Thirty-day Unplanned Reoperations After Posterior Surgery for Thoracic Spinal Stenosis: A Single-center Study Based on 1948 Patients.

STUDY DESIGN: A retrospective study. OBJECTIVE: The purpose of this study is to identify the incidences, causes, and risk factors of 30-day unplanned reoperation of posterior surgery for thoracic spinal stenosis (TSS) based on 1948 patients in a single center. SUMMARY OF BACKGROUND DATA: Unplanned reoperation is suggested to be a useful quality indicator for spine surgery. However, the incidences, causes, and risk factors of 30-day unplanned reoperation in patients who underwent posterior spinal surgery for TSS have not been well-established. MATERIALS AND METHODS: We retrospectively analyzed the clinical data of patients who underwent posterior spinal surgery for TSS from January 2011 to December 2021. Statistical methods including univariate and multivariate analyses were performed to assess the incidences, causes, and risk factors. RESULTS: A total of 1948 patients who underwent posterior spinal surgery for TSS in our institution were reviewed, and 77 (3.95%) required unplanned reoperations within 30 days because of epidural hematoma (1.64%), wound-related complications (1.02%), inadequate decompression (0.41%), and implant malposition or failure (0.36%), neurological deficit (0.26%), and other causes (0.26%). After univariate analysis, seven clinical factors were associated with unplanned reoperation ( P <0.05). Multivariate logistic regression analysis showed that upper thoracic spine surgery ( P =0.010), thoracic kyphosis ≥45° ( P =0.039), and intraoperative dural injury ( P =0.047) were independent risk factors for 30-day unplanned reoperation of posterior surgery for TSS. CONCLUSIONS: The incidence of 30-day unplanned reoperations after posterior surgical treatment for TSS was 3.95%. The most common causes were epidural hematoma, wound-related complications, inadequate decompression, and implant malposition or failure. Upper thoracic spine surgery, thoracic kyphosis ≥45°, and intraoperative dural injury led to an increased risk of unplanned reoperation within 30 days after posterior spinal surgery for TSS. LEVEL OF EVIDENCE: 4.

Arbuscular mycorrhizal fungi enhanced rice proline metabolism under low temperature with nitric oxide involvement.

Arbuscular mycorrhizal fungi (AMF) are known to improve plant stress tolerance by regulating proline accumulation, and nitric oxide (NO) plays an important signaling role in proline metabolism. Environmental nitrogen (N) affects AMF colonization and its contribution to host plants resistance to stress conditions. However, the relationship between proline metabolism and NO in mycorrhizal rice and the effect of N application on symbiont proline metabolism under low temperature have not been established. Pot culture experiments with different temperature, N and exogenous NO donor treatments were conducted with non-mycorrhizal and mycorrhizal rice. The results showed that AMF enhanced rice proline accumulation under low-temperature stress and decreased glutamate (Glu) and ornithine (Orn) concentrations significantly. In comparison with non-mycorrhizal rice, AMF colonization significantly decreased the Glu concentration, but had little effect on the Orn concentration under low-temperature stress, accompanied by increasing expression of OsP5CS2, OsOAT and OsProDH1. Exogenous application of NO increased proline concentration both under normal and low temperature, which exhibited a higher increase in mycorrhizal rice. NO also triggered the expression of key genes in the Glu and Orn pathways of proline synthesis as well as proline degradation. Higher N application decreased the AMF colonization, and AMF showed greater promotion of proline metabolism at low N levels under low temperature stress by regulating the Glu synthetic pathway. Meanwhile, AMF increased rice nitrate reductase (NR) and nitric oxide synthase (NOS) activities and then enhanced NO accumulation under low N levels. Consequently, it could be hypothesized that one of the mechanisms by which AMF improves plant resistance to low-temperature stress is the accumulation of proline via enhancement of the Glu and Orn synthetic pathways, with the involvement of the signaling molecule NO. However, the contribution of AMF to rice proline accumulation under low-temperature stress was attenuated by high N application.

PM2.5 and water-soluble inorganic ion concentrations decreased faster in urban than rural areas in China.

We investigated variations of PM2.5 and water-soluble inorganic ions chemical characteristics at nine urban and rural sites in China using ground-based observations. From 2015 to 2019, mean PM2.5 concentration across all sites decreased by 41.9 µg/m3 with a decline of 46% at urban sites and 28% at rural sites, where secondary inorganic aerosol (SIAs) contributed to 21% (urban sites) and 17% (rural sites) of the decreased PM2.5. SIAs concentrations underwent a decline at urban locations, while sulfate (SO42-), nitrate (NO3-), and ammonium (NH4+) decreased by 49.5%, 31.3% and 31.6%, respectively. However, only SO42- decreased at rural sites, NO3- increased by 21% and NH4+ decreased slightly. Those changes contributed to an overall SIAs increase in 2019. Higher molar ratios of NO3- to SO42- and NH4+ to SO42- were observed at urban sites than rural sites, being highest in the heavily polluted days. Mean molar ratios of NH3/NHx were higher in 2019 than 2015 at both urban and rural sites, implying increasing NHx remained as free NH3. Our observations indicated a slower transition from sulfate-driven to nitrate-driven aerosol pollution and less efficient control of NOx than SO2 related aerosol formation in rural regions than urban regions. Moreover, the common factor at urban and rural sites appears to be a combination of lower SO42- levels and an increasing fraction of NO3- to PM2.5 under NH4+-rich conditions. Our findings imply that synchronous reduction in NOx and NH3 emissions especially rural areas would be effective to mitigate NO3--driven aerosol pollution.

Zinc application after low temperature stress promoted rice tillers recovery: Aspects of nutrient absorption and plant hormone regulation.

Low temperature during the vegetative stage depresses rice tillering. Zinc (Zn) can promote rice tiller growth and improve plant resistance to abiotic stress. Consequently, Zn application after low temperature might be an effective approach to promote rice tiller recovery. A water culture experiment with treatments of two temperatures (12 °C and 20 °C) and three Zn concentrations (0.08 µM, 0.15 µM and 0.31 µM ZnSO4·7H2O) was conducted to determine by analyzing rice tiller growth, nutrient absorption and hormones metabolism. The results showed that low temperature reduced rice tiller numbers and leaf age, decreased as well. Increasing Zn application after low temperature could enhance not only rice tiller growth rate but also N metabolism and tillering recovery, and correlation analysis showed a significantly positive correlation between tiller increment and Zn and N accumulation after low temperature. In addition, higher cytokinin (CTK)/auxin (IAA) ratio was maintained by promoted synthesis of CTK and IAA as well as enhanced IAA transportation from tiller buds to other parts with increased Zn application after cold stress, which resulted in accelerated germination and growth of tiller buds. These results highlighted that Zn application after low temperature promoted rice tiller recovery by increasing N and Zn accumulation and maintaining hormones balance.

[Analysis of the Traits of Nitrogen Metabolism Pathways for Several Forest Soils in Eastern China].

Nitrogen metabolism pathways mediated by microorganisms play an important role in maintaining the structure and functional stability of soil ecosystems. Clarifying the relationships between microbial communities and nitrogen metabolism pathways can expand our understanding of nitrogen metabolism pathways at a microscopic level. However, the horizontal gene transfer of microorganisms means that taxonomy-based methods cannot be easily applied. A growing number of studies have shown that functional traits affect community construction and ecosystem functions. Using methods based on functional traits to study soil microbial communities can, therefore, better characterize nitrogen metabolism pathways. Here, five typical forest soils in China, namely black soil(Harbin, Heilongjiang), dark-brown earth(Changbaishan, Jilin), yellow-brown earth(Wuhan, Hubei), red earth(Fuzhou, Fujian), and humid-thermo ferralitic soil(Ledong, Hainan), were selected to study the traits of nitrogen metabolism pathways using metagenomic technology combined with the trait-based methods. The studied nitrogen metabolism pathways were ammonia assimilation, nitrate dissimilatory reduction, nitrate assimilatory reduction, denitrification, nitrification, nitrogen fixation, and anaerobic ammonia oxidation. The results showed that bacteria dominated the metagenomic library, accounting for 98.02% of all the sequences. Across all domains, the most common pathway was ammonia assimilation. For example, an average of 2830 ammonia assimilation pathway genes were detected for every million annotated bacterial sequences. In comparison, nitrogen fixation and anaerobic ammonia oxidation were the least detected pathways, accounting for 28.3 and 10.7 per million sequences, respectively. Different microorganisms can participate in a same nitrogen metabolism pathway, and the community structure of different soils was variable. The five typical forest soils in China show the same microbial nitrogen metabolism pathway traits; however, the community structure of the microorganisms mediating these processes was found to vary.

Magnesium Fertilization Affected Rice Yields in Magnesium Sufficient Soil in Heilongjiang Province, Northeast China.

Magnesium (Mg) plays a crucial role in rice yield. Heilongjiang Province is the main rice-producing region of China, playing an important role in guaranteeing China's and the world's grain security. However, rarely Mg fertilization is applied in this province. Soil Mg status of main rice-producing areas in Heilongjiang Province was investigated and Mg fertilizer experiments were conducted aiming to provide fertilizer recommendation in this region. A total of 358 soil samples from the 0-20 cm and 20-40 cm soil layer from the main rice-producing areas of Heilongjiang Province were collected to analyze soil exchangeable Mg (ex-Mg) and relative chemical properties. Meanwhile, field experiments of soil and foliar Mg application were performed in 2017-2019 to identify the effect of this nutrient on rice yield. The results showed that the ex-Mg concentration in the 0-20 cm and 20-40 cm soil layer was 282 mg kg-1 and 243 mg kg-1, respectively. Moreover, ex-Mg ranged on the abundant and exceptionally abundant level accounted for 75% in 0-20 cm and 55.3% in 20-40 cm. The ex-Mg concentration in the upper soil layer was higher than in the lower soil layer and varied depending on regions, which the west part of Heilongjiang Province showed the highest concentration in both soil layers. Correlation analysis showed that there had a significant (P < 0.05) linear relationship between ex-Mg and pH, CEC, ex-K, Ca, K/Mg, and Ca/Mg. Meanwhile, the results of path coefficients demonstrated that pH, CEC, and Ca/Mg had the most direct effect on ex-Mg concentration among these above factors. Soil Mg application had little effect on rice yield, which might be related to the soil Mg concentration and availability, and root uptake activity. Foliar Mg application increased rice yield by 8.45% (P < 0.05) compared to without Mg treatment, increased 1,000-grain weight by 2.62% (P < 0.05), and spikelet number per panicle by 4.19% (P < 0.05). In general, the paddy soil ex-Mg concentration in Heilongjiang Province was abundant. Soil-applied Mg played little role in rice yield in ex-Mg abundant regions, while foliar application increased rice yields significantly via increasing 1,000-grain weight and spikelet number per panicle.

The Involvement of Aquaporin-4 in the Interstitial Fluid Drainage Impairment Following Subarachnoid Hemorrhage.

The mechanism of brain injury following subarachnoid hemorrhage (SAH) has not yet been clarified. The glymphatic system (GS), a glia-dependent waste clearance pathway, drains away soluble waste proteins and metabolic products, even some toxic factors from the brain. Aquaporin-4 (Aqp4) is highly expressed on the astrocyte foot processes and facilitates the interstitial fluid (ISF) transportation in the GS system. In this study, the role of Aqp4 in the GS injury after SAH was explored using Aqp4 gene knockout (Aqp4-/-) Sprague Dawley rats. The results of MRI, fluorescent imaging, and transmission electron microscopy (TEM) indicated that, after SAH, the inflow of cerebrospinal fluid (CSF) into the brain and the clearance of ISF from the brain were both significantly decreased. Meanwhile, the expression level of Aqp4 around the artery was markedly higher than that around the vein following SAH. Aqp4 knockout exacerbated the GS damage after SAH. In summary, after SAH, there was an apparent GS impairment, and Aqp4 played key roles in modulating the function of GS in the brain.

Pursuing sustainable productivity with millions of smallholder farmers.

Sustainably feeding a growing population is a grand challenge, and one that is particularly difficult in regions that are dominated by smallholder farming. Despite local successes, mobilizing vast smallholder communities with science- and evidence-based management practices to simultaneously address production and pollution problems has been infeasible. Here we report the outcome of concerted efforts in engaging millions of Chinese smallholder farmers to adopt enhanced management practices for greater yield and environmental performance. First, we conducted field trials across China's major agroecological zones to develop locally applicable recommendations using a comprehensive decision-support program. Engaging farmers to adopt those recommendations involved the collaboration of a core network of 1,152 researchers with numerous extension agents and agribusiness personnel. From 2005 to 2015, about 20.9 million farmers in 452 counties adopted enhanced management practices in fields with a total of 37.7 million cumulative hectares over the years. Average yields (maize, rice and wheat) increased by 10.8-11.5%, generating a net grain output of 33 million tonnes (Mt). At the same time, application of nitrogen decreased by 14.7-18.1%, saving 1.2 Mt of nitrogen fertilizers. The increased grain output and decreased nitrogen fertilizer use were equivalent to US$12.2 billion. Estimated reactive nitrogen losses averaged 4.5-4.7 kg nitrogen per Megagram (Mg) with the intervention compared to 6.0-6.4 kg nitrogen per Mg without. Greenhouse gas emissions were 328 kg, 812 kg and 434 kg CO2 equivalent per Mg of maize, rice and wheat produced, respectively, compared to 422 kg, 941 kg and 549 kg CO2 equivalent per Mg without the intervention. On the basis of a large-scale survey (8.6 million farmer participants) and scenario analyses, we further demonstrate the potential impacts of implementing the enhanced management practices on China's food security and sustainability outlook.

Producing more grain with lower environmental costs.

Agriculture faces great challenges to ensure global food security by increasing yields while reducing environmental costs. Here we address this challenge by conducting a total of 153 site-year field experiments covering the main agro-ecological areas for rice, wheat and maize production in China. A set of integrated soil-crop system management practices based on a modern understanding of crop ecophysiology and soil biogeochemistry increases average yields for rice, wheat and maize from 7.2 million grams per hectare (Mg ha(-1)), 7.2 Mg ha(-1) and 10.5 Mg ha(-1) to 8.5 Mg ha(-1), 8.9 Mg ha(-1) and 14.2 Mg ha(-1), respectively, without any increase in nitrogen fertilizer. Model simulation and life-cycle assessment show that reactive nitrogen losses and greenhouse gas emissions are reduced substantially by integrated soil-crop system management. If farmers in China could achieve average grain yields equivalent to 80% of this treatment by 2030, over the same planting area as in 2012, total production of rice, wheat and maize in China would be more than enough to meet the demand for direct human consumption and a substantially increased demand for animal feed, while decreasing the environmental costs of intensive agriculture.

[Effects of selenium on soybean chloroplast ultra-structure and microelement content of soybean leaves under continuous cropping stress].

Pot and field experiments were carried out to study the effect of low Se concentration on soybean chloroplast ultra-structure and on Mg, Fe, Mn and contents in soybean leaves under continuous cropping stress. The results showed that Se could certainly increase the contents of Mg, Fe and Mn in soybean leaves when the application rate of Se was below 0.50 mg.kg-1 in pot experiment, and below 300 g.hm-2 in field experiment. In pot experiment, Se concentration positively correlated with Mg and Fe contents in soybean leaves, but the relationship between Mn and Se was hardly to be quantified. Transmission electron microscopic observation indicated that under continuous cropping stress, application of Se could hold the soybean chloroplast membrane structure in good condition. When Se was not applied, the chloroplast swelled, and its grana disappeared, and even, transformed into etioplast. These experiments indicated that application of low Se could alleviate peroxidative stress resulting from continuous cropping, and keep the soybean grow normally.