A Novel Nomogram for Predicting Early Rebleeding After Endoscopic Treatment of Esophagogastric Variceal Hemorrhage.

BACKGROUND: Early rebleeding is a significant complication of endoscopic treatment for esophagogastric variceal hemorrhage (EGVH). However, a reliable predictive model is currently lacking. AIMS: To identify risk factors for rebleeding within 6 weeks and establish a nomogram for predicting early rebleeding after endoscopic treatment of EVGH. METHODS: Demographic information, comorbidities, preoperative evaluation, endoscopic features, and laboratory tests were collected from 119 patients who were first endoscopic treatment for EGVH. Independent risk factors for early rebleeding were determined through least absolute shrinkage and selection operator logistic regression. The discrimination, calibration, and clinical utility of the nomogram were assessed and compared with the model for end-stage liver disease (MELD), Child-Pugh, and albumin-bilirubin (ALBI) scores using receiver-operating characteristic (ROC) curves, calibration plots, and decision curve analyses (DCA). RESULTS: Early rebleeding occurred in 39 patients (32.8%) within 6 weeks after endoscopic treatment. Independent early rebleeding factors included gastric variceal hemorrhage (GVH), concomitant hepatocellular carcinoma (HCC), international normalized ratio (INR), and creatinine. The nomogram demonstrated exceptional calibration and discrimination capability. The area under the curve for the nomogram was 0.758 (95% CI 0.668-0.848), and it was validated at 0.71 through cross-validation and bootstrapping validation. The DCA and ROC curves demonstrated that the nomogram outperformed the MELD, Child-Pugh, and ALBI scores. CONCLUSIONS: Compared with existing prediction scores, the nomogram demonstrated superior discrimination, calibration, and clinical applicability for predicting rebleeding in patients with EGVH after endoscopic treatment. Therefore, it may assist clinicians in the early implementation of aggressive treatment and follow-up.

A nomogram for predicting major gastrointestinal bleeding in patients treated with rivaroxaban.

BACKGROUND: Rivaroxaban is a direct oral anticoagulant with the highest risk of anticoagulant-induced major gastrointestinal bleeding (MGIB). Currently, there is a lack of tools to identify patients at high risk of rivaroxaban-induced MGIB. OBJECTIVE: To establish a nomogram model to predict the risk of MGIB in patients receiving rivaroxaban. METHODS: Demographic information, comorbidities, concomitant medications, and laboratory test results were collected from 356 patients (178 diagnosed with MGIB) who were taking rivaroxaban between January 2013 and June 2021. Univariate and multivariate logistic regression analyses were used to identify the independent predictors of MGIB, and a nomogram was constructed based on these predictors. A receiver operating characteristic curve, Brier score, calibration plot, decision curve, and internal validation was used to evaluate the calibration, discrimination, and clinical usefulness of the nomogram. RESULTS: Age, haemoglobin level, platelet count, creatinine level, prior peptic ulcer disease, prior bleeding, prior stroke, proton pump inhibitor use, and antiplatelet agent use were independent predictors of rivaroxaban-induced MGIB. These risk factors were used to establish the nomogram. The area under the curve of the nomogram was 0.833 (95%CI, 0.782-0.866), the Brier score was 0.171, the internal validation accuracy was 0.73, and the kappa value was 0.46. CONCLUSION: The nomogram demonstrated good discrimination, calibration, and clinical applicability. Therefore, it could accurately predict the risk of MGIB in patients treated with rivaroxaban.

Different responses of two Chinese cabbage (Brassica rapa L. ssp. pekinensis) cultivars in photosynthetic characteristics and chloroplast ultrastructure to salt and alkali stress.

MAIN CONCLUSION: Salt and alkali stress affected the photosynthetic characteristics of Chinese cabbages. A salt-tolerant cultivar maintained its tolerance by ensuring the high ability of photosynthesis. The synthesis of organic acids and carbohydrates in leaves played important roles in improving the photosynthetic capacity of alkali-tolerant plants. Soil salinization has become an increasingly serious ecological problem, which limits the quality and yield of crops. As an important economic vegetable in winter, however, little is known about the response of Chinese cabbage to salt, alkali and salt-alkali stress in photosynthetic characteristics and chloroplast ultrastructure. Thus, two Chinese cabbage cultivars, 'Qinghua' (salt-tolerant-alkali-sensitive) and 'Biyu' (salt-sensitive-alkali-tolerant) were investigated under stresses to clarify the similarities and differences between salt tolerance and alkali tolerance pathways in Chinese cabbage. We found that the root of Qinghua, the leaf ultrastructure and net photosynthetic rate (Pn), stomatal conductance (Gs), water use efficiency (WUE), maximum photochemical quantum yield of PSII (Fv/Fm) and nonphotochemical quenching (NPQ) were not affected by salt stress. However, Biyu was seriously affected under salt stress. Its growth indexes decreased by between 60 and 30% compared with the control and the photosynthetic indexes were also seriously affected under salt stress. This indicated that the salt-tolerant cultivar Qinghua improved the photosynthetic fluorescence ability to promote the synthesis of organic matter resulting in salt tolerance. In contrast, under alkali treatment, the root of Biyu was affected by alkali stress, but could still maintain good growth, and root and leaf structure were not seriously affected and could maintain the normal operations. Biyu improved its tolerance by improving the water use efficiency, regulating the synthesis of organic acids and carbohydrates, ensuring the synthesis of organic matter and ensured the normal growth of the plant.

Palaeoenvironment and its control on the formation of Miocene marine source rocks in the Qiongdongnan Basin, northern South China Sea.

The main factors of the developmental environment of marine source rocks in continental margin basins have their specificality. This realization, in return, has led to the recognition that the developmental environment and pattern of marine source rocks, especially for the source rocks in continental margin basins, are still controversial or poorly understood. Through the analysis of the trace elements and maceral data, the developmental environment of Miocene marine source rocks in the Qiongdongnan Basin is reconstructed, and the developmental patterns of the Miocene marine source rocks are established. This paper attempts to reveal the hydrocarbon potential of the Miocene marine source rocks in different environment and speculate the quality of source rocks in bathyal region of the continental slope without exploratory well. Our results highlight the palaeoenvironment and its control on the formation of Miocene marine source rocks in the Qiongdongnan Basin of the northern South China Sea and speculate the hydrocarbon potential of the source rocks in the bathyal region. This study provides a window for better understanding the main factors influencing the marine source rocks in the continental margin basins, including productivity, preservation conditions, and the input of terrestrial organic matter.

Distribution and sources of phthalate esters in the topsoils of Beijing, China.

Phthalate esters in the topsoil samples collected from Beijing were determined by derivatization and gas chromatography-mass spectrometry techniques. The results showed that diethyl phthalate (DEP), diisobutyl phthalate ester (DIBP), dibutyl phthalate ester (DBP), dibutyl (2-ethyl hexyl) phthalate (DEHP), and dimethyl phthalate (DMP) were found in the topsoils. The total concentrations of the five phthalate esters varied from 2.30 to 24.71 µg g(-1). According to phthalate esters (PAEs) control standards in soil of the USA, the standard exceeding rates of DMP, DBP, and DEHP were 100 %, 100 %, and 4.84 % in soils of Beijing, respectively. The rate of DBP exceeding soil remediation standard was 12.9 %. Overall, concentrations of PAEs in Beijing were at a high level in China. The concentrations of DBP, DEHP, and DIBP were high, and the total concentrations of all the phthalate esters were higher in the areas with intensive human activities than in the other areas, which may be related to the use of phthalate compounds (such as the use of plastic products). The total and individual concentrations of phthalate compounds were relatively low in the areas that used plastic films compared with other samples due to the diffusion of atmospheric motion, categories, and amounts of plastic products and other factors. The greatest contributor may be the usage amount of plastic products in people's daily lives.

Prophylactic endotracheal intubation before endoscopic surgery reduces the rebleeding rate in acute esophagogastric variceal bleeding patients.

Objectives: Esophagogastric variceal bleeding (EVB) is one of the main causes of cirrhosis-related deaths, and endoscopic therapy is the first-line treatment of choice. However, the efficacy of prophylactic endotracheal intubation (PEI) before endoscopy remains controversial. Methods: Data were collected from 119 patients who underwent endoscopic confirmation of an EVB. Inverse probability of treatment weighting was applied to reduce bias between the two groups. The primary outcomes included rebleeding rates within 24 h and 6 weeks post-endoscopic surgery and 6-week mortality. Results: After endoscopic surgery, the rebleeding rate within 24 h in the PEI group was significantly lower than non-PEI group (1.2 % VS 12.6 %, P-value = 0.025). Although PEI did not reduce 6-week mortality, it significantly reduced the risk of rebleeding within 24 h (odds ratio [OR]: 0.89, 95 % confidence interval [CI]: 0.82-0.97, P = 0.008) and within 6 weeks (hazard ratio [HR]: 0.36, 95%CI: 0.14-0.90, P = 0.029). In multivariate regression analyses, maximum varices diameter >1.5 cm (OR: 1.23, 95 % CI: 1.09-1.37, P < 0.001) was independent risk factor for rebleeding within 24 h. Creatinine (HR: 1.01, 95 % CI: 1.01-1.02, P < 0.001) and international normalized ratio (HR: 2.99, 95 % CI: 1.99-4.65, P < 0.001) were independent risk factors for rebleeding within 6 weeks. Conclusions: PEI before endoscopic surgery reduced the incidence of rebleeding within 24 h and 6 weeks after endoscopic surgery. However, PEI did not reduce the 6-week mortality rate after endoscopic surgery and might increase the length of hospital stay.

Neural Dielet 2.0: A 128-Channel 2mm×2mm Battery-Free Neural Dielet Merging Simultaneous Multi-Channel Transmission through Multi-Carrier Orthogonal Backscatter.

Miniaturization of wireless neural-recording systems enables minimally-invasive surgery and alleviates the rejection reactions for implanted brain-computer interface (BCI) applications. Simultaneous massive-channel recording capability is essential to investigate the behaviors and inter-connections in billions of neurons. In recent years, battery-free techniques based on wireless power transfer (WPT) and backscatter communication have reduced the sizes of neural-recording implants by battery eliminating and antenna sharing. However, the existing battery-free chips realize the multi-channel merging in the signal-acquisition circuits, which leads to large chip area, signal attenuation, insufficient channel number or low bandwidth, etc. In this work, we demonstrate a 2mm×2mm battery-free neural dielet, which merges 128 channels in the wireless part. The neural dielet is fabricated with 65nm CMOS process, and measured results show that: 1) The proposed multi-carrier orthogonal backscatter technique achieves a high data rate of 20.16Mb/s and an energy efficiency of 0.8pJ/bit. 2) A self-calibrated direct digital converter (SC-DDC) is proposed to fit the 128 channels in the 2mm×2mm die, and then the all-digital implementation achieves 0.02mm2 area and 9.87µW power per channel.

Transcriptome- and genome-wide systematic identification of expansin gene family and their expression in tuberous root development and stress responses in sweetpotato (Ipomoea batatas).

Introduction: Expansins (EXPs) are essential components of the plant cell wall that function as relaxation factors to directly promote turgor-driven expansion of the cell wall, thereby controlling plant growth and development and diverse environmental stress responses. EXPs genes have been identified and characterized in numerous plant species, but not in sweetpotato. Results and methods: In the present study, a total of 59 EXP genes unevenly distributed across 14 of 15 chromosomes were identified in the sweetpotato genome, and segmental and tandem duplications were found to make a dominant contribution to the diversity of functions of the IbEXP family. Phylogenetic analysis showed that IbEXP members could be clustered into four subfamilies based on the EXPs from Arabidopsis and rice, and the regularity of protein motif, domain, and gene structures was consistent with this subfamily classification. Collinearity analysis between IbEXP genes and related homologous sequences in nine plants provided further phylogenetic insights into the EXP gene family. Cis-element analysis further revealed the potential roles of IbEXP genes in sweetpotato development and stress responses. RNA-seq and qRT-PCR analysis of eight selected IbEXPs genes provided evidence of their specificity in different tissues and showed that their transcripts were variously induced or suppressed under different hormone treatments (abscisic acid, salicylic acid, jasmonic acid, and 1-aminocyclopropane-1-carboxylic acid) and abiotic stresses (low and high temperature). Discussion: These results provide a foundation for further comprehensive investigation of the functions of IbEXP genes and indicate that several members of this family have potential applications as regulators to control plant development and enhance stress resistance in plants.

Clinical associations with thyroid disease in ANCA-associated vasculitis.

OBJECTIVE: To evaluate the frequency and the clinical relevance of thyroid disease in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) patients. METHODS: A total of 305 AAV patients admitted to the Second Affiliated Hospital of Chongqing Medical University between October 2010 and December 2023 were analyzed. Demographic, clinical, and laboratory data were compared between AAV patients with and without thyroid disease. Univariate and multivariate logistic regression analyses were conducted to identify factors associated with thyroid disease in AAV patients. RESULTS: Among the 305 AAV patients, 52 (17.0%) had concurrent thyroid disease. In univariate analysis, gender, coronary artery disease, renal involvement, anti-Ro/SSA antibodies, anti-Ro52 antibodies, anti-thyroglobulin antibodies (TgAb), and anti-thyroid peroxidase antibodies (TPOAb) exhibited significant differences between AAV patients with and without thyroid disease (P < 0.05). Multivariate analysis revealed that female gender (odds ratio (OR) = 2.423, 95% confidence interval (95% CI) 1.241, 4.729; P = 0.009), concurrent coronary artery disease (OR = 2.998, 95% CI 1.280, 7.019; P = 0.011), and positive anti-Ro/SSA antibodies (OR = 4.697, 95% CI 1.960, 11.257; P = 0.001) were associated with thyroid disease in AAV patients. CONCLUSION: AAV patients have a higher incidence of thyroid disease. Regular monitoring of thyroid function is advised for AAV patients, particularly for women, those with coronary artery disease, and those who are positive for anti-Ro/SSA antibodies. Key Points • AAV patients have a higher incidence of thyroid disease. • The potential clinical relevance of AAV patients with thyroid disease was explored. • Regular monitoring of thyroid function is advised for AAV patients.

Measurement of superoxide dismutase: clinical usefulness for patients with anti-neutrophil cytoplasmic antibody-associated vasculitis.

OBJECTIVE: To investigate the clinical usefulness of serum superoxide dismutase (SOD) measurement in patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). METHODS: In this single-center retrospective study, demographic data, serum SOD levels, erythrocyte sedimentation rate (ESR), C reactive protein (CRP), the Birmingham Vasculitis Activity Score (BVAS), ANCA, organ involvement, and outcomes were analyzed for 152 AAV patients hospitalized in the Second Affiliated Hospital of Chongqing Medical University. Meanwhile, the serum SOD levels of 150 healthy people were collected as the control group. RESULTS: Compared to the healthy control group, serum SOD levels of the AAV group were significantly lower (P < 0.001). SOD levels of AAV patients were negatively correlated to ESR, CRP, and BVAS (ESR rho = - 0.367, P < 0.001; CRP rho = - 0.590, P < 0.001; BVAS rho = - 0.488, P < 0.001). SOD levels for the MPO-ANCA group were significantly lower than the PR3-ANCA group (P = 0.045). SOD levels for the pulmonary involvement group and the renal involvement group were significantly lower than those for the non-pulmonary involvement group and the non-renal involvement group (P = 0.006; P < 0.001, respectively). SOD levels in the death group were significantly lower than the survival group (P = 0.001). CONCLUSIONS: In AAV patients, low SOD levels might indicate disease associated oxidative stress. SOD levels in AAV patients were decreased with inflammation, suggesting that SOD levels could potentially be a surrogate marker for disease activity. SOD levels in AAV patients were closely related to ANCA serology, pulmonary involvement, and renal involvement, with low SOD levels an important indicator of a poor prognosis for AAV patients.

Comparative efficiency and safety of potassium competitive acid blockers versus Lansoprazole in peptic ulcer: a systematic review and meta-analysis.

Background: Lansoprazole, a proton-pump inhibitor (PPI), is the primary therapy for peptic ulcers (PU). Potassium competitive acid blockers (P-CAB) offer an alternative for acid suppression. However, the efficacy and safety of P-CABs versus lansoprazole in the management of PU has not been evaluated. Methods: Five databases were searched for randomized clinical trials in English until 31 August 2023. Data extraction provided outcome counts for ulcer healing, recurrent NSAID-related ulcer, and adverse events. The pooled effect, presented as rate difference (RD), was stratified by ulcer location, follow-up time, and the types of P-CAB, along with their corresponding 95% confidence intervals (95% CI). Results: The pooled healing rates of peptic ulcers were 95.3% (1,100/1,154) and 95.0% (945/995) for P-CABs and lansoprazole, respectively (RD: 0.4%, 95% CI: -1.4%-2.3%). The lower bounds of the 95% CI fell within the predefined non-inferiority margin of -6%. In subgroup analyses base on ulcer location, and follow-up time also demonstrated non-inferiority. The drug-related treatment-emergent adverse events (TEAEs) did not differ significantly among groups (RR: 0.997, 95% CI: 0.949-1.046, p = 0.893). However, P-CAB treatment was associated with an increased risk of the serious adverse events compared to lansoprazole (RR: 1.325, 95% CI: 1.005-1.747, p = 0.046). Conclusion: P-CABs demonstrated non-inferiority to lansoprazole in the management of peptic ulcer. The safety and tolerability profile are comparable, with similar TEAEs rates. However, P-CABs appear to have a higher risk of serious adverse events. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=458361 Identifier: PROSPERO (No. CRD42023458361).

Cause analysis of conversion to biologics in spondyloarthritis patients with poor response to conventional treatment.

OBJECTIVE: We sought to investigate the reasons why spondyloarthritis (SpA) patients failed to respond to non-steroidal anti-inflammatory drugs (NSAIDs) and conventional synthetic disease-modifying antirheumatic drugs (cDMARDs) and the influences of different initial cDMARDs on the likelihood of a switch to biologics. METHODS: SpA patients were divided into a conventional drug maintenance group and a biologics conversion group to determine the causes of conversion to biologics. Then, we divided all patients into three groups according to different initial cDMARDs, NSAID monotherapy, NSAID + (sulfasalazine or thalidomide) double combination, and NSAID + sulfasalazine + thalidomide triple combination therapy groups, to clarify the influence of initial treatment on later conversion to biologics. RESULTS: This study includes 202 patients, including 97 patients in the conventional drug maintenance group and 105 patients in the biologics conversion group. The mean age of the conventional drug maintenance group was higher than that of the biologics conversion group (40.8 ± 14.3 vs. 33.8 ± 12.3 years, P < 0.05). Uveitis (OR 5.356, P < 0.05) is positively correlated with conversion to biological therapy, while age (OR 0.940, P < 0.05) is negatively correlated. The proportion of NSAID monotherapy, double combination, and triple combination groups converted to biological agents was 80%, 51.1%, and 23.2%, respectively (P < 0.05). CONCLUSION: Age and uveitis are related to conversion to biologics therapy. The early combination of sulfasalazine and thalidomide with NSAIDs may lower the probability of conversion to biologics therapy in the later stage and offer a new option for patients with limited use of biologics in SpA patients. Key Points • Patients' move to biologics may be caused mostly by inadequate disease control by conventional oral medications. • Regardless of axial vs. peripheral joint involvement, combination drug therapy was superior to single drug therapy in controlling SpA and decreasing the probability of conversion to a biological agent. • For SpA patients who are not candidates for biologics due to contraindications or other reasons, early combination application of NSAIDs, sulfasalazine, and thalidomide may be a new choice.

Effect of ofloxacin levels on growth, photosynthesis and chlorophyll fluorescence kinetics in tomato.

Antibiotic pollution has become a global environmental pollution problem. Chlorophyll fluorescence is one of the most important indicators reflecting the degree to which plants are influenced by the environment. Ofloxacin (OFL) is a highly toxic antibiotic pollutant, and there are few reports on the effects of changes in OFL levels on tomato chlorophyll fluorescence parameters. In this study, we investigated the responses of tomato growth, photosynthetic activity and chlorophyll fluorescence kinetics to exogenous OFL exposure (as the concentrations of 0, 2.5, 5, 10 and 20 mg L-1). The results showed that lower concentrations of OFL (2.5 mg L-1) had little impact on tomato growth, while plant growth was inhibited with the OFL concentration increasing. At higher OFL concentrations (5, 10 and 20 mg L-1), chloroplasts ruptured, and chlorophyll became degraded, resulting in leaf etiolation. Furthermore, the photosynthetic and photochemical efficiency and electron transfer rate were significantly inhibited by OFL. Moreover, damage to the oxygen-evolving complex on the donor side of PSⅡ prevented electron transfer from QA to QB and led to photoinhibition. In conclusion, higher OFL concentration reduced photosynthesis by destroying the photosynthetic mechanism in tomato, resulting in tomato leaf etiolation and plant growth inhibition.

Broadband near-infrared emission of chromium-doped sulfide glass-ceramics containing Ga2S3 nanocrystals.

Upon 808 nm excitation, an intense broadband near-infrared emission from Cr4+ has been observed in 80GeS2-20Ga2S3 chalcogenide glass-ceramics (GCs) containing Ga2S3 nanocrystals. The emission band peaking at 1250 nm covers the O, E, S bands (1000-1500 nm). The formation of Ga2S3 nanocrystals (∼20 nm) increases the emission intensity of Cr4+ by more than three times. The quantum efficiency of the present GCs is as great as 36% at room temperature.

Silicon enhanced the resistance of Chinese cabbage (Brassica rapa L. ssp. pekinensis) to ofloxacin on the growth, photosynthetic characteristics and antioxidant system.

The negative impact of the misuse of antibiotics on agriculture and human health has become a popular research topic with the increasing usage of antibiotics; however, little information is available about the mechanisms of OFL (ofloxacin) and Si (silicon). In this experiment, we applied 7 OFL concentrations to two Chinese cabbage cultivars (Qinghua and Biyu) to screen proper OFL concentrations. OFL concentrations of 0, 1, 2.5 and 5 mg L-1 were selected for the subsequent test and 1.2 mmol L-1 Si was used as mitigation. The results showed that Biyu suffered more damage than Qinghua and the injury degree increased in a concentration-dependent manner. With increasing OFL concentrations, the photosynthetic fluorescence was weakened significantly; under 1, 2.5 and 5 mg L-1 OFL, the Pn reduced by 5.35%, 35.92% and 43.62% in Qinghua and 33.98%, 41.94% and 64.66% in Biyu, respectively. The production rate of O2-, H2O2 and the MDA content were increased and Biyu appeared higher increase rates. In addition, the antioxidant enzymes contents first increased and then decreased and that of Qinghua increased more than Biyu. Si ensured the growth under OFL and protected its photosynthetic ability. Under the OFL1+Si, OFL2.5 + Si and OFL5+Si treatments, Pn increased by 3.91%, 15.95 and 15.69% in Qinghua and 28.82%, 20.40% and 39.01% in Biyu. Si also maintained the structural integrity of leaf organelles and improved the scavenging ability of ROS by increasing the activity and relative gene expression of antioxidant enzymes. Moreover, varietal differences may play a more important role than Si.

Analysis of Risk Factors and the Establishment of a Predictive Model for Thrombosis in Patients with Antineutrophil Cytoplasmic Antibody-Associated Vasculitis.

Purpose: To explore the risk factors for thrombi occurring in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) and establish a risk prediction model to better predict the risk of thrombosis in patients with AAV. Patients and Methods: We retrospectively analyzed 117 AAV patients who had been hospitalized in The Second Affiliated Hospital of Chongqing Medical University between October 2010 and December 2021. For all patients, we recorded demographic characteristics and clinical data, analyzed the risk factors for thrombosis in AAV patients and then developed a risk prediction model. Results: Stepwise logistic regression analysis indicated that a high complement C3 level, a high BVAS score and a high Padua score were independent risk factors for thrombosis in AAV patients. According to multivariate analysis, a predictive model for thrombus risk was successfully established; the area under the ROC curve(AUC) was 0.803 (95% CI: 0.716-0.890) and the maximum Youden index, sensitivity and specificity were 0.487, 59.0% and 89.7%, respectively. Conclusion: A high complement C3 level, high BVAS score, and a high Padua score were shown to be independent risk factors for thrombosis in AAV patients. We developed a risk prediction model based on these three risk factors that could predict the risk of thrombosis in AAV patients to some extent.

Comparative Transcriptome Analysis of Two Contrasting Chinese Cabbage (Brassica rapa L.) Genotypes Reveals That Ion Homeostasis Is a Crucial Biological Pathway Involved in the Rapid Adaptive Response to Salt Stress.

Salt is the most important limiting factor in plant yield and quality. Different Chinese cabbage cultivars appeared different salt tolerances, but there are few studies attempting to elucidate the mechanism underlying this phenomenon. In this study, 100 mmol L-1 NaCl was found to be the most suitable treatment concentration according to a sprouting bag test of 39 Chinese cabbage cultivars, and through comprehensive comparison and analysis, the relative values of fresh weight and electrolyte leakage in leaves proved to be convenient indicators for the identification of salt tolerance in Chinese cabbage. We analyzed the physiological responses of Qinghua45 (salt-tolerant) and Biyuchunhua (salt-sensitive) in terms of the growth indexes, ion homeostasis and Photosynthesis, the results indicated that Qinghua45 could ensure osmotic regulation, ion homeostasis and photosynthesis under salt stress. Next, we compared the transcriptome dynamics of the two cultivars. Overall, 2,859 differentially expressed genes (DEGs) were identified, and the number of DEGs in Qinghua45 was significantly less than that in Biyuchunhua. VDAC promoted the release of Ca2+, which indirectly promoted the transport of Na+ to vacuoles through the SOS2 pathway. Cation/H (+) antiporter 17 and V-H + -ATPase improve the exchange of Na+ and H+ and maintain Na+ in the vacuoles, thereby reducing the injury affected by salt stress. Increases in galactinol synthase and soluble protein synthesis helped relieve osmotic stress caused by salt, together, they regulated the Na+ content and chlorophyll biosynthesis of the plant and enabled the plant to adapt to salt stress over time.

Grafting resulting in alleviating tomato plant oxidative damage caused by high levels of ofloxacin.

Antibiotic pollution has become a global problem threatening human health. Ofloxacin is one of the more widely used antibiotics, but reports on the reaction of plant to ofloxacin pollution are limited. In this study, using adversity-resistant (R), adversity-sensitive (S) and grafted plant S/R as models, we investigated the biological response of tomato to exogenous ofloxacin residues. The results showed that lower levels of ofloxacin treatment (5 mg L-1 and 10 mg L-1) promoted tomato growth, and 10 mg L-1 ofloxacin was the critical dose to stimulate growth among the different treatments. In addition, the photosynthetic and fluorescence parameters, antioxidant enzyme activities and transcription-level expression of the enzymes were stimulated by low ofloxacin treatment. However, high ofloxacin treatment (20 mg L-1 and 40 mg L-1) exhibited a significantly negative effect on plant growth, photosynthesis, fluorescence parameters, antioxidant enzyme activities and transcript levels expression. Reactive oxygen species (ROS) and malondialdehyde (MDA) levels increased with increasing ofloxacin concentrations, indicating that the oxidative damage of plants was severe with increasing doses. In contrast, the role of antioxidant enzymes in the antibiotic response was limited at high ofloxacin concentrations. The grafting experiment demonstrated that grafted plants had the ability to alleviate ofloxacin stress. In conclusion, ofloxacin can damage the photosynthetic machinery by promoting ROS accumulation, which results in the etiolation of tomato leaves and inhibits plant growth, but grafting can reduce its.

Polycyclic aromatic hydrocarbons in soils of Beijing and Tianjin region: vertical distribution, correlation with TOC and transport mechanism.

The contents and distribution of 20 polycyclic aromatic hydrocarbons (PAHs) and heterocyclic aromatic hydrocarbons (HAHs) were investigated in 16 soil profiles of Beijing and Tianjin region. Transport of high molecular weight PAHs (HMWPAHs) and the correlation between total organic carbon (TOC) and their concentrations were also discussed. The results indicated that highly contaminated sites were located at urban or wastewater irrigation areas and pollutants mainly accumulated in topsoil (< 40 cm), with a sharp content decrease at the vertical boundary of 30-40 cm. Total PAHs/HAHs concentrations in soils from Tianjin were markedly greater than those from Beijing. Even the contents at bottoms of soil profiles in Tianjin were higher than those in topsoils of Beijing soil profile. HMWPAHs dominated the PAH profiles, exhibiting a uniform distribution of pyrogenic origin between topsoils and deep layers. Furthermore, the percentages of HMWPAHs remained relative constant with the depth of soil profiles, which were consistent with the distribution of particulate matter-associated PAHs in the local atmospheric environments. Therefore, HMWPAHs transport with particulates might be the predominant source found in soil profiles.

Grafting improves tomato drought tolerance through enhancing photosynthetic capacity and reducing ROS accumulation.

Drought is the main meteorological threat to plants and limits plant growth, development, and adaptation to environmental changes. However, root-shoot communication plays a vital role in improving tomato plant drought tolerance, especially when cultivars are grafted onto drought-tolerant rootstock. In this study, the relationship between photosynthetic capacity and reactive oxygen species (ROS) in response to drought stress was studied in tomato grafted with different drought-resistant tomato seedlings. To determine the drought-relieving effect of drought-tolerant rootstocks, we measured the effects of grafting on plant growth, net photosynthetic rate (Pn), ROS accumulation, and antioxidant enzyme activities in tomato leaves and roots under drought stress. Plant growth and Pn were significantly inhibited by drought, but ROS accumulation and antioxidant enzyme activities were significantly increased. Treatment with drought-tolerant tomato seedlings significantly increased plant growth and increased Pn under water-deficit conditions compared with those grafted with drought-susceptible rootstock. In addition, the plants grafted with drought-tolerant seedlings had increased activities of partial antioxidant enzymes, leading to decreased ROS production. Our results indicate that tomato grafted with drought-tolerant seedlings alleviated the phytotoxicity and oxidative damage caused by drought by regulating antioxidant enzymes under drought stress.