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As a commonly used amendment to soil contaminated by heavy metals, biochar has attracted great attention and has been applied for decades due to the benefits to the soil. However, the effects of biochar on the dynamic behavior of soil properties and metal fractions are still unclear. Here, we used two biochars, derived from biowastes (reed and bamboo willow), to treat two cadmium (Cd)-contaminated soils, S1 (loamy sand) and S2 (sandy loam), and determined the dynamic effects. The incubation experiments were designed to investigate the effects of biochar on the dynamic behavior of soil pH, dissolved organic matter (DOM), bioavailable Cd, and the transformation of Cd fractions for 270 days. The results showed that the soil pH, DOM, and bioavailable Cd initially increased and then decreased with incubation time, and the soil pH and DOM were higher, but bioavailable Cd content was lower than the original value. The transformation of the metal fractions changed dynamically, and the exchangeable fraction of Cd decreased with incubation time. Furthermore, the correlation results showed that the DOM can directly control the redistribution of Cd fractions, while soil pH can control it indirectly by regulating the DOM. This study highlighted that biochar can affect soil pH and DOM, redistribute Cd fractions, decrease bioavailable Cd content, and lower the potential risk of heavy metals. This study suggests ways to immobilize heavy metals in contaminated soils using biochar.

The humic substance is a low-cost and effective adsorbent with abundant functional groups in remediating uranium (U) (VI)-contaminated water. In this research study, leonardite together with leonardite-derived humic acid (L-HA) was used to eliminate U(VI) from water under diverse temperatures (298, 308, and 318 K). L-HA showed a higher adsorption volume for U(VI) than leonardite. U adsorption was varied with pH and increased with temperature. The adsorption kinetics of L-HA had a higher determination coefficient (R2) for pseudo-second-order (R2 > 0.993) and Elovich (R2 > 0.987) models, indicating possible chemisorption-assisted adsorption. This was further supported with the activation energies (15.9 and 13.2 kJ/mol for leonardite and L-HA, respectively). Moreover, U(VI) equilibrium adsorption on leonardite was better depicted with the Freundlich model (R2 > 0.970), suggesting heterogeneous U(VI) adsorption onto the leonardite surface. However, U(VI) adsorption onto L-HA followed the Langmuir equation (R2 > 0.971), which implied the dominant role of monolayer adsorption in controlling the adsorption process. Thermodynamic parameters, including standard entropy change (ΔS0 > 0), Gibbs free energy (ΔG0 0), suggested a spontaneous and endothermal adsorption process. In addition, ionic species negatively affected U(VI) adsorption by leonardite and L-HA.

Uranium, a double-edged sword with high-efficiency energy and radioactive toxicity, attracts people to enjoy the advantages by generating power, but at the same time brings potential harm by nuclide migration. Therefore, it is necessary to develop a highly-efficient sensor to monitor uranyl ions in the field. However, the designed processes of the reported sensors are random, time-consuming and difficulty. It is urgent to find a new strategy to rationally, quickly and effectively screen out the required molecule for efficient uranium detection. Herein, with the guidance from the rational design method, the parameter, Egap, was applied to judge the chromatic aberration between the designed PADAP derivate and its uranyl complex. And the optimized structure sensor, 2-((3-bromo-5-(9,9-dioctyl-7-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9H-fluoren-2-yl)-2-pyridylazo)-5-(diethylamino)phenol (abbr. W1H), was screened and successfully synthesized. W1H exhibited significant color change (red to blue) after binding uranyl ions, and its detection limit for uranium was as low as nanomolar. More meaningfully, the coordination mechanism of W1H toward uranium was clarified by theoretical calculation of the electron cloud density distribution, Ebind, and 1H NMR, IR and MS for the first time. With the more excellent uranyl sensitivity, selectivity, and recyclability, W1H and its colorimetric test strip have been applied to the detection of low-concentration uranium in environmental samples around the uranium tailings, providing a useful on-site method to monitor trace uranium in actual samples.

Pulsatile non-Newtonian fluid flow was simulated in an artery bifurcation model, with three different inlet flow waveform shapes and an identical inlet mean velocity steady-state condition, to quantify the impact of three different waveform shapes on hemodynamics such as flow patterns, wall shear stress, and oscillatory shear index during a cardiac cycle. It was found that the degree of flow separation is insensitive to changes in flow waveform shape. There is remarkable similarity in the position and magnitude of the maximum wall shear stress at peak systole and the maximum time-averaged wall shear stress for all examined cases. The oscillatory shear index distributions are broadly similar except that the local maximum oscillatory shear index increases proportionally with the pulsatility index of the waveform shape. The maximum oscillatory shear index values on the planar branch are within 8.7% in all examined cases, while these oscillatory shear index values on the nonplanar branch are identical due to the effects of its curvature. The negligible hemodynamic differences between simplified and characteristic waveform cases suggest that changes in waveform shape play a minimal role in the progression and development of atherosclerosis. Although the computed hemodynamics is almost consistent for the three different waveform shapes, several slight differences were observed.

The impacts of partial confinement on the power extraction performance of a flapping foil generator at a Reynolds number of 1100 are numerically studied using an immersed boundary–lattice Boltzmann method. Four confinement levels are implemented with two thin plates of finite size symmetrically placed at the distance of 1.5, 2, 3, and 4 foil chord length from the neutral position of the flapping foil. Parametric studies on plate lengths varying from 10 to 50 foil chord lengths at the four confinement levels are conducted. The results show that the power-extraction efficiency increases nearly monotonically with the upstream plate lengths while the impact of the downstream plate lengths is much less significant, indicating that upstream confinement is the dominant factor influencing the power-extraction performance. Contrary to the performance improvement observed in studies on the effect of infinite walls, the efficiency decreases dramatically with the decrease in the distance from the plates to the foil. The reasons for the dramatically decreased performance due to confinement effects are found. First, the interactions between the boundary layer of the plates and leading edge vortices formed on the foil reduce the size of the low-pressure region on the suction surface of the foil, leading to reductions in lift forces and consequently to major reductions in the extracted power. In addition, large mass flow deficits between the finite plates are observed when the distance between the two plates is small, indicating substantial reductions in potential power that can be extracted from the inflow.

Cesarean Section (CS) is one of the most frequently executed surgical procedures in gynecology and obstetrics. After a cesarean section, surgical site infection (SSI) increases hospital stay, lengthens maternal morbidity, and upsurges treatment costs. The current study determines the prevalence and risk factors for surgical site infection following cesarean section in China. A retrospective study was conducted on 23 cases of pregnant women who underwent cesarean section and incision severe infection and detection from March 2017 to January 2020 at Wuhan Maternal and Child Healthcare Hospital in China as the study group, and 20 cases of uninfected cesarean section during the same period were selected as the control group. Data were compared with the controls based on study variables and the presence of SSI. The mean age was 31±2.6. High fever and blood loss were observed in serous SSI-infected patients. The incidence rate of severe surgical site infection was 0.15 %. SSI was observed to be expected in pregnant women who had premature rupture of membrane before surgery (p < 0.001), who underwent postoperative antibiotic therapy (p < 0.001), and the patients who had gestational diabetes mellitus (p

The nonlinear dynamics of a two-sided collapsible channel flow is investigated by using an immersed boundary-lattice Boltzmann method. The stability of the hydrodynamic flow and collapsible channel walls is examined over a wide range of Reynolds numbers $Re$ , structure-to-fluid mass ratios $M$ and external pressures $P_e$ . Based on extensive simulations, we first characterise the chaotic behaviours of the collapsible channel flow and explore possible routes to chaos. We then explore the physical mechanisms responsible for the onset of self-excited oscillations. Nonlinear and rich dynamic behaviours of the collapsible system are discovered. Specifically, the system experiences a supercritical Hopf bifurcation leading to a period-1 limit cycle oscillation. The existence of chaotic behaviours of the collapsible channel walls is confirmed by a positive dominant Lyapunov exponent and a chaotic attractor in the velocity-displacement phase portrait of the mid-point of the collapsible channel wall. Chaos in the system can be reached via period-doubling and quasi-periodic bifurcations. It is also found that symmetry breaking is not a prerequisite for the onset of self-excited oscillations. However, symmetry breaking induced by mass ratio and external pressure may lead to a chaotic state. Unbalanced transmural pressure, wall inertia and shear layer instabilities in the vorticity waves contribute to the onset of self-excited oscillations of the collapsible system. The period-doubling, quasi-periodic and chaotic oscillations are closely associated with vortex pairing and merging of adjacent vortices, and interactions between the vortices on the upper and lower walls downstream of the throat.

To assess the application value of mapping allele with resolved carrier status (MaReCs) technique for preimplantation genetic testing (PGT).The characteristics of MaReCs for PGT and outcome of patients were retrospectively analyzed.Compared with those who could not use the technique, carriers who have used the MaReCs technique were younger, had significantly higher level of anti-Mullerian hormone, more antral follicles, occytes, mature occytes, biopsied embryos and euploid embryos, and lower risks for de novo chromosomal abnormality (P0.05). It was necessary for couples with fewer oocytes, mature oocytes and balstocyst to preserve discarded embryos to facilitate the test. Carriers who have used the MaReCs technique had higher clinical pregnancy rate and abortion rate compared with those undergoing routine PGT, albeit no significant difference was found between the two groups (P0.05). Carriers undergoing MaReCs test could preferentially select embryos with normal chromosome structures for the transfer.Application of MaReCs has a prerequisite for having a minimum number of occytes and biopsied embryos and using discarded embryos sometimes. MaReCs is efficient for the detection of carrier status of embryos and attaining higher rate of pregnancy and live birth, which can significantly improve the outcome for couples carrying chromosomal translocations.

This paper presents a study on streamline penetration, velocity error, and consequences of a fluid–structure interaction (FSI) solver based on the feedback immersed boundary method (IBM). In the FSI solver, the fluid dynamics is solved by the lattice Boltzmann method; the solid structure deformation is solved by the finite difference method and the finite element method for two- and three-dimensional cases, respectively; and the feedback IBM is used to realize the interaction between the fluid and the structure. The IBM is implemented in non-iterative and iterative ways. For the non-iterative version, two types of integration are discussed: without and with velocity prediction step. Five benchmark cases are simulated to study the performance of the three implementations: a uniform flow over a cylinder, flow-induced vibration of a flexible plate attached behind a stationary cylinder in a channel, flow through a two-dimensional asymmetric stenosis, a one-sided collapsible channel, and a three-dimensional collapsible tube. Results show that both the IBM with prediction step, the iterative IBM, and one iteration IBM with proper feedback coefficients can suppress the spurious flow penetration on the solid wall. While the velocity error does not significantly affect the force production and structure deformation for external flows, reducing it significantly improves the prediction of the force distribution and structure deformation for internal flows. In addition, the iterative IBM with smaller feedback coefficient has better numerical stability. This work will provide an important guideline for the correct use of the feedback IBMs.

With rapid development of nuclear industry, the overexploitation of uranium has brought a series of radioactive pollution problems to water, soil, atmosphere and ecosystem. Uranium and its compounds are highly carcinogenic and biologically toxic, posing a deadly threat to human health. Therefore, how to design a highly selective and sensitive sensor to detect uranyl ions in the environment and organisms has become an urgent task. This review summarizes relevant literature on the detection of uranyl ions by different sensors over the years. The detection methods can be roughly divided into three categories: optical sensors, electrochemical sensors and other sensors; further classification has also been carried out according to their detection mechanism. The detection limits and performances of different sensors are discussed to intuitively understand different capability for these methods in detecting uranyl ions. We also discuss the trend and future direction of uranium to provide a valuable reference for further developing better uranyl sensors.

The palladium/cobalt/carbon (Pd/Co/C) nanopolyhedra were synthesized by calcinating the precursor prepared by a cyclodextrin (CD) modified palladium acetylacetonate loaded on ZIF-67, hydroxypropyl-β-cyclodextrin (HP-β-CD)-[Pd(acac)2]/ZIF-67. On one hand, the HP-β-CD was used to increase the solubility of Pd(acac)2 by supramolecular interactions, and on the other hand, ZIF-67 was employed to provide the Co/C as the magnetic support. The Pd/Co/C nanopolyhedra obtained with the assistance of HP-β-CD have high activity and reusability for the reduction of the dichromate ion in the presence of formic acid without using any buffer solution, and no significant leaching of metallic Co of the catalyst was observed. This could be ascribed to the fact that the presence of HP-β-CD could lead to a more homogeneous distribution of metallic Pd in the Pd/Co/C nanopolyhedra, which could prevent the dissolution of metallic Co by formic acid.

Graphical abstract, The ongoing SARS-CoV-2 pandemic infecting millions of people globally has given rise to serious public health threats. The need for early detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in asymptomatic pregnant women is compelling to detect vertical transmission timely. Here, 11 SARS-CoV-2 asymptomatic pregnant cases from Wuhan China were investigated. All the patients were initially tested negative for SARS-CoV-2 on RT-PCR, so a chest CT scan was performed. Also, serum antibody (IgM and IgG) titers were estimated. CT scan of patients revealed typical abnormalities related to SARS-CoV-2, indicating ground-glass opacity and infection lesions suggesting viral pneumonia. Elevated IgM and IgG antibodies levels (p

Human activities, from manufacturing and mining to consumption and waste disposal, have released a range and variety of pollutants into the ecosystem, posing a risk to environmental quality, food safety, and human health. Humic substances (HSs) are carbon materials with versatile properties and good potential for agricultural and environmental applications. They are adsorbents for heavy metals and organic pollutants in contaminated soils because they possess abundant functional groups. As soil conditioners, HSs can improve soil quality, plant growth, and crop production. Furthermore, being high in carbon content and recalcitrant to biodegradation, HSs are a vital carbon pool to mitigate greenhouse gas emission. The effectiveness of HSs in fulfilling their agricultural and environmental benefits, however, is controlled by intrinsic properties and extraneous factors, including the sources of organic materials, extraction procedures to obtain HSs, the solubility of HSs, types of pollutants, soil microbes, and ambient environmental conditions (e.g., pH). This chapter summarizes the potential of, the associated benefits from, and the limitations in HS application in agriculture, soil remediation, and carbon sequestration.

To explore the effect of chromosomal translocations on the composition of embryonic chromosomes and its mechanism.For 52 couples with one partner carrying a chromosomal translocation, results of next generation sequencing of all embryos derived from 61 cycles were divided into different groups based on the type of translocations, gender of the carrier, and maternal age. Effect of parental chromosomal translocations on the composition of embryonic chromosomes of each group was analyzed.A significant difference was found between carriers of reciprocal and Robertsonian translocations in terms of proportion of abnormal embryos and structurally normal chromosomes (63.3% vs. 27.5%, and 1.1% vs. 0.3%, respectively). Compared with male carriers, there was an increase in the rate of abnormalities for female carriers (67.2% vs. 58.3% for reciprocal translocations, and 45.5% vs. 13.8% for Robertsonian translocations). The risk for chromosomal abnormality also increased with the maternal age. No significant difference was found in the proportion of abnormal embryos between carriers divided by involvement of acrocentric chromosomes or terminal chromosomal breakpoints.The types of parental translocation, gender of carrier, maternal age, and interchromosomal effect have certain effect on the composition of embryonic chromosomes.

In the present work, Co3O4 and PdOx/Co3O4 nanocrystals were obtained via the calcination of Hydroxypropyl-β-cyclodextrin (HP-β-CD) assistant-synthesized ZIF-67 and Pd(acac)2/ZIF-67, respectively. The results suggested that although the HP-β-CD was used during the preparation of ZIF-67 in the ethanol, it could be removed by washing the ZIF-67 for several times. The structure and composition of the Co3O4 and PdOx/Co3O4 prepared without and with the assistance of HP-β-CD were investigated. Finally, the results from the catalytic oxidation of Bisphenol A in the presence of potassium persulfate indicated that a better performance was observed over the HP-β-CD assistant synthesized Co3O4, possibly due to an increased specific surface area. In addition, it was found that a high oxidation state (IV) of Pd species in the PdOx/Co3O4 synthesized with the help of HP-β-CD was noticed compared with that synthesized without HP-β-CD. It was worth noting that the further catalytic tests suggested HP-β-CD assisted synthesized PdOx/Co3O4 displayed more than 2-fold higher activity compared with Co3O4 as well as PdOx/Co3O4, which was possibly ascribed to the better dispersion as well as the presence of Pd(IV) species, respectively.

Excited state intramolecular proton transfer (ESIPT) and twisted intramolecular charge transfer (TICT) play fundamental roles during the excited state dynamics of dyes and fluorescent sensors. In this contribution, the ESIPT process is demonstrated to trigger the TICT process during the photo-physical process of a turn-on Al3+ sensor. The non-emissive TICT state can be facilely reached after the photo excitation and the ESIPT process, which quenches the fluorescence of the sensor. Al3+ is demonstrated to coordinate with the sensor and lock the twisted of the sensor, which eliminates the TICT state and turns on the fluorescence. Selective of the sensor is also revealed by study the interaction and electron transfer between the sensor and Cr3+.

Colorless and highly toxic phosgene has long been considered to be a great menace to human health and national security. Excellent AIE + TICT characteristic ratiometric and colorimetric fluorescent sensor TPE-CI was constructed with the combination of the TICT based 3-benzo[d]imidazole-chromen-2-imine unit and AIE based tetraphenylethene (TPE) unit. TPE-CI can detect phosgene not only in organic solvent through a change from the TICT process to the AIE process, but also in solid-state through a new change from the AIE + TICT process to the AIE process. TPE-CI exhibited convenient to use as a test strip, rapid response (less than 6 s in solvent and 2 min in air atmosphere), excellent selectivity and fair sensitivity for visual inspection of trace phosgene in the organic solvent and in the gas phase. The limit of detection (LOD) was calculated and derived as 0.36 μM in solvent and 0.27 ppm in the air atmosphere, which was far below the acute phosgene exposure level of human response. The satisfactory results indicate that this AIE + TICT strategy may offer valuable thinking to develop convenient solid-state optical sensors with dual ratiometric and colorimetric fluorescence response for gaseous phosgene identification.

It is still a challenge for scientists to eliminate interference and improve chromatic aberration in designing colorimetric uranyl ions sensors, and it is also not clear how the species of uranium and sensor synergistically affect the coloration mechanism and coordination mode of ligands containing nitrogen or oxygen atoms at different pH. Herein, we design and synthesize 2-(5′-(p-(diphenylamino)phenyl)-2′-pyridylazo)-5-(diethylamino)phenol (abbr. S-LH) for the colorimetric detection of uranyl ions in mixed solvents. The rational introduced triphenylamine group by density functional theory (DFT) calculation enhances the chromaticity difference of the S-LH toward uranyl ions, making the detection limits of the uranyl ions approximately one order of magnitude lower than that of the present UV–vis and visual method. The species of S-LH and uranium at different pH are clarified and it well explains the reason of different color changes after adding uranyl ions. Stability constant experiments show that S-LH has excellent anti-interference to other metal ions during detecting uranium. The coordination structure of S-LH towards UO22+ is further confirmed by HRMS, 1H NMR titration, and DFT calculation. Finally, colorimetric test strips with S-LH are prepared to detect uranium in Xiang River, providing an on-site and real-time method to detect uranyl ions in the environment.

OBJECTIVE: To investigate the usefulness of preimplantation genetic diagnosis (PGD) based on mutated allele revealed by sequencing with aneuploidy and linkage analyses (MARSALA) for a pedigree with X-linked retinitis pigmentosa (XLRP). METHODS: One pathogenic mutation (c.494G > A) of the retinitis pigmentosa GTPase regulator (RPGR) gene was identified in a pedigree affected by XLRP. Then, PGD was carried out for the couple, of which the wife was an XLRP carrier. Three blastocysts were biopsied and then MARSALA was performed by next-generation sequencing (NGS). Prenatal diagnosis was also carried out to confirm the PGD results. RESULTS: Three blastocysts were all unaffected. Then, one of the embryos was chosen randomly to be transferred, and the pregnancy was acquired successfully. The results of prenatal diagnosis were consistent with the PGD results. The fetus did not carry RPGR mutation (c.494G > A) and had normal chromosome karyotype. As a result, a healthy baby free of XLRP condition was born. CONCLUSION: The PGD method based on MARSALA was established and applied to a family with XLRP successfully. MARSALA will be a valid tool, not only for XLRP families but also for families affected with other monogenetic disorders, to prevent transmission of the genetic disease from parents to offspring.

In view of the few reports of the near-infrared emissive probe for fluorine ions, we herein designed and synthesized a new easy-to-get colorimetric and near-infrared emissive fluorescent probe (IS-NR-F) with a large Stokes shift (>127 nm). Based on specific F− triggered desilylation reaction induced enhanced ICT strategy involving the donor phenolate anion and the acceptor malononitrile, the probe exhibited dual colorimetric and fluorescent turn-on responses, and provided excellent selectivity for fluoride ions. The fluorescent response at 665 nm displayed very good linear relationship in the wide concentration range and deduced a low detection limit of 0.09 ppm. The detection mechanism was confirmed by 1H NMR, ESI-MS, and TLC calculation. Moreover, probe IS-NR-F has been successfully employed to detect F− in tap water, toothpaste samples, and fluorescent imaging of F− in HeLa cells.

Poisson’s ratio is defined as the negative value of the ratio of the radial strain and the corresponding axial strain, caused by uniformly distributed axial stress, within the scope of the material’s proportional limits. It reflects the lateral deformation of the material, and is widely used in elastic theory. Previous studies have shown that the upper and lower limits of Poisson’s ratio are 0.5 and -1, respectively, and Poisson’s ratio for the vast majority of materials is 1/3 (Lakes 1987; Shan et al. 2006). In the field of numerical analysis of geotechnical engineering and engineering design, Poisson’s ratio is an important parameter reflecting the lateral deformation of the rock and soil mass and it directly affects the strength and deformation characteristics of the rock and soil mass. According to Code for rock tests of hydroelectric and water conservancy engineering (Code DL/T 5368-2007), the Poisson’s ratio of rock material should be determined by uniaxial compression tests. Adopting this method, resistance strain gauges should be pasted onto the surface of standard samples to obtain the lateral and axial strains, and then the Poisson’s ratio can be obtained by the related formula. However, there are shortcomings to this method (Lau et al. 2004; You 2007; Zhou et al. 2007): (1) strain gauges can only measure the partial deformation of the rock sample and cannot represent the overall deformation properties of the sample; furthermore, the quality and direction of pasting and other factors will affect the measurement accuracy. (2) Under a uniaxial compression condition, the lateral strain of the rock accrues earlier, and then deviates faster from the linear relationship with the axial stress than the axial strain, which leads to a nonlinear relationship compared with the definition of Poisson’s ratio. (3) Most engineering rock mass experiences mechanical excavation and unloading processes, which are different from the loading process required by the specification. Based on the generalized Hooke’s law, we propose a method for determining the Poisson’s ratio of rock samples by changing the axial stress and unloading the lateral stress. By unloading axial and lateral stress triaxial tests (UAUL) and loading axial stress and unloading lateral X. Xu (&) R. Huang H. Li Q. Huang State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu University of Technology, Chengdu, Sichuan 610059, China e-mail: xtxu@cdut.edu.cn

A synchronization algorithm for FBMC is proposed by combination of CAZAC sequence. Using the CAZAC sequence as the pilot symbols, timing synchronization and frequency synchronization of the FBMC system are realized. Considering the effect of fading on the synchronization, the algorithm combining the CAZAC sequence is rational. Computer simulations verify that the estimation error is about 1e-4 under ordinary signal to noise ratio conditions.