The influence of grazing intensity on soil organic carbon storage in grassland of China: A meta-analysis.

Grazing can potentially affect grassland soil carbon storage through selective feeding, trampling and fecal excretion of livestock. The numerous case studies and a few meta-analyses have focused on grazing-induced changes in soil organic carbon (SOC) storage, but the effects of grazing on SOC in major grassland types of China are not clear. In this study, we performed a comprehensive meta-analysis to identify the impact of grazing on soil carbon in China. We found that the key factors affecting the SOC content of grazing grasslands is grazing intensity. Heavy grazing (HG) significantly decreased the SOC content by 7.5 % in major grassland types of China (95 % confidence interval (CI), -11.43 % to -3.57 %, P < 0.001). The SOC content in temperate desert steppes (7.22 %), temperate meadow-steppes (10.89 %) under heavy grazing (HG) showed significantly (P < 0.05) decreased. HG resulted in significant (P < 0.01) decreases in SOC content (6.91 %) of Kastanoze. Our study highlighted that formulating rational grazing strategies according to grassland and soil types was the key to increasing SOC storage and sequestration under climate change and increased human pressure.

Potential short-term effects of earthquake on the plant-soil interface in alpine grassland of the Qinghai-Tibetan Plateau.

Earthquakes are environmental disturbances affecting ecosystem functioning, health, and biodiversity, but their potential impacts on plant-soil interface are still poorly understood. In this study, grassland habitats in areas near and away from the seismo-fault in Madou, a region typical of alpine conditions on the Qinghai-Tibetan Plateau, were randomly selected. The impacts of earthquake on soil properties and plant nutrient content in the short term were emphasized, and their potential relationships with community diversity and productivity were examined. According to the findings of the study, the Maduo earthquake led to a decrease in soil nutrient content in alpine grassland ecosystems, especially soil TC, TN, TP, TCa, AP, AK, NH4 +-N, and SOC, and inhibited the absorption of N, Ca, and Mg nutrients by plants. In addition, the diversity and productivity of communities were affected by both direct and indirect earthquake pathways. The negative impacts of seismic fracture on soil structure had the most significant direct impact on plant community diversity. Earthquakes also indirectly reduced community productivity by reducing the soil N content and inhibiting the absorption of plant nutrients. Our findings suggested that earthquakes could potentially decrease the stability of the alpine grassland ecosystem on the QTP by affecting nutrient availability at the plant-soil interface.

Sodium citrate effectively used in shed mediastinal blood autotransfusion after cardiac surgery.

BACKGROUND: We used sodium citrate as an alternative anticoagulation agent to heparin in the procedure of autologous blood transfusion with patients with postoperative haemorrhage after CPB. The aim of study was to evaluate the efficacy and safety of sodium citrate used in shed mediastinal blood autotransfusion after cardiac surgery. METHODS: Ninety-three patients were divided into two groups in this study. In the control group, 52 patients' shed mediastinal blood was discarded. The reinfusion group consisted of 41 patients receiving a reinfusion of washed autologous red cells from shed mediastinal blood. Each 400 mL shed blood sample was anticoagulated by 140 mL of 1.6% diluted sodium citrate in the washing procedure using a blood recovery machine. Hemoglobin (Hb), hematocrit (Hct), and electrolyte concentrations in both the patients and shed mediastinal blood were measured before and after this procedure. RESULTS: The mean volume of autotransfused shed blood was 239.5 ± 54.6 mL.The Hct of the washed red cells was 56.8 ± 6.1%. Significantly, fewer units of allogeneic blood were required per patient in the reinfusion group at 24 h postoperatively (2.91 ± 1.34 vs 4.03 ± 0.19 U, p = 0.002). At 24 h postoperatively, Hb and Hct levels were higher in the reinfusion group than in the control group. The calcium ion concentration was very low in the shed mediastinal blood, 0.25 ± 0.08 mmol/L, and was lower after washing, 0.15 ± 0.04 mmol/L. CONCLUSIONS: Sodium citrate, as an alternative anticoagulant agent, can be used in autologous shed mediastinal blood transfusion after CPB cardiac surgery. This procedure can effectively reduce the amount of allogeneic blood for patients with haemorrhage.

Meta-Analysis of the Effect of Saline-Alkali Land Improvement and Utilization on Soil Organic Carbon.

There is a large amount of saline-alkali land in China. Through the improvement and utilization of saline-alkali land to improve the carbon content in soil, it can not only become a reserve resource of cultivated land or grazing grassland, but also become an important land "carbon sink". In this study, we performed a comprehensive meta-analysis to identify the impact of improvement and utilization of saline-alkali soil on soil organic carbon (SOC) in China. Our results showed that the soil salt and alkali content in Heilongjiang Province and Jilin Province in China was the highest, with an SOC content between 3.05 and 17.8 g/kg and pH between 8.84 and 9.94. Among the five methods of reclamation, halophyte planting, fertilization, biochar and modifier application, only biochar and modifier application significantly increased the SOC content (p < 0.05). The content of SOC in saline-alkali soil was 2.9−6.3 g/kg before biochar application, and significantly increased to 6.2−13.05 g/kg after biochar application (p < 0.01). The SOC content was 3.05−8.12 g/kg before the application of the modifier, and significantly increased to 3.68−9 g/kg (p < 0.05) after the application of the modifier. After utilization and improvement of saline-alkali land, the total nitrogen, available phosphorus and available potassium also increased significantly (p < 0.05). This study provides a scientific basis for further understanding the improvement and utilization of saline-alkali land in China and its potential for increasing carbon sinks.

Effects of seasonal grazing on plant and soil microbial diversity of typical temperate grassland.

Biodiversity is the decisive factor of grassland ecological function and process. As the most important human use of grassland, grazing inevitably affects the grassland biodiversity. However, comprehensive studies of seasonal grazing on plant and soil bacterial, archaeal and fungal diversity of typical temperate grassland are still lacking. We examined the impact of seasonal grazing, including no-grazing (NG), continuous grazing (CG), grazing in May and July (G57), grazing in June and August (G68), and grazing in July and September (G79) on grassland plant and soil microbial diversity based on a long-term field grazing experiment. The results showed that the aboveground plant biomass (AGB) of the seasonal grazing plots was significantly higher than that of the CG plots. Compared with NG, CG increased significantly the Margalef richness index of plant community, while did not significantly change the Shannon, Simpson and Pielou evenness of plant community. Grazing changed the composition and biomass of dominant vegetation. Long-term grazing decreased the proportion of Leymus chinensis (Trin.) Tzvel. and increased the proportion of Cleistogenes squarrosa (Trin.) Keng. There was no significant change in the Shannoneven, Shannon and Coverage indices of soil bacteria, archaea and fungi between NG and the grazing plots. But the Chao index of soil fungi in G57, G68 and G79 and archaea in G57, G79 was significantly higher than that in CG. The results of correlation analysis showed that the plant diversity in the CG plots was significantly negatively correlated with the soil bacterial diversity. The plant richness in the G57 and G68 plots was significantly positively correlated with the soil archaea richness. Our study showed that seasonal grazing was a sustainable grazing management strategy for maintaining typical grassland plant and soil microbial diversity in northern of China.

Impacts of Short-Term Grazing Intensity on the Plant Diversity and Ecosystem Function of Alpine Steppe on the Qinghai-Tibetan Plateau.

Livestock grazing is the primary land use of grasslands worldwide. Grazing has been asserted to alter grassland ecosystem functions, such as productivity, nutrient cycling, and biodiversity conservation. However, few studies have focused on the impact of grazing intensity on the ecosystem multifunctionality (EMF) of alpine grasslands. We conducted a field experiment of manipulating sheep grazing intensity effects on alpine steppe by surveying plant community characteristics and ecosystem functions. Our results showed that plant community composition was altered with increasing grazing intensity, and the dominant species shifted from grasses and sedges to forbs. EMF was the highest under no grazing (CK) and the lowest under heavy grazing (HG), but there was insignificant difference between CK and HG. HG significantly decreased some indicators that reflected nutrient cycling functions, such as soil available nitrogen, plant leaf nitrogen (PN) and phosphorus content (PP). Furthermore, plant diversity had strong correlations with SOC, total nitrogen (TN), and PN. The results could provide scientific bases for biodiversity conservation and sustainable grazing management of alpine steppe.

Effects of Strong Earthquake on Plant Species Composition, Diversity, and Productivity of Alpine Grassland on Qinghai-Tibetan Plateau.

Earthquakes occur frequently in fragile alpine grassland areas on the Qinghai-Tibet Plateau (QTP), but few studies have evaluated the impacts of seismo-fault of earthquake on alpine grassland vegetation diversity. In this study, we conducted a field survey of plant communities of alpine grassland along the fault zone in the 7.4 Maduo earthquake occurred on 22 May 2021. Surrounding grassland habitat far from the seismo-fault of earthquake was selected as the control. Plant community metrics around and far from seismic rupture were studied. The results showed that plant community metrics were negatively affected by seismo-fault of earthquake. Species composition around seismo-fault was being shifted from sedges-dominant into forbs-dominant. In addition, the diversity and aboveground biomass were significantly decreased around seismo-fault compared with the control. Our findings highlighted that earthquakes can cause species loss and plant community shift and finally lead to productivity reduction of alpine grassland. Additionally, forbs may be more competitive than other functional groups after the earthquake.

Doppler ultrasound and photoplethysmographic assessment for identifying pregnancy-induced hypertension.

The current study investigated whether placentation and systemic inflammation are associated with pregnancy-induced hypertension (PIH) or pre-eclampsia (PE), and evaluated some measurable indexes for assessment of maternal factors contributing to high-risk pregnancy. Photoplethysmographic reflection index (PPG RI), uterine artery (UtA) pulsatile index (PI) and reflection index (RI), as well as maternal serum placental growth factor (PlGF) and soluble endoglin (sEng) were measured in pregnant women with singleton pregnancy at the gestational age of 22 to 23 weeks. Study subjects were women with normal pregnancy (NP, n=24), PIH (n=14) and PE (n=16). It was found that individuals in the PIH group exhibited higher UtA RI and UtA PI values, as well as PPG RI values compared with individuals in the NP group. Individuals in the PE group had the highest UtA RI, UtA PI and PPG RI values among these 3 groups. UtA and PPG results were significantly different in PIH and PE groups compared with the NP group. Significant differences were found in both PlGF and sEng levels between PIH and PE groups. A strong inverse across-subject correlation was found between PlGF and sEng levels. A weak inverse correlation was found between PlGF and UtA RI, and PlGF and UtA PI. A moderate inverse correlation was found between PlGF and PPG RI. A moderate positive correlation was found between either sEng and UtA RI or sEng and UtA PI. A very strong positive correlation was found between sEng and PPG RI. Taken together, the current results indicated that maternal effects related to cardiovascular adaptation to placentation and systemic inflammation exhibited significant differences between NP and PIH or PE groups. Therefore, assessment of UtA and PPG could be used for identifying high-risk pregnancy.

Dissecting intramyocardial hematoma with flexuous channel in myocardium masquerading as a ventricular pseudoaneurysm.

We report a 58-year-old acute myocardial infarction patient with dissecting intramyocardial hematoma (DIH) disguised as a ventricular pseudoaneurysm. DIH with a flexuous and narrow channel in the myocardium was confirmed during the operation, which extended deeply into the periphery of the ventricular wall. This DIH connected with the left ventricle via a narrow-necked flexuous channel of the myocardial defect and looked like a bulged sac surrounded by a thin wall of myocadium. No pericardium effusion was seen. Based on this report, we believe that a DIH has plentiful variety and this specific kind of DIH should be differentially diagnosed with pseudoaneurysm.

Left atrial endocardial dysfunction and platelet activation in patients with atrial fibrillation and mitral stenosis.

OBJECTIVE: This study demonstrated left atrial endocardial dysfunction and platelet activation in patients with atrial fibrillation and mitral stenosis. METHODS: Study included 80 patients with mitral stenosis and atrial fibrillation (40 each with and without left atrial thrombosis), 15 healthy volunteers, and 10 left atrial appendage (LAA) specimens from donor hearts. Blood samples were collected through peripheral vein and left atrium, with peripheral blood samples of volunteers as controls. LAA specimens were collected during operations. LAA expressions of von Willebrand factor (vWF) and P-selectin were determined immunohistochemically; plasma concentrations were measured by enzyme-linked immunosorbent assay. LAA expressions of vWF and P-selectin genes in were quantitated with real-time fluorescent quantitative polymerase chain reaction. RESULTS: The difference in vWF and P-selectin plasma levels between left atrial and peripheral venous blood was not significant; however, peripheral plasma levels of vWF and P-selectin were significantly higher in those with thrombosis than without thrombosis, which in turn were higher than in healthy subjects. Both vWF and P-selectin proteins were stained in both left atrial endocardium and cardiomyocytes. The normalized vWF gene expression relative to control was 3.04 in patients with thrombosis and 2.16 in those without thrombosis (P<.01). The difference in P-selectin gene expressions among the groups was not significant. CONCLUSIONS: No differences were observed in plasma levels of vWF and P-selectin between left atrial and peripheral venous blood. Over expression of vWF gene in LAA may contribute to increased plasma vWF levels. P-selectin and vWF together may play a role in thrombosis.

Off-pump coronary artery bypass grafting with device closure of atrial septal defect.

Patients with coronary artery disease and atrial septal defect may have unique clinical characters. We describe an off-pump combined approach for intraoperative device closure of atrial septal defect during coronary artery bypass grafting.

Coronary artery bypass grafting in adults with congenital heart disease.

BACKGROUND: Adults with congenital heart disease (CHD) and coronary artery disease (CAD) have unique clinical manifestation due to the coexistence of intracardiac anomalies and CAD. Case reports are rare in surgical management of CHD combined with CAD. Our goal is to study the outcome of surgical intervention of CHD and CAD concomitantly. METHODS: From February 2002 to August 2009, 29 adult patients underwent coronary artery bypass grafting (CABG) and surgical correction of CHD concomitantly. Congenital cardiac anomalies include atrial septal defect (ASD) in 21 cases, ventricular septal defect in four cases, atrioventricular septal defect in three cases, and cor triatriatum in one case. Coronary angiography demonstrated: one-vessel disease in 10 cases, two-vessel disease in 11 cases, and three-vessel disease in eight cases. Coronary revascularization and intracardiac anomalies were corrected with cardiopulmonary bypass in 23 cases. There were six patients who had off-pump coronary artery pass grafting (OPCAB) and intraoperative device closure of ASD. RESULTS: One patient died of pulmonary infection and multiorgan failure. Follow-up time was from 2 to 89 months (mean, 42 ± 25 months). One patient with recurrent angina did not need intervention of the revascularization. Six patients who acquired OPCAB and intraoperative device closure of ASD had no complications after surgery. CONCLUSIONS: Surgery for adult patients who had CHD with CAD was a safe and effective management. OPCAB with intraoperative device closure of ASD was a reasonable approach for some selective patients.

Severe calcified saccular pulmonary artery aneurysm.

Pulmonary artery aneurysm is a very rare entity. Severe calcified saccular pulmonary artery aneurysm is not reported in the literature. A 19-year-old man with a severe calcified saccular pulmonary artery aneurysm is described.

[Coronary artery bypass graft for patients with ascending aorta atherosclerosis].

OBJECTIVE: The increasing number of aged patients with severe ascending aorta atherosclerosis who are undergoing coronary artery bypass graft (CABG) present high risk for ascending aortic cannulation, cross-clamping or partial occluding and proximal anastomosis. We reviewed the surgical experience in 22 patients of CABG with ascending aorta atherosclerosis and tried to find the way to minimize the complications. METHODS: Twenty-two patients with severe atherosclerotic and calcified ascending aorta underwent CABG in our hospital. Thirteen of them received CABG on beating heart. Nine patients had their CABG with extracorporeal circulation. With deep hypothermia, we reduced the flow rate and intermittently arrested the circulation for the proximal anastomosis on ascending aorta in 5 patients with neither cross-clamping nor partial occluding. The sequential grafts and "Y" type anastomosis between reversed saphenous venous grafts were employed. RESULTS: Twenty of the patients survived after surgery. One died of inhalation pneumonia in two weeks after surgery. Another died of right hemothorax in ten days after surgery. The complications include: pneumonia 4 patients (18%), angina 2 patients (9%), ventricular fibrillation 1 patients (5%), post-CABG myocardium infarction 1 case (5%) and hemothorax 1 case (5%). There is no neurologic complications or aortic dissection after CABG. CONCLUSION: CABG on beating heart with pedicel arterial grafts is the best approach to performing the surgery without touching the diseased ascending aorta. Ventricular fibrillation under mild hypothermia cardiopulmonary bypass and left ventricular suction were employed for quiet and bloodless field while distal anastomosis had no cross-clamping the ascending aorta. Also deep hypothermia and intermittently circulatory arrest offer quiet and bloodless field for the proximal anastomosis on ascending aorta without cross-clamping or partial-occluding. Distal sequential anastomosis and proximal "Y" type anastomosis are the effective approach to minimizing the proximal anastomosis on the ascending aorta.