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Abstract Accurately predicting and selecting patients who can benefit from targeted or immunotherapy is crucial for precision therapy. Trophoblast cell surface antigen 2 (Trop2) has been extensively investigated as a pan-cancer biomarker expressed in various tumours and plays a crucial role in tumorigenesis through multiple signalling pathways. Our laboratory successfully developed two 68Ga-labelled nanobody tracers that can rapidly and specifically target Trop2. Of the two tracers, [68Ga]Ga-NOTA-T4, demonstrated excellent pharmacokinetics in preclinical mouse models and a beagle dog. Moreover, [68Ga]Ga-NOTA-T4 immuno-positron emission tomography (immunoPET) allowed noninvasive visualisation of Trop2 heterogeneous and differential expression in preclinical solid tumour models and ten patients with solid tumours. [68Ga]Ga-NOTA-T4 immunoPET could facilitate clinical decision-making through patient stratification and response monitoring during Trop2-targeted therapies.

Soil biodiversity contains the metabolic toolbox supporting organic matter decomposition and nutrient cycling in the soil. However, as soil develops over millions of years, the buildup of plant cover, soil carbon and microbial biomass may relax the dependence of soil functions on soil biodiversity. To test this hypothesis, we evaluate the within-site soil biodiversity and function relationships across 87 globally distributed ecosystems ranging in soil age from centuries to millennia. We found that within-site soil biodiversity and function relationship is negatively correlated with soil age, suggesting a stronger dependence of ecosystem functioning on soil biodiversity in geologically younger than older ecosystems. We further show that increases in plant cover, soil carbon and microbial biomass as ecosystems develop, particularly in wetter conditions, lessen the critical need of soil biodiversity to sustain function. Our work highlights the importance of soil biodiversity for supporting function in drier and geologically younger ecosystems with low microbial biomass. This study demonstrates that soil BEF relationships diminish during long-term pedogenesis, highlighting the importance of soil biodiversity in sustaining multiple ecosystem functions in younger, drier soils. [ABSTRACT FROM AUTHOR]

Astragalus membranaceus is known as Hwang-gi in Korea, Huang Qi in Chinese and Radix Astragali in Latin, is a member of Fabaceae family. Traditionally, it has been used as an immunomodulator to treat people with cardiovascular disease as well as colds, fatigue, diarrhea, anorexia, and irregular uterine hemorrhage. In this study, an efficient micropropagation method of A. membranaceus was established, by which micropropagation can be achieved from 2 pathways: direct and indirect. For direct organogenesis, the multi-shoots were induced from apical or lateral shoots in MS medium with BAP at 1.0 mg/L and subsequently, they were proliferated in MS supplemented kinetin at 2.0 mg/L. For indirect organogenesis, the adventitious shoots were regenerated indirectly in MS with BAP at 1.0 mg/L and IBA at 0.5 mg/L media from callus, formed in MS with 2.4-D at 1.0 mg/L. Finally, the single shoot was transferred to 1/2 MS medium for rooting. Regenerated plants grown on hormone-free media for 1 month were transferred to polyethylene pots containing a cocopeat: perlite (3:1; v/v) mixture with a survival rate of approximately 93% 1 month after acclimatization. The results of this study make a significant contribution to the efficient micropropagation of this plant, which is useful for providing abundant and stable resources for further and more in-depth studies of this species such as the extraction of secondary metabolites with potential downstream applications or large-scale micropropagation offers an alternative within shorter time to grow this plant in the field for commercial and pharmaceutical uses.Please confirm if the author names are presented accurately and in the correct sequence (given name, middle name/initial, family name). Author 1 Given name: [Thi Ngoc Anh] Last name [Tran]. Also, kindly confirm the details in the metadata are correct.I confirmed information of all author and correectly in orderPlease provide key message for this article.Whole process for tissue culture of Astragalusc membranaceus were esbtablished [ABSTRACT FROM AUTHOR]

Copyright of Rare Metals is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Iron is an essential element for the normal functioning of living organisms, but excessive iron deposition can lead to organ damage. This study aims to investigate the interaction between the endoplasmic reticulum stress signaling pathway and the PI3K/AKT/mTOR signaling pathway in liver injury induced by iron overload in chicks. Rspectively, 150 one-day-old broilers were divided into three groups and supplemented with 50 (C), 500 (E1), and 1000 (E2) mg ferrous sulfate monohydrate/kg in the basal diet. Samples were taken after continuous feeding for 14 days. The results showed that iron overload could upregulate the levels of ALT and AST. Histopathological examination revealed bleeding in the central vein of the liver accompanied by inflammatory cell infiltration. Hoechst staining showed that the iron overload group showed significant bright blue fluorescence, and ultrastructural observations showed chromatin condensation as well as mitochondrial swelling and cristae disorganization in the iron overload group. RT-qPCR and Western blot results showed that iron overload upregulated the expression of Bax, Caspase-3, Caspase-9, GRP78, GRP94, P-PERK, ATF4, eIF2α, IRE1, and ATF6, while downregulating the expression of Bcl-2 and the PI3K/AKT/mTOR pathway. XBP-1 splicing experiment showed significant splicing of XBP-1 gene after iron overload. PCA and correlation analysis suggested a potential association between endoplasmic reticulum stress, the PI3K/AKT/mTOR signaling pathway, and liver injury in chicks. In summary, iron overload can induce cell apoptosis and liver injury by affecting endoplasmic reticulum stress and the PI3K/AKT/mTOR signaling pathway. [ABSTRACT FROM AUTHOR]

Background and Aims: The characteristics of microbial communities can directly reflect the physicochemical properties of soil which is important for successful ecological restoration in the tailings pond. Methods: The effects of aggregate spray seeding (S1), external-soil spray seeding restoration (S2), and naturally restored dam slope area (S3) on the structure and predicted function of soil bacterial communities and their correlation with environmental factors were analyzed. Results: Our study proved that different bacterial communities were formed based on the different ecological restoration methods, and soil water content (W), conductivity (EC), porosity (SP), soil bulk density (BD), organic matter (SOM), available potassium (AK), heavy metals, biomass and diversity of vegetation were the main factors influencing bacterial community composition. In S1, Bacillaceae and Rhizobiaceae were the dominant bacteria, thus the functional abundance involved in the nitrogen cycle was higher than the others. In addition, the dominant bacteria of S1 and S2, Bacillaceae, Rhizobiaceae, and Vicinamibacteraceae, were significantly positively correlated with W, EC, SP, SOM, AK, biomass and diversity of vegetation, while negatively correlated with BD and heavy metals content. The dominant bacterial families of S3, Geodermatophilaceae and Rhodobacteraceae, were significantly positively correlated with BD and soil heavy metal content. Conclusion: Different ecological restoration methods result in significant differences in soil bacterial community structure and predicted function. Aggregate spray seeding provided a double inoculation effect of Bacillaceae and Rhizobiaceae for ecological restoration of tailings pond. [ABSTRACT FROM AUTHOR]

This study investigated the soil physicochemical properties and vegetation community characteristics of the Baotou light rare earth tailings pond after 10 years of aggregate spray seeding ecological restoration (S1) and ordinary soil spray seeding ecological restoration (S2), and the naturally restored dam slope area without human intervention (S3). The results showed that the vegetation community of S1 was dominated by Caragana korshinskii Kom, and its importance and abundance values were 0.40 and 38.4, respectively, while the vegetation communities of S2 and S3 mainly comprised herbaceous plants. Additionally, the vegetation biomass of S1 was significantly higher than that of S2 and S3 by 215.20% and 1345.76%, respectively, and the vegetation diversity index of S1 was the highest among the three treatment groups. The soil porosity (SP), water content (W), electrical conductivity (EC), and available K were significantly improved in S1, while soil bulk density (BD) was significantly reduced compared with that of S2 and S3. In addition, redundancy analysis revealed that SP, EC, W, and K positively correlate with the biomass, Shannon, Pielou, Simpson, and Marglef indices. Principal component analysis further showed that the comprehensive score of S1 (0.983) was higher than that of S2 (− 0.261) and S3 (− 0.648). Collectively, these findings indicate that appropriate ecological restoration can improve soil structure and vegetation community characteristics, thereby accelerating vegetation restoration, ultimately increasing the stability of the ecosystem. [ABSTRACT FROM AUTHOR]

Background: Potassium bismuth citrate is a gastric mucosal protector and a key drug for treating peptic ulcers. Objective: To evaluate the pharmacokinetic characteristics and safety of 120-mg bismuth potassium citrate formulations administered orally under fasting conditions in healthy Chinese subjects. Method: A single-center open two-cycle trial was conducted on 12 healthy subjects who received a single oral dose of 120 mg of bismuth potassium citrate. The plasma concentration of bismuth was determined using a validated inductively coupled plasma mass spectrometry (ICP‒MS) method. The pharmacokinetic parameters, including maximum serum concentration (Cmax) and area under the curve concentration–time curve (AUC0–t and AUC0–∞), and safety were evaluated via noncompartment analysis. Results: The ratios of the least square geometric mean ratio between the test (T) and reference (R) formulations for Cmax, AUC0–t, and AUC0–∞ were 44.8%, 55.5%, and 64.4%, respectively; the bilateral 95% confidence intervals (Cis) for these parameters were 20.2–99.6%, 24.1–127.5%, and 23.7–175.0%, respectively, and the non-inferior limits for these parameters were 169.4%, 198.8%, and 200.5%, respectively. The upper limits of the one-sided 97.5% confidence interval for the least squares geometric mean ratio (T/R) were lower than the non-inferior limits. No serious adverse reactions or adverse reactions leading to detachment were observed among the subjects. Conclusion: The concentration of bismuth in the blood of healthy subjects in the T formulation was not greater than that in the R formulation. Similarly, the safety of oral administration of 120 mg of bismuth potassium citrate formulations to healthy subjects was good. The trial registration number (TRN) was [2018] 013, 6 December 2018. [ABSTRACT FROM AUTHOR]

A favorable tourism image of high-quality mountain scenic spots (HQMSS) is crucial for tourism prosperity and sustainability. This paper establishes a framework for investigating the tourism image based on cognitive-emotion theory and uses natural language processing (NLP) tools to clarify the cognition, emotion, and overall tourist image of the HQMSS in China from the perspective of tourist perception. This paper examines the multi-dimensional spatial differentiation of China's overall image, including province, scenic spot scales, as well as the spatial pattern of the overall comprehensive tourism image. Strategies for comprehensively improving HQMSS's tourism image are also formulated. The results show that: (1) The cognitive image of Chinese HQMSS is categorized into core and marginal images, and the core images such as scenery and cable car are the expression of the uniqueness of mountainous scenic spots. Additionally, the cognitive image is classified into six dimensions: tourism environment, tourism supporting facilities, tourism experience, tourism price, tourism service, and tourism safety. (2) Positive emotions are the dominant mood type of HQMSS in China, followed by neutral emotions, with negative emotions being the least frequent. Emotional images vary across dimensions, with tourism environment and tourism experience evoking relatively higher emotion. (3) The spatial pattern of HQMSS for each dimension at the national, provincial, and scenic scales is diversifying. This article provides a multidimensional perspective for investigating the tourism image of mountainous scenic spots, proposes targeted recommendations to improve the overall image of HQMSS in China, and can greatly contribute to the sustainable development of mountain tourism. [ABSTRACT FROM AUTHOR]

The gravity recovery and climate experiment (GRACE) has emerged as a crucial source of land water storage information in hydrological analysis and research. Numerous factors contribute to regional terrestrial water storage (TWS), resulting in a complex mechanism. In the Loess Plateau region, the continuous alteration of natural conditions and profound impact of human activities have posed a serious threat to the natural ecosystem, leading to an escalating trend of TWS reduction. Addressing the specific analysis of how natural conditions and human activities affect TWS represents a pressing issue. This study employed the residual analysis method to discern the contribution rates of natural conditions and human activities, elucidated the spatial and temporal changes associated with each factor, and ascertained their individual influence. The findings indicated that TWS on the Loess Plateau exhibited a downward trend of −4.89 mm·a−1 from 2003 to 2017. The combined effects of climate change and human activities accounted for alterations in water resource reserves across most areas of the Loess Plateau, with human activities predominantly driving these changes. Precipitation emerged as the primary natural factor influencing TWS variations, and NDVI demonstrated a positive feedback effect on TWS at approximately 30%. Substantial spatial disparities in TWS existed within the Loess Plateau, with human activities identified as the primary cause for the decreasing trend. Vegetation restoration plays a positive role in saving water resources in the Loess Plateau to some extent, and vegetation growth exceeding the regional load will lead to water shortage. [ABSTRACT FROM AUTHOR]

Objective: Sacubitril/valsartan is a commonly used medicine for treating heart failure (HF) patients, but the treatment effects significantly vary. Neprilysin (NEP) and carboxylesterase 1 (CES1) play an important role in the efficacy of sacubitril/valsartan. The purpose of this study was to explore the relationship between NEP and CES1 gene polymorphisms and the efficacy and safety of sacubitril/valsartan treatment in HF patients. Methods: Genotyping of 10 single nucleotide polymorphisms (SNPs) of the NEP and CES1 genes in 116 HF patients was performed by the Sequenom MassARRAY method, and logistic regression and haplotype analysis were used to evaluate the associations between SNPs and the clinical efficacy and safety of sacubitril/valsartan in HF patients. Results: A total of 116 Chinese patients with HF completed the whole trial, and T variations in rs701109 in NEP gene were an independent risk factor (P = 0.013, OR = 3.292, 95% CI:1.287–8.422) for the clinical efficacy of sacubitril/valsartan. Furthermore, haplotype analysis of 6 NEP SNPs (including rs701109) was performed and showed that the CGTACC and TGTACC haplotypes were significantly associated with clinical efficacy (OR = 0.095, 95%CI: 0.012–0.723, P = 0.003; OR = 5.586, 95% CI: 1.621–19.248, P = 0.005). Moreover, no association was found between SNPs of other selected genes in terms of efficacy in HF patients, and no association was observed between SNPs and symptomatic hypotension. Conclusion: Our results suggest an association between rs701109 and sacubitril/valsartan response in HF patients. Symptomatic hypotension is not associated with the presence of NEP polymorphisms. [ABSTRACT FROM AUTHOR]

Background: Cloperastine is a pivotal antibechic widely prescribed to treat cough caused by respiratory diseases. The present trial evaluated the pharmacokinetics (PK), bioequivalence (BE) and safety effects of the generic test (T) tablet of cloperastine after single-dose administration of cloperastine, compared with the original reference (R) tablet of cloperastine. Objective: The purpose of this trial was to compare the PK, BE and safety of a test 10 mg versus the reference 10 mg formulation of cloperastine under fasting and postprandial conditions in healthy Chinese volunteers. Methods: A single-centre, randomised, open, double-cycle, self-crossover, single oral administration Phase I trial was performed in healthy Chinese volunteers. A total of 60 subjects were enrolled in either the fasting (28 subjects) or the postprandial condition (32 subjects). Subjects randomly received a single dose of the T or R preparation (10 mg dose). Plasma concentrations of cloperastine were analysed by a validated LC-MS/MS method. The primary endpoints of the PK parameters were the area under the plasma concentration-time curve from zero to 72 h (AUC0–72h), under the plasma concentration-time curve from zero to infinity (AUC0–∞) and the maximal plasma concentration (Cmax). The equivalence standard range (80.0–125.0%) was used to evaluate the BE of the two preparations. The safety parameter as secondary endpoint was mainly evaluated by the occurrence of adverse events (AEs). Results: A total of 25 and 30 subjects in the fasting and postprandial conditions completed this clinical trial, respectively. The geometric mean ratio (GMR) of the T/R for the Cmax, AUC0–72h and AUC0–∞ were 102.1%, 103.8% and 104.0% in the fasting condition, respectively. In the postprandial condition, the GMR of the T/R for the Cmax, AUC0–72h and AUC0–∞ were 94.2%, 98.8% and 99.0%, respectively. All the values fell within the range (80.0–125.0%). The Cmax and AUC0–72h values of the T and R preparations in fasting and postprandial conditions were not statistically significant (P > 0.05). Furthermore, no serious adverse events (SAEs) occurred during the whole trial. Conclusions: The T and R preparations were bioequivalent under both conditions. Food has no significant effect on the absorption of cloperastine. Moreover, T and R preparations were well tolerated. The trial registration number (TRN) and date of registrations were CTR20212515, 13 October 2021. [ABSTRACT FROM AUTHOR]

Stenotrophomonas maltophilia has been recognized as an emerging global opportunistic pathogen, and it is intrinsically resistant to most antibiotics, which makes the limited choice for treating S. maltophilia infections. Bacteriophage with the proper characterization is considered as a promising alternative treatment option to control S. maltophilia infections. In this study, we isolated a novel Siphoviridae bacteriophage vB_SmaS_BUCT626 with lytic activity against S. maltophilia. Phage vB_SmaS_BUCT626 can lysis 10 of 20 S. maltophilia and was relatively stable at a wide range of temperatures (4–70 °C) and pH values (3.0–13.0) and exhibited good tolerance to chloroform. The genome of phage vB_SmaS_BUCT626 was a 61,662-bp linear double-stranded DNA molecule with a GC content of 56.2%, and contained 100 open-reading frames. It carried no antibiotic resistance, toxin, virulence-related genes, or lysogen-formation gene clusters. Together, these characteristics make phage vB_SmaS_BUCT626, a viable candidate as a biocontrol agent against S. maltophilia infection. [ABSTRACT FROM AUTHOR]

Objective: To study the effect of electroacupuncture (EA) on oxaliplatin-induced peripheral neuropathy (OIPN) in rats. Methods: Male Sprague-Dawley rats were equally divided into 3 groups using a random number table: the control group, the OIPN group, and the EA (OIPN + EA) group, with 10 rats in each. The time courses of mechanical, cold sensitivity, and microcirculation blood flow intensity were determined. The morphology of the dorsal root ganglion (DRG) was observed by electron microscopic examination. The protein levels of nuclear factor E2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and the transient receptor potential (TRP) protein family in DRGs were assayed by Western blot. Results: EA treatment significantly reduced mechanical allodynia and cold allodynia in OIPN rats (P<0.01). Notably, oxaliplatin treatment resulted in impaired microcirculatory blood flow and pathomorphological defects in DRGs (P<0.01). EA treatment increased the microcirculation blood flow and attenuated the pathological changes induced by oxaliplatin (P<0.01). In addition, the expression levels of Nrf2 and HO-1 were down-regulated, and the TRP protein family was over-expressed in the DRGs of OIPN rats (P<0.01). EA increased the expression levels of Nrf2 and HO-1 and decreased the level of TRP protein family in DRG (P<0.05 or P<0.01). Conclusion: EA may be a potential alternative therapy for OIPN, and its mechanism may be mainly mediated by restoring the Nrf2/HO-1 signaling pathway. [ABSTRACT FROM AUTHOR]

A landslide always results from a progressive process of slope deformation. In recent years, an increasing number of slope instabilities have occurred with regard to human engineering activities such as hydropower or traffic construction in mountainous area, which cause even greater casualties and economic loss compared with the natural hazards. The development of such earth surface process may hold long period with mechanisms still not fully understood. Using monitoring technology is an effective and intuitive approach to assist analyzing the slope deformation process and their driving factors. This study presents an engineering slope excavated during the construction of Changheba Hydropower Station, which is located in the upper reaches of Dadu River, Sichuan Province, southwest China. The engineering slope experienced and featured a five-year continuous deformation which caused continuous high risks to the engineering activities. We conducted in-depth analysis for such a long-term deformation process based on ground and subsurface monitoring data, collected successive data with a series of monitoring equipment such as automated total station, borehole inclinometers and other auxiliary apparatus, and identified the deformation process based on the comprehensive analysis of monitoring data as well as field investigation. After analyzing the effects of engineering activities and natural factors on the continuous deformation, we found that the overburden strata provided deformable mass while the excavation-produced steep terrain initiated the slope deformation in limit equilibrium state over a long period of time; afterwards, the intense rainwater accelerated slope deformation in the rainy season. [ABSTRACT FROM AUTHOR]

The health of the lower basin of the Volta River in Ghana was evaluated in January–February and May–June 2016 using physicochemical parameters and benthic macroinvertebrates sampled at 10 locations. Selected environmental variables were compared to accepted environmental water quality standard values where applicable. Principal component analysis (PCA) and redundancy analysis (RDA) were used to analyse the association between the benthic macroinvertebrates distribution and physicochemical variables. Pesticide concentrations were generally below the limit of detection 0.01 and 0.005 µg/L for organophosphate/synthetic pyrethroid and organochlorines respectively. Nutrient levels were also generally low; however, significant differences existed between the values of physicochemical parameters at the different sampling sites and seasons (Monte Carlo permutation test; p = 0.002), as well as between the abundance of macroinvertebrates at the different sites and seasons (p = 0.002). The environmental variables dissolved oxygen (DO), phosphate, pH, substratum (p < 0.05), turbidity, conductivity, total dissolved solids, total solids and nitrate (0.05 < p < 0.10) significantly explained the variation in macroinvertebrate composition between sampling stations in the Volta River. Polypedilum fuscipenne, was positively correlated with turbidity and DO concentrations; Physa sp., Centroptilum sp., Centroptiloides sp., Phaon iridipennis and juvenile fish were positively correlated with nitrate concentration and pH and negatively correlated with turbidity and DO. Polluted sites were dominated by the snail Lymnaea glabra. This demonstrates that physicochemical parameters and macroinvertebrates could be applied to describe the water quality and improve the biomonitoring for water resources management and the environmental protection in the Lower Volta River. [ABSTRACT FROM AUTHOR]

Background: More than half of Neuroblastoma (NB) patients presented with distant metastases and the relapse of metastatic patients was up to 90%. It is urgent to explore a biomarker that could facilitate the prediction of metastasis in NB patients. Methods and results: In the present study, we systematically analyzed Gene Expression Omnibus datasets and focused on identifying the critical molecular networks and novel key hub genes implicated in NB metastasis. In total, 176 up-regulated and 19 down-regulated differentially expressed genes (DEGs) were identified. Based on these DEGs, a PPI network composed of 150 nodes and 452 interactions was established. Through PPI network identification combined with qRT-PCR, ELISA and IHC, S100A9 was screened as an outstanding gene. Furthermore, in vitro tumorigenesis assays demonstrated that S100A9 overexpression enhanced the proliferation, migration and invasion of NB cells. Conclusions: Taken together, our findings suggested that S100A9 could participate in NB tumorigenesis and progression. In addition, S100A9 has the potential to be used as a promising clinical biomarker in the prediction of NB metastasis. [ABSTRACT FROM AUTHOR]

A new aerotolerant strain of Clostridium beijerinckii LY-5 was isolated from the pit mud of the Chinese Baijiu-making process for butanol production. Plackett–Burman design and artificial neural network were used to optimize the fermentation medium and a total of 13.54 ± 0.22 g/L butanol and 19.91 ± 0.52 g/L ABE were attained under aerotolerant condition. Moreover, distillers' grain waste (DGW), the main by-product in the Baijiu production process, was utilized as potential substrate for butanol production. DGW was hydrolyzed by α-amylase and glucoamylase and then fermented after a detoxifying process of overliming. Butanol and ABE concentrations were 9.02 ± 0.18 and 9.57 ± 0.19 g/L with the yield of 0.21 and 0.23 g/g sugar, respectively. The higher ratio of butanol to ABE might be caused by the inhibitors in DGW medium affecting the metabolic pathways of C. beijerinckii LY-5 and approximately 1.48 ± 0.04 g/L isopropanol was found at the end of fermentation. This work highlights the feasibility of using DGW as a promising feedstock for butanol production by a new aerotolerant strain of C. beijerinckii LY-5, with benefit to the environment. [ABSTRACT FROM AUTHOR]

Afforestation can greatly affect soil enzymes which are tightly associated with soil nutrient cycling. However, the spatial variations in enzyme activity (EA) in plantation forests and the underlying mechanisms are not well understood. The main goal of this study was to determine how the drivers including the biotic (for example, plant traits and microbial properties) and abiotic factors (for example, soil properties) best regulate spatial variations in EA (β-glucosidase, leucine aminopeptidase and acid phosphatase) in three selected sites [woodland, shrubland and adjacent open areas (that is, control)] in Central China. Specifically, we tried to determine: (1) whether the drivers of EA variations vary between woodland and shrubland sites at the plot scale (100 m2) and (2) whether the drivers vary depending on the presence of tree patch (tree patch microplot vs. open-interpatch microplot) at the microplot scale (1 m2) within sites. A spatially nested sampling was conducted within each site via a series of partial Mantel tests to examine the correlations between EA and the environmental factors. For each site, similar spatial distribution trends were observed for the three kinds of enzymes at the plot scale. Our results showed that the tree distribution-induced shifts in litter and root biomass, soil pH and microbial community structure primarily controlled the spatial variations in EA. Specifically, soil EA was significantly correlated with litter and root biomass in the woodland site at the plot scale and primarily dependent on soil pH and microbial properties in the shrubland site. In contrast, the drivers of EA variations at the microplot scale are inconsistent between the tree patch microplot and the interpatch microplot within sites. Additionally, soil EA was not correlated with any factor in the open area. Taken together, our results reveal a shift in drivers of EA under afforestation and a profound impact of tree patch on these drivers at the plot scale. [ABSTRACT FROM AUTHOR]

Salicylic acid (SA) and hydrogen sulfide (H2S) have been proved to be multifunctional signal molecules to participate in the response of plants to abiotic stresses. However, it is still unclear whether there is interaction between SA and H2S in response to chilling intensity of cucumber seedlings. Here, we found SA was sensitive to chilling intensity. Under normal condition, NaHS (H2S donor) or removing endogenous H2S with hypotaurine (HT, a specific scavenger of H2S) and DL-propargylglycine (PAG, a specific inhibitor of H2S) has no effect on endogenous SA level; however, SA induced endogenous H2S content and activated the activities and mRNA level of l-/d-cysteine desulfhydrase (l-/d-CD), and inhibiting endogenous SA with paclobutrazol (PAC) or 2-aminoindan-2-phosphonic acid (AIP) blocked this effect, implying H2S may play a role after SA signal. Further studies showed that both SA and NaHS notably alleviated chilling injury, which was evidenced by lower electrolyte leakage (EL), MDA content, and ROS accumulation, compared with H2O treatment. Of note, SA and H2S improved the activities and mRNA level of antioxidant enzymes (SOD, POD, CAT, APX, and GR) as well as the contents of AsA and GSH. Additionally, the chilling-response genes (ICE, CBF1, and COR) were obviously upregulated by exogenous SA and NaHS. However, the positive effect of SA on chilling tolerance was inhibited by HT, whereas PAC or AIP did not affect NaHS-induced chilling tolerance. Taken together, the data reveals that H2S acts as a downstream signal of SA-induced chilling tolerance of cucumber via modulating antioxidant system and chilling-response genes. [ABSTRACT FROM AUTHOR]

In this study, we analyzed the geological, gravity, magnetic, and electrical characteristics of depressions in the Erlian Basin. Based on the results of these analyses, we could identify four combined feature parameters showing strong correlations and sensibilities to the reservoir oil-bearing conditions: the average residual gravity anomaly, the average magnetic anomaly, the average depth of the conductive key layer, and the average elevation of the depressions. The feature parameters of the 65 depressions distributed in the whole basin were statistically analyzed: each of them showed a Gaussian distribution and had the basis of Bayesian theory. Our Bayesian predictions allowed the definition of a formula to calculate the posterior probability of oil occurrence in the depressions based on the combined characteristic parameters. The feasibility of this prediction method was verified by considering the results obtained for the 22 drilled depressions. Subsequently, we were able to determine the oil-bearing threshold of hydrocarbon potential for the depressions in the Erlian Basin, which can be used as a standard for quantitative optimizations. Finally, the proposed prediction method was used to calculate the probability of hydrocarbons in the other 43 depressions. Based on this probability and on the oil-bearing threshold, the five depressions with the highest potential were selected as targets for future seismic explorations and drilling. We conclude that the proposed method, which makes full use of massive gravity, magnetic, electric, and geological data, is fast, effective, and allows quantitative optimizations; hence, it will be of great value for the comprehensive geophysical evaluation of oil and gas in basins with depression group characteristics. [ABSTRACT FROM AUTHOR]

Aims: Secondary grasslands reestablished after deforestation in subtropical and tropical regions greatly alter terrestrial carbon (C) and nitrogen (N) dynamics and their associated ecosystem functions. However, reliable evaluations of C and N dynamics in secondary grasslands across regional climatic gradient remain challenging. Methods: We investigated natural 13C and 15N abundance in plants and soil as well as their associations with environmental factors (including climatic, plant and edaphic variables) from 20 sites across a 600 km climatic gradient in secondary grasslands of southern China. Results: The δ13C values in plants and soil declined with increasing mean annual precipitation (MAP) but increased as the mean annual temperature (MAT) increased. These changes were mostly attributed to the shift in plant functional group between C4 and C3. In contrast, increasing MAP and decreasing MAT had positive effects on soil δ15N values, which were mainly related to changes in edaphic factors, including soil pH, soil C and N content and soil C:N ratios. Conclusions: Our findings indicate inverse patterns and different controls on soil δ13C and δ15N values along the climatic gradient, providing novel insights into the underlying mechanisms of ecosystem C and N dynamics in response to climate and vegetation change in secondary grasslands. [ABSTRACT FROM AUTHOR]

In order to realize the compressive stress and antifatigue manufacturing of titanium alloy TI-6Al-4V, a compound processing of longitudinal-torsional ultrasonic vibration and milling (LTUM) is proposed, a theoretical prediction model of machining-induced residual stress (RS) is established, and it is validated by experiments. The trajectory model of cutting edge in LTUM is constructed; furthermore, the undeformed chip thickness (UCT) model of LTUM is structured; The mechanical stress model of LTUM is established from the shear stress and plow stress; the thermal stress model of LTUM is established from shear thermal stress and plow thermal stress; Considering mechanical and thermal stress, the residual stress of longitudinal-torsional ultrasonic milling is established by loading and releasing stress. From numerical simulation of mechanical stress and thermal stress model, it shows that in LTUM, stress fluctuates with ultrasonic vibration, and mechanical stress absolute value is larger than that of traditional machining (TM); thermal stress absolute value is less than that of TM. A series of experiments are carried out to verify the RS model of LTUM. From present work, through theoretical prediction and experimental verification of machining-induced residual stress, it is concluded that established theoretical model predicts properties, and distribution of residual stress with high accuracy and the LTUM significantly increases surface compressive stress and compressive stress layer depth. It lays a foundation for the compressive stress and fatigue resistance of titanium alloys. [ABSTRACT FROM AUTHOR]

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The effect of flooding on soil enzyme activities and soil organic carbon (SOC) dynamics remains a widely debated topic. Here, we investigated spatial variations in C-hydrolyzing enzyme activities, soil C contents in different fractions [i.e. labile and recalcitrant carbon (LC and RC)] from 6 sites with four different elevations at two soil depths (0–10 cm and 10–30 cm) in riparian zones of the Three Gorges Reservoir, China. At region scales, the SOC, RC contents, and RC/SOC (RIC) generally showed decreasing tendency from the upstream to the downstream. The C-hydrolyzing enzyme activities were higher in the midstream compared to other sites, which did not correspond well with the changing trend of SOC content, but matched with the spatial variation in LC content. At ecosystem scales, the RC and RIC declined with decreased elevations, but the LC showed opposite trend. Whereas, the four C-hydrolyzing enzyme activities and the specific enzyme activities were corresponded well with the changing trend of LC content. Soil C contents and enzyme activities were generally higher in top soil than deep soil across sites and elevation zones. These results reveal that the LC is the tightest factor in regulating C-hydrolyzing enzyme activities, whereas the soil C quality (i.e. RIC) and flooding collectively drive C-hydrolyzing enzyme activities possibly by affecting decomposition rates of SOC in the riparian zones. [ABSTRACT FROM AUTHOR]

Traditional network MIMO systems with joint data processing usually require a large amount of backhaul data and a central processing station with very high processing power. In order to address this problem, the capacity of access network with network-enabled MIMO systems with distributed data processing is investigated in this paper. A study of network throughput for a system with interference mitigation and base station cooperation techniques is given. We also propose a distributed iterative decoding network structure as an alternative of joint detection/decoding scheme with network-enabled MIMO configurations, where iterative signal processing is performed at network level. Simulation results show that, with the proposed schemes, the complexity of data processing required to compute the detection solution is restricted and the complexity is distributed across access base stations, which results in a significant reduction in complexity of signal processing in hub base stations. [ABSTRACT FROM AUTHOR]

Soil labile and recalcitrant carbon (C) and nitrogen (N) are strongly controlled by plant inputs and climatic conditions. However, the interrelation of labile and recalcitrant pools with changes in plant functional groups (i.e., C3 and C4) along precipitation gradients is not fully understood. Here, we investigated the soil organic C and N (SOC and SON), labile C and N (LC and LN), recalcitrant C and N (RC and RN), and their isotopes (δ13C, and δ15N) in relation to C3 and C4 plant inputs from 20 sites across a 600-km precipitation gradient in secondary grasslands of South China. The SOC content decreased first slightly and then increased along precipitation gradients, largely due to the increase in C4 plant C inputs in the lower precipitation regions. In contrast, the SON content increased with increasing N inputs from C3 plant at higher precipitation regions. The LC and LN contents increased with increasing precipitation, whereas RC and RN did not change with precipitation. The LC and LN were correlated with plant C and N contents, as well as the mean annual precipitation, respectively. Increases in LC and LN stocks were tightly related to enhanced plant C and N inputs influenced by precipitation, suggesting stronger sensitivity of labile pools to both plant functional groups inputs and precipitation compared to the recalcitrant pool. Moreover, the δ13C values in RC declined with precipitation, while the δ15N values of both labile and recalcitrant N increased with increasing precipitation, further revealing that soil labile and recalcitrant C and N pools closely related to the shift in the C3 and C4 plant along precipitation gradients. Overall, our findings indicated that soil labile and recalcitrant fractions should be considered in context of precipitation under which plant inputs takes place in predicting soil C and N dynamics. [ABSTRACT FROM AUTHOR]

Main conclusion: This report proves a cross talk between H2S and IAA in cold stress response, which has presented strong evidence that IAA acts as a downstream signal mediating the H2S-induced stress tolerance in cucumber seedlings. We evaluated changes in endogenous hydrogen sulfide (H2S) and indole-3-acetic acid (IAA) emission systems, and the interactive effect of exogenous H2S and IAA on chilling tolerance in cucumber seedlings. The results showed that chilling stress increased the activity and relative mRNA expression of l-/d-cysteine desulfhydrase (l-/d-CD), which in turn induced the accumulation of endogenous H2S. Similarly, the endogenous IAA system was triggered by chilling stress. We found that 1.0 mM sodium hydrosulfide (NaHS, an H2S donor) significantly enhanced the activity of flavin monooxygenase (FMO) and relative expression of FMO-like proteins (YUCCA2), which in turn elevated endogenous IAA levels in cucumber seedlings. However, IAA had little effects on activities of l-/d-CD and endogenous H2S levels. H2S-induced IAA production accompanied by increase in chilling tolerance, as shown by the decrease in stress-induced electrolyte leakage (EL) and reactive oxygen species (ROS) accumulation, and increase in gene expressions and enzyme activities of photosynthesis. 1-naphthylphthalamic acid (NPA, an IAA polar transport inhibitor) declined H2S-induced chilling tolerance and defense genes’ expression. However, scavenging of H2S had a little effect on IAA-induced chilling tolerance. These results suggest that IAA acting as a downstream signaling molecule is involved in the H2S-induced chilling tolerance in cucumber seedlings. [ABSTRACT FROM AUTHOR]

For difficult-to-cut materials such as titanium alloy, a machining method of longitudinal-torsion ultrasonic-assisted milling (LTUM) was put forward to realize the anti-fatigue manufacturing, and cutting force, cutting temperature and residual stress (RS) were analyzed by 3D finite element simulation (FES). Firstly, based on thermal mechanical coupling, a 3D FES model of ultrasonic milling was established, the simulation of the cutting force, cutting temperature and RS were realized. Then, based on the 3D FES milling model, the milling process was equivalent to the oblique cutting model, it effectively improved the computation efficiency and realized longitudinal-torsional ultrasonic compound in milling process. Base on 3D equivalent model, compared with traditional milling (TM) and LTUM from the cutting force, cutting temperature and machined-induced RS. It is concluded that the LTUM effectively reduces the cutting force and cutting temperature, increases surface compressive stress and compressive stress layer depth. Furthermore, experiments were carried out to verify the equivalent model of LTUM, it shows that the simulated results are in agreement with experimental results, and predicts cutting force, cutting temperature and RS with high precision. [ABSTRACT FROM AUTHOR]

Background and aims: Variations in plant nitrogen (N) and phosphorus (P) concentrations and ratios have great implications for primary productivity and nutrient cycling. Here, we reported their changes at functional group and community levels along an aridity gradient. Methods: We carried out a field investigation and set up 26 sampling sites along a transect in the drylands of northern China to examine the responses of plant nutrient status to increasing aridity and the relationships between plant and soil nutrients. Results: The responses of N and P concentrations to increasing aridity differed between woody (sub-) shrubs and herbaceous species (including annual/biennial forbs and grasses, perennial forbs and perennial grasses). Nitrogen and P concentrations of shrubs decreased while those of herbs generally increased with increasing aridity. Plant N:P ratios increased significantly with increasing aridity for the plant functional groups and at the community level. At both organizational levels, nutrient concentrations in plants were negatively related to those in soils. Conclusion: Our results indicated that the responses of plant nutrition to aridity were dependent on plant functional group. Plant growth appeared increasingly limited by P, and plant and soil nutrients become increasingly decoupled at large spatial scale with increasing aridity. [ABSTRACT FROM AUTHOR]

A feature of the Internet of Things (IoT) is that the data demanded users in the system need to be served with low energy consumption. To address this requirement, multi-input multi-output (MIMO) technology can be used in the communication modules. In this paper, a novel low-complexity parameter estimator combined with an MMSE detector and a constellation distance correction (CDC) structure is proposed for multiple antenna systems. A hard-output detector is proposed to enhance the reliability of the estimation output. By measuring the distance between constellation candidates and the MMSE estimated soft output, the proposed equalizer may avoid processing redundancy of candidates with decision distance. Simulation results show that the proposed MMSE-CDC technique may provide about the same BER performance as the other post detection processing (PDP) techniques but requires significant less computational complexity. [ABSTRACT FROM AUTHOR]

1,5-Pentamethylene diisocyanate, a novel aliphatic diisocyanate formed from bio-based 1,5-pentamethylenediamine, has been used as a hard segmented material to synthesize polyurethane. In this study, several waterborne polyurethane (WPU) dispersions have been successfully prepared by a prepolymer process from 1,5- pentamethylene diisocyanate poly(polyether) with different NCO/OH ratios and 1,6-hexanediol (HDO)/dimethylol propionic acid (DMPA) molar ratios. The Fourier transform infrared (FTIR) spectra, thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction, and a mechanical tensile test were used to investigate the structures, thermal stability, phase separation, crystallinity, mechanical properties, and adhesive performance of the WPU dispersions. The FTIR results indicate that the degree of hydrogen bonding and the numbers of urea groups increase as the NCO/OH ratio and HDO/DMPA molar ratio increase. Furthermore, the phase separation increases and the thermal stability decreases as the NCO/OH ratio increases or the HDO/DMPA molar ratio decreases. Finally, WPU3.0-2.4 (NCO/OH = 3, HDO/DMPA = 2.4) exhibits a maximum tensile strength and shear strength, pointing to its possible use as an adhesive. These results could provide a very valuable reference for industrial applications of WPU. [ABSTRACT FROM AUTHOR]

The selection of a suitable reference gene is an important prerequisite for the precise analysis of target gene expression by real-time quantitative PCR (qPCR). The present study aims to explore the expression pattern of the Macrobrachium nipponense (M. nipponense) β-actin gene under Aeromonas hydrophila bacterial infection conditions. The complete sequence of the β-actin gene from M. nipponense was cloned by PCR. Identified and named β-actin genes were searched in the NCBI database, and the characteristics of the β-actin gene were analyzed using bioinformatics methods. The expression profiles of β-actin under stresses challenged by bacteria after 3, 6, 12, 24 and 48 h were investigated by measuring Ct values by qPCR. The prokaryotic expression vector pET-30a-actin was constructed by PCR and recombinant DNA techniques. Fused protein was induced by IPTG in the transformed Escherichia coli BL21 (DE3). Recombinant rActin was purified by nickel column. The bioinformatics analysis result revealed that the deduced protein encoded by the β-actin gene from M. nipponense had the highest homology with other prawns in the homologous assay (99%). The phylogenetic tree indicates that the β-actin from M. nipponense and other crustaceans have a single cluster. The qPCR results revealed that a stable expression of β-actin was observed in response to the A. hydrophila challenge for 3-48 h, and the Ct value was 22 ± 1.5. β-actin was ranked as a stable gene after the bacterial challenge, which was selected as the appropriate reference gene in M. nipponense. [ABSTRACT FROM AUTHOR]

ChKRED20 is an efficient and robust anti-Prelog ketoreductase that can catalyze the reduction of ketones to chiral alcohols as pharmaceutical intermediates with great industrial potential. To overcome its limitation on the bioreduction of ortho-substituted acetophenone derivatives, the X-ray crystal structure of the apo-enzyme of ChKRED20 was determined at a resolution of 1.85 Å and applied to the molecular modeling and reshaping of the catalytic cavity via three rounds of iterative saturation mutagenesis together with alanine scanning and recombination. The mutant Mut3B was achieved with expanded catalytic scope that covered all the nine substrates tested as compared with two substrates for the wild type. It exhibited 13-20-fold elevated k / K values relative to the wild type or to the first gain-of-activity mutant, while retaining excellent stereoselectivity toward seven of the substrates (98-> 99% ee). Another mutant 29G10 displayed complementary selectivity for eight of the ortho-substituted acetophenone derivatives, with six of them delivering excellent stereoselectivity (90-99% ee). Its k / K value toward 1-(2-fluorophenyl)ethanone was 5.6-fold of the wild type. The application of Mut3B in elevated substrate concentrations of 50-100 g/l was demonstrated in 50-ml reactions, achieving 75-> 99% conversion and > 99% ee. [ABSTRACT FROM AUTHOR]

Background: Genistein is a natural isoflavone with many health benefits, including antitumour effects. Increased hypoxia-inducible factor 1 α (HIF-1α) levels and glycolysis in tumour cells are associated with an increased risk of mortality, cancer progression, and resistance to therapy. However, the effect of genistein on HIF-1α and glycolysis in hepatocellular carcinoma (HCC) is still unclear.Methods: Cell viability, apoptosis rate, lactate production, and glucose uptake were measured in HCC cell lines with genistein incubation. Lentivirus-expressed glucose transporter 1 (GLUT1) or/and hexokinase 2 (HK2) and siRNA of HIF-1α were used to test the direct target of genistein. Subcutaneous xenograft mouse models were used to measure in vivo efficacy of genistein and its combination with sorafenib.Results: Genistein inhibited aerobic glycolysis and induced mitochondrial apoptosis in HCC cells. Neither inhibitors nor overexpression of HK2 or GLUTs enhance or alleviate this effect. Although stabiliser of HIF-1α reversed the effect of genistein, genistein no longer has effects on HIF-1α siRNA knockdown HCC cells. In addition, genistein enhanced the antitumour effect of sorafenib in sorafenib-resistant HCC cells and HCC-bearing mice.Conclusions: Genistein sensitised aerobic glycolytic HCC cells to apoptosis by directly downregulating HIF-1α, therefore inactivating GLUT1 and HK2 to suppress aerobic glycolysis. The inhibitory effect of genistein on tumour cell growth and glycolysis may help identify effective treatments for HCC patients at advanced stages. [ABSTRACT FROM AUTHOR]

Aims: Soil organic nitrogen (N) turnover is significantly influenced by elevated N deposition, precipitation and human-caused disturbances, but the underlying mechanism remains unclear. Identifying the relationships among the soil organic N fractions and N-mineralizing enzymes activities may advance our knowledge of the dynamics of soil organic N. Methods: A field experiment was conducted in a semi-arid steppe and an abandoned cropland in northern China to investigate the effects of elevated N deposition and precipitation on soil organic N fractions and their relationships with N-mineralizing enzymes, i.e., protease, amidase, urease and N-acetyl-β-D-glucosaminidase (NAG) activities. Results: The concentrations of N in various fractions were consistently lower in the abandoned cropland compared with the steppe. Nitrogen addition consistently decreased amino acid N content and activities of urease, protease and amidase in both sites but increased amino sugar N content and NAG activity in the steppe. Water addition decreased hydrolysable ammonium N content but increased amino sugar N content and activities of protease and NAG in both sites. Furthermore, urease and NAG activities were significantly positively correlated with the proportions of amino acid N and amino sugar N and, explained significant proportions of the variations in soil organic N fractions in the steppe. However, soil organic carbon (C), rather than N-mineralizing enzymes, explained greatest proportion of the variations in soil organic N fractions in the abandoned cropland. Conclusions: The concurrent increase of N deposition and precipitation could promote the recovery of soil N (and C) losses in the abandoned cropland resulting from previous agriculture. Furthermore, in the steppe where NH was available at relative high concentrations, enzymatic mineralization was the dominant route involved in potential soil organic N turnover. However, the direct route may be favored over the enzymatic mineralization route with decreasing availability of C relative to N in the abandoned cropland, which is driven by the need for C. These findings confirmed that the forms of N available, and the relative availability of C and N determine N uptake pathways both through enzymatic mineralization route and direct uptake route in the semi-arid grasslands. [ABSTRACT FROM AUTHOR]

(1 S)-2-chloro-1-(3, 4-difluorophenyl) ethanol (( S)-CFPL) is an intermediate for the drug ticagrelor, and is manufactured via chemical approaches. To develop a biocatalytic solution to ( S)-CFPL, an inventory of ketoreductases from Chryseobacterium sp. CA49 were rescreened, and ChKRED20 was found to catalyze the reduction of the ketone precursor with excellent stereoselectivity (>99 % ee). After screening an error-prone PCR library of the wild-type ChKRED20, two mutants, each bearing a single amino acid substitution of H145L or L205M, were identified with significantly increased activity. Then, the two critical positions were each randomized by constructing saturation mutagenesis libraries, which delivered several mutants with further enhanced activity. Among them, the mutant L205A was the best performer with a specific activity of 178 μmol/min/mg, ten times of that of the wild-type. Its k / K increased by 15 times and half-life at 50 °C increased by 70 %. The mutant catalyzed the complete conversion of 150 and 200 g/l substrate within 6 and 20 h, respectively, to yield enantiopure ( S)-CFPL with an isolated yield of 95 %. [ABSTRACT FROM AUTHOR]

We demonstrate a quantum dash quantum cascade photodetector (QDash-QCD) by incorporating self-assembled InAs quantum dashes into the active region of a long wave infrared QCD. Sensitive photoresponse to normal incident light at 10 μm was observed, which is attributed to the intersubband (ISB) transitions in the quantum well/quantum dash (QW/QDash) hybrid absorption region and the following transfer of excited electrons on the extraction stair-like quantum levels separated by LO-phonon energy. The high density InAs quantum dashes were formed in the Stranski-Krastanow mode and stair-like levels were formed by a lattice matched InGaAs/InAlAs superlattice. A stable responsivity from 5 mA/W at 77 K to 3 mA/W at as high as 190 K was observed, which makes the QDash-QCD promising in high temperature operation. [ABSTRACT FROM AUTHOR]

Obtainment and characterization of the novel endosperm callus of Taxus chinensis Rehd. var. mairei are valuable for haploid breeding, genome, and functional genome in Taxus. Callus was obtained by hydropriming with sterile water for 3 days and suitable medium composition. The highest callus induction (70.89 %) and lower browning ratio (7.95 %) were obtained from Gamborg (B) medium supplemented with 30 g l of sucrose, 2.5 mg l of 2,4-dichlorophenoxyacetic (2,4-D), 0.5 mg l of 6-benzylademine (6-BA) and 7 g l of agar under dark conditions. The auxin of 2,4-D had a better efficiency of callus induction than naphthylacetic acid, and over 1 mg l of 6-BA was inhibitory to the callogensis of endosperm. The endosperm callus was haploid which was detectable by the flow cytometry. The genome block of homozygosity of callus was homozygous which was indicated by PCR-based SNP marks. The homozygous haploid of endosperm callus in vitro culture may be useful tools for taxoid-metabolism of gene engineering and bio-fermentation engineering. [ABSTRACT FROM AUTHOR]

Ethyl ( S)-4-chloro-3-hydroxybutanoate (( S)-CHBE) is an important chiral intermediate for the synthesis of 'blockbuster' drug statins. The carbonyl reductase ChKRED20 from Chryseobacterium sp. CA49 was found to catalyze the bio-reductive production of ( S)-CHBE with excellent stereoselectivity (>99.5 % ee). Perceiving a capacity for improvement, we sought to increase the thermostability of ChKRED20 to allow a higher reaction temperature. After one round of error-prone PCR (epPCR) library screening followed by the combination of beneficial mutations, a triple-mutant MC135 was successfully achieved with substantially enhanced thermostablity. The activity of MC135 at 50 °C was similar to the wild type. However, at its temperature optima of 65 °C, the mutant displayed 63 % increase of activity compared to the wild type and remained >95 % activity after being incubated for 15 days, while the wild type had a half-life of 11.9 min at 65 °C. At a substrate/catalyst ratio of 100 ( w/ w), the mutant catalyzed the complete conversion of 300 g/l substrate within 1 h to yield enantiopure ( S)-CHBE with an isolated yield of 95 %, corresponding to a space-time yield of 1824 mM/h. [ABSTRACT FROM AUTHOR]

How climatic factors influence the balance of sulfur (S) with carbon (C) and nitrogen (N) in soils is not well understood. Here we report the results of S, C and N concentrations in 550 soil samples along a 3500-km aridity gradient across arid and semi-arid grasslands in northern China. Our results showed that soil available S (AS) concentrations decreased with increasing aridity index (AI, calculated as '1-the ratio of mean annual precipitation to potential evapotranspiration') when AI < 0.91 (90-450 mm rainfall year), but increased when AI > 0.91 (30-90 mm rainfall year), having a threshold at AI = 0.91 (90 mm rainfall year). Soil AS concentrations were positively related to soil organic C (OC), soil total N (TN), microbial biomass C and N concentrations, and arylsulphatase activities when AI < 0.91, but were not positively related to these variables when AI > 0.91. Topsoil AS:OC and AS:TN ratios mainly depended on OC and TN concentrations when AI < 0.91, but mainly depended on AS concentrations when AI > 0.91. The decreased (AI < 0.91) and increased total S concentrations (AI > 0.91) with increasing AI along the gradient provided further evidence for the existence of this fundamental threshold. High concentrations of sulfate in drier soils were associated with long-term atmosphere inputs and groundwater-derived salts with minimal leaching rates. Overall, our findings imply that aridity asymmetrically controls the relationships of soil AS with OC and TN on the two sides of the threshold, i.e. biological processes exerted stronger controls in wetter sites, while geochemical processes played more significant roles in drier sites. These results should be incorporated into predictive models of global biogeochemical cycling under various global climate change scenarios. [ABSTRACT FROM AUTHOR]

The blends of polylactide (PLA) and poly(ethylene glycol) (PEG) with different contents (0, 5, 10, 15, and 20 wt%) and molecular weights ( $$ \overline{M}_{w} $$ 6000, 10,000 and 20,000, called respectively as PEG 6000, PEG 10,000, and PEG 20,000) were prepared by means of melt blending method. The effects of tensile speed, content and molecular weight of the PEG on the tensile properties of the PLA/PEG blends were investigated using a universal testing machine at 24 °C. With increasing tensile speed, the tensile modulus, strength and stress at break of the PLA/PEG blends marginally increased, while the tensile modulus and stress at break declined non-linearly, and the tensile strength dropped nearly linearly with increasing PEG 10,000 content. When the PEG 10,000 content was 5-15 wt%, the tensile strain at break of the PLA/PEG 10,000 blend markedly increased, and then decreased as the PEG 10,000 content exceeded 15 wt%. With increasing the molecular weight of PEG, tensile modulus and strength increased, whereas the tensile strain at break decreased. This showed that the application of right amount of lower molecular weight PEG was more conducive to improving the tensile toughness of the PLA/PEG blends, which was attributed to its better miscibility with PLA and increased mobility of PLA molecular chains. [ABSTRACT FROM AUTHOR]

Although research on microorganisms in the global ecosystem has considerably increased, there is still incomplete understanding of the microbial communities in alpine permafrost due to the inaccessibility. In this study, the microbial composition and diversity in the continuous permafrost beside the bitumen in the Qiangtang basin (CPBQ) was investigated by 454 pyrosequencing. Among the bacterial communities, the phylum Actinobacteria was dominant, ranging from 33.42 to 48.04 %, followed by Proteobacteria and Acidobacteria. In addition to the three characteristic phyla, Planctomycetes, Chloroflexi, and Nitrospirae were also important in the CPBQ. Crenarchaeota, especially the ammonia-oxidizing archaea Soil Crenarchaeotic Group (SCG), was the main archaea in the CPBQ. Moreover, four fungal phyla, Ascomycota, Mucoromycotina, Chytridiomycota and Glomeromycota, were detected in the CPBQ. Mortierella, Fusarium, and Tetracladium were the main genera. On the average, the proportion of No_rank and unclassified sequences in bacteria and fungi were high at low taxonomic levels, which could extend the list of extreme environmental microbial candidate divisions. The demonstrations of the microbial communities in the CPBQ could provide key data to improve the knowledge of microbes in the terrestrial extreme environments. [ABSTRACT FROM AUTHOR]