Search

In the past few years, due to the vigorous development of China’s industry and the rapid increase in urbanization, a series of adverse effects have been produced, such as the decline of groundwater levels, the pollution of groundwater resources, and the degradation of wetlands. Real-time monitoring of changes in groundwater volume and water quality under the influence of human activities is very important in the current era. It is not only of great significance for achieving sustainable development, but also indispensable for future specific planning. This paper mainly optimizes the design of the monitoring well pattern from the Yukou landfill to the water source of Zhongqiao in P District and establishes three optimization goals of pollution detection probability, early warning response time, and cost. Firstly, the deterministic model of P area was established by image super-resolution processing, and the pollution source was tracked by the software package MODPATH in GMS, so that the early warning response time occupies the primary position in the optimization goal. The first optimization plan was proposed, using Monte Carlo. The method randomizes the parameters of the permeability coefficient K and establishes a random model. Using the risk analysis in the random model, the probability capture area of the mining well at the water source is obtained. The probability of pollution detection takes the first place in the optimization objective. Taking the pollution detection probability as the primary position in the optimization objective, the second optimization scheme is proposed. Through the research on groundwater resource pollution detection and home sports training intervention, we will apply it to real life and promote its rapid development in the future.

Background The Yarkand hare (Lepus yarkandensis Günther, 1875) is endemic to oasis and desert areas around the Tarim Basin in the Xinjiang Uyghur Autonomous Region of northwest China; however, genome-wide information for this species remains limited. Moreover, the genetic variation, genetic structure, and phylogenetic relationships of Yarkand hare from the plateau mountain regions have not been reported. Thus, we used specific-length amplified fragment sequencing (SLAF-seq) technology to evaluate the genetic diversity of 76 Yarkand hares from seven geographic populations in the northern and southwestern parts of the Tarim Basin to investigate single-nucleotide polymorphism (SNP) marker-based population differentiation and evolutionary processes. Selective sweep analysis was conducted to identify genetic differences between populations. Results Using SLAF-seq, a total of 1,835,504 SNPs were initially obtained, of which 308,942 high-confidence SNPs were selected for further analysis. Yarkand hares exhibited a relatively high degree of genetic diversity at the SNP level. Based on pairwise FST estimates, the north and southwest groups showed a moderate level of genetic differentiation. Phylogenetic tree and population structure analyses demonstrated evident systematic phylogeographical structure patterns consistent with the geographical distribution of the hares. Hierarchical analysis of molecular variation further indicated that genetic variation was mainly observed within populations. Low to moderate genetic differentiation also occurred among populations despite a common genomic background, likely due to geographical barriers, genetic drift, and differential selection pressure of distinct environments. Nevertheless, the observed lineage-mixing pattern, as indicated by the evolutionary tree, principal component analysis, population structure, and TreeMix analyses, suggests a certain degree of gene flow between the north and southwest groups. This may be related to the migration of hares to high-altitude water sources southwest of the basin during glacial climatic oscillations, as well as river re-diffusion and oasis restoration in the basin following the glacial period. We also identified candidate genes, and their associated gene ontology terms and pathways, related to the adaptation of Yarkand hares to different environmental habitats. Conclusions The identified genome-wide SNPs, genetic diversity, and population structure of Yarkand hares expand our understanding of the genetic background of this endemic species and provide valuable insights into its environmental adaptation, allowing for further exploration of the underlying mechanisms.

In the past few years, due to the vigorous development of China’s industry and the rapid increase in urbanization, a series of adverse effects have been produced, such as the decline of groundwater levels, the pollution of groundwater resources, and the degradation of wetlands. Real-time monitoring of changes in groundwater volume and water quality under the influence of human activities is very important in the current era. It is not only of great significance for achieving sustainable development, but also indispensable for future specific planning. This paper mainly optimizes the design of the monitoring well pattern from the Yukou landfill to the water source of Zhongqiao in P District and establishes three optimization goals of pollution detection probability, early warning response time, and cost. Firstly, the deterministic model of P area was established by image super-resolution processing, and the pollution source was tracked by the software package MODPATH in GMS, so that the early warning response time occupies the primary position in the optimization goal. The first optimization plan was proposed, using Monte Carlo. The method randomizes the parameters of the permeability coefficient K and establishes a random model. Using the risk analysis in the random model, the probability capture area of the mining well at the water source is obtained. The probability of pollution detection takes the first place in the optimization objective. Taking the pollution detection probability as the primary position in the optimization objective, the second optimization scheme is proposed. Through the research on groundwater resource pollution detection and home sports training intervention, we will apply it to real life and promote its rapid development in the future.

Lepus yarkandensis is a national second-class protected animal endemic to China and distributed only in the hot and arid Tarim Basin in Xinjiang. We sequenced and described the complete mitogenome of L. yarkandensis to analyze its characteristics and phylogeny. The species’ DNA is a 17,047 bp circular molecule that includes 13 protein-coding genes (PCGs), two rRNA genes, 22 tRNA genes, and one control region. The overall base composition was as follows: A, 31.50%; T, 29.40%; G, 13.30% and C, 25.80%, with a high A+T bias of 60.9%. In the PCGs, ND6 had deviation ranges for AT skew (–0.303) and GC skew (0.636). The Ka/Ks values of ND1 (1.067) and ND6 (1.352) genes were >1, indicating positive selection, which might play an important role in the adaptation of L. yarkandensis to arid and hot environments. The conserved sequence block, the central conserved domain, and the extended termination-associated sequences of the control region and their features were identified and described. The phylogenetic tree based on the complete mitogenome showed that L. yarkandensis was closely related to the sympatric Lepus tibetanus pamirensis. These novel datasets of L. yarkandensis can supply basic data for phylogenetic studies of Lepus spp., apart from providing essential and important resource for further genetic research and the protection of this species.

Studies suggest that there is a relationship between body mass index (BMI) and thyroid-stimulating hormone (TSH) levels. But conflicting evidence exists regarding the relationship between the two variables. Moreover, thyroid function is closely related to female fertility and has certain effects on infertility. Therefore, the present study will explore the relationship between BMI and TSH levels in patients with infertility in our center. We retrospectively analyzed relevant indicators of 2,789 in Tubal Factor Infertility patients undergoing assisted reproduction technology from January 2016 to December 2018 in our center in order to analyze the relationship between BMI and serum TSH level. The medical histories of patients were reviewed. The relationship between BMI and TSH was assessed using smooth curve fitting and multivariate regression model. The smoothing curve fitting between BMI and TSH exhibited a non-linear relationship, and the resulting curve exhibited a two-stage change and a breakpoint. By multivariate piecewise linear regression, we found that the TSH level was increased with the increase of BMI when the BMI was greater than 25.3 kg/m2 (β 0.06, 95% CI 0.02, 0.01; p = 0.0028). In contrast, the TSH level was decreased with the increase of BMI when the BMI was less than 25.3 kg/m2 (β -0.02, 95% CI -‍0.05, 0.00; p = 0.0573). Collectively, our study described a non-linear relationship between BMI and TSH level in infertile patients after adjustment of potential confounders. However, such causal relationship between BMI and TSH in infertile women still needs to be further clarified in future investigations.

Background: Leukemia inhibitory factor (LIF) has played a vital role in a series of reproductive events, including follicle growth, embryo growth and differentiation. However, it is unclear whether the level of LIF in embryo culture medium can be used as a marker for clinical pregnancy. In this study, we aimed to investigate whether LIF level in embryo culture medium can act as a predictive marker for pregnancy outcome of in vitro fertilization-embryo transfer (IVF-ET) in infertile patients due to tubal problems.Methods: A total of 104 infertile patients due to tubal problems underwent IVF-ET treatment. The patients were divided into two groups according to whether they were clinically pregnant. The level of LIF in the embryo culture medium was measured, and the correlation between LIF level and embryo quality and clinical pregnancy outcome was analyzed. The embryo culture medium was collected on the day of blastocyst transplantation.Results: Compared to non-pregnant group, LIF level in the embryo culture medium on the day of blastocyst transplantation was significantly higher in the pregnant group.Conclusions: LIF level in the embryo culture medium may be used as a non-invasive auxiliary biomarker for predictive clinical pregnancy in infertile patients with tubal problems that using single blastocyst transfer method.

Lepus tibetanus pamirensis distributes only in the Pamir Plateau under a harsh environment with high attitude, cold and dry climates. The complete mitochondrial genome of the hare was determined (a...

Leukemia inhibitory factor (LIF) has played a vital role in a series of reproductive events, including follicle growth, embryo growth and differentiation. However, it is unclear whether the level of LIF in embryo culture medium can be used as a marker for clinical pregnancy. In this study, we aimed to investigate whether LIF level in embryo culture medium can act as a predictive marker for pregnancy outcome of in vitro fertilization-embryo transfer (IVF-ET) in infertile women due to tubal problems. A total of 208 infertile women due to tubal problems underwent IVF-ET treatment. The women were divided into two groups according to whether they were clinically pregnant. The level of LIF in the embryo culture medium was measured, and the correlation between LIF level and embryo quality and clinical pregnancy outcome was analyzed. The embryo culture medium was collected on the day of blastocyst transplantation. Compared to non-pregnant group, LIF level in the embryo culture medium on the day of blastocyst transplantation was significantly higher in the pregnant group. LIF level in the embryo culture medium may be used as a non-invasive auxiliary biomarker for predictive clinical pregnancy in infertile women with tubal problems that using single blastocyst transfer method.

The operation of a pulse-charged spark gap that is triggered by gallium arsenide (GaAs) photoconductive semiconductor switches (PCSSs) was investigated. By measuring the currents with the streamer discharge, we analyzed the mechanisms of breakdown between the semi-insulating GaAs PCSS and the spark gap. Two similar combination setups were studied by different gap structures. It was shown that the PCSS was a good candidate for generating high current (as high as 5.6 kA) or ultrafast pulse with 220-ps rise time and 400-ps full-width at half-maximum accompanied with good reproducibilities of waveforms.

Based on the analysis of temperature field generated when semi-insulating GaAs photoconductive switch irradiated by light pulse, the paper focuses on the light damage induced by nanosecond laser pulse with 1.06μm wavelength at high repetition frequencies in switch materials. On the basis of the thermal conduction theory, the transient temperature field in the materials is simulated in a computer by using the finite difference method, the main reasons of damage induced by laser in chip material are analyzed according to simulation results and experimental results of the damage test, and the damage mechanism is discussed.

A semiclassical Monte Carlo model is presented to study the time-varying conduct current and displacement current in a Terahertz photoconductive switch after photoexcitation.

This paper discussed the SI-GaAs photoconductive switch entering into the nonlinear mode under the high biased field and the result of photovoltaic delay, as well as, analyzed the phenomena of electric pulses delay under the high biased field. Meanwhile, pose a theory that the captive effects of impurities in deep energy level of semi-conductor materials is the main reason of photovoltaic delay, moreover, calculation to account the relationship between the transmission of charge domain and photovoltaic delay, and received a result that inosculate with the experiment.

In this paper, experiments of a lateral semi-insulating GaAs photoconductive semiconductor switch triggered by nanosecond laser pulses were reported. The switches were insulated by solid multi-layer transparent dielectrics. Jitter-free electrical pulses with steady voltage amplitude from the 0.5 mm-gap GaAs switches were observed when biased with low voltage and triggered by serial laser pulses. Its change of amplitude was less than 1.2%, the triggered jitter-time was less than 10ps, and pulse width was up to sub-nanosecond. The effect of pulse energy change on the amplitude generated photoconductive semiconductor switch was analyzed. It was indicated that ultra-fast electrical pulse with steady voltage amplitude and pico-second triggered jitter-time can be obtained by controlling switch trigger condition and optimizing switch design.

Monte-Carlo method is adopted in GaAs PCSS's simulation, In the case of high optical fluence, space-charge field can intensity influence the movement of the carrier. Thus, space-charge field can intensity influence not only the shape of photo-electric current of PCSS's, but also the terahertz out put of photo-conducting antenna. In this paper, the forming and movement of space-charge field are simulated by means of Monte-Carlo method. And the result of simulate indicates that optically activated charge multi-domain exists in photoconductor. The forming of multi-domain is also explained in this paper.

GaAs PCSS's can work under linear and nonlinear modes. When the PCSS's work at the field below 3.5 kV/cm, current pulse string and corresponding light pulse string have the same rise time and pulse width. The resistance of PCSS's recovers, as soon as the light pulse disappears. When the electrical field is larger than 4.3 kV/cm, the light energy is greater than 0.46 mJ, GaAs-PCSS's work at nonlinear mode, which also is called high gain mode or lock-on effect. By calculation, Gunn domains come into being in GaAs in lock-on effect, and the high-gain mechanism is explained by optically activated charge domain model. So the microcosmic conditions of lock-on have been found. The requirement on the triggering laser energy is essential to meet the requirement of Gunn-domain formation by generating enough carriers. The requirement on the electrical field threshold is borne on the requirement of NDR threshold (Gunn threshold), which ranges from 3.2 kV/cm to 4 kV/cm for GaAs. In our experiments, the electric field threshold of high-gain mode is from 4.1 kV/cm to 11 kV/cm, which is higher than NDR threshold of GaAs. We can reduce the electrical field down to Gunn threshold by designing the external circuit. In this paper, two circuits are introduced which is designed by Sandia National Laboratories, and can be used to induce fast recovery from lock-on.