An extranodal Richter's syndrome presenting with cardiac diffuse large B-cell lymphoma: a case report.

BACKGROUND: Richter's syndrome (RS) defines the transformation of chronic lymphocytic leukemia into high-grade lymphoma, which usually involves lymph nodes and bone marrow. Extranodal involvement of the heart is an extremely rare condition. Patients with heart involvement tended to have a low response to chemotherapy and relative poor prognosis. The transformation process of RS is often insidious and nonspecific making it challenging to diagnose. CASE PRESENTATION: A 64-year-old woman wih a history of chronic lymphocytic leukemia (CLL) presented with intermittent chest pain and was diagnosed with non-ST-elevation myocardial infarction (NSTEMI). However, the contrast enhanced echocardiography revealed a large irregular mass, measuring about 75.4 mm × 37.5 mm, located on the lateral and posterior wall of the right ventricle. Biopsy of the cardiac mass and the results revealed diffuse large B-cell lymphoma. CONCLUSIONS: We present a case of a 64-year-old woman with aggressive diffuse large B-cell lymphoma involving the heart. This case could provide some insights in the diagnosis of cardiac lymphoma.

Emergent weak antilocalization and wide-temperature-range electronic phase diagram in epitaxial RuO2thin film.

Binary ruthenium dioxide (RuO2) has gradually attracted much attention in condensed matter physics and material sciences due to its various intriguing physical properties, such as strain-induced superconductivity, anomalous Hall effect, collinear anti-ferromagnetism, etc. However, its complex emergent electronic states and the corresponding phase diagram over a wide temperature range remain unexplored, which is critically important to understanding the underlying physics and exploring its final physical properties and functionalities. Here, through optimizing the growth conditions by using versatile pulsed laser deposition, high-quality epitaxial RuO2thin films with clear lattice structure are obtained, upon which the electronic transport is investigated, and emergent electronic states and the relevant physical properties are unveiled. Firstly, at a high-temperature range, it is the Bloch-Grüneisen state, instead of the common Fermi liquid metallic state, that dominates the electrical transport behavior. Moreover, the recently reported anomalous Hall effect is also revealed, which confirms the presence of the Berry phase in the energy band structure. More excitingly, we find that above the superconductivity transition temperature, a new positive magnetic resistance quantum coherent state with an unusual dip as well as an angel-dependent critical magnetic field emerges, which can be attributed to the weak antilocalization effect. Lastly, the complex phase diagram with multiple intriguing emergent electronic states over a wide temperature range is mapped. The results greatly promote the fundamental physics understanding of the binary oxide RuO2and provide guidelines for its practical applications and functionalities.

[Effects of moxibustion on acupoints at "opening" time on testicular tissue apoptosis in aging rats].

OBJECTIVE: To observe the effect of "lingguibafa" moxibustion at "opening" time on the level of superoxide dismutase(SOD), malondialdehyde(MDA), the protein expressions of B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X protein (Bax) in aging model rats. METHODS: SD rats were randomly divided into blank control, model and lingguibafa groups, with 8 rats in each group. The aging model was established by daily intraperitoneal injection of D-galactose (500 mg/kg) for 42 consecutive days. After successful modeling, moxibustion intervention was applied at"lingguibafa" acupoints, 3 moxa-cone for each acupoint, once a day for 28 consecutive days. The contents of SOD and MDA in serum were detected by ELISA. Morphological changes of testicular tissue and the number of Leydig cells were observed after HE staining. Apoptosis rate of testicular cells was detected by TUNEL staining. The protein expression levels of Bcl-2 and Bax in testis were detected by Western blot. RESULTS: Compared with the blank control group, the SOD content in the serum, the number of testicular Leydig cells, the expression level of Bcl-2 protein in testis were significantly decreased (P<0.01) in the model group, while the MDA content in the serum, the apoptosis rate of testicular cells and the expression level of Bax protein in testis were significantly increased (P<0.01). Compared with the model group, the SOD content in serum, the number of testicular Leydig cells, the Bcl-2 protein expression in testis were significantly increased (P<0.01), while the MDA content in serum, the apoptosis rate of testicular cells, the expression level of Bax protein in testis were significantly decreased(P<0.01) in the lingguibafa group. CONCLUSION: Moxibustion on acupoints at "opening" time can delay testicular aging, and the mechanism may be related to balancing the metabolism of free radicals, reducing oxidative damage, and inhibiting the apoptosis of testicular cells.

Platelet CD36 links overweight and a prothrombotic phenotype in patients with non-valvular atrial fibrillation.

Introduction: The pathophysiological mechanisms linking the overweight and prothrombotic state of non-valvular atrial fibrillation (NVAF) are incompletely understood. Our objective was to evaluate the effect of platelet CD36 on the risk of stroke associated with overweight in NVAF patients. Methods: A cross-sectional study enrolled 182 subjects with NVAF in two groups: normal weight (18.5 < body mass index(BMI) < 25.0 kg/m2) and overweight (BMI ≥ 25.0 kg/m2). Clinical data, medical history, vital signs, transthoracic echocardiography parameters, and medication were recorded. Biochemical characteristics including blood glucose and serum lipid were analyzed in the Laboratory. Results: The expression of platelet CD36 and integrin αIIbß3 was detected by flow cytometry. Among the 182 patients with NVAF, 68 (37.36%) were classified as normal weight, 114 (62.64%) as overweight. With an increase in BMI, waist-hip ratio, cholesterol, triglycerides, left atrium diameters, and the ratio of mitral inflow E velocity to myocardial e' velocity in the mitral annulus (E/e') increased significantly (P < 0.05). The mean fluorescent intensity of platelet CD36 increased significantly in overweight patients (P < 0.01), in line with platelet activation biomarkers (platelet integrin αIIbß3). Platelet CD36 was positively correlated with BMI and platelet integrin αIIbß3, respectively (P < 0.05). Additionally, platelet CD36 and BMI were independent risk factors for platelet activation in patients with NVAF. Conclusions: Platelet CD36 is speculated to mediate the complex crosstalk between overweight and platelet hyperactivity, leading to the prothrombotic state in overweight patients with NVAF. Platelet CD36 could be a potential target for preventing the prothrombotic state in overweight patients with NVAF.

Does types of atrial fibrillation matter in the impairment of global and regional left ventricular mechanics and intra-ventricular dyssynchrony?

Background: Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, which is associated with cardiac dysfunction. This study aimed to compare the impairment severity of left ventricular strain and intra-ventricular dyssynchrony using echocardiography-derived velocity vector imaging in patients with different types of AF without heart failure. Methods: 168 non-valvular AF patients with normal left ventricular ejection fraction (98 paroxysmal AF patients and 70 persistent AF patients) and 86 healthy control subjects were included in this study. Regional and global left ventricular longitudinal and circumferential strain were measured. Time to regional peak longitudinal strain was measured and the standard deviation of all 12 segments (SDT-S) was used as a measure of intra-ventricular dyssynchrony. Results: Significantly lower GLS (-18.71 ± 3.00% in controls vs. -17.10 ± 3.01% in paroxysmal AF vs. -12.23 ± 3.25% in persistent AF, P < 0.05) and GCS (-28.75 ± 6.34% in controls vs. -24.43 ± 6.86% in paroxysmal AF vs. -18.46 ± 6.42% in persistent AF, P < 0.01) were observed in either persistent AF subjects or paroxysmal AF subjects compared with healthy control subjects (P < 0.05). The impairment was much worse in persistent AF subjects compared with paroxysmal AF subjects (P < 0.001). Intraventricular dyssynchrony was found in both persistent AF patients and paroxysmal AF patients, and it's worse in persistent AF patients (52 ± 18 ms in controls, 61 ± 17 ms in paroxysmal AF, and 70 ± 28 ms in persistent AF, P < 0.05). Multivariate regression analysis revealed AF types were independent risk factors of GLS, GCS, and intraventricular dyssynchrony. Conclusion: AF types were not only associated with impaired longitudinal and circumferential left ventricle mechanics but also intra-ventricular mechanical dyssynchrony. Worse systolic mechanics and intra-ventricular dyssynchrony were found in patients with persistent AF compared with these in patients with paroxysmal AF.

Calprotectin and Neutrophil Gelatinase-Associated Lipocalin As Biomarkers of Acute Kidney Injury in Acute Coronary Syndrome.

BACKGROUND: Acute kidney injury (AKI) is increasingly being seen in patients with acute coronary syndromes (ACS) and it is associated with higher short-term and long-term morbidity and mortality. Therefore, it is of paramount importance to identify those ACS patients at risk for the development of AKI. The objective of this study was to evaluate two different plasma biomarkers calprotectin and neutrophil gelatinase-associated lipocalin (NGAL) in early detecting the development of AKI in ACS patients. METHODS: 172 ACS patients admitted to the Coronary Care Unit in Yantai Yuhuangding Hospital were prospectively enrolled. Their blood samples were obtained on admission and subjected to enzyme-linked immunosorbent assay to determine the levels of novel biomarkers. The clinical data and biomarkers were recorded and analyzed. RESULTS: In this study, 23 (13.4%) patients had a diagnosis of AKI. Statistical analysis demonstrated that in ACS patients with AKI, the following two biomarkers were significantly higher than these without AKI: plasma calprotectin (5942.26 ± 1955.88 ng/mL vs. 3210.29 ± 1833.60 ng/mL, p < 0.001) and plasma NGAL (164.91 ± 43.63 ng/mL vs. 122.48 ± 27.33 ng/mL, p < 0.001). Plasma calprotectin and NGAL could discriminate the development of AKI respectively with an area under the ROC curve (AUC) of 0.864 and 0.850. A combination of the two plasma biomarkers calprotectin and NGAL could early discriminate AKI in ACS patients with an AUC of 0.898. CONCLUSIONS: This study demonstrated a promising panel of plasma calprotectin and NGAL as early diagnostic biomarkers for AKI in ACS patients.

Degradation of aqueous methylparaben by non-thermal plasma combined with ZnFe2O4-rGO nanocomposites: Performance, multi-catalytic mechanism, influencing factors and degradation pathways.

Non-thermal plasma (NTP) combined with zinc ferrite-reduced graphene oxide (ZnFe2O4-rGO) nanocomposites were used for the degradation of aqueous methylparaben (MeP). ZnFe2O4-rGO nanocomposites were prepared using the hydrothermal method, with the structure and photoelectric properties of nanocomposites then characterized. The effects of discharge power, initial MeP concentration, initial pH, and air flow rate on MeP degradation efficiency were investigated, and the multi-catalytic mechanism and MeP degradation pathways were established. Results showed that ZnFe2O4-rGO nanocomposites with a 10%:90% mass ratio of GO:ZnFe2O4 had an optimal catalytic effect. The MeP degradation efficiency of NTP combined with ZnFe2O4-rGO (10 wt%), was approximately 25% higher than that of NTP alone. Conditions favorable for MeP degradation included higher discharge power, lower MeP concentration, neutral pH value, and higher air flow rate. The degradation of MeP by NTP combined with ZnFe2O4-rGO nanocomposites followed pseudo-first-order kinetics. O2•-, •OH, H2O2, and O3 were found to play important roles in the MeP degradation, as part of the multi-catalytic mechanism of NTP combined with ZnFe2O4-rGO nanocomposites. MeP degradation pathways were proposed based on the degradation intermediates detected by gas chromatography mass spectrometry, including demethylation, hydroxylation, carboxylation, ring-opening, and mineralization reactions. The prepared ZnFe2O4-rGO nanocomposites provide an approach for improved contaminant degradation efficiency, with reduced energy consumption in the NTP process.

Plasma calprotectin was associated with platelet activation and no-reflow phenomenon in acute coronary syndrome.

BACKGROUND: No-reflow occurs in 3-4% of all percutaneous coronary interventions (PCIs) and has a strong negative impact on clinical outcomes of acute coronary syndrome (ACS). Therefore, the discovery of a biomarker that can early predict the occurrence of no-reflow has great clinical significance. Multiple factors including platelet activation are relevant to no-reflow. Calprotectin is found to be a biomarker of plaque instability and is identified to be a novel diagnostic and prognostic biomarker of cardiovascular diseases. The association of plasma calprotectin with platelet activation and no-reflow phenomenon in ACS is not clear. METHODS: In this prospective study performed at Yantai Yuhuangding Hospital from 2017 to 2018, a total of 176 Chinese patients with ACS who had undergone PCIs were recruited consecutively, aged from 30 to 88 years. Angiographic no-reflow was defined as thrombolysis in myocardial infarction grade less than 3. Blood samples were collected immediately at admission for the detection of plasma calprotectin and platelet-monocyte aggregates formation. Statistical analysis was performed for the variable's comparisons between groups and the prediction value of plasma calprotectin for no-reflow. RESULTS: The mean age of the 176 included ACS patients were 64(±11) years and acute ST-segment elevation myocardial infarction (STEMI) was present in 41.5% of patients. Twenty-two patients had no-reflow during the PCI procedures and the prevalence was 12.5%. Patients with higher plasma calprotectin had a higher level of platelet-monocyte aggregates (PMA) and a higher prevalence of no-reflow (p < 0.001). The multivariate regression showed that plasma calprotectin and admission hs-cTnI were independently associated with PMA, while plasma calprotectin and serum LDL-c were independent predictors of no-reflow (p < 0.001 and p = 0.017). AUC of calprotectin for predicting no-reflow were 0.898. The cut-off value of plasma calprotectin for no-reflow was 4748.77 ng/mL with a sensitivity of 0.95 and a specificity of 0.77. CONCLUSION: Plasma calprotectin was associated with platelet activation and may act as an early predictive biomarker of no-reflow in patients with acute coronary syndrome.

The microvesicle/CD36 complex triggers a prothrombotic phenotype in patients with non-valvular atrial fibrillation.

The mechanisms responsible for platelet activation, the prothrombotic state, in non-valvular atrial fibrillation (NVAF) are still obscure. Microvesicles (MVs) can transfer various messages to target cells and may be helpful for exploring the detailed mechanisms. We aimed to investigate the possible mechanisms by which proatherogenic factors of NVAF contribute to platelet activation. Two hundred and ten patients with NVAF were stratified as being at 'low to moderate risk' or 'high risk' for stroke according to the CHADS2 score. Levels of platelet-derived MVs (PMVs) and platelet activation were examined. CD36-positive or CD36-deficient human platelets were stimulated by MVs isolated from NVAF patients with or without various inhibitors in vitro. Levels of PMVs and platelet activation markers enhanced significantly in high-risk patients. The MVs isolated from plasma of NVAF patients bound to platelet CD36 and activated platelets by phosphorylating the mitogen-activated protein kinase 4/Jun N-terminal kinase 2 (MKK4/JNK2) pathways. However, CD36 deficiency protected against MV-induced activation of platelets. We reveal a possible mechanism of platelet activation in NVAF and suggest that the platelet CD36 might be an effective target in preventing the prothrombotic state in NVAF.

Synergistic degradation of acid orange 7 dye by using non-thermal plasma and g-C3N4/TiO2: Performance, degradation pathways and catalytic mechanism.

In order to harness the full capability of ultraviolet and visible light in the dielectric barrier discharge induced non-thermal plasma (DBD-NTP) process, g-C3N4/TiO2 catalysts were prepared and utilized in this process. Synergistic degradation of acid orange 7 (AO7) dye by DBD-NTP and g-C3N4/TiO2 was conducted, and the performance, degradation pathways and synergistic catalytic mechanism were investigated. The results showed that the degradation rate of AO7 in the DBD-NTP and g-C3N4-15/TiO2 process increased by 39.1% compared with that in the single DBD-NTP process at 12 min discharge time. At 20 W input power, initial concentration of AO7 was 5 mg/L, catalytic dosage was 0.5 g/L, initial pH value was 10.0 and air flow rate was 52 L/h, the degradation rate of AO7 reached 100.0% after 12 min discharge time. Higher discharge power and initial concentration of AO7 inhibited AO7 degradation, whereas increasing the air flow rate and initial pH value of the solution promoted AO7 degradation. The degradation pathways of AO7 consisted of azo structure destruction, ring opening reaction, hydroxylation, carboxylation and mineralization reaction. The results of radical trapping experiment showed that O2-, h+, OH, O3 and H2O2 were the main reactive species for AO7 degradation in the DBD-NTP and g-C3N4-15/TiO2 process. The Z-scheme photocatalytic mechanism for the g-C3N4/TiO2 catalyst was proposed.

[Characteristics of soil enzyme stoichiometry along an altitude gradient on Qinghai-Tibet Pla-teau alpine meadow, China]. / é’è—é«˜åŽŸé«˜å¯’è‰ç”¸ä¸åŒæµ·æ‹”åœŸå£¤é ¶åŒ–å­¦è®¡é‡ç‰¹å¾.

Soil enzymes play critical roles in material cycle and energy flow of ecosystems. Understanding soil enzyme activities is of great significance for exploring ecosystem functions. In this study, we investigated soil enzyme activities, stoichiometry and their driving factors at six different altitudes (4300-5100 m) on Qinghai-Tibet Plateau alpine meadow using Biolog microplate analysis. The results showed that ß-1,4-glucosidase (ßG) closely related to C cycle, ß-1,4-N-acetylglucosaminidase (NAG) and L-leucine aminopeptidase (LAP) closely related to N cycle and the activity of acid phosphatase (AP), which was closely related to P cycle, all exhibited unimodal trends with increasing altitude, with the order of 4800 m＞4950 m＞4400 m＞4650 m＞5100 m＞4300 m. Soil N:P enzyme activity ratio showed the same trend as soil enzyme activity, and reached the highest value at 4950 m, however, soil C:N and C:P enzyme activities ratios increased along the altitude. Pearson correlation analysis showed that SOC, TN and soil water content were significantly positively correlated with the activities of four types of enzymes. Mean annual precipitation was significantly negatively associated with the activities of NAG and AP. Mean annual precipitation, mean annual temperature, Shannon diversity, vegetation richness, vegetation coverage and TN affected ratios of soil C:P and N:P enzymes. Soil C:N activity ratio correlated with mean annual temperature, mean annual precipitation, vegetation richness, vegetation coverage, SOC and TN. In summary, soil enzyme activities and stoichiometry had remarkable difference along the altitude gradient on Qinghai-Tibet Plateau alpine meadow, with certain N limitation in high altitude areas. Soil water content, TN, SOC, mean annual precipitation and mean annual temperature were key factors driving such differences.

[Influence of long-term enclosure and free grazing on soil microbial community structure and carbon metabolic diversity of alpine meadow.] / é•¿æœŸå›´å°å’Œè‡ªç”±æ”¾ç‰§å¯¹é«˜å¯’è‰ç”¸åœŸå£¤å¾®ç”Ÿç‰©ç¾¤è½ç»“æž„åŠç¢³æºä»£è°¢å¤šæ ·æ€§çš„å½±å“.

Soil microbial community structure and functional diversity have great implications for the maintenance of the function and stability of grassland ecosystem. We studied the variation of soil microbial community structure, community diversity of carbon metabolism and their driving factors between the long-term enclosure and the free grazing grasslands in Qinghai-Tibet Plateau by using phospholipid fatty acid and Biolog techniques. The results showed that: 1) there were significant differences in soil microbial community structure and the utilization of carbon source between the long-term enclosed and free grazed grasslands. 2) Long-term enclosure significantly increased the content of total PLFA, bacteria, fungi and actinomycetes. 3) Soil carbon metabolic activity, diversity and richness in free-grazing grassland was significantly higher than the enclosed grassland, but evenness showed an opposite pattern. 4) Compared with the free grazed grassland, long-term enclosure significantly increased the utilization of polymers, carbohydrates, carboxylic acids, and amines by soil microorganisms. 5) Results from the redundancy analysis showed that vegetation coverage significantly affected soil microbial community structure and carbon metabolism. The soil microbial content, carbon metabolism diversity and richness in the long-term enclosed grassland were higher than those of the free grazing grassland, indicating that long-term enclosure was more conducive to improve the diversity and carbon metabolism of soil microbial community.

Development of knowledge management system for virtual teams in collaborative scientific research model / 中华医学图书情报杂志

The characteristics, status quo, design principles and implementing technology of knowledge management system for virtual teams in collaborative scientific research model were described, which was followed by an analysis of its functional system that is consisted of project management module, file management module, staff management module, communication tool model, statistical analysis module and file storage module. The developed knowledge management system for virtual teams could share the knowledge management and service, store the knowledge for a long time in the project community by integrating literature retrieval and management, experimental reports and pa-per publication, and librarians could provide sustained guidance for library holding resources and timely embedded knowledge service by joining into the project community.

Development of knowledge management system for virtual teams in collaborative scientific research model / 中华医学图书情报杂志

The characteristics, status quo, design principles and implementing technology of knowledge management system for virtual teams in collaborative scientific research model were described, which was followed by an analysis of its functional system that is consisted of project management module, file management module, staff management module, communication tool model, statistical analysis module and file storage module. The developed knowledge management system for virtual teams could share the knowledge management and service, store the knowledge for a long time in the project community by integrating literature retrieval and management, experimental reports and pa-per publication, and librarians could provide sustained guidance for library holding resources and timely embedded knowledge service by joining into the project community.

[Temperature sensitivity of soil organic carbon mineralization and ß-glucosidase enzymekinetics in the northern temperate forests at different altitudes, China].

Soil samples, which were collected from three typical forests, i.e., Betula ermanii forest, coniferous mixed broad-leaved forest, and Pinus koraiensis forest, at different altitudes along the southern slope of Laotuding Mountain of Changbai Mountain range in Liaoning Province of China, were incubated over a temperature gradient in laboratory. Soil organic carbon mineralization rates (Cmin), soil ß-1,4-glucosidase (ßG) kinetics and their temperature sensitivity (Q10) were measured. The results showed that both altitude and temperature had significant effects on Cmin · Cmin increased with temperature and was highest in the B. ermanii forest. The temperature sensitivity of Cmin [Q10(Cmin)] ranked in order of B. ermanii forest > P. koraiensis forest > coniferous mixed broad-leaved forest, but did not differ significantly among the three forests. Both the maximum activity (Vmax) and the Michaelis constant (Km) of the ßG responded positively to temperature for all the forests. The temperature sensitivity of Vmax [Q10(Vmax)] ranged from 1.78 to 1.90, and the temperature sensitivity of Km [Q10(Km)] ranged from 1.79 to 2.00. The Q10(Vmax)/Q10(Km) ratios were significantly greater in the B. ermanii soil than in the other two forest soils, suggesting that the ßG kinetics-dependent impacts of the global warming or temperature increase on the decomposition of soil organic carbon were temperature sensitive for the forests at the higher altitudes.

[Impacts of land-use types on soil C mineralization and temperature sensitivity of forests in Qianyanzhou, Jiangxi Province, China].

Decomposition of soil organic matter plays an important role in the regulation of carbon (C) cycles at ecosystem or regional scales, and is closely related to temperature, moisture, and land-use types. The influences of soil temperature, moisture, and land-use types on soil C mineralization in Citrus reticulata and Pinus elliottii forests were investigated at the Qianyanzhou Ecological Experiment Station, Chinese Academy of Sciences, by conducting incubation experiments at 5-level temperatures (5, 10, 15, 20 and 25 degrees C) and 3-level moistures (30%, 60% and 90% saturated soil moisture, SSM). The results showed that soil temperature, moisture, and land-use types had significant effects on soil C mineralization and they had significant interaction effects. Soil C mineralization was positively correlated with incubation temperature in the two forests, and the maximum of soil C mineralization was in the 60% SSM treatment. The accumulation of soil C mineralization was higher in the C. reticulata forest than in the P. elliottii forest under the same temperature and moisture conditions. The temperature sensitivity (Q10) of soil C mineralization was influenced by land-use type and soil moisture. Q10 increased with the increasing soil moisture in both C. reticulata and P. elliottii forests at incubation 7 and 42 d. Q10 in the C. reticulata forest was higher than in the P. elliottii forest in the same moisture level, and the deviation increased with the increasing soil moisture. The model including temperature and moisture could depict the response of soil C mineralization to temperature and moisture. Temperature and moisture together explained 79.9% -91.9% of the variation in soil C mineralization.

Convergent responses of nitrogen and phosphorus resorption to nitrogen inputs in a semiarid grassland.

Human activities have significantly altered nitrogen (N) availability in most terrestrial ecosystems, with consequences for community composition and ecosystem functioning. Although studies of how changes in N availability affect biodiversity and community composition are relatively common, much less remains known about the effects of N inputs on the coupled biogeochemical cycling of N and phosphorus (P), and still fewer data exist regarding how increased N inputs affect the internal cycling of these two elements in plants. Nutrient resorption is an important driver of plant nutrient economies and of the quality of litter plants produce. Accordingly, resorption patterns have marked ecological implications for plant population and community fitness, as well as for ecosystem nutrient cycling. In a semiarid grassland in northern China, we studied the effects of a wide range of N inputs on foliar nutrient resorption of two dominant grasses, Leymus chinensis and Stipa grandis. After 4 years of treatments, N and P availability in soil and N and P concentrations in green and senesced grass leaves increased with increasing rates of N addition. Foliar N and P resorption significantly decreased along the N addition gradient, implying a resorption-mediated, positive plant-soil feedback induced by N inputs. Furthermore, N : P resorption ratios were negatively correlated with the rates of N addition, indicating the sensitivity of plant N and P stoichiometry to N inputs. Taken together, the results demonstrate that N additions accelerate ecosystem uptake and turnover of both N and P in the temperate steppe and that N and P cycles are coupled in dynamic ways. The convergence of N and P resorption in response to N inputs emphasizes the importance of nutrient resorption as a pathway by which plants and ecosystems adjust in the face of increasing N availability.

Biogenic VOCs emission inventory development of temperate grassland vegetation in Xilin River basin, Inner Mongolia, China.

Given the key role of biogenic volatile organic compounds (VOCs) to tropospheric chemistry and regional air quality, it is important to generate accurate VOCs emission inventories. However, only a less fraction of plant species, in temperate grassland of Inner Mongolia, has been characterized by quantitative measurements. A taxonomic methodology, which assigns VOCs measurements to unmeasured species, is an applicable and inexpensive alternation for extensive VOCs emission survey, although data are needed for additional plant families and genera to further validate the taxonomic approach in grassland vegetation. In this experiment, VOCs emission rates of 178 plant species were measured with a portable photoionization detector (PID). The results showed the most of genera and some families have consistent feature of their VOCs emission, especially for isoprene, and provide the basic premise of taxonomic methodology to develop VOCs emission inventories for temperate grassland. Then, the taxonomic methodology was introduced into assigning emission rate to other 96 species, which no measured emission rates available here. A systematical emission inventory of temperate grassland vegetation in Inner Mongolia was provided and further evidence that taxonomy relationship can serve as a useful guide for generalizing the emissions behavior of many, but not all, plant families and genera to grassland vegetation.