Microplastics (MPs) are carbon-rich polymers that are ubiquitous in the environment. With the increase of plastic production, microplastic pollution may be exacerbated and result in significant changes in microbial communities and biogeochemical processes such as carbon cycling, eventually impacting greenhouse gas emission and carbon storage in terrestrial ecosystems. However, current research on the effect of MPs on soil carbon cycling is still limited, and there is a lack of systematic review of the scattered information obtained from previous studies. Accordingly, this review provides a systematic overview of the current knowledge on the effects of MPs on soil carbon cycling and gives future research suggestions. Emerging evidence indicates that MPs could affect soil carbon stability and CO2 and CH4 emission by modifying soil physicochemical and microbiological properties; though biodegradable MPs often exhibit a greater effect than nonbiodegradable ones, the specific effects are highly dependent on plastic type, size and concentration. The specific mechanisms of MPs’ impact on soil carbon cycles remain elusive, which are discussed mainly from the perspective of microbial changes, including microbial biomass, microbial community composition, and key enzymes and functional genes associated with carbon metabolism. Further research is needed to elucidate whether MPs have a positive priming effect on soil carbon decomposition and the biotic and abiotic mechanisms involved. This review paper helps researchers gain a clearer picture of how and through which way MPs impact carbon cycling in soil ecosystems.

The numerical investigation focuses on the flow patterns around a rectangular cylinder with three aspect ratios ($L/D=5$, $10$, $15$) at a Reynolds number of $1000$. The study delves into the dynamics of vortices, their associated frequencies, the evolution of the boundary layer and the decay of the wake. Kelvin–Helmholtz (KH) vortices originate from the leading edge (LE) shear layer and transform into hairpin vortices. Specifically, at $L/D=5$, three KH vortices merge into a single LE vortex. However, at $L/D=10$ and $15$, two KH vortices combine to form a LE vortex, with the rapid formation of hairpin vortex packets. A fractional harmonic arises due to feedback from the split LE shear layer moving upstream, triggering interaction with the reverse flow. Trailing edge (TE) vortices shed, creating a Kármán-like street in the wake. The intensity of wake oscillation at $L/D=5$ surpasses that in the other two cases. Boundary layer transition occurs after the saturation of disturbance energy for $L/D=10$ and $15$, but not for $L/D=5$. The low-frequency disturbances are selected to generate streaks inside the boundary layer. The TE vortex shedding induces the formation of a favourable pressure gradient, accelerating the flow and fostering boundary layer relaminarization. The self-similarity of the velocity defect is observed in all three wakes, accompanied by the decay of disturbance energy. Importantly, the decrease in the shedding frequency of LE (TE) vortices significantly contributes to the overall decay of disturbance energy. This comprehensive exploration provides insights into complex flow phenomena and their underlying dynamics.

Aphis spiraecola Patch is one of the most economically important tree fruit pests worldwide. The pyrethroid insecticide lambda-cyhalothrin is commonly used to control A. spiraecola. In this 2-year study, we quantified the resistance level of A. spiraecola to lambda-cyhalothrin in different regions of the Shaanxi province, China. The results showed that A. spiraecola had reached extremely high resistance levels with a 174-fold resistance ratio (RR) found in the Xunyi region. In addition, we compared the enzymatic activity and expression level of P450 genes among eight A. spiraecola populations. The P450 activity of A. spiraecola was significantly increased in five regions (Xunyi, Liquan, Fengxiang, Luochuan, and Xinping) compared to susceptible strain (SS). The expression levels of CYP6CY7, CYP6CY14, CYP6CY22, P4504C1-like, P4506a13, CYP4CZ1, CYP380C47, and CYP4CJ2 genes were significantly increased under lambda-cyhalothrin treatment and in the resistant field populations. A L1014F mutation in the sodium channel gene was found and the mutation rate was positively correlated with the LC50 of lambda-cyhalothrin. In conclusion, the levels of lambda-cyhalothrin resistance of A. spiraecola field populations were associated with P450s and L1014F mutations. Our combined findings provide evidence on the resistance mechanism of A. spiraecola to lambda-cyhalothrin and give a theoretical basis for rational and effective control of this pest species.

Hydrophobicity, swellability, and dispersion are important properties for organo-montmorillonites (OMnt) and have yet to be fully characterized for all OMnt configurations. The purpose of the present work was to examine the preparation of OMnt from the reaction of Ca2+-montmorillonite (Ca2+-Mnt) with a high concentration of surfactant and to reveal the relevant properties of hydrophobicity and dispersion of the resultant OMnt. A series of OMnt samples were prepared using a small amount of water and cetyltrimethylammonium bromide (CTAB) with a concentration more than the CTAB critical micelle concentration (CMC). The relationship between OMnt microstructure and the hydrophobicity and swellability properties was investigated in detail. The resulting OMnt samples were characterized using powder X-ray diffraction patterns (XRD), Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric and differential thermogravimetry (TG-DTG), water contact angle tests, swelling indices, and transmission electron microscopy (TEM). The addition of CTAB and water in the OMnt preparation affected the OMnt microstructure and properties. An increase in CTAB concentration led to a more ordered arrangement of cetyltrimethylammonium (CTA+) cations in the interlayer space of the OMnt and a large amount of CTA+ cations on the outer surfaces of the OMnt. The swelling indices and the water contact angles of OMnt samples depended on the distribution of the CTAB surfactant on OMnt and the orientation of the surfactant hydrophilic groups on the inner and on the outer surfaces of OMnt. A maximum swelling index of 39 mL/g in xylene was achieved with an average water contact angle of 62.0° ± 2.0° when the amount of CTAB added was 2 times the cation exchange capacity (CEC) of Mnt and the lowest water to dry Mnt mass ratio was 3 during the preparation of OMnt samples. The platelets of OMnt aggregated together in xylene by electrostatic attraction and by hydrophobic interactions.

Organo-montmorillonite (OMnt) has wide applications in paints, clay-polymer nanocomposites, biomaterials, etc. In most cases, the dispersibility and swellability of OMnt dictate the performance of OMnt in the target products. Previous studies have revealed that the properties can be improved when multiple organic species are co-introduced into the interlayer space of montmorillonite (Mnt). In the present study, single surfactant erucylamide (EA), dual-surfactants cetyltrimethyl ammonium bromide (CTAB) and octadecyltrimethyl ammonium chloride (OTAC), and ternary-surfactants EA, CTAB, and OTAC were co-introduced into Mnt by solution intercalation. The resulting OMnts were characterized by powder X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, thermogravimetry-differential thermogravimetry (TG-DTG), water contact-angle tests, scanning electronic microscopy (SEM), laser particle-size analysis, and swelling indices. Mnt co-modified by ternary CTAB, OTAC, and EA led to a large d001 value (4.20 nm), surface hydrophobicity with a contact angle of 95.6°, swellability (50 mL/g) with small average particle sizes (2.1−2.8 μm) in xylene, and >99% of the OMnt particles were kept as <5 μm in deionized water. The formation of EA-modified-Mnt was proposed according to hydrophobic affinity, hydrogen bonding, and van der Waals forces. The nanoplatelets of the CTA+, OTA+, and EA co-modified OMnts in xylene were assembled into a house-of-cards structure by face-to-edge and edge-to-edge associations. The electrostatic attractions, electrostatic and steric repulsions, and hydrophobic interactions were responsible for the good dispersibility of OMnt in xylene. The ternary surfactant co-modified OMnt with high dispersion and swellability will make OMnt better suited for real-world applications.

Montmorillonite (Mnt)-based solid acids have a wide range of applications in catalysis and adsorption of pollutants. For such solid acids, the acidic characteristic often plays a significant role in these applications. The objective of the current study was to examine the effects of H3PO4-activation and supporting WO3 on the textural structure and surface acidic properties of Mnt. The Mnt-based solid acid materials were prepared by H3PO4 treatment and an impregnation method with a solution of ammonium metatungstate (AMT) and were examined as catalysts in the dehydration of glycerol to acrolein. The catalysts were characterized by nitrogen adsorption-desorption, powder X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, scanning electronic microscopy (SEM), X-ray photoelectron spectroscopy (XPS), diffuse reflectance ultraviolet-visible (DR UV-Vis) spectroscopy, temperature programmed desorption of NH3 (NH3-TPD), diffuse reflectance Fourier-transform infrared (DR FTIR) spectroscopy of adsorbed pyridine, and thermogravimetric (TG) analyses. The phosphoric acid treatment of Mnt created Brönsted and Lewis acid sites and led to increases in specific surface areas, porosity, and acidity. WO3 species influenced total acidity, acid strength, the numbers of Brönsted and Lewis acid sites, and catalytic performances. A high turnover frequency (TOF) value (31.2 h−1) based on a maximal 60.7% yield of acrolein was reached. The correlation of acrolein yield with acidic properties indicated that the cooperative role of Brönsted and Lewis acid sites was beneficial to the formation of acrolein and a little coke deposition (<3.3 wt.%). This work provides a new idea for the design of solid acid catalysts with cooperative Brönsted and Lewis acidity for the dehydration of glycerol.

The aim of this study was to investigate the prevalence of anemia in twin pregnancies and the influence of anemia on maternal and neonatal outcomes. This retrospective study included twin pregnant women who delivered in a tertiary hospital in China from January 2018 to December 2018. Patients were divided by WHO criteria (hemoglobin <11.0 g/dL): the anemic and nonanemic groups. Patients with anemia were further classified as recovered or unrecovered subgroup after oral iron therapy. Maternal and neonatal outcomes in women carrying twins were compared using Student’s t test and the chi-squared test or the Fisher exact test. Univariable and multivariable logistic regression models were used to determine the association of maternal and neonatal characteristics with anemia. Linear regression analysis was used to estimate mean birth weight and gestational week. The prevalence of anemia was 42.6% (182/427) in twin pregnancies. The anemic group had higher rates of low 1-minute Apgar score (4.4% vs. 1.8%, p = .028), perinatal death (1.9% vs. 0.2%, p = .012) and neonatal intensive care unit (NICU) admission (27.2% vs. 20.2%, p = .017; adjusted OR, 1.478; 95% CI [1.07, 2.044]). The recovered subgroup had lower NICU admission rate (13.5% vs. 30.3%, p = .006; OR, 0.388; 95% CI [0.186, 0.809]), higher gestational week and birth weight (β, 0.954 week; 95% CI [0.114, 1.794] and β, 171.01 g; 95% CI [9.894, 332.126] respectively). The prevalence of anemia in twin gestation is high. Anemia is associated with adverse neonatal outcomes, and correction of anemia significantly improved the pregnancy outcomes.

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 investigate the energy transport and heat transfer efficiency in turbulent Rayleigh–Bénard (RB) convection laden with radiatively heated inertial particles. Direct numerical simulations combined with the Lagrangian point-particle mode were carried out in the range of density ratio $854.7\le \rho _p/\rho _0 \le 8547$ and radiation intensity $1\le \phi /\phi _{solar}\le 100$ for both two-dimensional (2-D) and three-dimensional (3-D) simulations. The Rayleigh number ranges from $2\times 10^6$ to $10^8$ for 2-D cases, and is $10^7$ for 3-D cases for $Pr=0.71$. It is found that particles with small density ratio that encounter strong radiation significantly alter the flow momentum transport and fluid heat transfer, so the fluid temperature of bulk is remarkably heated. We then derived the theoretical relation of the Nusselt number for interphase heat transfer in the heated particle-laden RB convection, which reveals that the heat transfer difference between the top and bottom plates stems from the interphase heat transfer. We further found that both the interphase heat transfer and the interphase thermal energy transport exhibit universal properties. They are both increased linearly with the reciprocal of the normalized density ratio. Additionally, both the interphase heat transfer and the interphase thermal energy transport increase linearly with the increase of radiation intensity. The growth rates exhibit specific scaling relations versus Rayleigh number and density ratio. Two different regimes distinguished by the critical density ratio, i.e. the exothermic particle regime and the endothermic particle regime, are observed. We further derived the power-law relation of the critical density ratios versus Rayleigh number and radiation intensity, i.e. $\rho _p/\rho _c \sim (\phi /\phi _{solar})^{1/2}\,Ra^{1/3}$, which is in remarkable agreement with the 3-D simulations.

Point-particle direct numerical simulations have been employed to quantify the turbulence modulation and particle responses in a turbulent particle-laden jet in the two-way coupled regime with an inlet Reynolds number based on bulk velocity and jet diameter $({D_j})$ of ~10 000. The investigation focuses on three cases with inlet bulk Stokes numbers of 0.3, 1.4 and 11.2. Special care is taken to account for the particle–gas slip velocity and non-uniform particle concentrations at the nozzle outlet, enabling a reasonable prediction of particle velocity and concentration fields. Turbulence modulation is quantified by the variation of the gas-phase turbulent kinetic energy (TKE). The presence of the particle phase is found to damp the gas-phase TKE in the near-field region within $5{D_j}$ from the inlet but subsequently increases the TKE in the intermediate region of (5–20)Dj. An analysis of the gas-phase TKE transport equation reveals that the direct impact of the particle phase is to dissipate TKE via the particle-induced source term. However, the finite inertia of the particle phase affects the gas-phase velocity gradients, which indirectly affects the TKE production and dissipation, leading to the observed TKE attenuation and enhancement. Particle response to the gas-phase flow is quantified. Particles are found to exhibit notably stronger response to the gas-phase axial velocity than to the radial velocity. A new dimensionless figure is presented that collapses both the axial and radial components of the particle response as a function of the local Stokes number based on their respective integral length scales.

It is important to know how much of the increased atmospheric CO2 is derived from fossil fuel emissions. Here, we review the progress in atmospheric fossil fuel CO2 (CO2ff) tracing over recent years by measurement of Δ14C in Chinese cities. In this paper we make progress by expanding the analysis from some locations to more regional views, by combining observations with modeling, and by making a preliminary comparison of observation-derived CO2ff with inventory-derived CO2ff. We have obtained a general picture of Chinese urban CO2ff and characteristics of its spatio-temporal variations at different scale, and identified the corresponding influencing factors. Interestingly, we found that the weekend effect of CO2ff was less evident in Chinese cities. In addition, we observed simultaneous variations in CO2ff and PM2.5 in a winter haze event in Beijing and a simultaneous decrease in annual averages of CO2ff and PM2.5 in Xi’an based on multi-year (2011–2016) Δ14CO2 monitoring. We found that local coal combustion was the main source of CO2ff in Xi’an, which is located in the Guanzhong basin, by applying a WRF-Chem model and looking at δ13C signatures. Thus, reduction of coal consumption is a crucial target for carbon emissions reduction in China.

Shaded coffee systems can mitigate climate change by fixation of atmospheric carbon dioxide (CO2) in soil. Understanding soil organic carbon (SOC) storage and the factors influencing SOC in coffee plantations are necessary for the development of sound land management practices to prevent land degradation and minimize SOC losses. This study was conducted in the main coffee-growing regions of Yunnan; SOC concentrations and storage of shaded and unshaded coffee systems were assessed in the top 40 cm of soil. Relationships between SOC concentration and factors affecting SOC were analysed using multiple linear regression based on the forward and backward stepwise regression method. Factors analysed were soil bulk density (ρb), soil pH, total nitrogen of soil (N), mean annual temperature (MAT), mean annual moisture (MAM), mean annual precipitation (MAP) and elevations (E). Akaike's information criterion (AIC), coefficient of determination (R2), root mean square error (RMSE) and residual sum of squares (RSS) were used to describe the accuracy of multiple linear regression models. Results showed that mean SOC concentration and storage decreased significantly with depth under unshaded coffee systems. Mean SOC concentration and storage were higher in shaded than unshaded coffee systems at 20–40 cm depth. The correlations between SOC concentration and ρb, pH and N were significant. Evidence from the multiple linear regression model showed that soil bulk density (ρb), soil pH, total nitrogen of soil (N) and climatic variables had the greatest impact on soil carbon storage in the coffee system.

Nowadays, theranostics drug delivery systems (DDSs) with imaging and therapy bi-functions have been regarded as a future orientation for imaging-guided cancer therapy. To achieve high imaging quality, a donor–acceptor (D–A)/Förster resonance energy transfer (FRET) bi-adjustment strategy is carried out for designing dual-colored DDSs with amplified aggregation-induced emission (AIE) behavior for imaging-guided cocktail cancer therapy in this study. In detail, four AIE-active conjugated polymers P-1 to P-4 are synthesized via the Suzuki reaction. Noteworthily, the D–A-type structure is applied in tuning the fluorescence color from orange (P-1) to far-red/near-infrared (P-2), while the intramolecular FRET process further enhanced the fluorescence signal for six times (P-3). Afterwards, P-3-based amphipathic polymer P-4 further acts as a drug carrier in preparing doxorubicin (Dox)- and curcumin (Cur)-loaded polymer dots (Pdots) (Dox-loaded Pdots as PDox and Cur-loaded Pdots as PCur). PDox + PCur DDS is successfully applied in imaging-guided cocktail cancer therapy to give obviously higher in vivo anticancer efficacy compared with single PDox or PCur. In addition, the drug-loaded Pdots also exhibit higher biocompatibility compared with free drugs. This work provides a novel D–A/FRET bi-adjustment strategy for developing high efficiency imaging-guided cocktail DDSs in cancer therapy.

Although the progression of invasive aspergillosis (IA) shares some risk factors in the development of active pulmonary tuberculosis (PTB), however, the prevalence of IA in suspected PTB remains unclear. During a period of 1 year (from January 2016 to December 2016), consecutive patients with suspected PTB were included in a referral TB hospital. Data, including demographic information and underlying diseases, were collected from medical records. PTB were all confirmed by mycobacterial culture (Lowenstein–Jensen medium). IA were diagnosed as proven or probable according to the criteria of the 2008 EORTC/MSG definitions. A descriptive analysis was performed to estimate the corresponding prevalence. During the study year, 1507 patients have a positive mycobacterial culture, with a mean age of 45.6 (s.d. 19.9) years old and a female:male ratio of 1:4. Among the 82 patients with non-tuberculous mycobacterial diseases, two patients (2.44%, 95% CI 0.67–8.46%) were diagnosed as IA (one proven and one probable); two probable IA patients (0.15%, 95% CI 0.04–0.55%) were diagnosed in PTB patients (n = 1315), and all were retreatment cases. In addition, all four IA patients (100%) exhibited cavities in both lobes on radiograph. In China, the prevalence of IA is low in active PTB patients. However, when high-risk factors for IA are encountered in PTB patients, further investigations are required and empirically treatment for IA might be warranted.