The nonlinear refractive index
n
2
is an important parameter for the nonlinear optical properties of a medium. This study primarily targets to measure the third-order nonlinear optical properties of ...potassium dihydrogen phosphate (KDP) and deuterated potassium dihydrogen phosphate (DKDP) with 70% deuteration content at
λ
= 532 nm using the Z-scan technique. The relationship between nonlinear refraction and direction has been studied in detail. Nonlinear refractive index
n
2
,
γ
and third-order nonlinear susceptibilities
x
k
3
(esu) were calculated through normalized transmittance curves and theoretical formulas. The results indicate that the nonlinear refractive indexes of KDP and DKDP are positive and possess obvious self-focusing effects in high-power laser systems.
The nonlinear refractive index
n
2
is an important parameter for the nonlinear optical properties of a medium. Especially for the anisotropic media, the nonlinear refractive index is closely related with the direction.
Singlet oxygen (
O
), as an important active reagent, has found wide applications in photodynamic therapy (PDT), synthetic chemistry, and materials science. Organic conjugated aromatics serving as ...hosts to capture and release singlet oxygen have been systematically investigated over the last decades. Herein, we present a 6 + 6 organoplatinum(II) metallacycle by using ∼180° dipyridylanthracene donor and ∼120° Pt(II) acceptor as the building blocks, which enables the capture and release of singlet oxygen with relatively high photooxygenation and thermolysis rate constants. The photooxygenation of the metallacycle to the corresponding endoperoxide was performed by sensitized irradiation, and the resulting endoperoxide is stable at room temperature and can be stored under ambient condition over months. Upon simple heating of the neat endoperoxide under inert atmosphere at 120 °C for 4 h, the resulting endoperoxide can be reconverted to the corresponding parent form and singlet oxygen. The photooxygenation and thermolysis products were characterized by NMR spectroscopy and electrospray ionization time-of-flight mass spectrometric analysis. Density functional theory calculations were conducted in order to reveal the frontier molecular orbital interactions and reactivity. This work provides a new material platform for singlet oxygen related promising applications.
Oncogenic alterations in the RAS/RAF/MEK/ERK pathway drive the growth of a wide spectrum of cancers. While BRAF and MEK inhibitors are efficacious against BRAF
-driven cancers, effective targeted ...therapies are lacking for most cancers driven by other pathway alterations, including non-V600E oncogenic BRAF, RAS GTPase-activating protein (GAP) NF1 (neurofibromin 1) loss and oncogenic KRAS. Here, we show that targeting the SHP2 phosphatase (encoded by PTPN11) with RMC-4550, a small-molecule allosteric inhibitor, is effective in human cancer models bearing RAS-GTP-dependent oncogenic BRAF (for example, class 3 BRAF mutants), NF1 loss or nucleotide-cycling oncogenic RAS (for example, KRAS
). SHP2 inhibitor treatment decreases oncogenic RAS/RAF/MEK/ERK signalling and cancer growth by disrupting SOS1-mediated RAS-GTP loading. Our findings illuminate a critical function for SHP2 in promoting oncogenic RAS/MAPK pathway activation in cancers with RAS-GTP-dependent oncogenic BRAF, NF1 loss and nucleotide-cycling oncogenic KRAS. SHP2 inhibition is a promising molecular therapeutic strategy for patients with cancers bearing these oncogenic drivers.
Sleep deprivation (SD) is one of the main risk factors for Alzheimer’s disease (AD), but the underlying mechanism is still unclear. Ketogenic diet (KD) has been shown widely neuroprotective effects ...but less known about its effect on SD-induced AD. In the present study, a continuous 21 days SD mouse model with or without KD was established. The changes of cognitive function, pathological hallmarks of AD, ferroptosis, and intracellular signal pathways in mice were detected by Morris water maze, ThS staining, diaminobenzidine (DAB)-enhanced Perls’ stain, antioxidant assay, immuno-histochemistry, and western blot. The results showed that KD can prevent the cognitive deficiency, amyloid deposition and hyperphosphorylated tau induced by chronic SD. Analysis of ferroptosis revealed that KD can inhibit iron dyshomeostasis by down-regulating the expression of TfR1 and DMT1 and up-regulating the expression of FTH1, FPN1. Meanwhile, KD alleviated oxidative stress with elevated xCT/GPX4 axis, FSP1 and reduced MDA. In addition, KD could promote neuronal repair by enhancing BDNF and DCX. Further studies demonstrated that KD activated Sirt1/Nrf2 signaling pathway in the hippocampus in SD-exposed mice. Our finding firstly suggested that KD could prevent chronic SD-induced AD by inhibiting ferroptosis and improving the neuronal repair ability
via
Sirt1/Nrf2 signaling pathway.
In the present work, five polysaccharides were selected as co-encapsulant of skim milk based matrix and used for the microencapsulation of Lactobacillus paracasei Lpc-37 by spray drying. The ...morphological characterization, physical properties, encapsulation efficiency, gastrointestinal simulation, and storage stability of microencapsules were examined to evaluate the protective capacity against the adverse conditions of the different wall matrices. Addition of polysaccharides was associated with the enhancement of physical performance of microencapsulated powders, such as the flowability and water activity. Encapsulation matrices containing gum Arabic showed the greatest encapsulation efficiency of 97.1% (maximum survival 7.78 log CFU/g). L. paracasei Lpc-37 encapsulated with the matrices incorporating sodium alginate or sodium carboxymethylcellulose exhibited higher survival (>6.5 log CFU/g) after exposed to simulated gastrointestinal condition and lower viability loss (<0.3 log CFU/g) after 8 weeks of refrigerated storage. The application of polysaccharides, however, showed the tendency of higher hygroscopicity and lower stability of the powders in high temperature and humid environment.
•The applied polysaccharides improved the flowability of microencapsulated powder.•Gum Arabic maintained L. paracasei viable during spray-drying process.•Sodium alginate and sodium carboxymethylcellulose enhanced L. paracasei viability during simulated digestion.
A slab laser based on Nd:CTGS crystal was reported for the first time. With a quasi-continuous wave semiconductor laser as the pump source, the maximum average output power reached 7.01 W, with a ...wavelength of 1064.5 nm, a single-pulse energy of 35 mJ, and a slope efficiency of 31%. Using a Cr 4+ :YAG crystal as the saturable absorber, the maximum average output power was 2.52 W, corresponding to a single-pulse energy of 1.26 mJ, a pulse duration of 37.2 ns, and a peak power reaches 33.9 kW. This work provides a good way to obtain pulsed slab lasers with simple structure and excellent performance, which are expected to be utilized in many fields like the photovoltaic industry, glass processing, tool manufacturing, mechanical engineering, and scientific research.
Abstract The hormone receptor (HR) status plays a significant role in breast cancer, serving as the primary guide for treatment decisions and closely correlating with prognosis. This study aims to ...investigate the predictive value of radiomics analysis in long-axis and short-axis ultrasound planes for distinguishing between HR-positive and HR-negative breast cancers. A cohort of 505 patients from two hospitals was stratified into discovery (Institute 1, 416 patients) and validation (Institute 2, 89 patients) cohorts. A comprehensive set of 788 ultrasound radiomics features was extracted from both long-axis and short-axis ultrasound planes, respectively. Utilizing least absolute shrinkage and selection operator (LASSO) regression analysis, distinct models were constructed for the long-axis and short-axis data. Subsequently, radiomics scores (Rad-scores) were computed for each patient. Additionally, a combined model was formulated by integrating data from long-axis and short-axis Rad-scores along with clinical factors. The diagnostic efficacy of all models was evaluated by the area under the receiver operating characteristic (ROC) curve (AUC). The long-axis and short-axis models, consisting of 11 features and 15 features, respectively, were established, yielding AUCs of 0.743 and 0.751 in the discovery cohort, and 0.795 and 0.744 in the validation cohort. The calculated long-axis and short-axis Rad-scores exhibited significant differences between HR-positive and HR-negative groups across all cohorts (all p < 0.001). Univariate analysis identified ultrasound-reported tumor size as an independent predictor. The combined model, incorporating long-axis and short-axis Rad-scores along with tumor size, achieved superior AUCs of 0.788 and 0.822 in the discovery and validation cohorts, respectively. The combined model effectively distinguishes between HR-positive and HR-negative breast cancers based on ultrasound radiomics features and tumor size, which may offer a valuable tool to facilitate treatment decision making and prognostic assessment.
2D transition metal dichalcogenides are attracting increased attention because of their excellent electronic and optical properties. Inspired by the natural weathering exfoliation of seaside rocks, a ...“chemical weathering” concept for fabricating atom‐thick 2D materials from their bulk counterparts is proposed. It is experimentally demonstrated that chemical weathering‐assisted exfoliation mechanism is a simple and efficient method of preparing atom‐thick MoS2 and WS2 monolayers. These monolayers are difficult to prepare using other approaches. Interestingly, the as‐prepared MoS2 and WS2 monolayers exhibit excellent saturable absorption and mode‐locking properties in all‐solid‐state lasers because of intermediate states resulting from S‐vacancy defects. The obtained passively Q‐switched laser operation with 60 ns pulse width and ultrafast mode locking with 8.6 ps pulse width are promising for all‐solid‐state laser application.
Inspired by the natural weathering exfoliation of seaside rocks, a “chemical weathering” concept is proposed for fabricating atom‐thick 2D materials from their bulk counterparts. Chemical weathering‐assisted exfoliation is a simple and efficient method of preparing atom‐thick MoS2 and WS2 monolayers. The as‐prepared monolayers exhibit excellent saturable absorption and mode‐locking properties in all‐solid‐state lasers because of intermediate states resulting from S‐vacancy defects.
Epilepsy is a chronic neurological disorder that is more prevalent in children, and recurrent unprovoked seizures can lead to cognitive impairment. Numerous studies have reported the benefits of ...docosahexaenoic acid (DHA) on neurodevelopment and cognitive ability, while comparatively less attention has been given to eicosapentaenoic acid (EPA). Additionally, little is known about the effects and mechanisms of DHA and EPA in relation to seizure-induced cognitive impairment in the young rodent model. Current research indicates that ferroptosis is involved in epilepsy and cognitive deficiency in children. Further investigation is warranted to determine whether EPA or DHA can mitigate seizure-induced cognitive deficits by inhibiting ferroptosis. Therefore, this study was conducted to compare the effects of DHA and EPA on seizure-induced cognitive deficiency and reveal the underlying mechanisms focused on ferroptosis in a pentylenetetrazol (PTZ)-kindling young mice model. Mice were fed a diet containing DHA-enriched ethyl esters or EPA-enriched ethyl esters for 21 days at the age of 3 weeks and treated with PTZ (35 mg/kg, i.p.) every other day 10 times. The findings indicated that both EPA and DHA exhibited ameliorative effects on seizure-induced cognitive impairment, with EPA demonstrating a superior efficacy. Further mechanism study revealed that supplementation of DHA and EPA significantly increased cerebral DHA and EPA levels, balanced neurotransmitters, and inhibited ferroptosis by modulating iron homeostasis and reducing lipid peroxide accumulation in the hippocampus through activating the Nrf2/Sirt3 signal pathway. Notably, EPA exhibited better an advantage in ameliorating iron dyshomeostasis compared to DHA, owing to its stronger upregulation of Sirt3. These results indicate that DHA and EPA can efficaciously alleviate seizure-induced cognitive deficiency by inhibiting ferroptosis in PTZ-kindled young mice.
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