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The micro-discharge effect limits the development of high-frequency microwave power components to miniaturization and integration. Therefore, it has become a focus of research to effectively suppress the micro-discharge effect, increase the micro-discharge threshold, and strengthen the environmental stability of high-frequency microwave devices. In this study, different elemental ratios of carbon (C)/silver (Ag)/titanium (Ti) composite films were obtained by multi-target magnetron co-sputtering technology and then systematically analyzed for micro-discharge effects. When the doping ratio of C/Ag/Ti was 3.538/1/0.013, the corresponding maximum secondary electron emission coefficient (δmax) decreased to 1.01 owing to the suppression of secondary electron emission by the increase in the content of sp2 hybrid bond. The micro-discharge threshold of Ku band waveguide filters coated with moderate C/Ag/Ti composite films showed an optimal performance of 10 000−12 500 W, which was increased by approximately 20 times. Moreover, the microstructure of the composite films exhibited higher density and flatness with a tiny increase in the titanium doping ratio, representing good environmental stability. Thus, the effective suppression of the secondary electron emission yield, significant improvement in the micro-discharge threshold, and enhancement of the environment stability of microwave components could be realized simultaneously by reasonably controlling the content of titanium in silver and titanium co-doped carbon-based composite films. [ABSTRACT FROM AUTHOR]

Objective To evaluate the clinical effect of integrated Traditional Chinese and Western medicine on abdominal distention and constipation after surgery for thoracolumbar fracture. Methods The CNKI, CBM, VIP and Wanfang Date databases were searched by computer. Randomized controlled trials (RCTs) on the efficacy of integrated Traditional Chinese and Western medicine in the treatment of abdominal distention and constipation after surgery for thoracolumbar fracture were included. RevMan 5. 4 software was used for data analysis from database construction to March 2022, and Jadad scale was used to evaluate the literature quality and funnel plot was used to analyze whether there were publication offset results in the included literature. Results After screening, 7 literatures were included, including 590 subjects: 301 in the experimental group and 289 in the control group. Meta-analysis showed that the nursing measures of integrated Traditional Chinese and Western medicine were significantly better than conventional nursing measures in treating and relieving postoperative abdominal distention and constipation(P＜0. 05). Conclusion Based on the current clinical evidence, the full application of the dialectical theory of traditional Chinese medicine and the adoption of appropriate Chinese medicine prescriptions combined with routine orthopedic nursing measures can effectively relieve the symptoms of abdominal distension and constipation in patients with thoracolumbar fracture after surgery, relieve discomfort and improve nursing satisfaction, which can provide clinical reference (目的 通过Meta分析系统评价中西医结合治疗胸腰段骨折术后腹胀便秘的临床效果。方法 计算机检索中国知网(CNKI)、中国生物医学文献库(CBM)、维普数据库(VIP)和万方数据(Wanfang Data)数据库, 纳入中西医结合治疗胸腰段骨折术后腹胀便秘疗效的随机对照试验(RCTs), 选取文献时间从建库至2022年3月。采用RevMan 5. 4软件进行数据分析、Jadad量表对文献质量进行评价、漏斗图分析纳入的文献是否存在发表偏移。结果 经筛选后最终纳入7个文献, 共590人, 试验组301人, 对照组289人。Meta分析结果表明中西医结合的护理措施在治疗和缓解患者术后腹胀便秘的症状明显优于常规护理措施(P＜0. 05)。结论 基于目前临床证据表明, 充分应用中医辨证论治理论, 采用合适的中药方剂结合骨科护理常规等措施, 能有效缓解胸腰段骨折术后患者腹胀便秘症状, 减轻不适感, 提高护理满意度, 可为临床提供参考。)

Background: The COVID‐19 pandemic is an unprecedented health crisis that has affected in vitro fertilization practices globally. Previous studies have shown that SARS‐CoV‐2 impacts the quality of embryos by inducing an immunological response in infertile patients. In this study, the early embryonic development of SARS‐CoV‐2‐infected infertile patients was investigated. Methods: Sixty‐five SARS‐CoV‐2 infected infertile patients and 258 controls were involved in this study. The major outcome parameters for the cycle were analyzed, including the number of oocytes, maturation oocytes, available embryos per cycle, and embryo morpho kinetic characteristics. Results: From SARS‐CoV‐2 infection until oocyte retrieval, it took an average of 6.63 days. The results revealed that the number of oocytes and high‐quality embryos on day 3 dramatically reduced in SARS‐CoV‐2‐infected infertile patients. SARS‐CoV‐2 was detected in the follicular fluid of three infertile patients. SARS‐CoV‐2 infection had negatively impacted the number of oocytes in multivariate linear regression models. The early embryonic development in the SARS‐CoV‐2 infection group had a noticeable delay from the six‐cell stage to blastocyst stage. Conclusions: SARS‐CoV‐2 infection reduced the number of oocytes and high‐quality embryos on day 3. It delays the early embryonic development from the six‐cell stage to blastocyst stage and has a negative impact on the quality of embryos. [ABSTRACT FROM AUTHOR]

Featured Application: The research provides a theoretical reference for transformer closing-control strategies, in which the superposition effect decreases as the reclosing interval increases. When a transformer suffers a permanent fault, it will suffer a short-circuit impulse again after reclosing. If the previous vibration of the winding is not attenuated completely and the winding is subjected to a secondary impulse within a short time, the secondary vibration response will have a superposition. The aim of this study was to analyze the effect of the anti-short-circuit ability of operational transformers subjected to a secondary short-circuit current impulse. In this paper, a model is established for calculating axial vibration in transformer windings and effects on the vibration response of windings under different closing phase angles and short-circuit intervals are analyzed. The results show that the vibration acceleration of windings is a V-shaped variation at phase angles from 0° to 180°, reaching the maximum values at 0° and 180° and reaching the minimum value at 90°. When the transformer recloses on a permanent short circuit, due to the superposition effect, the vibration acceleration amplitude of the secondary impulse will be greater than that of the primary impulse, but as the reclosing interval increases, the superposition effect decreases continuously. When the interval is 600 ms, the superposition effect for the vibration acceleration of the secondary impulse attenuates to 83.3%. The superposition effect is not significant after 600 ms. The research provides a theoretical reference for transformer closing-control strategies. [ABSTRACT FROM AUTHOR]

Ferroelectric memory is one of the most attractive emerging nonvolatile memory. Conventional methods to increase storage density in ferroelectrics include reducing the storage bit size or fabricating 3D stacks. However, the former will face a physical limit finally, and the integration of single‐crystalline ferroelectric oxide following the latter still remains a great challenge. Here, a new method is introduced to construct a scroll‐like 3D memory structure by self‐rolling‐up single‐crystalline ferroelectric oxides. PbZr0.3Ti0.7O3 single‐crystalline thin film is chosen as a prototype and epitaxially grown on another oxide stressor layer with a few lattice‐mismatch. Releasing such "Pb(Zr, Ti)O3/stressor" bilayered structure from the substrate induces self‐rolling‐up due to the internal stress from the lattice‐mismatch. High‐density information can be written in the form of switched ferroelectric domains on those flat "Pb(Zr, Ti)O3/stressor" membranes via piezoelectric force microscopy. In self‐rolling‐up membranes, information density can be experimentally enhanced up to 45 times. Theoretically, the freestanding "Pb(Zr, Ti)O3/stressor" membranes have a strongly driven force to self‐rolling‐up, and the area ratio can enhance 100–450 times, corresponding to an ultra‐high density information storage of 102 Tbit In−2. This study provides a new and general method to develop compact, high‐density, and 3D memories from oxide materials. [ABSTRACT FROM AUTHOR]

To improve the performances of AlGaN solar‐blind ultraviolet (UV) avalanche photodetectors (APDs), we propose a separate absorption and multiplication (SAM) AlGaN APD with a gradually doped charge layer. The calculation results indicate that the designed APD can significantly increase the maximum gain by almost 40%, and reduce the breakdown voltage by about 9% compared with the conventional AlGaN APD. The parameters of multiplication layer and p‐type layer are optimized, and the physical mechanism is described in detail, which provides theoretical guidance for high‐performance device structure design and experimental preparation. [ABSTRACT FROM AUTHOR]

Soil erosion is a major form of land degradation, especially in agroecosystems, which has been effectively controlled by vegetation restoration. However, the interactive role of erosion and cropland revegetation on soil enzyme activities and microbial nutrient limitations is less understood. To address this issue, we examined carbon (C), nitrogen (N), and phosphorus (P) in bulk soils and microbial biomass, enzyme activities, and microbial nutrient limitations in the 0–200 cm soils in eroded and deposited landscapes occupied by cropland, revegetated forest, and grassland. The results showed that the activities of C-, N-, and P-acquiring enzymes were larger in the deposited landscape than in the eroded landscape for 0–20 cm soils in forest and grassland but not in cropland. Microbial metabolism was co-limited by N and P, and the threshold element ratio (TERL) indicated that P was the most limiting factor. Microbial N limitation was lower in the deposited than the eroded zone, especially in surface soils in revegetated forest and grassland. The TERL value was larger at the deposited than at the eroded zone, and a greater difference was found in the surface soils of forest and grassland. Microbial nutrient limitations were mostly explained by C/P and N/P. Conclusively, the deposited areas were characterized by ameliorated enzyme activities, decreased microbial N limitation but relatively strengthened microbial P limitation compared to the eroded area, and such variations existed in the revegetated forest and grassland but not in the cropland, which thus contributes to a better understanding of C and nutrient cycling for agroecosystems and revegetation ecosystems in eroded environments. [ABSTRACT FROM AUTHOR]

The crosslinked polyethylene (XLPE) cable safety is affected by environmental factors and artificial defects during operation. This work proposes an improved locating method based on broadband impedance spectrum (BIS) to locate local defects in XLPE cables. The calculation process of the algorithm has been analyzed. The selection of the incident Gaussian signal and the peak recognition method have been discussed, where the pulse width of the Gaussian signal was found to be determined primarily by the upper limit frequency of the traveling wave transmitting in the cable. The centroid and function fitting methods were established to reduce the peak recognition error caused by the test sampling rate. This work verified the accuracy of the algorithm through experiments. A vector network analyzer (VNA) was used to test the BIS of the cable. A 20 m-long cable containing abrasion and an inserted nail with different depths was measured in the BIS test. It was found that the abrasion and the nail could be located. The locating deviation of abrasion was within ±1%, and the centroid and function fitting methods could effectively reduce the locating deviation. The locating deviation was within ±1% when the depth of the nail inserted into the cable accounted for less than 50% of the insulation thickness. When the depth exceeded 75% of the insulation thickness, the deviation of each method was more significant, and the maximum absolute value of the deviation was 4%. [ABSTRACT FROM AUTHOR]

Electrical treeing is one of the main causes of crosslinked polyethylene (XLPE) cable failure. The current methods for locating electrical trees are mainly based on the partial discharge (PD) signal. However, PD signals are easily attenuated in the long cable and the PD test voltage may cause damage to the insulation. This work proposes an improved broadband impedance spectrum (BIS) method to locate electrical trees in XLPE cable. A mathematical model of a long cable containing local electrical tree degradation is established. The Gaussian signal is chosen as the simulated incident signal to reduce the spectral leakage. The location spectrum is obtained by multiplying the frequency domain function of the single-ended reflection coefficient and the Gaussian pulse. It has been found that the location spectrum of the local capacitance change can be characterized as a typical double-peak waveform and the spectrum of the local conductance change can be regarded as a typical single-peak waveform. Electrical tree experiments at different temperatures were carried out to initiate different types of electrical trees. A vector network analyzer (VNA) was used to test the high frequency capacitance characteristics in the treeing process. The location spectra of the 20 m long cable containing different types of electrical trees was calculated by the improved location algorithm. The results show that the location error of local electrical tree degradation is less than 3%. The capacitance of the sliced sample decreases with treeing time. The effect of the bush-pine tree on capacitance parameters is greater than that of the branch-pine tree. A typical double-peak is found in the bush-pine tree location spectrum and a single-peak is found in the branch-pine tree spectrum. [ABSTRACT FROM AUTHOR]

Implant placement in the pterygoid region is a reliable treatment for posterior maxillary tooth loss. However, the surgery is not widely applied because the implant placement region is hard to access and the direct visual access is limited. This clinical report describes the use of a dynamic navigation system to improve the pterygoid implant placement surgery. Real-time imaging of the surgery area and full-time guidance are provided by the system to alleviate the problem of lack of visibility and to reduce the complexity of placement. [ABSTRACT FROM AUTHOR]

Human body temperature not only reflects vital signs, but also affects the state of various organs through blood circulation, and even affects lifespan. Here a wireless body temperature detection scheme was presented that the temperature was extracted by investigating the out-of-plane (OP) ferromagnetic resonance (FMR) field of 10.2 nm thick La0.7Sr0.3MnO3 (LSMO) film using electron paramagnetic resonance (EPR) technique. Within the range of 34–42 °C, the OP FMR field changes linearly with the increasing or decreasing temperature, and this variation comes from the linear responses of magnetization to the fluctuant temperature. Using this method, a tiny temperature change (< 0.1 °C) of organisms can be detected accurately and sensitively, which shows great potential in body temperature monitoring for humans and mammals. [ABSTRACT FROM AUTHOR]

Obesity is associated with an increasing tendency which is a typical metabolic syndrome resulting from metabolic disorders due to the excessive food intake, and thus leading to a citical threat to human health. Studies were proved that food reward was an important factor affecting feeding behavior and played a key role in the occurrence and development of obesity. Recent studies indicated that brain-gut peptide, leptin, insulin and gut microflora could directly or indirectly regulate appetite and stabilize body weight through dialogue between intestine and brain, which mediated a crucial role in preventing obesity. Therefore, this review highlighted the role of the dialogue between intestine and brain in food reward and expanded strategies for the prevention and treatment of obesity. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) MoS2 was grown on AlGaN(GaN) substrates by chemical vapor deposition (CVD) and 2D-3D MoS2-AlGaN(GaN) heterostructures were formed. The MoS2 crystal on AlGaN surface has a mixed and irregular shape including single and multiple layers, while the single layer of triangular MoS2 is basically prepared on GaN surface. Combined with theoretical first-principles analysis, it is found the adsorption of AlGaN to MoS2 is lower than that of GaN, which leads to the deposition of MoS2 molecules on AlGaN surface, forming multilayer shapes. In addition, Both the MoS2-AlGaN(GaN) heterostructures exhibit indirect band gaps and broad-band light absorption performances. [ABSTRACT FROM AUTHOR]

The noise caused by rail corrugation seriously affects the operation quality of metro vehicles. In this work, the rail corrugation, interior noise and wheel–rail noise of a metro line were tested, and the test results were compared with those after two kinds of treatments. The results show that rail corrugation is the main cause of the abnormal interior noise. The interior noise in many sections exceeds the limit, where clear rail corrugations from 31.5~63 mm are found. When the train passes through the rail corrugation section, the interior noise shows a clear increase, and the maximum increase is higher than 25 dB(A). After increasing the lateral stiffness of the track and rail grinding, the interior noise is reduced by 11.4 dB(A). After a long renovation time, the interior noise is effectively equal to that when the renovation was completed. The research results of this work can provide a reference for rail corrugation treatment and noise control. [ABSTRACT FROM AUTHOR]

Periodontitis is closely related to oral cancer, but the molecular mechanism of periodontal pathogens involved in the occurrence and development of oral cancer is still inconclusive. Here, we demonstrate that, in vitro , the cell proliferation ability and S phase cells of the periodontitis group (colonized by Porphyromonas gingivalis and Fusobacterium nucleatum , P+) significantly increased, but the G1 cells were obviously reduced. The animal models with an in situ oral squamous cell carcinoma (OSCC) and periodontitis-associated bacteria treatment were constructed, and micro-CT showed that the alveolar bone resorption of mice in the P+ group (75.3 ± 4.0 μm) increased by about 53% compared with that in the control group (48.8 ± 1.3 μm). The tumor mass and tumor growth rate in the P+ group were all higher than those in the blank control group. Hematoxylin–eosin (H&E) staining of isolated tumor tissues showed that large-scale flaky necrosis was found in the tumor tissue of the P+ group, with lots of damaged vascular profile and cell debris. Immunohistochemistry (IHC) of isolated tumor tissues showed that the expression of Ki67 and the positive rate of cyclin D1 were significantly higher in tumor tissues of the P+ group. The qRT-PCR results of the expression of inflammatory cytokines in oral cancer showed that periodontitis-associated bacteria significantly upregulated interleukin (IL)-6, tumor necrosis factor (TNF)-α, IL-18, apoptosis-associated speck-like protein containing a CARD (ASC) (up to six times), and caspase-1 (up to four times), but it downregulated nuclear factor (NF)-κB, NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3), and IL-1β (less than 0.5 times). In addition, the volume of spleen tissue and the number of CD4+ T cells, CD8+ T cells, and CD206+ macrophages in the P+ group increased significantly. IHC and Western blotting in tumor tissues showed that expression levels of γ-H2AX, p-ATR, RPA32, CHK1, and RAD51 were upregulated, and the phosphorylation level of CHK1 (p-chk1) was downregulated. Together, we identify that the periodontitis-related bacteria could promote tumor growth and proliferation, initiate the overexpressed NLRP3, and activate upstream signal molecules of ATR-CHK1. It is expected to develop a new molecular mechanism between periodontitis-related bacteria and OSCC. [ABSTRACT FROM AUTHOR]

The thymus plays an irreplaceable role as a primary lymphoid organ. However, the complicate processes of its development and involution are incompletely understood. Accumulating evidence indicates that non‐coding RNAs play key roles in the regulation of biological development. At present, the studies of the circRNA profiles and of circRNA‐associated competing endogenous RNAs (ceRNAs) in the thymus are still scarce. Here, deep‐RNA sequencing was used to study the biological mechanisms underlying the development process (from 2‐week‐old to 6‐week‐old) and the recession process (from 6‐week‐old to 3‐month‐old) of the mouse thymus. It was found that 196 circRNAs, 233 miRNAs and 3807 mRNAs were significantly dysregulated. The circRNA‐associated ceRNA networks were constructed in the mouse thymus, which were mainly involved in early embryonic development and the proliferation and division of T cells. Taken together, these results elucidated the regulatory roles of ceRNAs in the development and involution processes of the mouse thymus. [ABSTRACT FROM AUTHOR]

Highlights • Converting grassland to shrubland increased soil N availability and mineralization. • The positive effect on soil mineral N was higher in lower slope than upper slope. • The positive effect on soil mineral N was similar across soil textures. • The effect on net N mineralization varied with slope position and soil texture. Abstract Grassland afforestation, which is a major form of land-use change, has expanded considerably in the last few decades. However, the effect of conversion from grassland to shrubland on soil nitrogen (N) cycling and availability with regard to soil textures and slope positions is unclear. This lack of clarity has hindered our understanding of how grassland afforestation influences soil N availability and transformation on a larger spatial scale. In this study, we compared the net N mineralization rates and mineral N concentrations in soils from native grassland and under legume shrub (Caragana korshinskii Kom.) with contrasting soil textures (sandy-loam vs. loamy-sand) and slope positions (upper vs. lower) in the northern region of China's Loess Plateau. The objective of this study is to understand how soil texture and slope position regulate the response of soil N cycling to grassland afforestation. The results showed that the concentrations of soil nitrate and total mineral N and the rates of net nitrification and mineralization were higher in soils under shrub (0.64 ± 0.10 g N m−2, 1.01 ± 0.11 g N m−2, 23.19 ± 5.22 mg N m−2 d-1 and 22.07 ± 5.44 mg N m−2 d-1) than in grassland (0.22 ± 0.03 g N m−2, 0.56 ± 0.04 g N m−2, 1.48 ± 1.51 mg N m−2 d-1 and 1.36 ± 1.96 mg N m−2 d-1). However, soil ammonium concentration and net ammonification rate were not affected by grassland afforestation. The effect of afforestation on nitrate and total mineral N concentrations was greater in the lower slope than in the upper slope but was similar between the sandy-loam and loamy-sand soils. The effect of this land-use change on net nitrification and mineralization rates varied with soil texture and slope position, with greater effects in the upper slope than in the lower slope in more clayey soils, but with the opposite influencing pattern in more sandy soils. These results suggested that planting C. korshinskii in grassland ecosystems increased soil N mineralization and availability. More importantly, soil texture and slope position should be considered when assessing the effects of grassland afforestation in complex landscape conditions. [ABSTRACT FROM AUTHOR]

Abstract The creation of "fertile islands" beneath shrubs in dryland ecosystems has been widely reported worldwide and is the major factor influencing ecosystem structure and function. However, studies investigating whether and how shrubs affect soil biogeochemical cycles in deep soil layers are relatively limited. In this study, we examined the vertical distribution of the soil nutrient contents and enzymatic activities at the 0–100 cm soil profiles beneath three common xerophytic shrubs (Artemisia ordosica , Caragana korshinskii and Salix psammophila) and in interspace bare soils in a transition zone from desert to loess in the north of China. The soil metrics included the contents of organic carbon, total nitrogen, total phosphorus, nitrate and ammonium nitrogen, available phosphorus and potassium, and the activities of saccharase, urease, alkaline phosphatase and amylase. We found that the contents of organic carbon, total nitrogen and available potassium, and the activities of saccharase, urease and alkaline phosphatase were higher in the soils beneath shrubs than in the interspace bare areas, but these differences only occurred in the 0–10 cm soil profile but not in the soils below the depth of 10 cm. The soil quality index was consistently improved among the three shrub species in the topsoil. In addition, the soil nutrients were positively correlated with enzymatic activities, and the organic carbon content explained approximately 50% of the variations in the enzymatic activities. Collectively, our results demonstrated that the establishment of xerophytic shrubs improved the soil chemical and biological conditions in the desert-loess transition region, and the effect was restricted to the 0–10 cm soil layer. Highlights • Xerophytic shrubs significantly increased soil nutrient contents and enzymatic activities. • Effects of shrubs on soil nutrients and enzyme activities occurred at 0–10 cm depth. • Soil quality index was similar among A. ordosica , C. korshinskii and S. psammophila. • Soil nutrient contents were positively correlated with enzymatic activities. • Organic carbon explained ~50% of the variations in enzymatic activities. [ABSTRACT FROM AUTHOR]

Abstract Shrubs play a vital role in ecosystem restoration in the desert transition zone, which suffers intensive desertification, land degradation, and nitrogen (N) limitation. To evaluate the effects of different shrub species on soil N availability, transformation, and their seasonal dynamics, we determined mineral N contents and mineralization rates in soils under three common shrub species (Artemisia ordosica Krasch., Caragana korshinskii Kom., and Salix psammophila C.) and in bare land during the growing season in the desert-loess transition zone in northwestern China. The average contents of soil nitrate N and mineral N were 153% and 55% greater, respectively, and cumulative net N nitrification and mineralization were 101.2 and 121.0 mg N m−2 higher, respectively, in soils beneath C. korshinskii than in bare land (P < 0.05) at the 0–10 cm depth over the growing season. The net N mineralization rate in 0–10 cm depth was significantly higher in soils under C. korshinskii than that in bare land during 21 Jun-23 Jul and 23 Aug-15 Oct of the growing season. However, C. korshinskii did not influence soil N metrics at the 10–20 cm depth. The incorporation of A. ordosica and S. psammophila into bare land did not influence soil N availability or transformation rates. Our results demonstrated that C. korshinskii was more preferable than A. ordosica and S. psammophila in ameliorating soil N cycling in the desert-loess transition zone. Highlights • Xeric shrub species: Artemisia ordosica , Caragana korshinskii , Salix psammophila • The fragile transition zone between the desert and the Loess Plateau of China • C. korshinskii increased mineral N content and net N mineralization rate • Effects of C. korshinskii were greater in dry and cold period and the 0–10 cm soil. • A. ordosica and S. psammophila did not influence soil N mineralization. [ABSTRACT FROM AUTHOR]

Abstract The presence of vegetation has significant effects on soil nitrogen (N) turnover. However, whether these effects vary with slope aspect, vegetation type and time of season were not understood in previous studies, precluding our ability to understand how vegetation affects soil N cycling in sloping land. In this study, we investigated the effects of vegetation presence (plots with vs. without vegetation), vegetation type (grassland vs. woodland) and slope aspect (east vs. west slope) on soil N turnover during the growing season in sloping lands of the Loess Plateau, China. Soil metrics measured included concentrations of ammonium (NH 4 +), nitrate (NO 3 −) and total mineral N (Min-N) in soil solution and rates of ammonification (R a), nitrification (R n) and net N mineralization (R m). We hypothesized that the presence of vegetation would deplete the soil Min-N pool and decrease R m and that these effects would be greater in east slopes and woodlands than in west slopes and grasslands. In partial support of these hypotheses, vegetation presence decreased soil Min-N concentration but did not affect R m. NH 4 + and NO 3 − contributed similarly to Min-N, while R n dominated R m. The effects of vegetation presence on soil mineral N and N mineralization varied with the time of the season but were not related to the vegetation type and slope aspect. The soil Min-N and R m were significantly higher in woodlands, east slopes and 0–10 cm depth than grasslands, west slopes and 10–20 cm depth, respectively. The R a and NH 4 + increased, while the R n , R m , NO 3 − and Min-N decreased with increasing soil moisture. These results indicated that soil Min-N and R m in the sloping lands of the Loess Plateau consistently respond to vegetation presence across slope aspect and vegetation type, and were regulated by soil moisture. Highlights • Vegetation decreased soil inorganic N pool because of plant uptake. • Effects of vegetation presence (plots with vs. without vegetation) on soil mineral N and N mineralization varied with season. • Effects of vegetation presence on N turnover were irrespective to vegetation type and slope aspect. • Soil mineral N pool and mineralization rate were higher in woodland and east than grassland and west slope. [ABSTRACT FROM AUTHOR]

Soil erosion can dramatically alter soil nitrogen (N) cycling, but it has rarely been examined under in-situ conditions due to the complicated interaction between erosion and vegetation. Comparing the effects of vegetation presence at eroding and depositional sites would provide a direct understanding of such effects. Herein, we investigated how soil N dynamics (mineral N pools and net N mineralization rates) responded to vegetation presence (plot with vs. without vegetation), landscape position (eroding vs. depositional sites) and vegetation type (grassland vs. woodland) during a two-year manipulation experiment using an in-situ incubation method in the hilly-gully region of China's Loess Plateau. The results showed that soils on eroding site had higher concentrations of nitrate (3.820 ± 0.302 vs. 2.642 ± 0.280 mg kg-1) and mineral N (5.853 ± 0.320 vs. 4.308 ± 0.287 mg kg-1) but similar rates of net nitrification (0.057 ± 0.013 vs. 0.051 ± 0.011 mg kg-1 d-1) and mineralization (0.056 ± 0.014 vs. 0.056 ± 0.013 mg kg-1 d-1) in comparison to depositional site in all grassland plots. The concentrations of soil nitrate and mineral N and rates of net nitrification and mineralization in legume woodland were 26%, 19%, 88% and 64% higher than that in grassland in all slope plots, respectively. Although vegetation presence significantly decreased soil nitrate (−57%) and total mineral N (−27%) concentrations, it did not affect the rates of net nitrification and mineralization. The effects of vegetation presence on soil net N mineralization occurred irrespective of landscape position and vegetation type(P > 0.05), but varied with season or year, with greater effects in 2017 growing season than in the non-growing season and 2018 growing season. Redundancy analysis and hierarchical partitioning indicated that the above- and blow-ground biomass accounted for most of the variation in soil N mineralization. These results suggested that the variations in soil mineral N and net N mineralization in relation to vegetation presence in this eroding watershed were consistent across different landscape positions and vegetation types, but showed intra- and inter-annual variability. • Vegetation presence decreased soil mineral N pools because of plant uptake. • Soil mineral N concentrations in eroding site were higher than deposition site for the grassland. • Soil mineral N and mineralization rates were higher in woodland than grassland for the eroding sites. • Effects of vegetation presence on soil mineral N and mineralization rates were irrespective to landscape position and vegetation type, but varied with season or year. [ABSTRACT FROM AUTHOR]

Re-vegetation of cropland is an important measure for carbon (C) sequestration, while the combined effects of land-use change, re-vegetation type and time on soil organic C (OC) turnover and temperature sensitivity have been less studied. Here, we investigated soil cumulative OC mineralization (C min), specific OC mineralization (C min /C 0 , normalized by initial OC) and temperature sensitivity (Q 10) with an 84-d incubation experiment after the conversion of cropland to artificial grassland (6, 10, 15 and 20 yr), to natural grassland (6, 10 and 20 yr) and to pea shrub woodland (10, 20 and 40 yr) in the agro-pastoral ecotone of northern China. Results showed that re-vegetation significantly increased C min (from 38.21 to 57.79 mg kg−1 soil, +51%) at the 0–10 cm depth but not the 10–20 cm depth, with greater increases after the conversion of cropland to artificial grassland (+77%) than the other two patterns but similar among different conversion years for each pattern. Variations in C min among different re-vegetation patterns and times were mostly explained by changes in total nitrogen concentration (TN) in the macro-aggregate fraction. Across all treatments, 6.20–20.29 g kg−1 OC was mineralized during the incubation and Q 10 was 1.16–2.40. The C min /C 0 and Q 10 changed not significantly during the post-agricultural re-vegetation chronosequences for each pattern, which were mostly due to the unchanged TN concentration in silt and clay fraction. Re-vegetation also changed the dependence of C min , C min /C 0 on N availability, with significant relationships in re-vegetated artificial grassland and pea shrub woodland which may due to the influence of legumes on microbes. In conclusion, OC mineralization increased with conversion, varying by re-vegetation type, while OC decomposability and temperature sensitivity were stable regardless of re-vegetation type and time, indicating the similar biodegradability and stability in face of warming. • OC mineralization and Q 10 were tested in varied re-vegetation types and times. • Cropland re-vegetation increased C min especially for artificial grassland. • •N in macro-aggregate explained about 50% of cumulative OC mineralization. • •OC biodegradability and Q 10 were similar during the post agricultural restoration. [ABSTRACT FROM AUTHOR]