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In order to gain a better understanding of clay and Fe (oxyhydr)oxide minerals formed during pedogenesis of basalts in tropical monsoonal Hainan (southern China), a basalt-derived lateritic soil at Nanyang, Hainan, was investigated comprehensively. The results show that the lateritic regolith consists uniformly of kaolinite and Fe (oxyhydr)oxide minerals, with trace gibbsite only in the AE horizon. Abundant dioctahedral smectite in the basalt bedrock formed due to primary hydrothermal alteration, and transformed to kaolinite rapidly in the highly weathering saprolite horizon. The ‘crystallinity’ of kaolinite is notably low and its Hinckley index fluctuates along the soil profile, resulting from intense ferrolysis due to fluctuations between wet/dry climate conditions. From the base to the top of the profile, maghemite shows a decreasing trend, whereas magnetite, hematite, and goethite exhibit a slightly increasing trend, indicating that maghemite formed as an initial product of basalt weathering. Formation of Fe (oxyhydr)oxide species in basalt-derived soil is mainly controlled by local environmental conditions such as soil moisture, redox, and acidic conditions; thus, iron mineral-based paleoclimatic proxies could not be used for subtropical to tropical soils. The highly weathered saprolite has a similar δ56Fe value (+0.06‰) to that (+0.07‰) of the parent rock, while the AE to middle E horizons have greater δ56Fe values of +0.12‰ to +0.19‰. Fe isotopic signatures correlate positively with the Fe mass transfer coefficient (R2=0.77, n=6, ρ<0.05), indicating repetitive weathering and relative accumulation of isotopically heavier Fe in the upper soil horizons, which occurred by reductive dissolution of organic matter under oxic conditions, as reflected by the greater U/Th.
The mid-infrared optical frequency comb is a powerful tool for gas sensing. In this study, we demonstrate a simple mid-infrared dual-comb spectrometer covering 3–4 μm in LiNbO3 waveguides. Based on a low-power fiber laser system, the mid-infrared comb is achieved via intra-pulse difference frequency generation in the LiNbO3 waveguide. We construct pre-chirp management before supercontinuum generation to control spatiotemporal alignment for pump and signal pulses. The supercontinuum is directly coupled into a chirped periodically poled LiNbO3 waveguide for the 3–4 μm idler generation. A mid-infrared dual-comb spectrometer based on this approach provides a 100 MHz resolution over 25 THz coverage. To evaluate the applicability for spectroscopy, we measure the methane spectrum using the dual-comb spectrometer. The measured results are consistent with the HITRAN database, in which the root mean square of the residual is 3.2%. This proposed method is expected to develop integrated and robust mid-infrared dual-comb spectrometers on chip for sensing.
This paper presents a review of the main trends of contemporary political philosophy in China. First, it provides a general picture of the presence of contemporary western political philosophy in China. It shows how the different political positions (New Left, liberalist, conservative) relate to the different stances adopted before Western authors, and focuses in particular on the reception of Carl Schmitt and Leo Strauss in China's academic and cultural circles. Second, it provides an account of what might be contemporary Chinese political philosophers’ unique contributions to political theory. It pays particular attention to two Chinese scholars, Gan Yang and Zhao Tingyang. While both of them specialize in western philosophy, they neither echo western political philosophy nor repeat traditional Chinese political thought, but, rather, commit themselves to a transformation of Chinese tradition thought, in order to figure out some original and debatable theories. By focusing on analyzing these philosophers’ ideas and influences, the author hopes to answer two distinct but interrelated questions: how and why are they are so fashionable or popular, and whose thought might retain some pertinence in the context and issues of Chinese political tradition and the existing political practices.
We present the results of two population surveys conducted 10 years apart (December 2010–February 2011 and December 2020–January 2021) of the Critically Endangered white-headed langur Trachypithecus leucocephalus in the Chongzuo White-Headed Langur National Nature Reserve, Guangxi Province, China. In the first survey, we recorded 818 individuals in 105 groups and 16 solitary adult males. In the second survey, we recorded 1,183 individuals in 128 groups and one solitary adult male. As a result of government policies, poaching for food and traditional medicine is no longer a primary threat to these langurs. However, severe forest loss and fragmentation caused by human activities could limit any future increase of this langur population.
We report a compact, tunable, self-starting, all-fiber laser-based asynchronous optical sampling (ASOPS) system. Two Er-doped fiber oscillators were used as the pulsed-laser source, whose repetition rate could be set at 100 MHz with a tuning range of 1.25 MHz through a fiber delay line. By employing phase-locked and temperature control loops, the repetition rate offset of the two lasers was stabilized with 7.13 × 10−11 fractional instability at an average time of 1 s. Its capabilities in the terahertz regime were demonstrated by terahertz time-domain spectroscopy, achieving a spectral bandwidth of 3 THz with a dynamic range of 30 dB. The large range of repetition rate adjustment in our ASOPS system has the potential to be a powerful tool in the terahertz regime.
The purpose of this study was to analyse the clinical characteristics of patients with severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) PCR re-positivity after recovering from coronavirus disease 2019 (COVID-19). Patients (n = 1391) from Guangzhou, China, who had recovered from COVID-19 were recruited between 7 September 2021 and 11 March 2022. Data on epidemiology, symptoms, laboratory test results and treatment were analysed. In this study, 42.7% of recovered patients had re-positive result. Most re-positive patients were asymptomatic, did not have severe comorbidities, and were not contagious. The re-positivity rate was 39%, 46%, 11% and 25% in patients who had received inactivated, mRNA, adenovirus vector and recombinant subunit vaccines, respectively. Seven independent risk factors for testing re-positive were identified, and a predictive model was constructed using these variables. The predictors of re-positivity were COVID-19 vaccination status, previous SARs-CoV-12 infection prior to the most recent episode, renal function, SARS-CoV-2 IgG and IgM antibody levels and white blood cell count. The predictive model could benefit the control of the spread of COVID-19.
Gain-parameter-dependent transfer functions and phase-noise performances in a mode-locked Yb-doped fiber laser are measured in this study. It is discovered that the corner frequency in the amplitude and phase domains is determined by the absorption coefficient of the gain fiber, when the total absorption and other cavity parameters are fixed. This shows that an oscillator using gain fiber with higher dopant concentration accumulates more phase noise. Furthermore, we present net cavity dispersion-dependent transfer functions to verify the effect of dispersion management on the frequency response. We derive a guideline for optimizing mode-locked fiber laser design to achieve low phase noise and timing jitter.
We report on the generation of a mid-infrared (mid-IR) frequency comb with a maximum average output power of 250 mW and tunability in the 2.7–4.0 μm region. The approach is based on a single-stage difference frequency generation (DFG) starting from a compact Yb-doped fiber laser system. The repetition rate of the near-infrared (NIR) comb is locked at 75 MHz. The phase noise of the repetition rate in the offset-free mid-IR comb system is measured and analyzed. Except for the intrinsic of NIR comb, environmental noise at low frequency and quantum noise at high frequency from the amplifier chain and nonlinear spectral broadening are the main noise sources of broadening the linewidth of comb teeth, which limits the precision of mid-IR dual-comb spectroscopy.
Six acidic dykes were discovered surrounding the Laiziling pluton, Xianghualing area, in the western Cathaysia Block, South China. A number of captured zircons are found in two of these acidic dykes. By detailed U–Pb dating, Lu–Hf isotopes and trace-element analysis, we find that these zircons have ages clustered at c. 2.5 Ga. Two acidic dyke samples yielded upper intersection point 206U/238Pb ages of 2505 ± 42 Ma and 2533 ± 22 Ma, and weighted mean 207Pb/206Pb ages of 2500 ± 30 Ma and 2535 ± 16 Ma. The majority of these zircons have high (Sm/La)N, Th/U and low Ce/Ce* ratios, indicating a magmatic origin, but some grains were altered by later hydrothermal fluid. Additionally, the magmatic zircons have high Y, U, heavy rare earth element, Nb and Ta contents, indicating that their host rocks were mainly mafic rocks or trondhjemite–tonalite–granodiorite rock series. Equally, their moderate Y, Yb, Th, Gd and Er contents also indicate that a mafic source formed in a continental volcanic-arc environment. These zircons have positive ϵHf(t) values (2.5–6.9) close to zircons from the depleted mantle, with TDM (2565–2741 Ma) and TDM2 (2608–2864 Ma) ages close to their formation ages, indicating that these zircons originated directly from depleted mantle magma, or juvenile crust derived from the depleted mantle in a very short period. We therefore infer that the Cathaysia Block experienced a crustal growth event at c. 2.5 Ga.
We report on a compact and robust self-referenced optical frequency comb with a tunable repetition rate, generated by an all-polarization-maintaining (PM) mode-locked Er-doped fiber laser. The spacing between comb teeth can be tuned above 300 kHz at a repetition rate of 101 MHz. The repetition rate and the carrier–envelope offset of the laser are stabilized separately, and the relative residual phase noises are determined to be $336~\unicode[STIX]{x03BC}\text{rad}$ and 713 mrad (1 Hz–1 MHz). The accurate frequency characteristics and the stable structure show great potential for the use of such a comb in applications of precision measurements.
Endometrial injury is an important cause of intrauterine adhesion (IUA), amenorrhea and infertility in women, with limited effective therapies. Recently, stem cells have been used in animal experiments to repair and improve injured endometrium. To date, our understanding of adipose-derived stem cells (ADSCs) in endometrial injury repair and their further therapeutic mechanisms is incomplete. Here, we examined the benefit of ADSCs in restoration of injured endometrium by applying a rat endometrial injury model. The results revealed by immunofluorescence showed that green fluorescent protein (GFP)-labelled ADSCs can differentiate into endometrial epithelial cells in vivo. At 30 days after ADSCs transplantation, injured endometrium was significantly improved, with increased microvessel density, endometrial thickness and glands when compared with the model group. Furthermore, the fertility of rats with injured endometrium in ADSCs group was improved and had a higher conception rate (60% vs 20%, P = 0.014) compared with the control phosphate-buffered saline (PBS) group. However, there was no difference in the control group compared with the sham group. In addition, expression levels of the oestrogen receptor Eα/β (ERα, ERβ) and progesterone receptor (PR) detected by western blot and enzyme-linked immunosorbent assay (ELISA) were higher in the ADSCs group than in the PBS group. Taken together, these results suggested that ADSC transplantation could improve endometrial injury as a novel therapy for IUA.
Existing data on folate status and hepatocellular carcinoma (HCC) prognosis are scarce. We prospectively examined whether serum folate concentrations at diagnosis were associated with liver cancer-specific survival (LCSS) and overall survival (OS) among 982 patients with newly diagnosed, previously untreated HCC, who were enrolled in the Guangdong Liver Cancer Cohort (GLCC) study between September 2013 and February 2017. Serum folate concentrations were measured using chemiluminescent microparticle immunoassay. Cox proportional hazards models were performed to estimate hazard ratios (HR) and 95 % CI by sex-specific quartile of serum folate. Compared with patients in the third quartile of serum folate, patients in the lowest quartile had significantly inferior LCSS (HR = 1·48; 95 % CI 1·05, 2·09) and OS (HR = 1·43; 95 % CI 1·03, 1·99) after adjustment for non-clinical and clinical prognostic factors. The associations were not significantly modified by sex, age at diagnosis, alcohol drinking status and Barcelona Clinic Liver Cancer (BCLC) stage. However, there were statistically significant interactions on both multiplicative and additive scale between serum folate and C-reactive protein (CRP) levels or smoking status and the associations of lower serum folate with worse LCSS and OS were only evident among patients with CRP > 3·0 mg/l or current smokers. An inverse association with LCSS were also observed among patients with liver damage score ≥3. These results suggest that lower serum folate concentrations at diagnosis are independently associated with worse HCC survival, most prominently among patients with systemic inflammation and current smokers. A future trial of folate supplementation seems to be promising in HCC patients with lower folate status.
In dense networks, the tremendous computational complexity and communication overhead of cooperative localisation are the two main bottlenecks that limit practical application. In this study, we introduce a bootstrap percolation scheme into Gaussian message passing-based cooperative localisation for precise positioning, aimed at reducing the system overhead. Considering the uncertainty information and geometric distribution of neighbours, an approximate collinear detection criterion is proposed to detect the possible flip ambiguities in cooperative localisation. According to the detection result and our connection constraint, agents are divided into three categories and are approximated by different distribution families. A message passing rule is designed to control the propagation direction from high precision to low precision, thereby mitigating potential error propagation. Additionally, a layer-by-layer positioning mechanism is established where the agents are located gradually. Analytical and simulation results indicate that when the ranging standard deviation is 0·2 m, 89·3% of the agent nodes can be located within 0·4 m using the proposed algorithm. Compared with the Hybrid Sum-Product Algorithm over A Wireless Network (H-SPAWN), this ratio is increased by 8·4% and the computational complexity is reduced by 72%.
Underground Nuclear Astrophysics in China (JUNA) will take the advantage of the ultra-low background in Jinping underground lab. High current accelerator with an ECR source and detectors were commissioned. JUNA plans to study directly a number of nuclear reactions important to hydrostatic stellar evolution at their relevant stellar energies. At the first period, JUNA aims at the direct measurements of 25Mg(p,γ)26 Al, 19F(p,α) 16 O, 13C(α, n) 16O and 12C(α,γ) 16O near the Gamow window. The current progress of JUNA will be given.
Rhizoma et Radix Notopterygii is often used as a traditional medicine in China. In our recent work, we found that the ethanol crude extract of Rhizoma et Radix Notopterygii could reduce phytotoxicity of acetochlor on rice. The crude extract of Rhizoma et Radix Notopterygii was isolated and purified by activity-guided fractionation. Two coumarins, isopimpinellin and 5-methoxypsoralen (5-MOP) were identified, and their bioactivity was tested in a growth chamber. The results showed that the two coumarins increased herbicide tolerance of rice shoots, and 5-MOP demonstrated better protection than isopimpinellin. The treatment of 5-MOP at 50 g ai ha−1 recovered the shoot height of rice from 42.6% (treated with acetochlor only) to 81.6% of the control treated without acetochlor, whereas the phytocidal activity of acetochlor on barnyardgrass was not impaired by 5-MOP. Further study suggested that 5-MOP increases herbicide tolerance of rice by enhancing the glutathione S-transferase level of activity in rice. Our findings suggest that isopimpinellin and 5-MOP have the potential to be applied as safeners for rice.
Schizophrenia (SZ) is a common severe psychiatric disorder and a complex polygenic inherited disease that has not yet been fully interpreted. Heredity was proven to play an important role in the development of SZ. The association between the NOTCH4 gene rs3131296 polymorphism and SZ was reported to reach significance at the genome-wide level; therefore, it is necessary to replicate this association in other different populations.
Methods
To evaluate the association of the NOTCH4 gene rs3131296 polymorphism with the risk for SZ, and to explore whether a significant association could be replicated in different ethnic groups of China, we conducted this case–control study on 282 SZ cases (188 Han and 94 Zhuang) and 282 controls (188 Han and 94 Zhuang) among the Chinese Zhuang and Han populations.
Results
The results showed no statistically significant difference in the genotype or allele frequencies of the NOTCH4 gene variant rs3131296 between SZ patients and healthy controls in either the Zhuang or Han samples (p > 0.05). In addition, no significant difference was found in genotype or allele frequencies of the NOTCH4 gene variant rs3131296 between cases and controls in the combined samples including Zhuang and Han samples.
Conclusions
Our study failed to replicate the significant association between the NOTCH4 gene rs3131296 polymorphism and the risk for SZ.
Celestial navigation is an important type of autonomous navigation technology which could be used as an alternative to Global Navigation Satellite Systems (GNSS) when a vessel is at sea. After several centuries of development, a variety of astronomical vessel position (AVP) determination methods have been invented, but the basic concepts of these methods are all based on angular observations with a device such as a sextant, which has disadvantages including low accuracy, manual operation, and a limited period of observation. This paper proposes a new method that utilises a fisheye camera to image the celestial bodies and horizon simultaneously. Then, we calculate the obliquity of the fisheye camera's principal optical axis according to the image coordinates of the horizon. Next, we calculate the altitude of the celestial bodies according to the image coordinates of the celestial bodies and the obliquity. Finally, the AVP is determined by the altitudes according to the robust estimation method. Experimental results indicate that this method not only could realize automation and miniaturization of the AVP determination system, but could also greatly improve the efficiency of celestial navigation.
Cu2ZnSnSe4 (CZTSe) precursor films were deposited by one-step RF sputtering process at room temperature under various sputtering power, and then films were annealed at different pressure of 10-3 Pa and 100 Pa. Films annealed at high vacuum of 10-3 Pa exhibit significant loss of Sn element and they construct with two phases of Cu1.8Se and ZnSe. Higher annealing pressure at 100 Pa can drastically reduce the loss of Sn element and result in single kesterite CZTSe phase of the annealed films. Loss of Se element is found in all the annealed films and the values of [Se]/[Metal] and [Sn]/[Zn] are related with sputtering power. High vacuum annealed films show cracks and porous structure on the surface, meanwhile, films annealed at 100 Pa show compact, densely packed homogeneous morphology.
Round spermatid injection (ROSI) into mammalian oocytes can result in the development of viable embryos and offspring. One current limitation to this technique is the identification of suitable round spermatids. In the current paper, round spermatids were selected from testicular cells with phase contrast microscopy (PCM) and fluorescence-activated cell sorting (FACS), and ROSI was performed in two strains of mice. The rates of fertilization, embryonic development and offspring achieved were the same in all strains. Significantly, round spermatids selected by PCM and FACS were effectively used to rescue the infertile Pten-null mouse. The current results indicate that FACS selection of round spermatids can not only provide high-purity and viable round spermatids for use in ROSI, but also has no harmful effects on the developmental capacity of subsequently fertilized embryos. It was concluded that round spermatids selected by FACS are useful for mouse strain rederivation and rescue of infertile males; ROSI should be considered as a powerful addition to the armamentarium of assisted reproduction techniques applicable in the mouse.
Red-emitting phosphor of Ca0.8Zn0.2TiO3:0.2 mol% Pr3+ was synthesized by the hydrothermal method with urea as a mineralizer. The crystalline structure, micromorphology, and luminescent properties of the resultant phosphor were investigated. Results show that elevated calcination temperature does not change the shape of particles that are hollow spheres with a shell thickness of 210–480 nm, and smaller particles are in the middle of the larger ones. The emission intensity at 612 nm originated from 1D2 → 3H4 transition of Pr3+ ions increases with the elevated calcination temperature due to a higher crystallinity. Excitation curves consist of two strong broad bands centered at about 330 and 380 nm and a weaker broad band range from 450 to 500 nm. The sample prepared by the hydrothermal method has better luminescent properties than that of its counterpart prepared by the solid-state method, especially the improvement of near-UV region (380 nm) excitation intensity.