs: 0.59 ± 0.29; MTNs: 0.25 ± 0.25; p-value < 0.03). STs showed higher ADC values, though the difference was not statistically significant (p-value < 0.25). A model combining T2W, DWI, and DCE features showed the best overall diagnostic accuracy with area under ROC curve of 0.99 and confidence interval ranging from 0.94 to 1. Multi-parametric MRI can potentially differentiate benign stromal tumors from malignant testicular neoplasms, which can help to avoid radical orchiectomy. However, future studies using larger sample sizes are needed to validate our results.

Influence of acid leaching surface treatment on indentation cracking of soda lime silicate glass

Past work has shown that water or acid soaking treatments can increase the mechanical strength of soda lime silicate (SLS) glasses. In this work, we show that acid leaching treatments result in an increase in the apparent crack resistance of the acid-leached surface of SLS glass during indentation. Vickers indentation tests in controlled environments show a humidity dependence of radial cracking, suggesting that the transport of water through the leached layer plays a critical role in the propagation of cracks to the glass surface. Molecular dynamics simulations with reactive force fields indicate that the leached surface layer can undergo pressure-induced mechanochemical reactions during indentation, which increases the bridging oxygen connectivity in the silica network of the leached layer. Such structural changes can hinder transport of water molecules from the environment to the subsurface crack tip. Based on experimental observations and simulation results, a new hypothesis is proposed that mechanochemical restructuring in the leached layer in response to the applied load may lower the transport kinetics of molecular water to critical flaws, resulting in an apparent enhancement in the crack resistance of the acid-leached surface of SLS glass.