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Helicon plasma source is known as efficient generator of uniform and high density plasma. A helicon plasma source was developed for investigation of plasma neutralization and plasma lens in the Institute of Modern Physics in China. In this paper, the characteristics of helicon plasma have been studied by using Langmuir four-probe and a high argon plasma density up to 3.9×1013 cm-3 have been achieved with the Nagoya type III antenna at the conditions of the magnetic intensity of 200 G, working gas pressure of 2.8×10-3 Pa, and rf power of 1200 W with a frequency of 27.12 MHz. In the experiment, the important phenomena have been found: for a given magnetic induction intensity, the plasma density became greater with the increase in rf power and tended to saturation, and the helicon mode appeared at the rf power between 200 and 400 W. [ABSTRACT FROM AUTHOR]

Triclocarban (TCC), a broad-spectrum lipophilic antibacterial agent, is the main ingredient of personal and health care products. Nonetheless, its ubiquitous presence in the environment has been established to negatively affect the reproduction in humans and animals. In this work, we studied the possible toxic effects of TCC on mouse oocytes maturation in vitro. Our findings revealed that TCC-treated immature mouse oocytes had a significantly reduced rate of polar body extrusion (PBE) compared to that of control. Further study demonstrated that the cell cycle progression and cytoskeletal dynamics were disrupted after TCC exposure, which resulted in the continuous activation of spindle assembly checkpoint (SAC). Moreover, TCC-treated oocytes had mitochondrial damage, reduced ATP content, and decreased mitochondrial membrane potential (MMP). Furthermore, TCC exposure induced oxidative stress and subsequently triggered early apoptosis in mouse oocytes. Besides, the levels of histone methylation were also affected, as indicated by increased H3K27me2 and H3K27me3 levels. In summary, our results revealed that TCC exposure disrupted mouse oocytes maturation through affecting cell cycle progression, cytoskeletal dynamics, oxidative stress, early apoptosis, mitochondria function, and histone modifications in vitro. Image 1 • TCC exposure perturbed the meiotic maturation of mouse oocytes. • TCC exposure disturbed the cytoskeletal dynamic. • TCC exposure induced mitochondrial dysfunction. • TCC exposure induced oxidative stress and triggered early apoptosis. • TCC exposure affected epigenetic modification. TCC exposure disrupted mouse oocytes maturation through inducing mitochondrial dysfunction and oxidative stress in vitro. [ABSTRACT FROM AUTHOR]

Based on the geological data and drainage dynamic data, the characteristics of drainage dynamic was analyzed, formation mechanism of well performance was explained from system theory and geological factors and CBM development strategy was proposed in Shouyang block. The study shows that the single well in Shouyang block is characteristized by “high water yield but low gas production” in the process of drainage. Multi-layer drainage produces more water than that of one layer, which leads to a phenomenon of “1+1>2”. The typical daily gas production shows a negative enveloping relationship with typical daily water production meaning that high water production is detrimental to gas production. There are two factors for high water production. First, the wellbore-drainage system is an open system since faults or vertical hydraulic fractures connect sandstone aquifers, which leads to low efficient depressurization. Second, with branch channel sand body extensively developed and high dip angle existed, faults easily connect sand aquifers for multi-layer drainage. Building a high productive well is essential to create a closed system borehole-drainage system by staying away faults firstly, and then avoiding vertical hydraulic fractures connecting sand aquifers. Since the coal seam is easier to fracturing, it is proposed to reduce the fracturing volume adopted before for future CBM exploration and development practice in Shouyang block. For a coal interval to be hydraulically fractured in a well, the fracturing volume should be optimized on considering the thickness of proof and floor aquifluids to avoid hydraulic link between the fracturing interval and nearby sandstone aquifers. [ABSTRACT FROM AUTHOR]

Objective To explore the change of serum sex hormones and 25-hydroxycholecalciferol [25-(OH)-D3 ] level in postmenopausal female patients with benign paroxysmal positional vertigo (BPPV). Methods Electrochemiluminescence (ECL) assay was employed to detect the serum levels of estradiol (E2), progesterone, luteinizing hormone (LH), follicle stimulating hormone (FSH), and 25-(OH)-D3 in 63 female postmenopausal BPPV patients with age 50-80 years from September 1, 2015 to February 1, 2017. Spearman rank correlation analysis was used to analyze the relation between age and E2 , E2 and 25-(OH)-D3. Univariate and multivariate stepwise Logistic regression analysis were used to screen the risk factors for BPPV. Results The serum levels of E2 [15.67 (10.96, 22.15) pg/ml] and 25-(OH)-D3 [(24.24 ± 1.05) ng/ml] in BPPV group were lower than those in control group [E2: 31.78 (25.60, 39.50) pg/ml, 25-(OH)-D3: (27.62 ± 0.76) ng/ml], and the differences were statistically significant (Z = -6.768, P = 0.000; t = -2.605, P = 0.010). There was no significant difference on progesterone, LH and FSH between 2 groups. Correlation analysis showed there was no relation between E2 and 25-(OH)-D3 levels in both groups. There was a negative correlation between age and E2 in control group (rs = -0.263, P = 0.038), but no correlation in BPPV group. Multivariate Logistic regression analysis showed decreased serum E2 and 25-(OH)-D3 levels maybe the risk factors for postmenopausal female BPPV patients. Conclusions E2 and 25-(OH)-D3 deficiency are independent risk factors for BPPV in postmenopausal female patients. DOI: 10.3969/j.issn.1672-6731.2019.01.007

Hydraulic support plays a key role in ground control of longwall mining. The smart prediction methods of support load are important for achieving intelligent mining. In this paper, the hydraulic support load data is decomposed into trend term, cycle term, and residual term, and it is found that the data has clear trend and period features, which can be called time series data. Based on the autoregression theory and weighted moving average method, the time series model is built to analyze the load data and predict its evolution trend, and the prediction accuracy of the sliding window model, ARIMA (Autoregressive Integrated Moving Average) model, and SARIMA (Seasonal Autoregressive Integrated Moving Average) model to the hydraulic support load under different parameters are evaluated, respectively. The results of single-point and multipoint prediction test with various sliding window values indicate that the sliding window method has no advantage in predicting the trend of the support load. The ARIMA model shows a better short-term trend prediction than the sliding window model. To some extent, increasing the length of the autoregressive term can improve the long-term prediction accuracy of the model, but it also increases the sensitivity of the model to support load fluctuation, and it is still difficult to predict the load trend in one support cycle. The SARIMA model has better prediction results than the sliding window model and the ARIMA model, which reveals the load evolution trend accurately during the whole support cycle. However, there are many external factors affecting the support load, such as overburden properties, hydraulic support moving speed, and worker’s operation. The smarter model of SARIMA considering these factors should be developed to be more suitable in predicting the hydraulic support load.

The western flower thrips, Frankliniella occidentalis, is one of the most destructive sucking pests of vegetables, fruits and ornamental crops in China. Spinosad is one of the most commonly used insecticides to manage thrips. To assess the incidence of spinosad resistance in F. occidentalis field populations in eastern China, survival rates for 24 different populations were compared with those of a susceptible laboratory strain. All populations showed significantly higher resistance to spinosad compared with the control as determined by comparing median lethal concentrations. Two populations from Shouguang and Liaocheng in Shandong Province were classified as having moderate and high levels of resistance to spinosad with a mean resistance ratio of 17.0 and 89.2, respectively. Our research indicates a widespread reduction in spinosad efficacy for controlling F. occidentalis field populations, and that resistance management strategies should be implemented as soon as practicable, to reduce the potential of progressive resistance development and loss of efficacy.

According to the official report, the first case of COVID-19 and the first death in the United States occurred on January 20 and February 29, 2020, respectively. On April 21, California reported that the first death in the state occurred on February 6, implying that community spreading of COVID-19 might have started earlier than previously thought. Exactly what is time zero, i.e., when did COVID-19 emerge and begin to spread in the U.S. and other countries? We develop a comprehensive predictive modeling framework to address this question. Using available data of confirmed infections to obtain the optimal values of the key parameters, we validate the model and demonstrate its predictive power. We then carry out an inverse inference analysis to determine time zero for 10 representative states in the U.S., plus New York City, United Kingdom, Italy, and Spain. The main finding is that, in both the U.S. and Europe, COVID-19 started around the new year day.

Developments in chemotherapeutics have enhanced the survival rate of cancer patients, however, adverse effects of chemotherapeutics on ovarian functions causes the fertility loss in young female cancer patients. Doxorubicin (DOX), as an anthracycline antitumor antibiotic, is extensively used to cure various malignancies. Recent studies have suggested that DOX can cause ovarian damage and affect the oocyte maturation, nevertheless the mechanism by which DOX on oocytes meiosis is poorly understood. In this study, we explored the mechanism for DOX-induced oocytes meiotic failure in vitro at human relevant exposure levels and time periods. Results described that DOX (100 nM) can interrupt the mouse oocytes meiotic maturation directly with reduced first polar body extrusion. Cell cycle analysis showed that most oocytes were arrested at metaphase I (MI) stage. However, DOX treatment had no effect on spindle structure but chromosomal misalignment. We observed that kinetochore-microtubule structure was affected and the spindle assemble checkpoint was provoked after DOX treatment. Moreover, severe DNA damage was found in DOX-treated oocytes indicated by the positive γ-H2A.X foci signal, which then may trigger oocytes early apoptosis. Besides, metaphase II oocytes with disorganized spindle morphologies and misaligned chromosomes were observed after DOX treatment. In conclusion, DOX have the potential to disrupt oocyte meiotic maturation through DNA damage induced meiotic arrest mediated by spindle assemble checkpoint activation. These findings can contribute to design the new therapies to alleviate DNA damage to preserve fertility for young female cancer patients with chemotherapeutics. [ABSTRACT FROM AUTHOR]

An adverse tendency induced by the environmental estrogens in female reproductive health is one serious problem worldwide. Diethylstilbestrol (DES), as a synthetic estrogen, is still used as an animal growth stimulant in terrestrial livestock and aquaculture illegally. It has been reported to negatively affect ovarian function and oogenesis. Nevertheless, the mechanism and toxicity of DES on oocyte meiotic maturation are largely unknown. Herein, we found that DES (40 μM) intervened in mouse oocyte maturation and first polar body extrusion (PBE) was decreased in vitro. Cell cycle analysis showed meiotic process was disturbed with oocytes arrested at metaphase I (MI) stage after DES exposure. Further study showed that DES exposure disrupted the spindle assembly and chromosome alignment, which then continuously provoke the spindle assemble checkpoint (SAC). We also observed that the acetylation levels of α-tubulin were dramatically increased in DES-treated oocytes. In addition, the dynamics of actin were also affected. Moreover, the distribution patterns of estrogen receptor α (ERα) were altered in DES-treated oocyte, as indicated by the significant signals accumulation in the spindle area. However, ERα inhibitor failed to rescue the defects of oocyte maturation caused by DES. Of note, the same phenomenon was observed in estrogen-treated oocytes. Collectively, we showed that DES exposure lead to the oocyte meiotic failure via impairing the spindle assembly and chromosome alignment. Our research is helpful to understand how environmental estrogen affects female germ cells and contribute to design the potential therapies to preserve fertility especially for occupational exposure. • DES exposure caused the failure of first polar body extrusion in mouse oocytes and disturbed cell cycle process. • DES exposure disturbed the cytoskeletal dynamic and chromosome alignment. • DES exposure increased acetylation level of α-tubulin. • DES exposure continuously activated the spindle assembly checkpoint. • DES exposure changed the distribution pattern of estrogen receptor α. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the impact of different nitrogen forms on soil physicochemical properties and microbial community structure in perennial alpine cultivated grasslands, in order to provide scientific basis for developing nitrogen addition strategies for perennial alpine cultivated grasslands. In June 2022, a 4-year-old Qinghai grassland mixed with Poa pratensis Qinghai and Festuca sinensis Qinghai was established at the Bakatai Farm in Gonghe County, Hainan Tibetan Autonomous Prefecture, Qinghai Province. The study was conducted without fertilization as a control (CK), and three different forms of nitrogen treatments were set up, namely, U:urea (amide nitrogen), A:ammonium sulfate (ammonium nitrogen), and N:calcium nitrate (nitrate nitrogen); the nitrogen application rate for each treatment was 67.5 kg·(hm 2 ·a) -1 , and the composition and diversity of soil nutrients and microbial communities under different treatments were analyzed. The results showed that the input of exogenous ammonium nitrogen significantly increased NH 4 + -N content, AP content, and EC; amide nitrogen input significantly increased SOC content and TN content; and nitrate nitrogen input significantly increased NO 3 - -N content, AN content, and TC content. Exogenous nitrogen input changed the structure of soil bacterial and fungal communities, as well as the relative abundance of dominant phyla and genera, but it did not significantly affect the alpha diversity of bacterial and fungal communities. Principal coordinate analysis (PCoA) showed that different forms of nitrogen addition had a significant impact on the Beta diversity of bacterial communities, whereas the impact on fungal communities was not significant. Redundancy analysis (RDA) indicated that nitrogen addition mainly changed the composition and structure of microbial communities through soil ammonium nitrogen. Overall, ammonium nitrogen fertilizer should be given priority in the soil remediation process of perennial cultivated grasslands in the Qinghai Tibet Plateau.

Symmetries, due to their fundamental importance to dynamical processes on networks, have attracted a great deal of current research. Finding all symmetric nodes in large complex networks typically relies on automorphism groups from algebraic-group theory, which are solvable in quasipolynomial time. We articulate a conceptually appealing and computationally extremely efficient approach to finding and characterizing all symmetric nodes by introducing a structural position vector (SPV) for each node in networks. We establish the mathematical result that symmetric nodes must have the same SPV value and demonstrate, using six representative complex networks from the real world, that all symmetric nodes in these networks can be found in linear time. Furthermore, the SPVs not only characterize the similarity of nodes but also quantify the nodal influences in propagation dynamics. A caveat is that the proved mathematical result relating the SPV values to nodal symmetries is not sufficient; i.e., nodes having the same SPV values may not be symmetric, which arises in regular networks or networks with a dominant regular component. We point out with an analysis that this caveat is, in fact, shared by the known existing approaches to finding symmetric nodes in the literature. We further argue, with the aid of a mathematical analysis, that our SPV method is generally effective for finding the symmetric nodes in real-world networks that typically do not have a dominant regular component. Our SPV-based framework, therefore, provides a physically intuitive and computationally efficient way to uncover, understand, and exploit symmetric structures in complex networks arising from real-world applications.

We uncover a phenomenon in coupled nonlinear networks with a symmetry: as a bifurcation parameter changes through a critical value, synchronization among a subset of nodes can deteriorate abruptly, and, simultaneously, perfect synchronization emerges suddenly among a different subset of nodes that are not directly connected. This is a synchronization metamorphosis leading to an explosive transition to remote synchronization. The finding demonstrates that an explosive onset of synchrony and remote synchronization, two phenomena that have been studied separately, can arise in the same system due to symmetry, providing another proof that the interplay between nonlinear dynamics and symmetry can lead to a surprising phenomenon in physical systems.

Objectives: To evaluate the depression and anxiety status and related risk factors in patients with lumbar disc herniation, and help spine surgeons better identify those patients who need psychological care., Methods: A cross-sectional study was performed on patients with lumbar disc herniation treated in our hospital between October 2015 and August 2018. Visual analog scale and Oswestry disability index were used to assess pain intensity and lumbar function, and Zung self-rating depression and anxiety scale were employed to evaluate the depression and anxiety status of the patients, and the demographic and clinical data including age, gender, marital status, occupation type, employment status, education level, surgery history, herniation type, disease duration, and insurance status were collected for analysis., Results: In the current study, 165 patients were enrolled based on the inclusion and exclusion criteria. In multivariate logistic regression analysis, gender (p=0.03), pain intensity (p=0.01), self-rating anxiety scale (SAS) (p=0.00), and disease duration (p=0.001) were identified as independent risk factors for depression status, and pain intensity (p=0.02), disease duration (p=0.002) and SDS (Zung self-rating depression scale) (p=0.003) were independent risk factors for anxiety status in patients with lumbar disc herniation. There was a significant correlation between Zung self-rating depression and anxiety scale in patients with lumbar disc herniation (p<0.05)., Conclusion: Psychological intervention is critical for patients with lumbar disc herniation, especially for those female patients with severe pain and longer disease duration.

Objective: To evaluate the efficacy of core stability exercise versus conventional exercise in the treatment of lumbar spinal stenosis., Methods: Between January 2014 and May 2017, patients with lumbar spinal stenosis were recruited and divided into group of core stability exercise or conventional exercise randomly. All the patients were treated using middle frequency electrotherapy, in addition to that, the patients in group of core stability exercise were treated using core stability exercise. The patients in group of conventional exercise were treated using conventional exercise. The outcome was evaluated using Japanese Orthopedic Association (JOA) score, self-reported walking capacity and lumbar lordosis angle at baseline and after treatment., Results: In the current study, sixty-two patients with lumbar spinal stenosis met the inclusion and exclusion criteria, in which 33 patients were included in group of core stability exercise and 29 in group of conventional exercise. After treatment, both Japanese Orthopedic Association scores (p<0.05) and self-reported walking capacity (p<0.05) increased significantly in each group when compared with baseline. The self-reported walking capacity and JOA scores in the group of core stability exercise were significantly higher than those in the conventional exercise group (p<0.05). However, both the intragroup and intergroup comparison of lumbar lordosis presented with no significance (p>0.05)., Conclusion: Core stability exercise presents with better efficacy than conventional exercise in the treatment of lumbar spinal stenosis.

At the spinal level, mu-opioids exert their actions on nociceptive primary afferent neurons both pre- and postsynaptically. In the present study, we used an in vitro isolated neonatal rat (11-15 days old) spinal cord preparation to examine the effects of morphine and the endogenous mu-opioid ligands endomorphin-1 (EM-1) and endomorphin-2 (EM-2) on the polysynaptic reflex (PSR) of dorsal root-ventral root (DR-VR) reflex. The actions of mu-opioids on spinal nociception were investigated by quantification of the firing frequency and the mean amplitude of the PSR evoked by stimuli with 20 x threshold intensity. EM-1 decreased the mean amplitude of PSR, whereas EM-2 and morphine decreased the firing frequency. The pattern of the effects elicited by morphine was the same as that for EM-2, except at high concentration. Naloxonazine, a selective mu(1) opioid receptor antagonist, had no significant effect on PSR by itself, but blocked the inhibition of PSR firing frequency or amplitude induced by EM-1, -2 and morphine. This may suggest that EM-1, EM-2 and morphine modulate spinal nociception differently and act mainly at the mu(1)-opioid receptors. Although they all act via mu(1)-opioid receptors, their different effects on the PSR may suggest the existence of different subtypes of the mu(1)-opioid receptor. The present data is also consistent with a further hypothesis, namely, that morphine and EM-2 activate a subtype of mu(1)-opioid receptor presynaptically, while EM-1 acts mainly through another subtype postsynaptically. However, since other reports indicate that EM-2, but not EM-1, could stimulate the release of enkephalins or dynorphin, presynaptic delta and kappa receptors may be also involved indirectly in the different regulation by mu-opioids at the spinal level.