Plant growth strategies and microbial contributions to ecosystem nitrogen retention along a soil acidification gradient.

Nitrogen (N) retention is a critical ecosystem function associated with sustainable N supply. Lack of experimental evidence limits our understanding of how grassland N retention can vary with soil acidification. A N-labeling experiment was conducted for 2 years to quantify N retention by soil pathways and plant functional groups across a soil-acidification gradient in a meadow.

Differential responses of soil phosphorus fractions to varied nitrogen compound additions in a meadow steppe.

Nitrogen (N) addition can greatly influence soil inorganic phosphorus (Pi) and organic phosphorus (Po) transformations. However, whether and how the N compound forms may differentially affect the soil P fractions remain unclear. Here, we investigated the responses of soil Pi (labile Pi, moderately-occluded Pi, and recalcitrant Pi) and Po fractions (labile Po and stable Po) to varying addition rates of three N compounds ((NH)SO, NHNO, and urea) in a meadow steppe in northern China.

Mowing aggravates the adverse effects of nitrogen addition on soil acid neutralizing capacity in a meadow steppe.

Soil acidification induced by reactive nitrogen (N) inputs is a major environmental issue in grasslands, as it lowers the acid neutralizing capacity (ANC). The specific impacts of different N compound forms on ANC remain unclear. Grassland management practices like mowing and grazing can remove a considerable amount of soil N and other nutrients, potentially mitigating soil acidification by removing N from the ecosystem or aggravating it by removing base cations.

Nitrogen addition alleviates the adverse effects of drought on plant productivity in a temperate steppe.

Drought and nitrogen enrichment could profoundly affect the productivity of semiarid ecosystems. However, how ecosystem productivity will respond to different drought scenarios, especially with a concurrent increase in nitrogen availability, is still poorly understood. Using data from a 4-year field experiment conducted in a semiarid temperate steppe, we explored the responses of aboveground net primary productivity (ANPP) to different drought scenarios and nitrogen addition, and the underlying mechanisms linking soil properties, plant species richness, functional diversity (community-weighted means of plant traits, functional dispersion) and phylogenetic diversity (net relatedness index) to ANPP.

Decoupled responses of above- and below-ground beta-diversity to nitrogen enrichment in a typical steppe.

Increased atmospheric nitrogen (N) deposition affects biodiversity in terrestrial ecosystems. However, we do not know whether the effects of N on above-ground plant β-diversity are coupled with changes occurring in the soil seed bank. We conducted a long-term N-addition experiment in a typical steppe and found that above-ground β-diversity increased and then decreased with increasing N addition, whereas below-ground β-diversity decreased linearly.

Applied phosphorus is maintained in labile and moderately occluded fractions in a typical meadow steppe with the addition of multiple nutrients.

Phosphorus (P) is a limiting nutrient second only to nitrogen (N) in the drylands of the world. Most previous studies have focused on N transformation processes in grassland ecosystems, particularly under artificial fertilization with N and atmospheric N deposition. However, P cycling processes under natural conditions and when P is applied as an inorganic P fertilizer have been understudied.

Nitrogen addition and mowing alter drought resistance and recovery of grassland communities.

Nitrogen enrichment and land use are known to influence various ecosystems, but how these anthropogenic changes influence community and ecosystem responses to disturbance remains poorly understood. Here we investigated the effects of increased nitrogen input and mowing on the resistance and recovery of temperate semiarid grassland experiencing a three-year drought. Nitrogen addition increased grassland biomass recovery but decreased structural recovery after drought, whereas annual mowing increased grassland biomass recovery and structural recovery but reduced structural resistance to drought.

Using leaf traits to explain species co-existence and its consequences for primary productivity across a forest-steppe ecotone.

Trait-based approaches have been widely applied to uncover the mechanisms determining community assembly and biodiversity-ecosystem functioning relationships. However, they have rarely been used in forest-steppe ecotones. These ecosystems are extremely sensitive to disturbances due to their relatively complex ecosystem structures, functionings and processes.

[Changes of persistent soil seed bank along a precipitation gradient in forest-steppe ecotone].

This study aimed to examine the responses of persistent soil seed bank to future precipitation reduction of global climate change in the forest-steppe ecotone of Hulunbuir. Samples of soil seed bank were collected from 0-10 cm soil layer along a precipitation gradient. We examined the density, species composition, diversity of seed bank and their relationship with vegetation.

[Changes of non-structural carbohydrates and nitrogen contents of needles and twigs in var. plantations along an aridity gradient].

With six var. plantations (Huinan, Xifeng, Fujia, Zhanggutai, Naiman and Wulanaodu) along an aridity gradient in the Horqin sandy land, we examined the changes in non-structural carbohydrates (NSCs) and nitrogen (N) contents of current and one-year-old needles and twigs, to explore the carbon supply and demand status as well as the nutrient accumulation strategies of var. under drought.

[Effects of nutrient and water addition on soil inorganic phosphorus fractions in an old-field grassland].

Reasonable nutrient and water management is effective ways to improve productivity and biodiversity of degraded grasslands. However, little is known about the effects of nutrient and water addition on soil inorganic phosphorus (P) fractions in old-field grasslands. Based on a field experiment with nutrient addition (N: 10 g·m·a, P: 10 g·m·a ) and water addition (180 mm water irrigated during plant growing season) in Duolun County, Inner Mongolia in 2005, we examined the changes of inorganic P fractions and Olsen-P contents in the topsoil (0-10 cm).

Nitrogen enrichment buffers phosphorus limitation by mobilizing mineral-bound soil phosphorus in grasslands.

Phosphorus (P) limitation is expected to increase due to nitrogen (N)-induced terrestrial eutrophication, although most soils contain large P pools immobilized in minerals (P ) and organic matter (P ). Here we assessed whether transformations of these P pools could increase plant available pools alleviating P limitation under enhanced N availability. The mechanisms underlying these possible transformations were explored by combining results from a 10-year field N addition experiment and a 3700-km transect covering wide ranges in soil pH, soil N, aridity, leaching, and weathering that could affect soil P status in grasslands.

A new approach to the treatment of nontuberculous mycobacterium skin infections caused by iatrogenic manipulation: Photodynamic therapy combined with antibiotics: A pilot study.

Background: Recently, the number of nontuberculous mycobacterium (NTM) infections caused by iatrogenic procedures, especially rapid NTM skin infections, has been increasing. Due to the nonspecific clinical manifestations and nonstandard treatment guidelines, these infections are often misdiagnosed and challenging to treat.

Methods: In this study, eight patients had NTM skin infections caused by iatrogenic procedures, and were diagnosed by bacterial culture and flight mass spectrometry tests.

Effects of nitrogen addition on plant-soil micronutrients vary with nitrogen form and mowing management in a meadow steppe.

Nitrogen (N) addition and mowing can significantly influence micronutrient cycling in grassland ecosystems. It remains largely unknown about how different forms of added N affect micronutrient status in plant-soil systems. We examined the effects of different N compounds of (NH)SO, NHNO, and urea with and without mowing on micronutrient Fe, Mn, Cu, and Zn in soil-plant systems in a meadow steppe.

Natural abundance of C and N provides evidence for plant-soil carbon and nitrogen dynamics in a N-fertilized meadow.

Natural abundance of carbon (C) and nitrogen (N) stable isotope ratios (δ C and δ N) has been used to indicate ecosystem C and N status and cycling; however, use of this approach to infer plant and microbial N preference under projected ecosystem N enrichment is limited. Here, we investigated natural abundance δ C and δ N of five dominant plant species, and soil δ N of microbial biomass and available N forms under N addition in a meadow steppe. Additional N, applied as urea, led to decreases in δ N of soil NO (δ N , from 3.

Intensity and frequency of nitrogen addition alter soil chemical properties depending on mowing management in a temperate steppe.

Anthropogenic nitrogen (N) enrichment can significantly alter soil chemical properties in various ecosystems. Previous manipulative N experiments mainly focused on the intensity of N addition on soil properties by changing N input rates. It remains unclear, however, whether frequency of N addition can affect soil chemical properties.

Effects of nitrogen and water addition on trace element stoichiometry in five grassland species.

A 9-year manipulative experiment with nitrogen (N) and water addition, simulating increasing N deposition and changing precipitation regime, was conducted to investigate the bioavailability of trace elements, iron (Fe), manganese (Mn), copper (Cu), and zinc (Zn) in soil, and their uptake by plants under the two environmental change factors in a semi-arid grassland of Inner Mongolia. We measured concentrations of trace elements in soil and in foliage of five common herbaceous species including 3 forbs and 2 grasses. In addition, bioaccumulation factors (BAF, the ratio of the chemical concentration in the organism and the chemical concentration in the growth substrate) and foliar Fe:Mn ratio in each plant was calculated.

Glucose deprivation induces chemoresistance in colorectal cancer cells by increasing ATF4 expression.

Aim: To investigate the role of activating transcription factor 4 (ATF4) in glucose deprivation (GD) induced colorectal cancer (CRC) drug resistance and the mechanism involved.

Methods: Chemosensitivity and apoptosis were measured under the GD condition. Inhibition of ATF4 using short hairpin RNA in CRC cells under the GD condition and in ATF4-overexpressing CRC cells was performed to identify the role of ATF4 in the GD induced chemoresistance.

miR-139-5p sensitizes colorectal cancer cells to 5-fluorouracil by targeting NOTCH-1.

Multidrug resistance (MDR), a phenomenon that often occurs with drug treatment and is characterized by relapse or attenuation of drug efficacy, is almost unavoidable in colorectal cancer (CRC) patients receiving 5-fluorouracil (5-FU)-based chemotherapy. MicroRNAs (miRNAs) are small noncoding RNAs that post-transcriptionally regulate gene expression. Our previous study has identified miR-139-5p as a potential tumor suppressor in CRC, but its role in chemoresistance of CRC has not been elucidated.

LncRNA-UCA1 enhances cell proliferation and 5-fluorouracil resistance in colorectal cancer by inhibiting miR-204-5p.

Recent preliminary studies reported the in vitro tumor-promoting effects of long non-coding RNA urothelial carcinoma associated 1 (UCA1) in colorectal cancer (CRC). However, the in vivo functions and molecular mechanism of UCA1 in CRC remain unclear. Therefore, we investigated the detailed role and mechanism of UCA1 in CRC.

Systematic analysis of key miRNAs and related signaling pathways in colorectal tumorigenesis.

The development of colorectal cancers (CRC) is accompanied with the acquisition and maintenance of specific genomic alterations. These alterations can emerge in premalignant adenomas and faithfully maintained in highly advanced tumors. miRNAs are a class of small non-coding RNAs that are frequently deregulated in human cancers and negatively regulate a wide variety of protein coding genes.