Photon penetration depth in human brain for light stimulation and treatment:A realistic Monte Carlo simulation study

Light has been clinically utilized as a stimulation in medical treatment,such as Low-level laser therapy and photodynamic thenapy,which has been more and more widely accepted in public.The penetration depth of the treatment light is important for precision treatment and safety control.The isue of light penetration has been highlighted in biomedical optics field for decades.However,quantitative research is sparse and even there are conflicts of view on the capability of near-infrared light penet ration into brain tissue.This study attempts to quantitatively revisit this issue by innovative high-realistic 3D Monte Caro modeling of stimulated light penetnation within high precision Visible Chinese human head.The properties of light,such as its wave-length,ilumination profle and size are concern in this study.We made stra ightforward and quantitative comparisons among the ffects by the light properties(i.e.,wavelengths:660,810 and 980 nn;beam types:Gaussi an and flat beamn;bear dianeters:0,2,4 and 6 cm)which are in the range of light treatment.The findings include about 3%of light dosage within brain tisue;the combination of Gaussian beam and 810nm light make the max imum light penetration(>5cm),which allows light to cross through gray matter into white mater.This study offered us,the first time as we know,quantitative guide for light stimulation parameter optimization in medical treatment.

Comparison of Rapid Freezing and Vitrification for Human Sperm Cryopreservation Using Trehalose as a Cryoprotective Agent

Rapid freezing and vitrification are becoming popular for human sperm cryopreservation;however, it remains unclear which method is better. The aims of the present study were to determine the optimal trehalose concentration and to compare the cryoprotective effects of rapid freezing and vitrification. The results showed that: 1) The optimal trehalose concentration was 0.25 mol/L;2) The post-thaw recovery rates of total and progressive sperm motilities after rapid freezing (38.6% ± 3.0% and 41.1% ± 5.0%) were significantly higher (P 0.05) than that after vitrification (26.1% ± 3.1% and 27.2% ± 1.3%) when 0.5 mL straws were used;3) However, the recovery rates of total and progressive motilities after rapid freezing in 0.5 mL straw (26.7% ± 9.6% and 26.8% ± 8.7%) were significantly lower (P 0.05) than that after vitrification in a novel straw-in-straw system (43.1% ± 4.2% and 41.8% ± 15.5%);and 4) The post-thaw sperm nuclear DNA damage level after rapid freezing in 0.5 mL straw (8.7% ± 2.8%) was not significantly different from that of sperm after vitrification in the straw-in-straw system (9.2% ± 2.5%). It was concluded that rapid freezing is superior to vitrification when using 0.5 mL straws;however, vitrification is superior to rapid freezing when using the straw-in-straw systems.

Effects of MTG and GSH on Human Sperm Motility and DNA Integrity during Vitrification in the Presence of Trehalose

Limited information exists about the effects of antioxidants on sperm motility and DNA integrity during vitrification in humans. This study compared the effects of reduced glutathione (GSH) and monothioglycerol (MTG) at different concentrations on post-thaw sperm motility and DNA integrity after vitrification in humans using 0.25 M trehalose as a cryoprotective agent, and found that supplementation of MTG or GSH at 0.5 mM resulted in significantly higher (P < 0.05) recovery rates of post-thaw total and progressive motilities. GSH was more powerful than MTG at the same concentration in cryoprotecting sperm motility (38.9% ± 3.6% vs 32.8% ± 2.4% compared to the control 26.8% ± 2.1% in recovery rate of progressive motility), but both had no significant influence on sperm DNA integrity during vitrification. It was concluded that sperm motility is more sensitive to oxidative stress during vitrification than sperm nuclear DNA, and supplementation of MTG or GSH in vitrification medium is beneficial in cryoprotecting sperm motility.

Stabilizing high-efficiency iridium single atoms via lattice confinement for acidic oxygen evolution

Stable and efficient single atom catalysts(SACs)are highly desirable yet challenging in catalyzing acidic oxygen evolution reaction(OER).Herein,we report a novel iridium single atom catalyst structure,with atomic Ir doped in tetragonal PdO matrix(IrSAs-PdO)via a lattice-confined strategy.The optimized IrSAs-PdO-0.10 exhibited remarkable OER activity with an overpotential of 277 mV at 10 mA·cm^(-2) and long-term stability of 1000 h in 0.5 M H_(2)SO_(4).Furthermore,the turnover frequency attains 1.6 s^(-1) at an overpotential of 300 mV with a 24-fold increase in the intrinsic activity.The high activity originates from isolated iridium sites with low valence states and decreased Ir–O bonding covalency,and the excellent stability is a result of the effective confinement of iridium sites by Ir–O–Pd motifs.Moreover,we demonstrated for the first time that SACs have great potential in realizing ultralow loading of iridium(as low as microgram per square center meter level)in a practical water electrolyzer.

Suppressing the lattice oxygen diffusion via high-entropy oxide construction towards stabilized acidic water oxidation

The scale-up deployment of ruthenium(Ru)-based oxygen evolution reaction(OER)electrocatalysts in proton exchange membrane water electrolysis(PEMWE)is greatly restricted by the poor stability.As the lattice-oxygen-mediated mechanism(LOM)has been identified as the major contributor to the fast performance degradation,impeding lattice oxygen diffusion to inhibit lattice oxygen participation is imperative,yet remains challenging due to the lack of efficient approaches.Herein,we strategically regulate the bonding nature of Ru–O towards suppressed LOM via Ru-based high-entropy oxide(HEO)construction.The lattice disorder in HEOs is believed to increase migration energy barrier of lattice oxygen.As a result,the screened Ti_(23)Nb_(9)Hf_(13)W_(12)Ru_(43)O_(x) exhibits 11.7 times slower lattice oxygen diffusion rate,84%reduction in LOM ratio,and 29 times lifespan extension compared with the state-of-the-art RuO_(2) catalyst.Our work opens up a feasible avenue to constructing stabilized Ru-based OER catalysts towards scalable application.

Parameter vertex method and its parallel solution for evaluating the dynamic response bounds of structures with interval parameters

In this article, we propose a parameter vertex method to determine the upper and lower bounds of the dynamic response of structures with interval parameters, which can be regarded as an extension of the matrix vertex method proposed by Qiu and Wang. The matrix vertex method requires considerable computation time and encounters the dependency problem in practice,thereby limiting its application in engineering. The proposed parameter vertex method can avoid the dependency problem, and the number of possible vertex combinations in the proposed method is significantly less than that in the matrix vertex method.The parameter vertex method requires that each matrix element in the dynamic differential equation is monotonic with respect to the uncertain parameter, and that the dynamic response reaches its extreme value when the uncertain parameter is at its endpoint.To further reduce the runtime, both vertical and transversal parallel algorithms are introduced and integrated into the parameter vertex method to improve its computational efficiency. Two numerical examples are presented to demonstrate the proposed method combined with both parallel algorithms. The performances of the two parallel algorithms are thoroughly studied. The parameter vertex method combined with parallel algorithm can be used for large-scale computing.

Advanced high-order nonlinear chirp scaling algorithm for high-resolution wide-swath spaceborne SAR

Spaceborne Synthetic Aperture Radar(SAR) is a well-established and powerful imaging technology that can provide high-resolution images of the Earth’s surface on a global scale. For future SAR systems, one of the key capabilities is to acquire images with both high-resolution and wide-swath. In parallel to the evolution of SAR sensors, more precise range models, and effective imaging algorithms are required. Due to the significant azimuth-variance of the echo signal in High-Resolution Wide-Swath(HRWS) SAR, two challenges have been faced in conventional imaging algorithms. The first challenge is constructing a precise range model of the whole scene and the second one is to develop an effective imaging algorithm since existing ones fail to process highresolution and wide azimuth swath SAR data effectively. In this paper, an Advanced High-order Nonlinear Chirp Scaling(A-HNLCS) algorithm for HRWS SAR is proposed. First, a novel Second-Order Equivalent Squint Range Model(SOESRM) is developed to describe the range history of the whole scene, by introducing a quadratic curve to fit the deviation of the azimuth FM rate. Second, a corresponding algorithm is derived, where the azimuth-variance of the echo signal is solved by azimuth equalizing processing and accurate focusing is achieved through a high-order nonlinear chirp scaling algorithm. As a result, the whole scene can be accurately focused through one single imaging processing. Simulations are provided to validate the proposed range model and imaging algorithm.

A Generic TC-Based Method to Find the Weakness in Different Phases of Masking Schemes

Masking is one of the most commonly used Side-Channel Attack （SCA） countermeasures and is built on a security framework, such as the ISW framework, and ensures theoretical security through secret sharing. Unfortunately, the theoretical security cannot guarantee practical security, because several possible weaknesses may exist in the actual implementation. These weaknesses likely come from the masking schemes or are introduced by the implementation methods. Finding the possible weakness of the masking scheme is an interesting and important issue for real applications. In this paper, the possible weaknesses for masking schemes in Field- Programmable Gate Array （FPGA） design are discussed. It was found that the combinational circuit is the key to the security of masking schemes. The Toggle Count （TC） method and its extension are utilized to evaluate the security of masking schemes in the design phase and the implementation phase separately. Comparing different logic-level simulators for the Xilinx FPGA platform, the behavioral and post-translate simulations are considered as the analysis method in the design phase, while the post-map and the post-route simulations are used to find the weakness during the implementation phase. Moreover, a Standard Delay Format （SDF） based improvement scheme is proposed to significantly increase the effectiveness of the TC model.