Brusatol attenuated proliferation and invasion induced by KRAS in differentiated thyroid cancer through inhibiting Nrf2

BACKGROUND

Poorly differentiated thyroid cancer (PDTC) and anaplastic thyroid cancer (ATC) can be developed from differentiated thyroid cancer, and this dedifferentiated transformation leads to poor prognosis and high mortality. The role of Nrf2 in the dedifferentiation of differentiated thyroid cancer (DTC) induced by KRAS remains unclear.

METHODS AND MATERIALS

In this study, two DTC cell lines, BCPAP and WRO, were used to evaluate the function of Nrf2 in the dedifferentiation caused by wild-type KRAS (KRAS-WT) and G12V point mutation KRAS (KRAS-G12V).

RESULTS

The overexpression of KRAS-WT and KRAS-G12V increased the proliferative and invasive ability of BCPAP and WRO cells. Aggressive morphology was observed in KRAS-WT and KRAS-G12V overexpressed WRO cells. These results suggested that overexpression of KRAS-WT or KRAS-G12V may induce dedifferentiation in DTC cells. The expression of Nrf2 was increased by KRAS-WT and KRAS-G12V in DTC cells. In addition, compared with normal thyroid tissues, the expression of Nrf2 protein was considerably higher in thyroid cancer tissues on immunohistochemistry (IHC) staining, and the increased expression of Nrf2 indicated a poor prognosis of thyroid cancer. These results indicated that Nrf2 is the KRAS downstream molecule in thyroid cancer. Functional studies showed that the Nrf2 inhibitor Brusatol counteracted the proliferative and invasive abilities induced by KRAS-WT and KRAS-G12V in BCPAP and WRO cells. In addition, the xenograft assay further confirmed that Brusatol inhibits tumor growth induced by KRAS-WT and KRAS-G12V.

CONCLUSION

Collectively, this study suggests that Nrf2 could be a promising therapeutic target in KRAS-mediated dedifferentiation of thyroid cancer.

Intelligently Quantifying the Entire Irregular Dental Structure

Quantitative analysis of irregular anatomical structures is crucial in oral medicine, but clinicians often typically measure only several representative indicators within the structure as references. Deep learning semantic segmentation offers the potential for entire quantitative analysis. However, challenges persist, including segmentation difficulties due to unclear boundaries and acquiring measurement landmarks for clinical needs in entire quantitative analysis. Taking the palatal alveolar bone as an example, we proposed an artificial intelligence measurement tool for the entire quantitative analysis of irregular dental structures. To expand the applicability, we have included lightweight networks with fewer parameters and lower computational demands. Our approach finally used the lightweight model LU-Net, addressing segmentation challenges caused by unclear boundaries through a compensation module. Additional enamel segmentation was conducted to establish a measurement coordinate system. Ultimately, we presented the entire quantitative information within the structure in a manner that meets clinical needs. The tool achieved excellent segmentation results, manifested by high Dice coefficients (0.934 and 0.949), intersection over union (0.888 and 0.907), and area under the curve (0.943 and 0.949) for palatal alveolar bone and enamel in the test set. In subsequent measurements, the tool visualizes the quantitative information within the target structure by scatter plots. When comparing the measurements against representative indicators, the tool's measurement results show no statistically significant difference from the ground truth, with small mean absolute error, root mean squared error, and errors interval. Bland-Altman plots and intraclass correlation coefficients indicate the satisfactory agreement compared with manual measurements. We proposed a novel intelligent approach to address the entire quantitative analysis of irregular image structures in the clinical setting. This contributes to enabling clinicians to swiftly and comprehensively grasp structural features, facilitating the design of more personalized treatment plans for different patients, enhancing clinical efficiency and treatment success rates in turn.

Networks of Limited-Valency Patchy Particles

Equilibrium gels provide physically attractive counterparts of nonequilibrium gels, allowing statistical understanding and design of the equilibrium gel structure. Here, we assemble two-dimensional equilibrium gels from limited-valency "patchy" colloidal particles and follow their evolution at the particle scale to elucidate cluster-size distributions and free energies. By finely adjusting the patch attraction with critical Casimir forces, we let a mixture of two-valent and pseudo-three-valent patchy particles approach the percolated network state through a set of equilibrium states. Comparing this equilibrium route with a deep quench, we find that both routes approach the percolated state via the same equilibrium states, revealing that the network topology is uniquely set by the particle bond angles, independent of the formation history. The limited-valency system follows percolation theory remarkably well, approaching the percolation point with the expected universal exponents.

Mechanisms of immune response and cell death in ischemic stroke and their regulation by natural compounds

Ischemic stroke (IS), which is the third foremost cause of disability and death worldwide, has inflammation and cell death as its main pathological features. IS can lead to neuronal cell death and release factors such as damage-related molecular patterns, stimulating the immune system to release inflammatory mediators, thereby resulting in inflammation and exacerbating brain damage. Currently, there are a limited number of treatment methods for IS, which is a fact necessitating the discovery of new treatment targets. For this review, current research on inflammation and cell death in ischemic stroke was summarized. The complex roles and pathways of the principal immune cells (microglia, astrocyte, neutrophils, T lymphocytes, and monocytes/macrophage) in the immune system after IS in inflammation are discussed. The mechanisms of immune cell interactions and the cytokines involved in these interactions are summarized. Moreover, the cell death mechanisms (pyroptosis, apoptosis, necroptosis, PANoptosis, and ferroptosis) and pathways after IS are explored. Finally, a summary is provided of the mechanism of action of natural pharmacological active ingredients in the treatment of IS. Despite significant recent progress in research on IS, there remain many challenges that need to be overcome.

Association of Plasma Markers of Alzheimer's Disease, Neurodegeneration, and Neuroinflammation with the Choroid Plexus Integrity in Aging

The choroid plexus (CP) is a vital brain structure essential for cerebrospinal fluid (CSF) production. Moreover, alterations in the CP's structure and function are implicated in molecular conditions and neuropathologies including multiple sclerosis, Alzheimer's disease, and stroke. Our goal is to provide the first characterization of the association between variation in the CP microstructure and macrostructure/volume using advanced magnetic resonance imaging (MRI) methodology, and blood-based biomarkers of Alzheimer's disease (Aß42/40 ratio; pTau181), neuroinflammation and neuronal injury (GFAP; NfL). We hypothesized that plasma biomarkers of brain pathology are associated with disordered CP structure. Moreover, since cerebral microstructural changes can precede macrostructural changes, we also conjecture that these differences would be evident in the CP microstructural integrity. Our cross-sectional study was conducted on a cohort of 108 well-characterized individuals, spanning 22-94 years of age, after excluding participants with cognitive impairments and non-exploitable MR imaging data. Established automated segmentation methods were used to identify the CP volume/macrostructure using structural MR images, while the microstructural integrity of the CP was assessed using our advanced quantitative high-resolution MR imaging of longitudinal and transverse relaxation times (T1 and T2). After adjusting for relevant covariates, positive associations were observed between pTau181, NfL and GFAP and all MRI metrics. These associations reached significance (p<0.05) except for CP volume vs. pTau181 (p=0.14), CP volume vs. NfL (p=0.35), and T2 vs. NFL (p=0.07). Further, negative associations between Aß42/40 and all MRI metrics were observed but reached significance only for Aß42/40 vs. T2 (p=0.04). These novel findings demonstrate that reduced CP macrostructural and microstructural integrity is positively associated with blood-based biomarkers of AD pathology, neurodegeneration/neuroinflammation and neurodegeneration. Degradation of the CP structure may co-occur with AD pathology and neuroinflammation ahead of clinically detectable cognitive impairment, making the CP a potential structure of interest for early disease detection or treatment monitoring.

The Effect of the Human Brainstem Myelination on Gait Speed in Normative Aging

The brainstem functions as a relay and integrative brain center and plays an essential role in motor function. Whether brainstem tissue deterioration, including demyelination, affects motor function has not been studied. Understanding the potential relationship between brainstem demyelination and motor function may be useful for the early diagnosis of neurodegenerative diseases and to understand age-related gait impairments that have no apparent cause. In this work, we investigated the associations between rapid or usual gait speeds, as integrative measures of motor function, and cerebral myelin content. In 118 individuals (age 22-94 years) free of neurodegenerative diseases or cognitive impairment, myelin content was assessed as the myelin water fraction, a direct magnetic resonance imaging measure of myelin content, and longitudinal and transverse relaxation rates (R1 and R2), which are sensitive magnetic resonance imaging measures of myelin content. Our results indicate that participants with lower usual or rapid gait speed exhibited lower values of myelin water fraction and R1 in the main brainstem regions, which were more evident and statistically significant in the midbrain. In contrast, we found no significant associations between gait speeds and R2, an expected result because various physiological factors confound R2. These original findings provide evidence that the level of brainstem myelination may affect gait performance among cognitively unimpaired adults who are free from any clinically detectable neurodegenerative diseases. Further studies are needed to understand the longitudinal changes in brainstem myelination with aging and neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease.

REUSED: A deep neural network method for rapid whole-brain high-resolution myelin water fraction mapping from extremely under-sampled MRI

Changes in myelination are a cardinal feature of brain development and the pathophysiology of several central nervous system diseases, including multiple sclerosis and dementias. Advanced magnetic resonance imaging (MRI) methods have been developed to probe myelin content through the measurement of myelin water fraction (MWF). However, the prolonged data acquisition and post-processing times of current MWF mapping methods pose substantial hurdles to their clinical implementation. Recently, fast steady-state MRI sequences have been implemented to produce high-spatial resolution whole-brain MWF mapping within ∼20 min. Despite the subsequent significant advances in the inversion algorithm to derive MWF maps from steady-state MRI, the high-dimensional nature of such inversion does not permit further reduction of the acquisition time by data under-sampling. In this work, we present an unprecedented reduction in the computation (∼30 s) and the acquisition time (∼7 min) required for whole-brain high-resolution MWF mapping through a new Neural Network (NN)-based approach, named NN-Relaxometry of Extremely Under-SamplEd Data (NN-REUSED). Our analyses demonstrate virtually similar accuracy and precision in derived MWF values using NN-REUSED compared to results derived from the fully sampled reference method. The reduction in the acquisition and computation times represents a breakthrough toward clinically practical MWF mapping.

C-NODDI: a constrained NODDI model for axonal density and orientation determinations in cerebral white matter

Purpose

Neurite orientation dispersion and density imaging (NODDI) provides measures of neurite density and dispersion through computation of the neurite density index (NDI) and the orientation dispersion index (ODI). However, NODDI overestimates the cerebrospinal fluid water fraction in white matter (WM) and provides physiologically unrealistic high NDI values. Furthermore, derived NDI values are echo-time (TE)-dependent. In this work, we propose a modification of NODDI, named constrained NODDI (C-NODDI), for NDI and ODI mapping in WM.

Methods

Using NODDI and C-NODDI, we investigated age-related alterations in WM in a cohort of 58 cognitively unimpaired adults. Further, NDI values derived using NODDI or C-NODDI were correlated with the neurofilament light chain (NfL) concentration levels, a plasma biomarker of axonal degeneration. Finally, we investigated the TE dependence of NODDI or C-NODDI derived NDI and ODI.

Results

ODI derived values using both approaches were virtually identical, exhibiting constant trends with age. Further, our results indicated a quadratic relationship between NDI and age suggesting that axonal maturation continues until middle age followed by a decrease. This quadratic association was notably significant in several WM regions using C-NODDI, while limited to a few regions using NODDI. Further, C-NODDI-NDI values exhibited a stronger correlation with NfL concentration levels as compared to NODDI-NDI, with lower NDI values corresponding to higher levels of NfL. Finally, we confirmed the previous finding that NDI estimation using NODDI was dependent on TE, while NDI derived values using C-NODDI exhibited lower sensitivity to TE in WM.

Conclusion

C-NODDI provides a complementary method to NODDI for determination of NDI in white matter.

Lower Myelin Content Is Associated With Lower Gait Speed in Cognitively Unimpaired Adults

Mounting evidence indicates that abnormal gait speed predicts the progression of neurodegenerative diseases, including Alzheimer's disease. Understanding the relationship between white matter integrity, especially myelination, and motor function is crucial to the diagnosis and treatment of neurodegenerative diseases. We recruited 118 cognitively unimpaired adults across an extended age range of 22-94 years to examine associations between rapid or usual gait speeds and cerebral myelin content. Using our advanced multicomponent magnetic resonance relaxometry method, we measured myelin water fraction (MWF), a direct measure of myelin content, as well as longitudinal and transverse relaxation rates (R1 and R2), sensitive but nonspecific magnetic resonance imaging measures of myelin content. After adjusting for covariates and excluding 22 data sets due to cognitive impairments or artifacts, our results indicate that participants with higher rapid gait speed exhibited higher MWF, R1, and R2 values, that is, higher myelin content. These associations were statistically significant within several white matter brain regions, particularly the frontal and parietal lobes, splenium, anterior corona radiata, and superior fronto-occipital and longitudinal fasciculus. In contrast, we did not find any significant associations between usual gait speed and MWF, R1, or R2, which suggests that rapid gait speed may be a more sensitive marker of demyelination than usual gait speed. These findings advance our understanding on the implication of myelination in gait impairment among cognitively unimpaired adults, providing further evidence of the interconnection between white matter integrity and motor function.

Hypertensive Adults Exhibit Lower Myelin Content: A Multicomponent Relaxometry and Diffusion Magnetic Resonance Imaging Study

BACKGROUND

It is unknown whether hypertension plays any role in cerebral myelination. To fill this knowledge gap, we studied 90 cognitively unimpaired adults, age range 40 to 94 years, who are participants in the Baltimore Longitudinal Study of Aging and the Genetic and Epigenetic Signatures of Translational Aging Laboratory Testing to look for potential associations between hypertension and cerebral myelin content across 14 white matter brain regions.

METHODS

Myelin content was probed using our advanced multicomponent magnetic resonance relaxometry method of myelin water fraction, a direct and specific magnetic resonance imaging measure of myelin content, and longitudinal and transverse relaxation rates (R1 and R2), 2 highly sensitive magnetic resonance imaging metrics of myelin content. We also applied diffusion tensor imaging magnetic resonance imaging to measure fractional anisotropy, mean diffusivity, radial diffusivity, and axial diffusivity values, which are metrics of cerebral microstructural tissue integrity, to provide context with previous magnetic resonance imaging findings.

RESULTS

After adjustment of age, sex, systolic blood pressure, smoking status, diabetes status, and cholesterol level, our results indicated that participants with hypertension exhibited lower myelin water fraction, fractional anisotropy, R1 and R2 values and higher mean diffusivity, radial diffusivity, and axial diffusivity values, indicating lower myelin content and higher impairment to the brain microstructure. These associations were significant across several white matter regions, particularly in the corpus callosum, fronto-occipital fasciculus, temporal lobes, internal capsules, and corona radiata.

CONCLUSIONS

These original findings suggest a direct association between myelin content and hypertension and form the basis for further investigations including longitudinal assessments of this relationship.

Lower myelin content is associated with more rapid cognitive decline among cognitively unimpaired individuals

INTRODUCTION

The influence of myelination on longitudinal changes in cognitive performance remains unclear.

METHODS

For each participant (N = 123), longitudinal cognitive scores were calculated. Myelin content was probed using myelin water fraction (MWF) or longitudinal relaxation rate (R1 ); both are MRI measures sensitive to myelin, with MWF being specific.

RESULTS

Lower MWF was associated with steeper declines in executive function (p < .02 in all regions) and lower R1 was associated with steeper declines in verbal fluency (p < .03 in all regions). Additionally, lower R1 was associated with steeper declines in executive function (p < .02 in all regions) and memory (p < .04 in occipital and cerebral white matter) but did not survive Bonferroni correction.

DISCUSSION

We demonstrate significant relationships between myelin content and the rates of change in cognitive performance among cognitively normal individuals. These findings highlight the importance of myelin in cognitive functioning and suggest MWF and R1 as imaging biomarkers to predict cognitive changes.

Investigation of the association between central arterial stiffness and aggregate g-ratio in cognitively unimpaired adults

Stiffness of the large arteries has been shown to impact cerebral white matter (WM) microstructure in both younger and older adults. However, no study has yet demonstrated an association between arterial stiffness and aggregate g-ratio, a specific magnetic resonance imaging (MRI) measure of axonal myelination that is highly correlated with neuronal signal conduction speed. In a cohort of 38 well-documented cognitively unimpaired adults spanning a wide age range, we investigated the association between central arterial stiffness, measured using pulse wave velocity (PWV), and aggregate g-ratio, measured using our recent advanced quantitative MRI methodology, in several cerebral WM structures. After adjusting for age, sex, smoking status, and systolic blood pressure, our results indicate that higher PWV values, that is, elevated arterial stiffness, were associated with lower aggregate g-ratio values, that is, lower microstructural integrity of WM. Compared to other brain regions, these associations were stronger and highly significant in the splenium of the corpus callosum and the internal capsules, which have been consistently documented as very sensitive to elevated arterial stiffness. Moreover, our detailed analysis indicates that these associations were mainly driven by differences in myelination, measured using myelin volume fraction, rather than axonal density, measured using axonal volume fraction. Our findings suggest that arterial stiffness is associated with myelin degeneration, and encourages further longitudinal studies in larger study cohorts. Controlling arterial stiffness may represent a therapeutic target in maintaining the health of WM tissue in cerebral normative aging.

MRI and fluid biomarkers reveal determinants of myelin and axonal loss with aging

OBJECTIVE

White matter damage is a feature of Alzheimer's disease, yet little is known about how facets of the Alzheimer's disease process relate to key features of white matter structure. We examined the association of Alzheimer's disease (Aß_42/40 ratio; pTau181), neuronal injury (NfL), and reactive astrogliosis (GFAP) biomarkers with MRI measures of myelin content and axonal density.

METHODS

Among cognitively normal participants in the BLSA and GESTALT studies who received MRI measures of myelin content (defined by myelin water fraction [MWF]) and axonal density (defined by neurite density index [NDI]), we quantified plasma levels of Aβ₄₂ , Aβ₄₀ , pTau181, NfL, and GFAP. Linear regression models adjusted for demographic variables were used to relate these plasma biomarker levels to the MRI measures.

RESULTS

In total, 119 participants received MWF imaging (age: 56 [SD 21]), of which 43 received NDI imaging (age: 50 [SD 18]). We found no relationship between plasma biomarkers and total brain myelin content. However, secondary analysis found higher GFAP was associated with lower MWF in the temporal lobes (ß = -0.13; P = 0.049). Further, higher levels of NfL (ß = -0.22; P = 0.009) and GFAP (ß = -0.29; P = 0.002) were associated with lower total brain axonal density. Secondary analyses found lower Aβ_42/40 ratio and higher pTau181 were also associated with lower axonal density, but only in select brain regions. These results remained similar after additionally adjusting for cardiovascular risk factors.

INTERPRETATION

Plasma biomarkers of neuronal injury and astrogliosis are associated with reduced axonal density and region-specific myelin content. Axonal loss and demyelination may co-occur with neurodegeneration and astrogliosis ahead of clinically meaningful cognitive decline.

Recent Progress in Electrochemical Nano-Biosensors for Detection of Pesticides and Mycotoxins in Foods

Pesticide and mycotoxin residues in food are concerning as they are harmful to human health. Traditional methods, such as high-performance liquid chromatography (HPLC) for such detection lack sensitivity and operation convenience. Efficient, accurate detection approaches are needed. With the recent development of nanotechnology, electrochemical biosensors based on nanomaterials have shown solid ability to detect trace pesticides and mycotoxins quickly and accurately. In this review, English articles about electrochemical biosensors in the past 11 years (2011-2022) were collected from PubMed database, and various nanomaterials are discussed, including noble metal nanomaterials, magnetic metal nanoparticles, metal-organic frameworks, carbon nanotubes, as well as graphene and its derivatives. Three main roles of such nanomaterials in the detection process are summarized, including biomolecule immobilization, signal generation, and signal amplification. The detection targets involve two types of pesticides (organophosphorus and carbamate) and six types of mycotoxins (aflatoxin, deoxynivalenol, zearalenone, fumonisin, ochratoxin A, and patulin). Although significant achievements have been made in the evolution of electrochemical nano-biosensors, many challenges remain to be overcome.

Evidence of An Association Between Cerebral Blood Flow and Microstructural Integrity in Normative Aging Using a Holistic MRI Approach

BACKGROUND

Cerebral tissue integrity decline and cerebral blood flow (CBF) alteration are major aspects of motor and cognitive dysfunctions and neurodegeneration. However, little is known about the association between blood flow and brain microstructural integrity, especially in normal aging.

PURPOSE

To assess the association between CBF and cerebral microstructural integrity.

STUDY TYPE

Cross sectional.

POPULATION

A total of 94 cognitively unimpaired adults (mean age 50.7 years, age range between 22 and 88 years, 56 Men).

FIELD STRENGTH/SEQUENCE

A 3 T; pseudo-continuous arterial spin labeling (pCASL), diffusion tensor imaging (DTI), Bayesian Monte Carlo analysis of multicomponent driven equilibrium steady-state observation of T₁ and T₂ (BMC-mcDESPOT).

ASSESSMENT

Lobar associations between CBF derived from pCASL, and longitudinal relaxation rate (R₁ ), transverse relaxation rate (R₂ ) and myelin water fraction (MWF) derived from BMC-mcDESPOT, or radial diffusivity (RD), axial diffusivity (AxD), mean diffusivity (MD) and fractional anisotropy (FA) derived from DTI were assessed.

STATISTICAL TESTS

Multiple linear regression models were used using the mean region of interest (ROI) values for MWF, R₁ , R₂ , FA, MD, RD, or AxD as the dependent variable and CBF, age, age² , and sex as the independent variables. A two-sided P value of <0.05 defined statistical significance.

RESULTS

R₁ , R₂ , MWF, FA, MD, RD, and AxD parameters were associated with CBF in most of the cerebral regions evaluated. Specifically, higher CBF values were significantly associated with higher FA, MWF, R₁ and R₂ , or lower MD, RD and AxD values.

DATA CONCLUSION

These findings suggest that cerebral tissue microstructure may be impacted by global brain perfusion, adding further evidence to the intimate relationship between cerebral blood supply and cerebral tissue integrity.

EVIDENCE LEVEL

4 TECHNICAL EFFICACY: Stage 4.

Characterization and differentiation of pollen lipidomes and proteomes from different intrafloral stamens in heterantherous Senna bicapsularis

Numerous compounds in pollen can affect the foraging decision-making of bees. Clarification of phytochemical components and identification of key substances for bee foraging preference in pollen are essential steps for apiculture and developing a conservation strategy. Senna bicapsularis, a heterantherous plant that possesses three different stamen types in the same flower, among which bees forage selectively, provides us with an ideal research model for identification of potential substances of bee foraging preference. The lipid and protein compositions of pollen from the anthers of different stamens of S. bicapsularis were investigated and compared. The polyunsaturated fatty acids (PUFAs) and monounsaturated FAs (MUFAs) were highest among lipid molecules in pollen from short (S) stamens than from long (L) and medium (M) stamens. This result is consistent with the FA content measurement, showing the highest FAs and UFAs content in S pollen, especially α-linolenic acid. We inferred that α-linolenic acid might be one of the key substances for bee foraging preference in pollen. Moreover, proteomic analysis showed that several differentially expressed proteins involved in lipid biosynthesis were highly accumulated in S pollen, such as choline kinase 2, 3-oxoacyl-ACP synthase-like protein and choline/ethanolamine phosphotransferase 1, in line with the highest FA content of S pollen. Additionally, DEPs involved in 'starch and sucrose metabolism', 'phenylpropanoid biosynthesis' and 'cyanoamino acid metabolism' were more represented in S compared with L and M pollen. The study suggests that differences in proteomic and lipidomic profiling among the three different stamen types might affect foraging decision-making of bumblebees.

CARBONATED BEVERAGES AFFECT LEVELS OF ANDROGEN RECEPTOR AND TESTOSTERONE SECRETION IN MICE

Objectives

This work aimed to study the influences of carbonated beverages (CBs) on the testis growth and the expression levels of androgen receptor (AR) of mice.

Methods

Two experimental groups of 30 mice each PEP-1 and PEP-2 drank 50% and 100% Pepsi-Cola, respectively for 15 days. Other 2 experimental groups of 30 mice each COC-1 and COC-2 drank 50% and 100% Coca-Cola, respectively for 15 days. The control group (CG) of 30 mice drank water. Bilateral testes were harvested aseptically on days 0, 5, 7, 10, 13 and 15. Real-time PCR and Western blot were implemented to detect levels of androgen receptor (AR) mRNA and protein in testis tissues.

Results

Testes masses of PEP-2, COC-1 and COC-2 were greater than those of PEP-1 and CG (P < 0.05). On day 15, testis longitudinal diameter (TLD) of CBs-treated mice was increased as compared to CG. TLD, testes transverse diameters (TTD) and AR proteins levels of PEP-2 and COC-2 were increased in comparison with CG (P<0.05). Serum testosterone concentrations of PEP-2 were higher than that of COC-1 and CG (P < 0.05). Levels of AR mRNAs of four CBs-treated mice were increased by 60.18%, 67.26%, 65.93% and 78.76%.

Conclusions

A high concentration of Coca-Cola and Pepsi-Cola could raise TLD and TDD, enhance testosterone secretion, and increase serum EGF concentrations.

P-382 Decrease of serum estradiol prior to human chorionic gonadotrophin administration have an impact on live birth in IVF/ICSI cycles

Study question

Whether decrease of serum estradiol prior to human chorionic gonadotrophin administration have an impact on live birth in IVF/ICSI cycles?

Summary answer

The E2 change before the day of hCG administration had significant correlation with live birth. The live birth rate decreased with decreasing serum E2 level.

What is known already

The objective of this study was to assess the effects of a decrease of estradiol (E2) levels on the day of human chorionic gonadotrophin (hCG) administration on in vitro fertilization /intracytoplasmic sperm injection (IVF/ICSI) outcomes, including cycles with long, antagonist and micro stimulus protocols.

Study design, size, duration

In this retrospective cohort study, 1303 patients who received IVF/ICSI non-donor treatment were identified. Patients were divided into two groups according to live birth and the characteristics of IVF/ICSI cycles were compared between groups, including baseline infertility parameters, ovarian stimulation characteristics and embryo laboratory manipulation parameters.

Participants/materials, setting, methods

In this retrospective cohort study, 1303 patients who received IVF/ICSI non-donor treatment were identified. Patients were divided into two groups according to live birth and the characteristics of IVF/ICSI cycles were compared between groups, including baseline infertility parameters, ovarian stimulation characteristics and embryo laboratory manipulation parameters. The multivariate logistic regression model was performed to adjust potential confounders and assess correlation between E2 dynamics before hCG administration and live birth.

Main results and the role of chance

Our results revealed that patients without live birth had higher age (32.13 ± 4.33 vs. 30.21 ± 3.71, P &lt; 0.001) and pervious miscarriages (0.57 ± 0.95 vs. 0.46 ± 0.83, P = 0.0295), while had lower number of oocytes retrieved (8.95 ± 4.69 vs. 12.36 ± 5.54, P &lt; 0.001), day of hCG E2 (8269.53 ± 4104.22 vs. 9580.71 ± 3534.11, P &lt; 0.001) and endometrium thickness (10.37 ± 3.66 vs. 11.50 ± 3.40, P &lt; 0.001) compared with patients with live birth. Additionally, the multivariate logistic regression analysis displayed significant impact of serum E2 change on the live birth, and the achievement of live birth [OR (95%CI) 0.81 (0.71, 0.92), P = 0.001] decreased with the decreasing level of serum E2 before hCG trigger day. Estradiol stratification analyses displayed the OR and 95% CI for the association between △E2 and live birth among patients with different levels of estradiol decline (&lt;25%, 25%–50%, 50%–75%, &gt;75%). Compared with the &lt;25% decline and 25%–50% decline groups, the ORs of 50%–75% and &gt;75% decline groups were 1.66 (95% CI: 1.12-2.45, P = 0.012) and 2.00 (95% CI: 1.39-2.89, P &lt; 0.001), respectively, after adjusting potential confounders.

Limitations, reasons for caution

There was concealment of randomization and blinding of outcome assessments reducing the risk of selection and measurement bias.

Wider implications of the findings

In summary, the E2 change before the day of hCG administration had significant correlation with live birth, and the live birth decreased with the decreasing level of serum E2 before hCG trigger day. The patients with a greater decline in the E2 level more likely to had poor clinical outcomes.

Trial registration number

Chi CTR1900026088

Insights into human cerebral white matter maturation and degeneration across the adult lifespan

White matter (WM) microstructural properties change across the adult lifespan and with neuronal diseases. Understanding microstructural changes due to aging is paramount to distinguish them from neuropathological changes. Conducted on a large cohort of 147 cognitively unimpaired subjects, spanning a wide age range of 21 to 94 years, our study evaluated sex- and age-related differences in WM microstructure. Specifically, we used diffusion tensor imaging (DTI) magnetic resonance imaging (MRI) indices, sensitive measures of myelin and axonal density in WM, and myelin water fraction (MWF), a measure of the fraction of the signal of water trapped within the myelin sheets, to probe these differences. Furthermore, we examined regional correlations between MWF and DTI indices to evaluate whether the DTI metrics provide information complementary to MWF. While sexual dimorphism was, overall, nonsignificant, we observed region-dependent differences in MWF, that is, myelin content, and axonal density with age and found that both exhibit nonlinear, but distinct, associations with age. Furthermore, DTI indices were moderately correlated with MWF, indicating their good sensitivity to myelin content as well as to other constituents of WM tissue such as axonal density. The microstructural differences captured by our MRI metrics, along with their weak to moderate associations with MWF, strongly indicate the potential value of combining these outcome measures in a multiparametric approach. Furthermore, our results support the last-in-first-out and the gain-predicts-loss hypotheses of WM maturation and degeneration. Indeed, our results indicate that the posterior WM regions are spared from neurodegeneration as compared to anterior regions, while WM myelination follows a temporally symmetric time course across the adult life span.

Exogenous melatonin prevents type 1 diabetes mellitus-induced bone loss, probably by inhibiting senescence

Exogenous melatonin inhibited the senescence of preosteoblast cells in type 1 diabetic (T1D) mice and those cultured in high glucose (HG) by multiple regulations. Exogenous melatonin had a protective effect on diabetic osteoporosis, which may depend on the inhibition of senescence.

INTRODUCTION

Senescence is thought to play an important role in the pathophysiological mechanisms underlying diabetic bone loss. Increasing evidence has shown that melatonin exerts anti-senescence effects. In this study, we investigated whether melatonin can inhibit senescence and prevent diabetic bone loss.

METHODS

C57BL/6 mice received a single intraperitoneal injection of 160 mg/kg streptozotocin, followed by the oral administration of melatonin or vehicle for 2 months. Then, tissues were harvested and subsequently examined. MC3T3-E1 cells were cultured under HG conditions for 7 days and then treated with melatonin or not for 24 h. Sirt1-specific siRNAs and MT1- or MT2-specific shRNA plasmids were transfected into MC3T3-E1 cells for mechanistic study.

RESULTS

The total protein extracted from mouse femurs revealed that melatonin prevented senescence in T1D mice. The micro-CT results indicated that melatonin prevented bone loss in T1D mice. Cellular experiments indicated that melatonin administration prevented HG-induced senescence, whereas knockdown of the melatonin receptors MT1 or MT2 abolished these effects. Sirt1 expression was upregulated by melatonin administration but significantly reduced after MT1 or MT2 was knocked down. Knockdown of Sirt1 blocked the anti-senescence effects of melatonin. Additionally, melatonin promoted the expression of CDK2, CDK4, and CyclinD1, while knockdown of MT1 or MT2 abolished these effects. Furthermore, melatonin increased the expression of the polycomb repressive complex (PRC), but knockdown of MT1 or MT2 abolished these effects. Furthermore, melatonin increased the protein levels of Sirt1, PRC1/2 complex-, and cell cycle-related proteins.

CONCLUSION

This work shows that melatonin protects against T1D-induced bone loss, probably by inhibiting senescence. Targeting senescence in the investigation of diabetic osteoporosis may lead to novel discoveries.

Large Culprit Plaque and More Intracranial Plaques Are Associated with Recurrent Stroke: A Case-Control Study Using Vessel Wall Imaging

BACKGROUND AND PURPOSE

Intracranial atherosclerotic plaque features are potential factors associated with recurrent stroke, but previous studies only focused on a single lesion, and few studies investigated them with perfusion impairment. This study aimed to investigate the association among whole-brain plaque features, perfusion deficit, and stroke recurrence.

MATERIALS AND METHODS

Patients with ischemic stroke due to intracranial atherosclerosis were retrospectively collected and categorized into first-time and recurrent-stroke groups. Patients underwent high-resolution vessel wall imaging and DSC-PWI. Intracranial plaque number, culprit plaque features (such as plaque volume/burden, degree of stenosis, enhancement ratio), and perfusion deficit variables were recorded. Logistic regression analyses were performed to determine the independent factors associated with recurrent stroke.

RESULTS

One hundred seventy-five patients (mean age, 59 [SD, 12] years; 115 men) were included. Compared with the first-time stroke group (n = 100), the recurrent-stroke group (n = 75) had a larger culprit volume (P = .006) and showed more intracranial plaques (P < .001) and more enhanced plaques (P = .003). After we adjusted for other factors, culprit plaque volume (OR, 1.16 per 10-mm³ increase; 95% CI, 1.03-1.30; P = .015) and total plaque number (OR, 1.31; 95% CI, 1.13-1.52; P < .001) were independently associated with recurrent stroke. Combining these factors increased the area under the curve to 0.71.

CONCLUSIONS

Large culprit plaque and more intracranial plaques were independently associated with recurrent stroke. Performing whole-brain vessel wall imaging may help identify patients with a higher risk of recurrent stroke.

A 2-year locomotive exploration and scientific investigation of the lunar farside by the Yutu-2 rover

The lunar nearside has been investigated by many uncrewed and crewed missions, but the farside of the Moon remains poorly known. Lunar farside exploration is challenging because maneuvering rovers with efficient locomotion in harsh extraterrestrial environment is necessary to explore geological characteristics of scientific interest. Chang'E-4 mission successfully targeted the Moon's farside and deployed a teleoperated rover (Yutu-2) to explore inside the Von Kármán crater, conveying rich information regarding regolith, craters, and rocks. Here, we report mobile exploration on the lunar farside with Yutu-2 over the initial 2 years. During its journey, Yutu-2 has experienced varying degrees of mild slip and skid, indicating that the terrain is relatively flat at large scales but scattered with local gentle slopes. Cloddy soil sticking on its wheels implies a greater cohesion of the lunar soil than encountered at other lunar landing sites. Further identification results indicate that the regolith resembles dry sand and sandy loam on Earth in bearing properties, demonstrating greater bearing strength than that identified during the Apollo missions. In sharp contrast to the sparsity of rocks along the traverse route, small fresh craters with unilateral moldable ejecta are abundant, and some of them contain high-reflectance materials at the bottom, suggestive of secondary impact events. These findings hint at notable differences in the surface geology between the lunar farside and nearside. Experience gained with Yutu-2 improves the understanding of the farside of the Moon, which, in return, may lead to locomotion with improved efficiency and larger range.

Cerebral aggregate g-ratio mapping using magnetic resonance relaxometry and diffusion tensor imaging to investigate sex and age-related differences in white matter microstructure

Axonal demyelination is a cardinal feature of aging and age-related diseases. The g-ratio, mathematically defined as the inner-to-outer diameter of a myelinated axon, is used as a structural index of optimal axonal myelination and has been shown to represent a sensitive imaging biomarker of microstructural integrity. Several magnetic resonance imaging (MRI) methods for whole-brain mapping of aggregate g-ratio have been introduced. Computation of the aggerate g-ratio requires estimates of the myelin volume fraction (MVF) and the axonal volume fraction (AVF). While accurate determinations of MVF and AVF can be obtained through multicomponent relaxometry or diffusion analyses, respectively, these methods require lengthy acquisition times making their implementation challenging in a clinical context. Therefore, any attempt to overcome this drawback is needed. Expanding on our previous work, we introduced a new MRI method for whole-brain mapping of aggregate g-ratio. This new approach is based on the use of a single-shell diffusion for AVF determination, reducing the acquisition time by approximately ~10 min from our recently introduced approach, while offering the possibility to investigate g-ratio differences in previous studies with existing data for MVF mapping and single-shell diffusion data for AVF mapping. Our comparison analysis indicates that our newly derived aggregate g-ratio values were similar to those derived from our previous method, which requires a longer acquisition time. Further, in agreement with our previous observations, we found quadratic U-shaped relationships between aggregate g-ratio and age in this much larger study cohort. However, our results show that sexual dimorphism in g-ratio was not significant in any brain region investigated.

[Gut microbiome composition in pre-adolescent children with different meat consumption patterns]

OBJECTIVE

To compare the composition of gut microbiome in pre-adolescent children with different meat consumption patterns.

METHODS

This study was conducted among 44 healthy school-age children (age range 8-10 years) in Shenzhen. According to the monthly intake frequency ratio of white meat and red meat, the children were divided into red-meat group (n=15), balanced group (n=16) and white-meat group (n=13). The Food Frequency Questionnaire (FFQ) was used to investigate the children's diet, and samples of morning feces were collected to study the gut microbiome. The fecal DNA was extracted and amplified, and the composition of the intestinal microbiome of the children was analyzed using Illumina Miseq high-throughput sequencing.

RESULTS

The children in red meat and white meat groups showed significantly lower abundance and diversity of gut microbiota than those with a balanced diet (P < 0.05). LEfSe analysis of the genus in the fecal samples showed that Escherichia-Shigella, Coprobacillus and Peptoniphilus were enriched in red-meat group and Holdemanella was enriched in the white-meat group as compared with the balanced group. In the samples of the balanced group, 31 and 25 genus (such as Laurespirillum and Rumenococcus) were significantly enriched as compared with the samples of the red-meat group and the white-meat group, respectively. Prediction of the gut microbiota KEGG pathway using PICRUSt2 suggested that compared with that in the balanced group, the gut microbiota in red-meat group had significant activation of the pathways involving lipopolysaccharide biosynthesis (P < 0.01), arachidonic acid metabolism (P < 0.01), thyroid hormone synthesis (P < 0.001), and carbohydrate digestion and absorption (P < 0.05). But compared with the white-meat group, the red-meat group showed only significant activation of the pathways of arachidonic acid metabolism (P < 0.05) and thyroid hormone synthesis (P < 0.05).

CONCLUSION

The preference of red meat and white meat consumption may significantly reduce the abundance and diversity of gut microbiota in pre-adolescent children. A red meat-rich diet may cause enrichment of Escherichia-Shigella and significant activation of lipopolysaccharide biosynthesis pathway, suggesting the potential benefit of a balanced diet for pre-adolescent children.

Reverse-dialysis can be misleading for drug release studies in emulsions as demonstrated by NMR dilution experiments

Emulsions are an important class of carriers for the delivery of hydrophobic drugs. While knowledge of drug release kinetics is critical to optimizing drug carrying emulsions, there remain many open questions about the validity of standard characterization methods such as the commonly used reverse-dialysis. In this paper, the kinetic parameters of isoflurane release in perfluorotributylamine emulsions determined from both reverse-dialysis and nuclear magnetic resonance (NMR) dilution experiments are compared. The NMR-determined kinetic parameters of isoflurane release were found to be approximately seven orders of magnitude larger than those determined from conventional reverse-dialysis and were also shown to be consistent with prior in vivo observations of the anesthetization of rats.

Characterization of Age-Related Differences in the Human Choroid Plexus Volume, Microstructural Integrity, and Blood Perfusion Using Multiparameter Magnetic Resonance Imaging

The choroid plexus (CP) is an important cerebral structure involved in cerebrospinal fluid production and transport of solutes into the brain. Recent studies have uncovered the involvement of the CP in neurological disorders such as Alzheimer's disease and multiple sclerosis. However, our understanding of human age-related microstructural and functional changes in the CP with aging and neuropathology is limited. In this cross-sectional study, we investigated age and sex differences in the CP structure and function using advanced quantitative magnetic resonance imaging methodology in a large cohort (n = 155) of cognitively unimpaired individuals over a wide age range between 21 and 94 years. Our analysis included volumetric measurements, relaxometry measures (T 1 and T 2), diffusion tensor imaging (DTI) measures of fractional anisotropy (FA) and mean diffusivity (MD), as well as measures of cerebral blood flow (CBF). Our results revealed that CP volume was increasing with advancing age. We conjecture that this novel observation is likely attributed to alterations in the CP microstructure or function as well as to ventriculomegaly. Indeed, we also found that CBF was lower with advanced age, while, consistent with previous studies, T 1, T 2 and MD were higher, and FA was lower with advanced age. We attribute these functional and microstructural differences to a deteriorated CP structural integrity with aging. Furthermore, our relaxometry and DTI measures were found to be associated with differences in blood perfusion revealing lower microstructural integrity with lower CBF. Finally, in agreement with literature, sex-related differences in MD and CBF were statistically significant. This work lays the foundation for ongoing investigation of the involvement of CP in neurodegeneration.

Determining chemical exchange rate constants in nanoemulsions using nuclear magnetic resonance

In this work, the second-order kinetics of molecules exchanging between chemically distinct microenvironments, such as those found in nanoemulsions, is studied using nuclear magnetic resonance (NMR). A unique aspect of NMR exchange studies in nanoemulsions is that the difference in molecular resonance frequencies between the two phases, which determines whether the exchange is fast, intermediate, or slow on the NMR timescale, can depend upon the emulsion droplet composition, which is also determined by the kinetic exchange constants themselves. Within the fast-exchange regime, changes in resonance frequencies and line widths with dilution were used to extract the exchange rate constants from the NMR spectra in a manner analogous to determining the kinetic parameters in NMR ligand binding experiments. As a demonstration, the kinetic exchange parameters of isoflurane release from an emulsification of isoflurane and perflurotributylamine (FC43) were determined using NMR dilution and diffusion studies.

Application of Nanotechnology in Analysis and Removal of Heavy Metals in Food and Water Resources

Toxic heavy metal contamination in food and water from environmental pollution is a significant public health issue. Heavy metals do not biodegrade easily yet can be enriched hundreds of times by biological magnification, where toxic substances move up the food chain and eventually enter the human body. Nanotechnology as an emerging field has provided significant improvement in heavy metal analysis and removal from complex matrices. Various techniques have been adapted based on nanomaterials for heavy metal analysis, such as electrochemical, colorimetric, fluorescent, and biosensing technology. Multiple categories of nanomaterials have been utilized for heavy metal removal, such as metal oxide nanoparticles, magnetic nanoparticles, graphene and derivatives, and carbon nanotubes. Nanotechnology-based heavy metal analysis and removal from food and water resources has the advantages of wide linear range, low detection and quantification limits, high sensitivity, and good selectivity. There is a need for easy and safe field application of nanomaterial-based approaches.

Osteoporosis is accompanied by reduced CD274 expression in human bone marrow-derived mesenchymal stem cells

Underlying pathomechanisms of osteoporosis are still not fully elucidated. Cell-based therapy approaches pose new possibilities to treat osteoporosis and its complications. The aim of this study was to quantify differences in human bone marrow-derived mesenchymal stem cells (hBMSCs) between healthy donors and those suffering from clinically manifest osteoporosis. Cell samples of seven donors for each group were selected retrospectively from the hBMSC cell bank of the Trauma Department of Hannover Medical School. Cells were evaluated for their adipogenic, osteogenic and chondrogenic differentiation potential, for their proliferation potential and expression of surface antigens. Furthermore, a RT2 Osteoporosis Profiler PCR array, as well as quantitative real-time PCR were carried out to evaluate changes in gene expression. Cultivated hBMSCs from osteoporotic donors showed significantly lower cell surface expression of CD274 (4.98 % ± 2.38 %) than those from the control group (26.03 % ± 13.39 %; p = 0.007), as assessed by flow cytometry. In osteoporotic patients, genes involved in inhibition of the anabolic WNT signalling pathway and those associated with stimulation of bone resorption were significantly upregulated. Apart from these changes, no significant differences were found for the other cell surface antigens, adipogenic, osteogenic and chondrogenic differentiation ability as well as proliferation potential. These findings supported the theory of an influence of CD274 on the regulation of bone metabolism. CD274 might be a promising target for further investigations of the pathogenesis of osteoporosis and of cell-based therapies involving MSCs.

Revealing pseudorotation and ring-opening reactions in colloidal organic molecules

Colloids have a rich history of being used as 'big atoms' mimicking real atoms to study crystallization, gelation and the glass transition of condensed matter. Emulating the dynamics of molecules, however, has remained elusive. Recent advances in colloid chemistry allow patchy particles to be synthesized with accurate control over shape, functionality and coordination number. Here, we show that colloidal alkanes, specifically colloidal cyclopentane, assembled from tetrameric patchy particles by critical Casimir forces undergo the same chemical transformations as their atomic counterparts, allowing their dynamics to be studied in real time. We directly observe transitions between chair and twist conformations in colloidal cyclopentane, and we elucidate the interplay of bond bending strain and entropy in the molecular transition states and ring-opening reactions. These results open the door to investigate complex molecular kinetics and molecular reactions in the high-temperature classical limit, in which the colloidal analogue becomes a good model.

Diagnostic magnetic resonance imaging in synovial chondromatosis of the temporomandibular joint

The aim of this paper was to investigate the clinical and magnetic resonance imaging (MRI) features of synovial chondromatosis (SC) of the temporomandibular joint (TMJ). Fourteen patients with SC of the TMJ were included in the study. Clinical and MRI features were analysed and divided into three types based on MRI classification: type I with loose bodies, type II with homogeneous masses, and type III with a mixture of loose bodies and homogeneous masses. All SCs occurred in the superior compartment of the TMJ. There were two patients (14%) categorised as type I, five (36%) as type II and seven (50%) as type III. Four patients (29%) had disc perforation, and nine had bone erosion; among those nine, seven (78%) had type III and two (22%) type II. Histological examination showed inflammation and calcification in the synovial membrane and, and cartilage of the hyaline type in all cases. MRI has advantages in the diagnosis of SC.

Triplex qRT-PCR with specific probe for synchronously detecting Bovine parvovirus, bovine coronavirus, bovine parainfluenza virus and its applications

Bovine parvovirus (BPV), bovine coronavirus (BCoV) and bovine parainfluenza virus (BPIV) are common etiologies causing gastrointestinal and respiratory diseases in dairy herds. However, there are few reports on the synchronous detection of BPV, BCoV and BPIV. The present article aimed to develop a quick and accurate RT-PCR assay to synchronously detect BPV, BCoV and BPIV based on their specific probes. One pair universal primers, one pair specific primers and one specific probe was designed and synthesized. After the concentrations of primer and probe and annealing temperature were strictly optimized, the specificity, sensitivity and repeatability of the established triplex probe qRT-PCR were evaluated, respectively. The results showed the recombinant plasmids of pMD18-T-BPV, pMD18-T-BCoV and pMD18-T-BPIV were 554bp, 699bp and 704bp, respectively. The optimal annealing temperature was set at 45.0°C for triplex qRT-PCR. The triplex probe qRT-PCR can only synchronously detect BPV, BCoV and BPIV. Detection sensitivities were 2.0×102, 2.0×102 and 2.0×101 copies/μL for BPV, BCoV and BPIV, being 1000-fold greater than that in the conventional PCR. Detection of clinical samples demonstrated that triplex probe qRT-PCR had a higher sensitivity and specificity. The intra-assay and inter-assay coefficient of variation were lower than 2.0%. Clinical specimens verified that the triplex qRT-PCR had a higher sensitivity and specificity than universal PCR. In conclusion, this triplex probe qRT-PCR could detect only BPV, BCoV and BPIV. Minimum detection limits were 2.0×102 copies/μL for BPV and BCoV, and 2.0×101 copies/μL for BPIV. The sensitivity of this triplex probe qRT-PCR was 1000-fold greater than that in the conventional PCR. The newly qRT-PCR could be used to monitor or differentially diagnose virus infection.

Direct laser acceleration of electrons assisted by strong laser-driven azimuthal plasma magnetic fields

A high-intensity laser beam propagating through a dense plasma drives a strong current that robustly sustains a strong quasistatic azimuthal magnetic field. The laser field efficiently accelerates electrons in such a field that confines the transverse motion and deflects the electrons in the forward direction. Its advantage is a threshold rather than resonant behavior, accelerating electrons to high energies for sufficiently strong laser-driven currents. We study the electron dynamics via a test-electron model, specifically deriving the corresponding critical current density. We confirm the model's predictions by numerical simulations, indicating energy gains two orders of magnitude higher than achievable without the magnetic field.

Energy gain by laser-accelerated electrons in a strong magnetic field

This paper deals with electron acceleration by a laser pulse in a plasma with a static uniform magnetic field B_{*}. The laser pulse propagates perpendicular to the magnetic field lines with the polarization chosen such that (E_{laser}·B_{*})=0. The focus of the work is on the electrons with an appreciable initial transverse momentum that are unable to gain significant energy from the laser in the absence of the magnetic field due to strong dephasing. It is shown that the magnetic field can initiate an energy increase by rotating such an electron, so that its momentum becomes directed forward. The energy gain continues well beyond this turning point where the dephasing drops to a very small value. In contrast to the case of purely vacuum acceleration, the electron experiences a rapid energy increases with the analytically derived maximum energy gain dependent on the strength of the magnetic field and the phase velocity of the wave. The energy enhancement by the magnetic field can be useful at high laser amplitudes, a_{0}≫1, where the acceleration similar to that in the vacuum is unable to produce energetic electrons over just tens of microns. A strong magnetic field helps leverage an increase in a_{0} without a significant increase in the interaction length.

Diffusion Selective Pulses

The self-diffusion coefficient, D, provides important chemical and physical information about a molecular species and its environment, and D can be routinely measured under equilibrium conditions using nuclear magnetic resonance (NMR). Differences in diffusion coefficients can also be exploited in NMR to suppress signals from fast diffusing species relative to slow diffusing species. To date, no method for selectively suppressing signals only from species with a particular diffusion coefficient has been presented. In this work, diffusion selective pulses are developed that selectively suppress the magnetization only from species for which D = D^Sel. This is accomplished by interleaving NMR relaxation selective pulses between pulsed field gradients, where the effective transverse relaxation of the magnetization is related to D. Experimental demonstrations of diffusion selective pulses on water and water/acetone/dimethyl sulfoxide samples and on a magnetic resonance imaging phantom are presented.

TaqMan real-time PCR for detecting bovine viral diarrhea virus

The present study was aimed to establish a novel TaqMan real-time PCR (RTm-PCR) for detecting and typing bovine viral diarrhea virus (BVDV), and also to develop a diagnostic protocol which simplifies sample collection and processing. Universal primers and TaqMan-MGB probes were designed from the known sequences of conserved 5' - and 3'-untranslated regions (5'UTR, 3'UTR) of the NADL strain of BVDV. Prior to optimizing the assay, cDNAs were transcribed in vitro to make standard curves. The sensitivity, specificity and stability (reproducibility) were evaluated. The RTm-PCR was tested on the 312 feces specimens collected from persistently infected (PI) calves. The results showed the optimum conditions for RTm-PCR were 17.0 μmol/L primer, 7.5 μmol/L probe and 51.4°C annealing temperature. The established TaqMan RTm-PCR assay could specially detect BVDV without detecting any other viruses. Its detection limit was 1.55×100 copies/μL for viral RNA. It was 10000-fold higher than conventional PCR with excellent specificity and reproducibility. 312 samples were tested using this method and universal PCR from six dairy farms, respectively. Positive detections were found in 49 and 44 feces samples, respectively. The occurrence rate was 89.80%. In conclusion, the established TaqMan RTm-PCR could rapidly detect BVDV and effectively identify PI cattle. The detection limit of RTm-PCR was 1.55 copies/μL. It will be beneficial for enhancing diagnosis and therapy efficacy and reduce losses in cattle farms.

Deflection of a reflected intense circularly polarized light beam induced by asymmetric radiation pressure

A deflection effect of an intense laser beam with spin angular momentum is revealed theoretically by an analytical modeling using radiation pressure and momentum balance of laser plasma interaction in the relativistic regime as a deviation from the law of reflection. The reflected beam deflects out of the plane of incidence with a deflection angle up to several milliradians, when a nonlinear polarized laser, with the intensity I_{0}∼10^{19}W/cm^{2} and duration around tens of femtoseconds, is obliquely incident and reflected by an overdense plasma target. This effect originates from the asymmetric radiation pressure caused by spin angular momentum of the laser photons. The dependence of the deflection angle of a Gaussian-type laser on the parameters of laser pulse and plasma foil is theoretically derived, which is also confirmed by three-dimensional particle-in-cell simulations of circularly polarized laser beams with the different intensity and pulse duration.

Radiation reaction as an energy enhancement mechanism for laser-irradiated electrons in a strong plasma magnetic field

Conventionally, friction is understood as a mechanism depleting a physical system of energy and as an unavoidable feature of any realistic device involving moving parts. In this work, we demonstrate that this intuitive picture loses validity in nonlinear quantum electrodynamics, exemplified in a scenario where spatially random friction counter-intuitively results in a highly directional energy flow. This peculiar behavior is caused by radiation friction, i.e., the energy loss of an accelerated charge due to the emission of radiation. We demonstrate analytically and numerically how radiation friction can dramatically enhance the energy gain by electrons from a laser pulse in a strong magnetic field that naturally arises in dense laser-irradiated plasma. We find the directional energy boost to be due to the transverse electron momentum being reduced through friction whence the driving laser can accelerate the electron more efficiently. In the considered example, the energy of the laser-accelerated electrons is enhanced by orders of magnitude, which then leads to highly directional emission of gamma-rays induced by the plasma magnetic field.

EDACO, a derivative of myricetin, inhibits the differentiation of Gaoyou duck embryonic osteoclasts in vitro

1. This study determined the effects of (E)-3-(2-(4-(3-(2,4-dimethoxyphenyl)acryloyl)phenoxy)ethoxy)-5,7-dimethoxy-2-(3,4,5-trimethoxyphenyl)-4H-chromen-4-one (EDACO) on the differentiation of Gaoyou duck embryonic osteoclasts cultured in vitro. 2. Bone marrow mononuclear cells (BM-MNC) were collected from 23-d-old Gaoyou duck embryos and induced by macrophage colony-stimulating factor and receptor activator of nuclear factor κB ligand in the presence of EDACO at different concentrations (i.e. 10, 20, 40, 80 and 160 µM). Tartrate-resistant acid phosphatase (TRAP) staining and resorption ability determination were conducted. 3. Results suggested that EDACO suppressed the shaping of positive multinucleated cells and the number of TRAP-positive cells in the 20, 40, 80 and 160 μM EDACO groups was significantly decreased (P < 0.05 or P < 0.01). Besides, the absorption activity of differentiated duck embryonic osteoclasts was significantly inhibited (P < 0.05) in both 80 and 160 μM EDACO groups. 4. Overall, EDACO can inhibit the differentiation of BM-MNC into mature osteoclasts in duck embryos.1.

[Rush poppers use and risks of human papillomavirus infection among men who have sex with men in Urumqi: mediation effect through high-risk sexual behaviors]

Objective: To study the prevalence of rush poppers use among men who have sex with men (MSM) in Urumqi and to analyze the mediating effect of high-risk sexual behavior between the use of rush poppers and human papillomavirus (HPV) infection. Methods: From January to June 2018, 651 MSM were recruited through network and publicity. Data was collected by using online questionnaire and anal swab were collected from them for HPV genotyping. According to Baron and Kenny's criterion, multivariate logistic regression models was used to analyze the mediation effect of high-risks sexual behaviors (multiple sexual partners, anal intercourse condom use) between rush poppers use and HPV infection. Results: A total of 651 subjects were (32.0±8.0) years old, and 174 subjects (26.7%) had ever used rush poppers in the past 6 months, while 350 subjects (46.9%) had more than 2 sexual partners and 188 subjects (28.9%) did not use anal condom. After adjusting age and marital status, rush poppers use was associated with HPV infection (OR (95%CI) was 2.34 (1.63-3.36), P<0.05), and sexual partners in the past 6 months (OR (95%CI) was 2.72 (1.89-3.93), P<0.05).After adjustment for age, marital status, sexual partners in the past 6 months, and anal condom use, rush poppers use was still associated with HPV infection (OR (95%CI) was 2.21 (1.53-3.19), P<0.05).After adjustment and adjustment of age, marital status, rush poppers use and anal sex condom use, the number of sexual partners at nearly 6 months was still associated with HPV infection (OR (95%CI) was 1.46 (1.05-2.04), P<0.05). Conclusion: Sexual partners in the past 6 months have a mediation effect between rush poppers use and HPV infection in Urumqi. For the prevention of sexually transmitted diseases, we should focus on rush poppers use.

Creation of Electron-Positron Pairs in Photon-Photon Collisions Driven by 10-PW Laser Pulses

A novel approach is proposed to demonstrate the two-photon Breit-Wheeler process by using collimated and wide-bandwidth γ-ray pulses driven by 10-PW lasers. Theoretical calculations suggest that more than 3.2×10^{8} electron-positron pairs with a divergence angle of 7° can be created per shot, and the signal-to-noise ratio is higher than 10^{3}. The positron signal, which is roughly 100 times higher than the detection limit, can be measured by using the existing spectrometers. This approach, which could demonstrate the e^{-}e^{+} pair creation process from two photons, would provide important tests for two-photon physics and other fundamental physical theories.

Visible light communication using dual camera on one smartphone

Dual camera is becoming increasingly prevalent among smartphone camera schemes these days. This paper demonstrates a system prototype by using the color and monochrome cameras on one smartphone simultaneously for visible light communication. To achieve this, we propose a novel dual-modulation scheme. The baseband signal is firstly modulated by color ratio modulation-color shift keying (CRM-CSK) to broadcast color ratio information that can be distinguished by the color camera. Next to it, gray level modulation (GLM) is utilized to generate CRM symbols with gray levels that can be distinguished by the monochrome camera. Our experiment shows a significant improvement in the downlink data rate of the optical camera communication (OCC) using a single light source.