Meta-analysis of impacts of microplastics on plant heavy metal(loid) accumulation

The co-occurrence of microplastics (MPs) and heavy metal(loid)s (HMs) has attracted growing scientific interest because of their wide distribution and environmental toxicity. Nevertheless, the interactions between MPs and HMs in soil-plant systems remain unclear. We conducted a meta-analysis with 3226 observations from 87 independent studies to quantify the impact of MPs addition on the plant biomass and HMS accumulation. Co-occurrence of MPs and HMs (except for As) induced synergistic toxicity to plant growth. MPs promoted their uptake in the shoot by 11.0% for Cd, 30.0% for Pb, and 47.1% for Cu, respectively. In contrast, MPs caused a significant decrease (22.6%, 17.9-26.9%) in the shoot As accumulation. The type and dose of MPs were correlated with the accumulation of HMs. MPs increased available concentrations of Cd, Pb, and Cu, but decreased available As concentration in soils. Meanwhile, MPs addition significantly lowered soil pH. These findings may provide explanations for MPs-mediated effects on influencing the accumulation of HMs in plants. Using a machine learning approach, we revealed that soil pH and total HMs concentration are the major contributors affecting their accumulation in shoot. Overall, our study indicated that MPs may increase the environmental risks of HMs in agroecosystems, especially metal cations.

[Geographic environment-related research advances on children's myopia: intraocular and environmental exposure factors and analytical methods]

Myopia has become a global phenomenon, transitioning into a significant public health issue of worldwide reach. The escalating prevalence of myopia may lead to an increase in the incidence of related complications, potentially resulting in irreversible vision damage for individuals. This not only causes considerable economic strain on societies but also poses a serious threat to vital sectors like national defense. This review outlines various external and internal exposure factors related to childhood myopia. It places particular focus on the analysis of the interaction between geographical environmental factors and internal exposure factors, and examines the limitations of applying traditional methods in studying the relationship between childhood myopia and geographical environmental factors. The paper also introduces two spatial regression methodologies based on frequency estimation and Bayesian estimation, summarizing their feasibility and merits when applied in the study of external exposure elements related to childhood myopia. Finally, it provides a fresh perspective on regional childhood myopia prevention strategies that are conscious of geographical environmental factors.

Experimental Study on the Adhesion of Abalone to Surfaces with Different Morphologies

To date, research on abalone adhesion has primarily analyzed the organism's adhesion to smooth surfaces, with few studies on adhesion to non-smooth surfaces. The present study examined the surface morphology of the abalone's abdominal foot, followed by measuring the adhesive force of the abalone on a smooth force measuring plate and five force measuring plates with different surface morphologies. Next, the adhesion mechanism of the abdominal foot was analyzed. The findings indicated that the abdominal foot of the abalone features numerous stripe-shaped folds on its surface. The adhesion of the abalone to a fine frosted glass plate, a coarse frosted glass plate, and a quadrangular conical glass plate was not significantly different from that on a smooth glass plate. However, the organism's adhesion to a small lattice pit glass plate and block pattern glass plate was significantly different. The abalone could effectively adhere to the surface of the block pattern glass plate using the elasticity of its abdominal foot during adhesion but experienced difficulty in completely adhering to the surface of the quadrangular conical glass plate. The abdominal foot used its elasticity to form an independent sucker system with each small lattice pit, significantly improving adhesion to the small lattice pit glass plate. The elasticity of the abalone's abdominal foot created difficulty in handling slight morphological size changes in roughness, resulting in no significant differences in its adhesion to the smooth glass plate.

Interaction of microplastics with heavy metals in soil: Mechanisms, influencing factors and biological effects

Microplastics (MPs) and heavy metals (HMs) in soil contamination are considered an emerging global problem that poses environmental and health risks. However, their interaction and potential biological effects remain unclear. Here, we reviewed the interaction of MPs with HMs in soil, including its mechanisms, influencing factors and biological effects. Specifically, the interactions between HMs and MPs mainly involve sorption and desorption. The type, aging, concentration, size of MPs, and the physicochemical properties of HMs and soil have significant impacts on the interaction. In particular, MP aging affects specific surface areas and functional groups. Due to the small size and resistance to decomposition characteristics of MPs, they are easily transported through the food chain and exhibit combined biological effects with HMs on soil organisms, thus accumulating in the human body. To comprehensively understand the effect of MPs and HMs in soil, we propose combining traditional experiments with emerging technologies and encouraging more coordinated efforts.

Research and Implementation of Millet Ear Detection Method Based on Lightweight YOLOv5

As the millet ears are dense, small in size, and serious occlusion in the complex grain field scene, the target detection model suitable for this environment requires high computing power, and it is difficult to deploy the real-time detection of millet ears on mobile devices. A lightweight real-time detection method for millet ears is based on YOLOv5. First, the YOLOv5s model is improved by replacing the YOLOv5s backbone feature extraction network with the MobilenetV3 lightweight model to reduce model size. Then, using the multi-feature fusion detection structure, the micro-scale detection layer is augmented to reduce high-level feature maps and low-level feature maps. The Merge-NMS technique is used in post-processing for target information loss to reduce the influence of boundary blur on the detection effect and increase the detection accuracy of small and obstructed targets. Finally, the models reconstructed by different improved methods are trained and tested on the self-built millet ear data set. The AP value of the improved model in this study reaches 97.78%, F1-score is 94.20%, and the model size is only 7.56 MB, which is 53.28% of the standard YoloV5s model size, and has a better detection speed. Compared with other classical target detection models, it shows strong robustness and generalization ability. The lightweight model performs better in the detection of pictures and videos in the Jetson Nano. The results show that the improved lightweight YOLOv5 millet detection model in this study can overcome the influence of complex environments, and significantly improve the detection effect of millet under dense distribution and occlusion conditions. The millet detection model is deployed on the Jetson Nano, and the millet detection system is implemented based on the PyQt5 framework. The detection accuracy and detection speed of the millet detection system can meet the actual needs of intelligent agricultural machinery equipment and has a good application prospect.

Hybrid Quantum Mechanical/Molecular Mechanical Methods For Studying Energy Transduction in Biomolecular Machines

Hybrid quantum mechanical/molecular mechanical (QM/MM) methods have become indispensable tools for the study of biomolecules. In this article, we briefly review the basic methodological details of QM/MM approaches and discuss their applications to various energy transduction problems in biomolecular machines, such as long-range proton transports, fast electron transfers, and mechanochemical coupling. We highlight the particular importance for these applications of balancing computational efficiency and accuracy. Using several recent examples, we illustrate the value and limitations of QM/MM methodologies for both ground and excited states, as well as strategies for calibrating them in specific applications. We conclude with brief comments on several areas that can benefit from further efforts to make QM/MM analyses more quantitative and applicable to increasingly complex biological problems.

[A case of delayed peripheral neuropathy caused by diquat poisoning]

Diquat is a kind of conductive contact-killing herbicides. The damage of central nervous system is relatively common, but the peripheral neuropathy caused by diquat has not been reported yet. In September 2021, we treated a patient with diquat poisoning. During the hospitalization, the patient was diagnosed with peripheral neuropathy. Therapy for peripheral nerve injury was given on the basis of conventional treatment of poisoning. The patient was discharged after his condition was stable. The follow-up showed that the peripheral neuropathy of patient was better than before. According to the condition of this patient, it is suggested that we should not only protect the function of gastrointestinal tract, liver, kidney, and central nervous system early, but should also pay attention to the damage of peripheral nervous system in clinical work. We should intervene earlier to improve the prognosis of patients.

Crop residue return sustains global soil ecological stoichiometry balance

Although soil ecological stoichiometry is constrained in natural ecosystems, its responses to anthropogenic perturbations are largely unknown. Inputs of inorganic fertilizer and crop residue are key cropland anthropogenic managements, with potential to alter their soil ecological stoichiometry. We conducted a global synthesis of 682 data pairs to quantify the responses of soil carbon (C), nitrogen (N), and phosphorus (P) and grain yields to combined inputs of crop residue plus inorganic fertilizer compared with only inorganic fertilizer application. Crop residue inputs enhance soil C (10.5%-12%), N (7.63%-9.2%), and P (2.62%-5.13%) contents, with an increase in C:N (2.51%-3.42%) and C:P (7.27%-8.00%) ratios, and grain yields (6.12%-8.64%), indicating that crop residue alleviated soil C limitation caused by inorganic fertilizer inputs alone and was able to sustain balanced stoichiometry. Moreover, the increase in soil C and C:N(P) ratio reached saturation in ~13-16 years after crop residue return, while grain yield increase trend discontinued. Furthermore, we identified that the increased C, N, and P contents and C:N(P) ratios were regulated by the initial pH and C content, and the increase in grain yield was not only related to soil properties, but also negatively related to the amount of inorganic N fertilizer input to a greater extent. Given that crop residual improvement varies with soil properties and N input levels, we propose a predictive model to preliminary evaluate the potential for crop residual improvement. Particularly, we suggest that part of the global budget should be used to subsidize crop residue input management strategies, achieving to a win-win situation for agricultural production, ecological protection, and climate change mitigation.

Construction of activated biochar/Bi2WO6 and /Bi2MoO6 composites to enhance adsorption and photocatalysis performance for efficient application in the removal of pollutants and disinfection

To synergistically enhance the adsorption and photocatalytic performance of Bi2WO6 and Bi2MoO6, using activated biochar (ACB) as substrate, ACB-Bi2WO6 and ACB-Bi2MoO6 composites were facilely prepared by hydrothermal synthesis. Their adsorption-photocatalytic degradation effects on rhodamine B (RhB), tetracycline (TC), and norfloxacin (NOR) were comparatively investigated. Additionally, the effects of environmental factors, wastewater treatment tests, and disinfection were systematically studied, and the enhancement mechanisms and reasons for the degradation differences were highlighted. The results showed that ACB-Bi2WO6 and ACB-Bi2MoO6 were confirmed to form intimately contacted heterojunctions by various advanced characterization techniques. The introduction of ACB narrowed the band-gap energy of Bi2WO6 and Bi2MoO6, and improved the visible light absorption range and specific surface area. The optimal loading ratios of ACB-Bi2WO6 and ACB-Bi2MoO6 were 1:1.06 and 1:0.58, respectively. The removal rate of ACB-Bi2WO6 for high concentrations of RhB (200 mg·L-1), TC and NOR (50 mg·L-1) were 89.15%, 87.27%, and 72.17%, respectively, which were higher than those of ACB-Bi2MoO6 and significantly stronger than those of Bi2WO6 and Bi2MoO6. This was attributed to the more effective inhibition of photogenerated carrier recombination, higher absorbance, and uniform morphology via ACB-Bi2WO6. ·OH and holes were dominant active species in photocatalysis, and the possible photogenerated carrier transfer path is type II heterojunction. Furthermore, ACB-Bi2WO6 possessed good reusability, and the removal of RhB and TC from the actual wastewater exceeded 80.63% and 58.54%, respectively. The sterilization rates of ACB-Bi2WO6 reached 99% and 95% for E. coli and S. aureus within 24 h, respectively. Therefore, ACB-Bi2WO6 was more recommended for environmental applications.

Synergistic interplay between Azospirillum brasilense and exogenous signaling molecule H2S promotes Cd stress resistance and growth in pak choi (Brassica chinensis L.)

Inoculation with growth-promoting rhizobacteria inoculation and the addition of exogenous signaling molecules are two distinct strategies for improving heavy metal resistance and promoting growth in crops through several mechanisms. However, whether rhizobacteria and phyllosphere signaling molecules can act synergistically alleviate heavy metal stress and promote growth and the mechanisms underlying these effects remain unclear. Here, a novel strategy involving the co-application of growth-promoting rhizobacteria and an exogenous signaling molecule was developed to reduce cadmium (Cd) phytotoxicity and promote pak choi growth in Cd-contaminated soil. We found that the co-application of Azospirillum brasilense and hydrogen sulfide (H₂S) resulted in significant improvements in shoot biomass and antioxidant enzyme content and a decline in the levels of Cd translocation factors. In addition, this co-application significantly improved pak choi Cd resistance. Furthermore, we observed a significant negative correlation between abscisic acid concentration and Cd content of pak choi and a positive correlation between H₂S concentration and biomass. These findings revealed that the co-application of rhizobacteria and exogenous signaling molecules synergistically promoted the growth of vegetable crops subjected to heavy metal stress. Our results may serve as a guide for improving the food safety of crops grown in soil contaminated with heavy metals.

Micronization Effects on Structural, Functional, and Antioxidant Properties of Wheat Bran

To explore the effect of micronization on the structural, functional, and antioxidant properties of wheat bran, wheat bran with mean particle size (D₅₀) of 46.08, 34.29, 26.51, 26.35, and 26.05 μm were prepared by using an ultrafine pulverizer under different rolling frequencies (0, 6, 9, 12, and 15 times). The main chemical components and structural, functional, and antioxidant properties of the wheat bran were compared and a correlation analysis was conducted. As the D₅₀ of the wheat bran decreased from 46.08 μm to 26.05 μm, the micromorphology exhibited the destruction of the bundle structure, which is formed by starch and fiber, during which the starch particles peeled off, the fiber fragments destructed, and some of the slim fiber fragments attached to the surfaces of the starch granules. According to the X-ray diffraction pattern, part of the crystalline structure was transformed into an amorphous structure and the crystallization index decreased from 13.08% to 3.95%. According to the near-infrared spectrum, more active groups, such as the hydroxyl group, were exposed; however, no new groups were generated. These structural changes accordingly caused changes in the chemical components, functional properties, and antioxidant properties of the wheat bran. Specifically, the protein, total phenols, total flavonoids, and fatty acid content increased by 6.72%, 23.47%, 19.07%, and 172.88%, respectively. The lipase activity, antioxidant activity in vitro (DPPH• scavenging activity, ABTS⁺• scavenging activity, and ferric reducing antioxidant power), and the water-holding, cholesterol-adsorption, sodium nitrite-adsorption, and cation-exchange capacities, were enhanced to some extent. The oil-holding capacity decreased from 3.01 g/g to 1.32 g/g. The swelling capacity decreased first and then increased and the swelling capacity of the wheat bran with a D₅₀ of 34.29 μm was the lowest (3.62 mL/g). Therefore, the micronization could be used as a pretreatment method to improve the functional and antioxidant properties of wheat bran; however, the optimal particle size of wheat bran is based on the function of the product.

Phytoremediation of potentially toxic elements (PTEs) contaminated soils using alfalfa (Medicago sativa L.): A comprehensive review

Soil contamination with potentially toxic elements (PTEs) is an increasing environmental problem, posing serious threats to the living organisms. Phytoremediation is a sustainable and highly accepted technology for remediation of PTE-contaminated soils. Alfalfa has been widely adopted for the phytoremediation of PTE-contaminated soils due to its large biomass productivity, high PTE tolerance, and strong capacity to take up PTEs. However, there are still no literature reviews systematically summarized the potential of alfalfa in the phytoremediation. Therefore, we review the available literatures that present its PTE uptake, phytotoxicity, tolerance mechanisms, and aided techniques improving the phytoremediation efficiency. In this review, alfalfa shows high amounts of PTEs accumulation, especially in their root tissue. Meanwhile, the inner mechanisms of PTE tolerance and accumulation in alfalfa are discussed including: (i) the activation of antioxidant enzyme system, (ii) subcellular localization, (iii) production of glutathione, phytochelatins, and proline, and (iv) regulation of gene expression. Indeed, excessive PTE can overcome the defense system, which causes oxidative damage in alfalfa plants, thereby inhibiting growth and physiological processes and weakening the ability of PTE uptake. Till now, several approaches have been developed to improve the tolerance and/or accumulation of PTE in alfalfa plants as follows: (i) selection of PTE tolerant cultivars, (ii) applying plant growth regulators, (iii) addition of chelating agents, fertilizer, and biochar materials, and (iv) inoculation of soil microbes. Finally, we indicate that the selection of PTE-tolerant cultivars along with inoculation of soil microbes may be an efficient and eco-friendly strategy of the soil PTE phytoremediation.

A critical review of microplastics in the soil-plant system: Distribution, uptake, phytotoxicity and prevention

Microplastics (MPs) are creating an emerging threat on the soil ecosystems and are of great global concern. However, the distribution in soil-plant system, as well as the phytotoxicity and impact mechanisms of MPs remain largely unexplored so far. This study introduced the diverse sources of MPs and showed the significant spatial variation in the global geographic distribution of MPs contamination based on data collected from 116 studies (1003 sampling sites). We systematically discussed MPs phytotoxicity, such as plant uptake and migration to stems and leaves, delaying seed germination, impeding plant growth, inhibiting photosynthesis, interfering with nutrient metabolism, causing oxidative damage, and producing genotoxicity. We further highlighted the alterations of soil structure and function by MPs, as well as their self and load toxicity, as potential mechanisms that threaten plants. Finally, this paper provided several preventive strategies to mitigate soil MPs pollution and presented research gaps in the biogeochemical behavior of MPs in soil-plant systems. Meanwhile, we recommended that methods for the quantitative detection of MPs accumulated in plant tissues should be explored and established as soon as possible. This review will improve the understanding of the environmental behavior of MPs in soil-plant systems and provide a theoretical reference to better assess the ecological risk of MPs.

Prognostic value of late gadolinium enhancement in arrhythmogenic right ventricular cardiomyopathy: a meta-analysis

AIM

To assess systematically the prognostic value of cardiac magnetic resonance imaging (CMRI) in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC).

MATERIALS AND METHODS

The full text of studies of the clinical efficacy of late gadolinium enhancement (LGE) in ARVC was retrieved in multiple databases. Stata 14 was adopted for meta-analysis and bias analysis. Heterogeneity was assessed with the I² statistic.

RESULTS

After exclusions, 561 patients were included in five studies, and the eligibility criteria were met. The meta-analysis suggested that there was a significant difference between LGE positive and negative patients with ARVC in all-cause mortality (relative risk [RR] = 4.78, 95% confidence interval [CI] = 1.41, 16.23, p=0.012; p for heterogeneity = 0.692, I² = 0%); major adverse cardiovascular events (MACE) (RR=2.48, 95% CI = 1.24, 4.96, p=0.010; p for heterogeneity = 0.596, I² = 0%); ventricular tachycardia (RR=3.13, 95% CI = 1.69, 5.78, p<0.001; p for heterogeneity = 0.825, I² = 0%); implanted cardiac defibrillators (RR=3.15, 95% CI = 1.69, 5.87], p<0.001; p for heterogeneity = 0.353, I² = 9.4%).

CONCLUSION

LGE in ARVC patients is a predictor of all-cause mortality and MACE.

Morning Serum Cortisol as a Predictor for the HPA Axis Recovery in Cushing's Disease

BACKGROUND

The suppressed hypothalamic-pituitary-adrenal (HPA) axis after successful surgery for Cushing's disease (CD) will recover in almost all patients. We aimed to identify the predictive factors for HPA axis recovery in CD patients with postoperative remission. Design and Methods. This observational retrospective cross-sectional study enrolled 69 CD patients with postoperative remission in Huashan Hospital from 2015 to 2019. All subjects had a detailed clinical evaluation. The low-dose ACTH stimulation test (LDT) was conducted as the gold standard for assessing the HPA axis function.

RESULTS

Peak cortisol in LDT was found only to be positively correlative with morning serum cortisol (MSC) (ρ=0.451, p < 0.001). The MSC was higher (p < 0.001), and the median postoperative course was significantly longer (p=0.025) in the patients with the recovered HPA axis function compared with unrecovered patients. The AUC value of MSC for predicting the recovery of the HPA axis was 0.701, and the optimal cutoff was 6.25 μg/dl (sensitivity 85.19% and specificity 47.62%). Other useful cutoff values were 10.74 μg/dl (specificity 100%) and 4.18 μg/dl (sensitivity 100%). Besides, combined with the postoperative course, the AUC values were higher than MSC alone (0.935 vs. 0.701, p < 0.001).

CONCLUSIONS

MSC is a viable first-step diagnostic predictor for HPA axis recovery in CD patients with postoperative remission. For the patients with cortisol levels between 4.18 and 10.74 μg/dl, a confirmatory test should be conducted. When the MSC level was 10.74 μg/dl or greater, the replacement therapy could be discontinued.

Phosphorus recovery by core-shell γ-Al2O3/Fe3O4 biochar composite from aqueous phosphate solutions

Biochar can act as an adsorbent for phosphate removal from water sources, which can be highly beneficial in limiting eutrophication and recycling elemental phosphorus (P). However, it is difficult to use a single biochar material to overcome problems such as low adsorption efficiency, difficulty in reuse, and secondary pollution. This study addresses these challenges using a novel core-shell structure γ-Al₂O₃/Fe₃O₄ biochar adsorbent (AFBC) with significant P uptake capabilities in terms of its high adsorption capacity (205.7 mg g^-1), magnetic properties (saturation magnetization 24.70 emu g^-1), and high reuse stability (91.0% removal efficiency after five adsorption-desorption cycles). The highest partition coefficient 1.04 mg g^-1 μM^-1, was obtained at a concentration of 322.89 μM. Furthermore, AFBC exhibited strong regeneration ability in multiple cycle trials, making it extremely viable for sustainable resource management. P removal mechanisms, i.e., electrostatic attraction and inner-sphere complexation, were explained using Fourier transform infrared (FT-IR) spectra and X-ray photoelectron spectroscopy (XPS) measurements. A surface complexation model was established by considering the formation of monodentate mononuclear and bidentate binuclear surface complexes of P to illustrate the adsorption process. Owing to its high adsorption efficiency, easy separation from water, and environmental friendliness, AFBC is a potential adsorbent for P recovery from polluted waters.

Effect of three artificial aging techniques on physicochemical properties and Pb adsorption capacities of different biochars

Biochar is beneficial for soil amendment, but further research is still required on changes in its physicochemical properties during aging, especially in oxygen-containing functional groups and associated adsorption behaviors. Here, we used two different biochars, apple tree branch biochar and maize stalk biochar, and simulated the aging process by using freeze-thaw cycles, dry-wet cycles, and chemical oxidation methods. We investigated the changes in the physicochemical properties and Pb adsorption behavior of the biochars before and after aging treatments. The characterization results showed that the biochar surface structure changed after aging treatments. In general, the specific surface areas (SSAs) of the two biochars increased after chemical oxidation treatment but decreased after the other two treatments. The elemental content analyses indicated a decrease in the C content and increase in O content after artificial aging. In addition, the content of oxygen-containing functional groups in most biochars is increasing after treatment. The increase or decrease in SSA resulted in an increase or decrease in adsorption sites, respectively, thereby enhancing or reducing the adsorption capacity of the biochar. Furthermore, oxygen-containing functional groups enhanced the Pb adsorption capacity of biochar by complexation of free carboxyl and hydroxyl functional groups with Pb. Our research indicated that aging can lead to changes in the Pb adsorption capacity of biochar and that these changes vary depending on the type of aging and biochar. Our results will help to provide a better understanding of the changes in physicochemical properties and Pb adsorption capacity of biochar during the aging process in soil toward making full use of biochar for soil amendment.

Synthesis of a novel magnetic Caragana korshinskii biochar/Mg–Al layered double hydroxide composite and its strong adsorption of phosphate in aqueous solutions

Phosphate pollution of aquatic ecosystems is of great concern and requires the development of high-performance materials for effective pollution treatment. To realize efficient phosphate removal from aqueous solution, an easily separable magnetic (Fe₃O₄) Caragana korshinskii biochar/Mg–Al layered double hydroxide composite (denoted as FCB/MAC) was synthesized via two-step electro-assisted modification for the first time. Subsequently, the physical and chemical properties of FCB/MAC were characterized. Furthermore, the sorption mechanism for phosphate removal was investigated in detail. The results indicated that Fe₃O₄ and the Mg–Al layered double hydroxide were successfully embedded in the biochar matrix. Moreover, FCB/MAC exhibited a high phosphate adsorption capacity and excellent magnetic properties for easy recovery. The maximum phosphate sorption capacity of FCB/MAC was 252.88 mg g⁻¹, which is much higher than the capacities of most magnetic phosphate adsorbents. In addition, the adsorption kinetics and isotherms indicated that phosphate adsorption by FCB/MAC was controlled by the pseudo-second-order kinetic model and the Langmuir–Freundlich isotherm model. The phosphate adsorption mechanism involves anion exchange, electrostatic attraction, and ligand exchange. After five adsorption–desorption cycles, the phosphate adsorption capacity of FCB/MAC was 25.71 mg g⁻¹ with 51.43% removal efficiency and high recyclability. Thus, the composite prepared in this study is a promising adsorbent for phosphate removal from aqueous solution, and this work provides an excellent reference for constructing novel biochar-based phosphate adsorbents.

This study describes an optimized two-step electro-assisted modification process for the preparation of biochar modified with Fe₃O₄ and Mg–Al layered double hydroxide.

Clinical and molecular insights into Glanzmann's thrombasthenia in China

Glanzmann's thrombasthenia (GT) is a rare bleeding disorder characterized by spontaneous mucocutaneous bleeding. The disorder is caused by quantitative or qualitative defects in integrin αIIbβ3 (encoded by ITGA2B and ITGB3) on the platelet and is more common in consanguineous populations. However, the prevalence rate and clinical characteristics of GT in non-consanguineous populations have been unclear. We analyzed 97 patients from 93 families with GT in the Han population in China. This analysis showed lower consanguinity (18.3%) in Han patients than other ethnic populations in GT-prone countries. Compared with other ethnic populations, there was no significant difference in the distribution of GT types. Han females suffered more severe bleeding and had a poorer prognosis. We identified a total of 43 different ITGA2B and ITGB3 variants, including 25 previously unidentified, in 45 patients. These variants included 14 missense, 4 nonsense, 4 frameshift, and 3 splicing site variants. Patients with the same genotype generally manifested the same GT type but presented with different bleeding severities. This suggests that GT clinical phenotype does not solely depend on genotype. Our study provides an initial, yet important, clinical and molecular characterization of GT heterogeneity in China.

Backstepping control for a 3DOF model helicopter with input and output constraints

In this article, a backstepping control scheme is developed for the motion control of a Three degrees of freedom (3DOF) model helicopter with unknown external disturbance, modelling uncertainties and input and output constraints. In the developed robust control scheme, augmented state observers are applied to estimate the unknown states, unknown external disturbance and modelling uncertainties. Auxiliary systems are designed to deal with input saturation. A barrier Lyapunov function is employed to handle the output saturation. The stability of closed-loop system is proved by the Lyapunov method. Simulation results show that the designed control scheme is effective at dealing with the motion control of a 3DOF model helicopter in the presence of unknown external disturbance and modelling uncertainties, and input and output saturation.

Slater Insulator in Iridate Perovskites with Strong Spin-Orbit Coupling

The perovskite SrIrO_{3} is an exotic narrow-band metal owing to a confluence of the strengths of the spin-orbit coupling (SOC) and the electron-electron correlations. It has been proposed that topological and magnetic insulating phases can be achieved by tuning the SOC, Hubbard interactions, and/or lattice symmetry. Here, we report that the substitution of nonmagnetic, isovalent Sn^{4+} for Ir^{4+} in the SrIr_{1-x}Sn_{x}O_{3} perovskites synthesized under high pressure leads to a metal-insulator transition to an antiferromagnetic (AF) phase at T_{N}≥225  K. The continuous change of the cell volume as detected by x-ray diffraction and the λ-shape transition of the specific heat on cooling through T_{N} demonstrate that the metal-insulator transition is of second order. Neutron powder diffraction results indicate that the Sn substitution enlarges an octahedral-site distortion that reduces the SOC relative to the spin-spin exchange interaction and results in the type-G AF spin ordering below T_{N}. Measurement of high-temperature magnetic susceptibility shows the evolution of magnetic coupling in the paramagnetic phase typical of weak itinerant-electron magnetism in the Sn-substituted samples. A reduced structural symmetry in the magnetically ordered phase leads to an electron gap opening at the Brillouin zone boundary below T_{N} in the same way as proposed by Slater.

QM/MM Analysis of Transition States and Transition State Analogues in Metalloenzymes

Enzymology is approaching an era where many problems can benefit from computational studies. While ample challenges remain in quantitatively predicting behavior for many enzyme systems, the insights that often come from computations are an important asset for the enzymology community. Here we provide a primer for enzymologists on the types of calculations that are most useful for mechanistic problems in enzymology. In particular, we emphasize the integration of models that range from small active-site motifs to fully solvated enzyme systems for cross-validation and dissection of specific contributions from the enzyme environment. We then use a case study of the enzyme alkaline phosphatase to illustrate specific application of the methods. The case study involves examination of the binding modes of putative transition state analogues (tungstate and vanadate) to the enzyme. The computations predict covalent binding of these ions to the enzymatic nucleophile and that they adopt the trigonal bipyramidal geometry of the expected transition state. By comparing these structures with transition states found through free energy simulations, we assess the degree to which the transition state analogues mimic the true transition states. Technical issues worth treating with care as well as several remaining challenges to quantitative analysis of metalloenzymes are also highlighted during the discussion.

The efficacy of high-intensity, focused ultrasound treatment for non-neoplastic epithelial disorders of the vulva

Non-neoplastic epithelial disorders of the vulva (NNEDV) are common types of vulval lesions. Although corticosteroids represent a first-line treatment for NNEDV, concerns exist about the safety associated with long-term topical corticosteroid use. Recently, several clinical trials have identified high-intensity focused ultrasound (HIFU) as a promising treatment modality for NNEDV. The aim of this multi-center, randomized, controlled clinical trial was to investigate the efficacy of HIFU therapy in women with NNEDV based on histological alterations. We enrolled patients who were clinically diagnosed with NNEDV. They were randomized into 2 treatment groups: 1) halcinonide for 3 months or 2) HIFU once. A total of 123 patients were biopsied both prior to and after the therapy, and 62 and 61 patients were assigned to the HIFU and halcinonide groups, respectively. The histological changes were then analyzed. After the treatments, the therapeutic effects were observed in both groups. Comparing the diagnosis and alterations in lichenoid and sclerotic patterns and in chronic inflammation, we found statistically significant differences. Furthermore, when compared with the halcinonide group, the HIFU group exhibited enhanced curative effects that were statistically significant (P = 0.039). Based on the histological evidence from this randomized, controlled trial, HIFU represents an effective method for the treatment of NNEDV.

Rab3A, Rab27A, and Rab35 regulate different events during mouse oocyte meiotic maturation and activation

Rab family members play important roles in membrane trafficking, cell growth, and differentiation. Almost all components of the cell endomembrane system, the nucleus, and the plasma membrane are closely related to RAB proteins. In this study, we investigated the distribution and functions of three members of the Rab family, Rab3A, Rab27A, and Rab35, in mouse oocyte meiotic maturation and activation. The three Rab family members showed different localization patterns in oocytes. Microinjection of siRNA, antibody injection, or inhibitor treatment showed that (1) Rab3A regulates peripheral spindle and cortical granule (CG) migration, polarity establishment, and asymmetric division; (2) Rab27A regulates CG exocytosis following MII-stage oocyte activation; and (3) Rab35 plays an important role in spindle organization and morphology maintenance, and thus meiotic nuclear maturation. These results show that Rab proteins play important roles in mouse oocyte meiotic maturation and activation and that different members exert different distinct functions.

PDK1/Akt/PDE4D axis identified as a target for asthma remedy synergistic with β2 AR agonists by a natural agent arctigenin

BACKGROUND

Asthma is a heterogenetic disorder characterized by chronic inflammation with variable airflow obstruction and airway hyper-responsiveness. As the most potent and popular bronchodilators, β2 adrenergic receptor (β2 AR) agonists bind to the β2 ARs that are coupled via a stimulatory G protein to adenylyl cyclase, thereby improving cAMP accumulation and resulting in airway smooth muscle relaxation. We previously demonstrated arctigenin had a synergistic function with the β2 AR agonist, but the target for this remained elusive.

METHOD

Chemical proteomics capturing was used to enrich and uncover the target of arctigenin in human bronchial smooth muscle cells, and reverse docking and molecular dynamic stimulation were performed to evaluate the binding of arctigenin and its target. In vitro enzyme activities and protein levels were demonstrated with special kits and Western blotting. Finally, guinea pig tracheal muscle segregation and ex vivo function were analysed.

RESULTS

Arctigenin bound to PDK1 with an ideal binding free energy -25.45 kcal/mol and inhibited PDK1 kinase activity without changing its protein level. Additionally, arctigenin reduced PKB/Akt-induced phosphorylation of PDE4D, which was first identified in this study. Attenuation of PDE4D resulted in cAMP accumulation in human bronchial smooth muscle. The inhibition of PDK1 showed a synergistic function with β2 AR agonists and relaxed the constriction of segregated guinea pig tracheal muscle.

CONCLUSIONS

The PDK1/Akt/PDE4D axis serves as a novel asthma target, which may benefit airflow obstruction.

Dielectric function of two-phase colloid-polymer nanocomposite

The plasmon resonance of metal nanoparticles determines their optical response in the visible spectral range. Many details such as the electronic properties of gold near the particle surface and the local environment of the particles influence the spectra. We show how the cheap but highly precise fabrication of composite nanolayers by spin-assisted layer-by-layer deposition of polyelectrolytes can be used to investigate the spectral response of gold nanospheres (GNS) and gold nanorods (GNR) in a self-consistent way, using the established Maxwell-Garnett effective medium (MGEM) theory beyond the limit of homogeneous media. We show that the dielectric function of gold nanoparticles differs from the bulk value and experimentally characterize the shape and the surrounding of the particles thoroughly by SEM, AFM and ellipsometry. Averaging the dielectric functions of the layered surrounding by an appropriate weighting with the electric field intensity yields excellent agreement for the spectra of several nanoparticles and nanorods with various cover-layer thicknesses.

TRAF3IP3, a novel autophagy up-regulated gene, is involved in marginal zone B lymphocyte development and survival

Tumour necrosis factor receptor-associated factor 3 (TRAF3) interacting protein 3 (TRAF3IP3; also known as T3JAM) is expressed specifically in immune organs and tissues. To investigate the impact of TRAF3IP3 on immunity, we generated Traf3ip3 knock-out (KO) mice. Interestingly, these mice exhibited a significant reduction in the number of common lymphoid progenitors (CLPs) and inhibition of B cell development in the bone marrow. Furthermore, Traf3ip3 KO mice lacked marginal zone (MZ) B cells in the spleen. Traf3ip3 KO mice also exhibited a reduced amount of serum natural antibodies and impaired T cell-independent type II (TI-II) responses to trinitrophenol (TNP)-Ficoll antigen. Additionally, our results showed that Traf3ip3 promotes autophagy via an ATG16L1-binding motif, and MZ B cells isolated from mutant mice showed a diminished level of autophagy and a high rate of apoptosis. These results suggest that TRAF3IP3 contributes to MZ B cell survival by up-regulating autophagy, thereby promoting the TI-II immune response.

The injury resistant ability of melanopsin-expressing intrinsically photosensitive retinal ganglion cells

Neurons in the mammalian retina expressing the photopigment melanopsin have been identified as a class of intrinsically photosensitive retinal ganglion cells (ipRGCs). This discovery more than a decade ago has opened up an exciting new field of retinal research, and following the initial identification of photosensitive ganglion cells, several subtypes have been described. A number of studies have shown that ipRGCs subserve photoentrainment of circadian rhythms. They also influence other non-image forming functions of the visual system, such as the pupillary light reflex, sleep, cognition, mood, light aversion and development of the retina. These novel photosensitive neurons also influence form vision by contributing to contrast detection. Furthermore, studies have shown that ipRGCs are more injury-resistant following optic nerve injury, in animal models of glaucoma, and in patients with mitochondrial optic neuropathies, i.e., Leber’s hereditary optic neuropathy and dominant optic atrophy. There is also an indication that these cells may be resistant to glutamate-induced excitotoxicity. Herein we provide an overview of ipRGCs and discuss the injury-resistant character of these neurons under certain pathological and experimental conditions.

Lyn regulates cytotoxicity in respiratory epithelial cells challenged by cigarette smoke extracts

Cigarette smoking is associated with a series of lung diseases such as cancer, chronic obstructive pulmonary disease (COPD), and asthma. Despite the intense interest, the underlying molecular mechanism in smoking-related diseases is incompletely understood. Here, we show that Lyn is involved in cytotoxicity of respiratory epithelial cells induced by cigarette smoke extracts (CSE), an in vitro culture model for evaluating tobacco toxicity. In addition, exposure to CSE promotes the activation of JAK2 and STAT1, which is responsible for CSE-induced cytotoxicity. Moreover, a Lyn specific siRNA, Lyn dominant negative construct and pharmacological inhibitor all alleviated CSE-induced cytotoxicity in lung cells to different extents, respectively. Furthermore, Lyn also influences the phagocytosis of bacteria by murine alveolar macrophages, extending its impact on innate immunity. Taken together, these findings indicate that Lyn may play a role in the regulation of cigarette smoking-induced lung cell death, and may be a potential novel therapeutic target for cigarette smoking related lung diseases.

Cardiac mass in Behçet's disease

Cardiac mass is a rare manifestation of Behçet's disease (BD). Intracardiac thrombosis, endomyocardiofibrosis, endocardial fibroelastosis, inflammatory mass and cystic change have been reported as different entities of cardiac mass in BD. Here we presented 6 cases of this rare manifestation of BD. The clinical and pathological features were reviewed.

Disruption and formation of surface salt bridges are coupled to DNA binding by the integration host factor: a computational analysis

Revealing the thermodynamic driving force of protein-DNA interactions is crucial to the understanding of factors that dictate the properties and function of protein-DNA complexes. For the binding of DNA to DNA-wrapping proteins, such as the integration host factor (IHF), Record and co-workers proposed that the disruption of a large number of preexisting salt bridges is coupled with the binding process [Holbrook, J. A., et al. (2001) J. Mol. Biol. 310, 379]. To test this proposal, we have conducted explicit solvent MD simulations (multiple ∼25-50 ns trajectories for each salt concentration) to examine the behavior of charged residues in IHF, especially concerning their ability to form salt bridges at different salt concentrations. Of the 17 cationic residues noted by Record and co-workers, most are engaged in salt bridge interactions for a significant portion of the trajectories, especially in the absence of salt. This observation suggests that, from a structural point of view, their proposal is plausible. However, the complex behaviors of charged residues observed in the MD simulations also suggest that the unusual thermodynamic characteristics of IHF-DNA binding likely arise from the interplay between complex dynamics of charged residues both in and beyond the DNA binding site. Moreover, a comparison of MD simulations at different salt concentrations suggests that the strong dependence of the IHF-DNA binding enthalpy on salt concentration may not be due to a significant decrease in the number of stable salt bridges in apo IHF at high salt concentrations. In addition to the Hofmeister effects quantified in more recent studies of IHF-DNA binding, we recommend consideration of the variation of the enthalpy change of salt bridge disruption at different salt concentrations. Finally, the simulation study presented here explicitly highlights the fact that the electrostatic properties of DNA-binding proteins can be rather different in the apo and DNA-bound states, which has important implications for the design of robust methods for predicting DNA binding sites in proteins.

Growth and characterization of ceria thin films and Ce-doped γ-Al2O3 nanowires using sol-gel techniques

γ-Al(2)O(3) is a well known catalyst support. The addition of Ce to γ-Al(2)O(3) is known to beneficially retard the phase transformation of γ-Al(2)O(3) to α-Al(2)O(3) and stabilize the γ-pore structure. In this work, Ce-doped γ-Al(2)O(3) nanowires have been prepared by a novel method employing an anodic aluminium oxide (AAO) template in a 0.01 M cerium nitrate solution, assisted by urea hydrolysis. Calcination at 500 °C for 6 h resulted in the crystallization of the Ce-doped AlOOH gel to form Ce-doped γ-Al(2)O(3) nanowires. Ce(3+) ions within the nanowires were present at a concentration of < 1 at.%. On the template surface, a nanocrystalline CeO(2) thin film was deposited with a cubic fluorite structure and a crystallite size of 6-7 nm. Characterization of the nanowires and thin films was performed using scanning electron microscopy, transmission electron microscopy, electron energy loss spectroscopy, x-ray photoelectron spectroscopy and x-ray diffraction. The nanowire formation mechanism and urea hydrolysis kinetics are discussed in terms of the pH evolution during the reaction. The Ce-doped γ-Al(2)O(3) nanowires are likely to find useful applications in catalysis and this novel method can be exploited further for doping alumina nanowires with other rare earth elements.

CHARMM: the biomolecular simulation program

CHARMM (Chemistry at HARvard Molecular Mechanics) is a highly versatile and widely used molecular simulation program. It has been developed over the last three decades with a primary focus on molecules of biological interest, including proteins, peptides, lipids, nucleic acids, carbohydrates, and small molecule ligands, as they occur in solution, crystals, and membrane environments. For the study of such systems, the program provides a large suite of computational tools that include numerous conformational and path sampling methods, free energy estimators, molecular minimization, dynamics, and analysis techniques, and model-building capabilities. The CHARMM program is applicable to problems involving a much broader class of many-particle systems. Calculations with CHARMM can be performed using a number of different energy functions and models, from mixed quantum mechanical-molecular mechanical force fields, to all-atom classical potential energy functions with explicit solvent and various boundary conditions, to implicit solvent and membrane models. The program has been ported to numerous platforms in both serial and parallel architectures. This article provides an overview of the program as it exists today with an emphasis on developments since the publication of the original CHARMM article in 1983.

The role of macrophages in optic nerve regeneration

Following injury to the nervous system, the activation of macrophages, microglia, and T-cells profoundly affects the ability of neurons to survive and to regenerate damaged axons. The primary visual pathway provides a well-defined model system for investigating the interactions between the immune system and the nervous system after neural injury. Following damage to the optic nerve in mice and rats, retinal ganglion cells, the projection neurons of the eye, normally fail to regenerate their axons and soon begin to die. Induction of an inflammatory response in the vitreous strongly enhances the survival of retinal ganglion cells and enables these cells to regenerate lengthy axons beyond the injury site. T cells modulate this response, whereas microglia are thought to contribute to the loss of retinal ganglion cells in this model and in certain ocular diseases. This review discusses the complex and sometimes paradoxical actions of blood-borne macrophages, resident microglia, and T-cells in determining the outcome of injury in the primary visual pathway.

The Effects of Open Lung Ventilation on Respiratory Mechanics and Haemodynamics in Atelectatic Infants after Cardiopulmonary Bypass

Acute lung injury (ALI) frequently occurs in infants after cardiopulmonary bypass (CPB) surgery and it sometimes develops into acute respiratory distress syndrome in critically ill infants, which can be life threatening. This study investigated the effects of open lung ventilation on the haemodynamics and respiratory mechanics of 64 infants (34 males; 30 females) with a mean ± SD age of 8.3 ± 0.3 months who developed ALI following CPB surgery. Open lung ventilation significantly improved the respiratory mechanics and oxygenation parameters of the infants, including the partial pressure of oxygen in arterial blood (PaO2), the ratio of PaO2/FiO2 (fraction of inspired oxygen), peak inspiratory pressure, static compliance and airway resistance. It is concluded that open lung ventilation can greatly improve oxygenation and respiratory mechanics in infants with ALI following CPB surgery.

Differentiation block of oligodendroglial progenitor cells as a cause for remyelination failure in chronic multiple sclerosis

Impaired function/differentiation of progenitor cells might provide an explanation for the limited remyelination observed in the majority of chronic multiple sclerosis lesions. Here, we establish that in the normal adult human CNS, the transcription factors Nkx2.2 and Olig2 are strongly expressed in progenitor cells while mature oligodendrocytes are characterized by low levels of Olig2 or Nkx2.2. In vitro studies confirmed the expression of Olig2 in oligodendroglial progenitor cells and mature oligodendrocytes while astrocytes, microglial cells and neurons were negative for Olig2. In early multiple sclerosis lesions, we found Olig2-positive progenitor cells throughout all lesion stages and in periplaque white matter (PPWM). The number of progenitors in PPWM was significantly increased compared with the white matter from controls. In chronic multiple sclerosis lesions progenitor cells were still present, however, in significantly lower numbers than in early multiple sclerosis lesions. A subpopulation of progenitor cells in early multiple sclerosis lesions and PPWM but not in control cases co-expressed NogoA, a marker of mature oligodendrocytes. The co-expression of these two markers suggested that these cells were maturing oligodendrocytes recently recruited from the progenitor pool. In contrast, in chronic multiple sclerosis lesions maturing progenitors were only rarely present. In summary, we provide evidence that a differentiation block of oligodendroglial progenitors is a major determinant of remyelination failure in chronic multiple sclerosis lesions.

Possible role of hydrogen sulfide on the preservation of donor rat hearts

OBJECTIVE

The aim of this study was to observe the preservative effect of hydrogen sulfide (H2S) on donor rat hearts.

MATERIALS AND METHODS

The hearts of 24 Sprague-Dawley rats were perfused on a Langendorff perfusion column for 30 minutes. We calculated and recorded the left ventricular-developed pressure (LVDP), and positive and negative derivatives of left ventricular systolic pressure (LVSP; +dP/dt and -dP/dt). Hearts were then arrested and stored for 6 hours at 4 degrees C: group 1, Krebs-Henseleit (KH) solution; group 2, KH solution with 1 micromol/L NaHS; group 3, KH solution with 1 micromol/L NaHS and 10 micromol/L glibenclamide; group 4, St. Thomas II solution. Hearts were transferred back to the Langendorff column. After stabilizing for 30 minutes, LV performance was assessed as before. The donor hearts were kept for pathological study including myocardial water ratio, ATP content, and myocyte apoptosis index.

RESULTS

The recovery rates of +dp/dtmax, -dp/dtmax, and LVDP of groups 2 and 4 were much better than those of groups 1 and 3. The hearts contracted immediately after reperfusion in group 4. Ventricular fibrillation was seen before contraction in the other 3 groups, with the longest duration in group. No significant difference in myocardial water ratio was found. The ATP content was the highest in group 2. Apoptosis was observed in the 4 groups with the lowest apoptosis index in group 2.

CONCLUSIONS

H2S has a protective effect on rat donor hearts at the concentration of 1 micromol/L. The protective effect is better than that of St. Thomas II solution. The protective effect of H2S can be blocked by glibenclamide.

Differential roles of phosphatidylinositol 3-kinase/akt pathway in retinal ganglion cell survival in rats with or without acute ocular hypertension

Intraocular pressure (IOP) elevation has often been used as an experimental model to study mechanisms underlying retinal ganglion cell (RGC) death associated with ocular ischemic injury and glaucoma. The aim of the present study, using both in vitro and in vivo approaches, was to investigate the role of phosphatidylinositol 3-kinase (PI3K)/akt pathway in RGC viability in normal rats and rats following transient IOP elevation. For in vivo studies, pathway inhibitors were administered intravitreally on days 3, 9, and 15 post-2-h IOP elevation at 110 mm Hg. Toward the end of the 3-week examination period, the fluorescent dye Fluorogold was used to retrogradely label surviving RGCs. In order to examine the role of macrophages that were recruited into the eye following the pathway inhibition, clodronate liposomes were used to deplete phagocytic cells in the eye. PI3K/akt pathway activity and location in the retina were examined using Western blot and immunohistochemistry, respectively. Here we showed that PI3K/akt inhibitors 2-(4-morpholinyl)-8-phenyl-1(4H)-benzopyran-4-one hydrochloride (LY294002) and KY12420 at low concentrations (2 microM or 20 microM) did not influence RGC survival but caused RGC loss at high concentration (200 muM) in retinal explants derived from intact rats. In contrast, both LY294002 and KY12420 at 20 microM led to RGC loss in retinal explants derived from IOP-elevated eyes. A detrimental action of phagocytic cells on RGC survival was also seen in these retinas. In vivo results confirmed the detrimental actions of PI3K/akt inhibition and macrophages on RGC survival in IOP-elevated, but not intact eyes even with high concentration of LY294002. Low level of PI3K/akt activity was detected in the ganglion cell layer (GCL) in intact retina. Acute IOP elevation activated PI3K/akt pathway in the inner nuclear layer and GCL including RGCs. This study thus demonstrates that PI3K/akt pathway mediates RGC survival after IOP elevation but not under normal condition.