Rodents mediate the relationship between seed rain, seed bank, and plant community with increased grazing disturbance.

Seed rain and the soil seed bank represent the dispersal of seeds in space and time, respectively, and can be important sources of recruitment of new individuals during plant community regeneration. However, the temporal dynamics of seed rain and the mechanisms by which the seed rain and soil seed bank may play a role in plant community regeneration with increased grazing disturbance remain unclear. Seed rain, soil seed bank, aboveground vegetation, and rodent density were sampled along a grazing gradient in an alpine marsh on the eastern Tibetan Plateau. We described the temporal dynamics of seed dispersal using Bayesian generalized mixed models, and nonmetric multidimensional scaling and the structural equation model were used to examine the effects of grazing disturbance on the relative role of seed rain and soil seed bank on aboveground plant community regeneration. The temporal dynamics of seed rain changed from a unimodal to a bimodal pattern with increased grazing disturbance. Both species diversity and seed density of the seed rain and seed bank increased significantly with increased grazing disturbance. Increased grazing disturbance indirectly increased the similarity of composition between seed rain, seed bank, and aboveground plant community by directly increasing species diversity and abundance of aboveground plant community. However, increased grazing disturbance also indirectly decreased the similarity of seed rain, soil seed bank, and aboveground plant community by directly increasing rodent density. The similarity between seed rain and aboveground plant community was greater than that of the soil seed bank and aboveground plant community with increased grazing disturbance. Grazing disturbance spreads the risk of seed germination and seedling establishment by changing the temporal dynamics of seed dispersal. Plants (positive) and rodents (negative) mediated the role of seed rain and soil seed bank in plant community regeneration. The role of seed rain in plant community regeneration is higher than the seed bank in disturbed alpine marshes. Our findings increase our understanding of the regeneration process of the plant community, and they provide valuable information for the conservation and restoration of alpine marsh ecosystems.

Mechanisms of increased small nanoplastic particle retention in water-saturated sand media with montmorillonite and diatomite: Particle sizes, water components, and modelling.

The processes by which small nanoplastics (NPs) accumulate in soil are unclear. To clarify the different deposition processes that affect small NPs (< 30 nm) compared to larger NPs in the soil environment, due to their interaction with clays as major soil components, the transport behavior of two-sized NPs (20 and 80 nm) with two clays (diatomite (Diat) and montmorillonite (Mont)) in NaCl and CaCl2 solutions were investigated in water-saturated quartz sand columns. The experimental results showed that more 20 nm NPs could enter the lattice structure of Diat than Mont in NaCl solution. This contributed to the stronger deposition of 20 nm NPs by Diat on sand, which was associated with a lower k1d/k1 value (obtained from two-site kinetic attachment model). In contrast, 80 nm NPs had a stronger reversible retention than 20 nm NPs with Mont, even though both sizes of NPs-Mont displayed a similar transportability. In CaCl2 solution, the larger NPs-Mont hetero-aggregates formed with a stronger suppressed depth of φmax based on Derjaguin-Landau-Verwey-Overbeek theory. Thus, Mont had a stronger transport inhibition than Diat for both NPs sizes, with a lower k1d/k1. These findings could benefit in predicting the size-based deposition of NPs in a heterogenous soil environment.

Facial-onset sensory and motor neuronopathy with myasthenia gravis: A case report.

RATIONALE: Facial-onset sensory and motor neuronopathy (FOSMN) is a greatly rare disease, so far, autopsy evidence that is associated with neurodegenerative. Myasthenia gravis (MG) is an antibody-mediated and complement-involved acquired autoimmune disorder of the post-synaptic neuromuscular junction. There have been few reports about if there is related between the 2. In this study, we present the case of a man who was diagnosed as FOSMN with MG in continuity. PATIENT CONCERNS: The patient chief complaints were right-side facial numbness and right-eyelid incomplete closure, followed by slurred speech and dysphagia, and the symptoms gradually progressed. The patient serum was positive for anti-AchR and anti-Titin antibodies. DIAGNOSES: The patient was diagnosed FOSMN with MG. INTERVENTIONS: The patient symptoms were relieved after pyridostigmine bromide and prednisolone treatment. OUTCOMES: Symptoms have improved. LESSONS: Facial-onset sensory and motor neuronopathy and MG have disparate clinical features. Therefore, we reported a rare case in which the 2 conditions concurrently existed. Immune dysfunction might be the pathogenesis of this association, while there is no definite evidence to support it, further studies are needed.

Nano-size plastics inhibited Cr(VI) species transformation during facilitated transport of green synthesized nano-iron in the presence of oxyanions.

Remediating hexavalent chromium (Cr(VI))-contaminated soils using green synthesized nano-iron (g-nZVI), which merits high reactivity, low cost, and environmental friendliness, has attracted significant attention. However, the broad existence of nano plastics (NPs) could adsorb Cr(VI) and subsequently influence in situ remediation of Cr(VI)-contaminated soil by g-nZVI. To clarify this issue and improve the remediation efficiency, we investigated the co-transport between Cr(VI) and g-nZVI coexisting with sulfonyl-amino-modified nano plastics (SANPs) in water-saturated sand media in the presence of oxyanions (i.e., phosphate and sulfate) at environmentally relevant conditions. This study found that SANPs inhibited the Cr(VI) reduction to Cr(III) (i.e., Cr2O3) by g-nZVI, attributed to nZVI-SANPs hetero-aggregates and Cr(VI) adsorption on SANPs. Notably, "nZVI-[SANPs•••Cr(III)]" agglomerate happened via complexation of [-NH3•••Cr(III)] between Cr(III) from Cr(VI) reduced by g-nZVI and amino group on SANPs. Further, the co-presence of phosphate (stronger adsorption on SANPs than g-nZVI) remarkably suppressed Cr(VI) reduction. Then, it promoted the co-transport of Cr(VI) with nZVI-SANPs hetero-aggregates, which could potentially threaten underground water. Fundamentally, sulfate would instead concentrate on SANPs, hardly impacting the reactions between Cr(VI) and g-nZVI. Overall, our findings provide crucial insights into understanding the Cr(VI) species transformation during co-transport with g-nZVI in ubiquitous complexed soil environments (i.e., containing oxyanions) contaminated by SANPs.

Simultaneous effect of different chromatographic conditions on the chromatographic retention of pentapeptide derivatives (HGRFG and NPNPT).

Introduction: Oligopeptides exhibit great prospects for clinical application and its separation is of great importance in new drug development. Methods: To accurately predict the retention of pentapeptides with analogous structures in chromatography, the retention times of 57 pentapeptide derivatives in seven buffers at three temperatures and four mobile phase compositions were measured via reversed-phase high-performance liquid chromatography. The parameters ( k H A , k A , and p K a ) of the acid-base equilibrium were obtained by fitting the data corresponding to a sigmoidal function. We then studied the dependence of these parameters on the temperature (T), organic modifier composition (φ, methanol volume fraction), and polarity ( P m N parameter). Finally, we proposed two six-parameter models with (1) pH and T and (2) pH and φ or P m N as the independent variables. These models were validated for their prediction capacities by linearly fitting the predicted retention factor k-value and the experimental k-value. Results: The results showed that log k H A and log k A exhibited linear relationships with 1 / T , φ or P m N for all pentapeptides, especially for the acid pentapeptides. In the model of pH and T, the correlation coefficient (R2) of the acid pentapeptides was 0.8603, suggesting a certain prediction capability of chromatographic retention. Moreover, in the model of pH and φ or P m N , the R2 values of the acid and neutral pentapeptides were greater than 0.93, and the average root mean squared error was approximately 0.3, indicating that the k-values could be effectively predicted. Discussion: In summary, the two six-parameter models were appropriate to characterize the chromatographic retention of amphoteric compounds, especially the acid or neutral pentapeptides, and could predict the chromatographic retention of pentapeptide compounds.

Warming reduced flowering synchrony and extended community flowering season in an alpine meadow on the Tibetan Plateau.

The timing of phenological events is highly sensitive to climate change, and may influence ecosystem structure and function. Although changes in flowering phenology among species under climate change have been reported widely, how species-specific shifts will affect phenological synchrony and community-level phenology patterns remains unclear. We conducted a manipulative experiment of warming and precipitation addition and reduction to explore how climate change affected flowering phenology at the species and community levels in an alpine meadow on the eastern Tibetan Plateau. We found that warming advanced the first and last flowering times differently and with no consistent shifts in flowering duration among species, resulting in the entire flowering period of species emerging earlier in the growing season. Early-flowering species were more sensitive to warming than mid- and late-flowering species, thereby reducing flowering synchrony among species and extending the community-level flowering season. However, precipitation and its interactions with warming had no significant effects on flowering phenology. Our results suggest that temperature regulates flowering phenology from the species to community levels in this alpine meadow community, yet how species shifted their flowering timing and duration in response to warming varied. This species-level divergence may reshape flowering phenology in this alpine plant community. Decreasing flowering synchrony among species and the extension of community-level flowering seasons under warming may alter future trophic interactions, with cascading consequences to community and ecosystem function.

Quantitative structure-chromatographic retention relationship of synthesized peptides (HGRFG, NPNPT) and their derivatives.

Carapax Trionycis extract peptides (HGRFG, NPNPT) are able to protect against CCl4-induced liver fibrosis. Therefore, this study applies to deal with chromatographic lipophilicity determination of synthesized peptides (HGRFG, NPNPT) and their derivatives using reversed-phase high performance liquid chromatography (RP-HPLC) combined with methanol-water mobile phase and two reversed-phase chromatographic columns (COSMOISL 5C18-MS-II and SHIMADZU-C18). The chromatographic lipophilicity of the analyzed compounds was expressed as logkw constant and correlated with lipophilicity descriptors. Quantitative structure-retention relationships (QSRR) analysis was performed to imitate chromatographic lipophilicity behavior using molecular descriptors. Modeling was performed using linear regression (LR) and multiple linear regression (MLR) methods with the help of principal component analysis (PCA) and hierarchical cluster analysis (HCA). The most influential molecular descriptors were lipophilicity descriptors, which are important for molecules ability to pass through biological membranes. All established QSRR models were statistically validated by standards, cross- and external validation parameters. According to these statistical validation parameters, MLR models (R2 > 0.856) were better for chromatographic lipophilicity prediction of peptide compounds. It can be concluded that chromatographic systems with COSMOISL 5C18-MS-II column were better for modeling of logkw than systems with SHIMADZU-C18 column. Modeling was performed in order to obtain lipophilicity profiles of investigated compounds as future drug candidates.

Analysis of detection results of thyroid function-related indexes in pregnant women and establishment of the reference interval.

Detection results of free thyroxine (FT4), thyroid stimulating hormone (TSH) and thyroid peroxidase antibody (TPOAb) in pregnant women in Linyi region were investigated. A total of 22,235 healthy pregnant women admitted to Women and Children's Health Care Hospital of Linyi from October 2016 to October 2017 were selected and divided into the first-trimester, second-trimester and third-trimester pregnancy groups. Non-pregnant women in the same period were selected as the control group. Roche E601 electrochemiluminescence apparatus was applied to detect FT4, TSH and TPOAb, and statistical analysis was then carried out for the detected data. The positive rate in the third trimester of pregnancy was obviously higher than those in the first and second trimesters of pregnancy (P<0.05). With the prolongation of pregnancy, the reference interval of FT4 was gradually decreased, among which the intervals in the second and third trimesters of pregnancy were significantly lower than those in the non-pregnancy (P<0.05). With the prolongation of pregnancy, the interval in the first trimester of pregnancy was markedly smaller than that in the non-pregnancy group. With the increase of age, the levels of FT4 and TSH tended to be reduced, but the TSH level was increased to a certain degree in patients aged over 40 years. There were differences in the FT4 and TSH reference intervals during pregnancy in comparison among different regions and different detection methods. Region-specific reference intervals need to be established for different trimesters of pregnancy and different detection methods, which is conducive to accurate clinical judgment of thyroid function during pregnancy. TPOAb monitoring needs to be strengthened in the third trimester of pregnancy, and attention should be paid to the changes in thyroid function in pregnant women aged over 40 years.

Socioeconomic and geographic variations in the prevalence, awareness, treatment and control of dyslipidemia in middle-aged and older Chinese.

BACKGROUND AND AIMS: Unevenly socioeconomic development and nutrition transition might bring large variations in the epidemiology of dyslipidemia. We aimed to estimate the prevalence, awareness, treatment and control of dyslipidemia in different socioeconomic statuses and geographic regions in China, and to assess the associated factors and comorbidities of dyslipidemia. METHODS: We included participants aged 45 years and above from a nationally representative investigation: the China Health and Retirement Longitudinal Study 2011. Dyslipidemia was defined based on the 2016 guideline of Chinese Prevention and Treatment of Dyslipidemia in adults. Multivariable logistic regression was adopted to assess the potentially associated factors and commodities of dyslipidemia. RESULTS: In 2010, the prevalence of dyslipidemia was 42.84% among people aged 45 years and above. Low level of high-density lipoprotein cholesterol (HDL-C) was the most common type of dyslipidemia. The awareness, treatment and control rates among dyslipidemic subjects were 20.27%, 14.41% and 4.94%, respectively. In dyslipidemic patients who were under treatment, the control rate was 34.26%. People aged 50-59 years were at a significantly higher risk of dyslipidemia than those aged 45-49 years. Male gender, living in North China, overweight, obesity, central obesity, hypertension, diabetes and hyperuricemia were significantly associated with a higher risk of dyslipidemia. Current alcohol drinking and underweight were linked to a lower prevalence of dyslipidemia. CONCLUSIONS: Our study revealed a high prevalence of dyslipidemia among middle-aged and older Chinese. The awareness, treatment and control rates were far from ideal and geographic inequality was highlighted. More efforts are needed to prevent and manage dyslipidemia in China.

MNX1 promotes cell proliferation and activates Wnt/ß-catenin signaling in colorectal cancer.

Aberrant Wnt/ß-catenin signaling is a characteristic feature of colorectal cancer (CRC), therefore, understanding the underlying mechanisms of aberrant Wnt/ß-catenin signaling will improve the treatment outcome of CRC. Expression of MNX1 in paired fresh CRC tissues and corresponding adjacent normal tissues were examined by qPCR and Western blotting. The levels of MNX1 in paraffin-embedded CRC specimens were detected by immunohistochemistry (IHC). The role of MNX1 in growth and proliferation of CRC cells was evaluated by MTT and colony formation assay. Luciferase reporter analysis and western blotting were carried out to explore the influence of MNX1 on Wnt/ß-catenin signaling. The results showed that expression of MNX1 is markedly upregulated in CRC tissues and positively correlated with level of Ki67, and overexpression of MNX1 significantly promotes the proliferation of CRC cells. Further study showed that ectopic expression of MNX1 activates the Wnt/ß-catenin signaling and upregulates the expression of c-Myc and CCND1, the downstream genes of Wnt/ß-catenin signaling. Therefore, MNX1 plays an indispensable role in promoting of human CRC progression and may represent a novel therapeutic target for CRC.

A hypothesis study on a four-period prevention model for high altitude disease.

BACKGROUND: High altitude disease (HAD) can reduce combat effectiveness and damage the health of soldiers at high altitudes. The objective of this hypothesis study is to build a four-period prevention model for high altitude disease that can be applied at high altitudes of over 3000 m. PRESENTATION OF THE HYPOTHESIS: We divided the time at high altitude into nine periods, with three stages from the ascent preparation to the descent to the plain, and applied a continuous dynamic and systematic four-period prevention model across the nine periods. Each period of three stages has its own different measures and targets high altitude health care services for the prevention of high altitude disease. A standard four-period prevention model for high altitude disease was constructed for the high altitude health services at the population level. TESTING THE HYPOTHESIS: Our hypothesized HAD prevention model represents a continuous dynamic and systematic four-period prevention model across the nine periods. This hypothesis can be tested from three aspects. The first one isassessment of soldiers' operating efficacies. The second is comparison of the long-term high altitude population health basic data and development and utilization of big data. The third is descent population health status comparative study and historical retrospective study on prevention. IMPLICATIONS: As we know, it is necessary to protect soldiers' health through the ascent and descent. Through the standard four-period model, we can protect soldiers' health by preventing high altitude diseases, screening the susceptible population, securely tracking their location and maintaining soldiers' health statuses; we also maintain their operational capabilities, eliminate their psychological fears and ease their family troubles.

Evaluation of toxic effects of CdTe quantum dots on the reproductive system in adult male mice.

Fluorescent quantum dots (QDs) are highly promising nanomaterials for various biological and biomedical applications because of their unique optical properties, such as robust photostability, strong photoluminescence, and size-tunable fluorescence. Several studies have reported the in vivo toxicity of QDs, but their effects on the male reproduction system have not been examined. In this study, we investigated the reproductive toxicity of cadmium telluride (CdTe) QDs at a high dose of 2.0 nmol per mouse and a low dose of 0.2 nmol per mouse. Body weight measurements demonstrated there was no overt toxicity for both dose at day 90 after exposure, but the high dose CdTe affected body weight up to 15 days after exposure. CdTe QDs accumulated in the testes and damaged the tissue structure for both doses on day 90. Meanwhile, either of two CdTe QDs treatments did not significantly affect the quantity of sperm, but the high dose CdTe significantly decreased the quality of sperm on day 60. The serum levels of three major sex hormones were also perturbed by CdTe QDs treatment. However, the pregnancy rate and delivery success of female mice that mated with the treated male mice did not differ from those mated with untreated male mice. These results suggest that CdTe QDs can cause testes toxicity in a dose-dependent manner. The low dose of CdTe QDs is relatively safe for the reproductive system of male mice. Our preliminary result enables better understanding of the reproductive toxicity induced by cadmium-containing QDs and provides insight into the safe use of these nanoparticles in biological and environmental systems.

Rapid preparation of single-layer transition metal dichalcogenide nanosheets via ultrasonication enhanced lithium intercalation.

In this report, we have developed a rapid and versatile ultrasonication enhanced lithium intercalation (ULI) method to prepare single-layer transition metal dichalcogenide nanosheets (TMDC NSs, including MoS2, WS2, and TiS2) by using n-butyllithium (n-BuLi).

[Effects of Panax notoginseng saponins on proliferation, apoptosis and cell cycle of K562 cells in vitro and the mechanisms].

OBJECTIVE: To investigate the effects of Panax notoginseng saponins (PNS) on the proliferation, apoptosis and cell cycle of K562 cells and explore the molecular mechanisms underlying these effects. METHODS: PNS-induced growth inhibition of K562 cells was detected by MTT assay; the cell apoptosis was evaluated by AO/EB staining and Annexin V-FITC/ PI staining; flow cytometry was used to detect cell cycle changes in the treated cells. The mRNA expressions of the molecules in mTOR signaling pathway were examined by RT-PCR, and the cellular expressions of cleaved caspeas-3, cyclin D1 and major proteins in mTOR signaling pathway were detected using Western blotting. RESULTS: MTT assay showed that treatment with 100-800 µg/mL PNS significantly inhibited the proliferation, promoted the cell apoptosis, and caused cell cycle arrest in G0/G1 phase in K562 cells. Western blotting revealed increased protein expression of cleaved caspase-3 and decreased expression of cyclin D1 in PNS-treated cells, in which the proteins expressions of mTOR, p-mTOR, p-p70S6K and p-4E-BP 1 and the mRNA expression of mTOR were all decreased. CONCLUSION: PNS can inhibit the proliferation, induce apoptosis and cause cell cycle arrest in K562 cells possibly by up-regulating cleaved caspase 3 and down-regulating cyclin D1 and mTOR signaling pathway.

[Lentivirus-mediated stable Fas gene silencing in human umbilical cord-derived mesenchymal stem cells].

OBJECTIVE: To construct a lentivirus-mediated vector for RNA interference (RNAi) of Fas and establish a human umbilical cord-derived mesenchymal stem cells (UC-MSCs) line with stable Fas gene silencing. METHODS: Four short hairpin RNA sequences targeting the coding region of human Fas mRNA were designed. The synthesized oligonucleotides were ligated with the lentivirus vectors harvested from BamHI and EcoRI double digestion of LV3 recombinant vector. The recombinant lentivirus vectors were transfected into the packaging cells 293T, and the lentivirus titers were determined. Cultured UC-MSCs were infected with the lentivirus, and real-time PCR and Western blotting were used to detect the expressions of Fas mRNA and protein in the transfected cells. RESULTS: Restriction digestion and DNA sequencing showed that the lentiviral vectors were successfully constructed, and the titer of lentivirus reached 3 × 108 TU/ml in the packaging cells. Real-time PCR and Western blot demonstrated significantly suppressed Fas gene expression in UC-MSCs after infection with the recombinant lentivirus. CONCLUSION: Lentivirus-mediated RNAi can effectively inhibit Fas gene expression in cultured UC-MSCs.