Association mapping for root system architecture traits under two nitrogen conditions in germplasm enhancement of maize doubled haploid lines

Root system architecture (RSA) contributes to nitrogen (N) uptake and utilization in maize. In this study, a germplasm enhancement of maize double haploid population of 226 lines genotyped with 61,634 SNPs was used to investigate the genetic basis of RSA under two N levels using a genome-wide association study (GWAS). GLM + PCA, FarmCPU, and MLM models were utilized to balance false positives and false negatives. In total, 33 and 51 significant SNP-trait associations were detected under high and low N conditions, respectively. Under high N, SNP S9_2483543 was detected by all models. Linkage disequilibrium (LD) regions of some SNPs overlapped with the intervals of QTL for RSA and N response that were detected in previous studies. In particular, several known genes, Rtcs, Rtcl, Rtcl, and Ms44, were located in the LD regions of S1_9992325, S9_151726472, S9_154381179, and S4_197073985, respectively. Among the candidate genes identified by this study, GRMZM2G139811, GRMZM2G314898, GRMZM2G054050, GRMZM2G173682, GRMZM2G470914, GRMZM2G462325, GRMZM2G416184, and GRMZM2G064302 were involved in seedling, seed, and root system development or N metabolism in Arabidopsis or rice. The markers identified in this study can be used for marker-assisted selection of RSA traits to improve nitrogen use efficiency in maize breeding, and the candidate genes will contribute to further understanding of the genetic basis of RSA under diverse N conditions

Sca-1+ Cardiac Stem Cells Mediate Acute Cardioprotection via Paracrine Factor SDF-1 following Myocardial Ischemia/Reperfusion

Cardiac stem cells (CSCs) promote myocardial recovery following ischemia through their regenerative properties. However, little is known regarding the implication of paracrine action by CSCs in the setting of myocardial ischemia/reperfusion (I/R) injury although it is well documented that non-cardiac stem cells mediate cardioprotection via the production of paracrine protective factors. Here, we studied whether CSCs could initiate acute protection following global myocardial I/R via paracrine effect and what component from CSCs is critical to this protection.A murine model of global myocardial I/R was utilized to investigate paracrine effect of Sca-1+ CSCs on cardiac function. Intracoronary delivery of CSCs or CSC conditioned medium (CSC CM) prior to ischemia significantly improved myocardial function following I/R. siRNA targeting of VEGF in CSCs did not affect CSC-preserved myocardial function in response to I/R injury. However, differentiation of CSCs to cardiomyocytes (DCSCs) abolished this protection. Through direct comparison of the protein expression profiles of CSCs and DCSCs, SDF-1 was identified as one of the dominant paracrine factors secreted by CSCs. Blockade of the SDF-1 receptor by AMD3100 or downregulated SDF-1 expression in CSCs by specific SDF-1 siRNA dramatically impaired CSC-induced improvement in cardiac function and increased myocardial damage following I/R. Of note, CSC treatment increased myocardial STAT3 activation after I/R, whereas downregulation of SDF-1 action by blockade of the SDF-1 receptor or SDF-1 siRNA transfection abolished CSC-induced STAT3 activation. In addition, inhibition of STAT3 activation attenuated CSC-mediated cardioprotection following I/R. Finally, post-ischemic infusion of CSC CM was shown to significantly protect I/R-caused myocardial dysfunction.This study suggests that CSCs acutely improve post-ischemic myocardial function through paracrine factor SDF-1 and up-regulated myocardial STAT3 activation

Quantitative analysis of water vapor budget of a persistent rainstrom event in Tongren of Guizhou Province

This paper focus on revealing the features of the water vapor transport, water vapor budget and the contribution percentage of water vapor source regions of the persistent rainstorm in Tongren from July 13th to 16th, 2014 based on precipitation observation data, ERA5 and NCEP GDAS (National Centers for Environmental Prediction, Global Data Assimilation System) reanalysis data and the HYSPLIT4 (Hybrid Single-Particle Lagrangian Integrated Trajectory Model) mode. The results show that: (1) the eastward South Asian High and coupling mechanism of high and low level jets enhanced the dynamic mechanism of convergence at low level and divergence at high level which is conducive to the convergence of water vapor in the target region to condense and then form precipitation. (2) The water vapor over the ocean was continuously transported to the rainstorm area by the water vapor channel built by the synergistic effect of the subtropical high which table controlled the south of Guizhou province, shortwave trough lay the northwest side of subtropical high, and tropical cyclone in the Indian Peninsula at 500 hPa. (3) The air particles in the rainstorm area mainly came from the Arabian Sea, the Bay of Bengal and the South China Sea at a lower height, while a few particles came from the north of Tongren to Eurasia, the Atlantic Ocean at a higher height by 120 h backward trajectory simulation. (4) The contribution percentage of water vapor source regions of the south of Tongren-South China Sea and its nearby islands and water, the east of the Indian Peninsula-the Bay of Bengal, the Arabian Sea-the west of the Indian Peninsula were 48.29%, 32.17 % and 10.47% respectively. In addition, the water vapor the north of Tongren to Eurasia and the Atlantic Ocean also contributed to the rainstorm in Tongren (9.07%). (5) 850 hPa and 700 hPa were the main water vapor contribution levels which provided nearly 3/4 of water vapor to the rainstorm area, the remaining quarter was transported by 500 hPa

Evaluation of left ventricular function in patients with coronary slow flow: A systematic review and meta-analysis

Background: Coronary slow flow (CSF) is an angiographic finding defined as delayed distal vessel perfusion without severe stenosis of the epicardial coronary arteries. However, definite alterations in left ventricular (LV) function in patients with CSF remains inconsistent. This study aimed to clarify the changes in LV function in patients with CSF and explore the factors that may influence LV function. Methods: PubMed, Embase, and Cochrane Library databases were systematically searched. Standardized mean differences and 95% confidence intervals (CI) for the LV function parameters were calculated. Subgroup analysis, meta-regression analysis, and correlation analysis were performed to explore the factors influencing LV function. Results: Twenty-two studies (1101 patients with CSF) were included after searching three databases. In patients with CSF, LV ejection function in patients with CSF was marginally lower (61.8%; 95% CI: 61.0%, 62.7%), global longitudinal strain was decreased (–18.2%; 95% CI: –16.7%, –19.7%). Furthermore, left atrial diameter, left atrial volume index, and E/e′ were significantly increased, while E/A and e’ were significantly decreased. The mean thrombolysis in myocardial infarction frame count (TFC) was linearly associated with LV function; the larger the mean TFC, the greater the impairment of LV function. Conclusions: Left ventricular systolic and diastolic functions were impaired in patients with CSF, and this impairment was aggravated with increasing mean TFC

Cross-reaction mediated by distinct key amino acid combinations in the complementary-determining region (CDR) of a monoclonal antibody

In immunology, cross-reaction between antigens and antibodies are commonly observed. Prior research has shown that various monoclonal antibodies (mAbs) can recognize a broad spectrum of epitopes related to influenza viruses. However, existing theories on cross-reactions fall short in explaining the phenomena observed. This study explored the interaction characteristics of H1-74 mAb with three peptides: two natural peptides, LVLWGIHHP and LPFQNI, derived from the hemagglutinin (HA) antigen of the H1N1 influenza virus, and one synthetic peptide, WPFQNY. Our findings indicate that the complementarity-determining region (CDR) of H1-74 mAb comprised five antigen-binding sites, containing eight key amino acid residues from the light chain variable region and 16 from the heavy chain variable region. These critical residues formed distinct hydrophobic or hydrophilic clusters and functional groups within the binding sites, facilitating interaction with antigen epitopes through hydrogen bonding, salt bridge formation, and π–π stacking. The study revealed that the formation of the antibody molecule led to the creation of binding groups and small units in the CDR, allowing the antibody to attach to a variety of antigen epitopes through diverse combinations of these small units and functional groups. This unique ability of the antibody to bind with antigen epitopes provides a new molecular basis for explaining the phenomenon of antibody cross-reaction

Transcranial Magnetic Stimulation to the Middle Frontal Gyrus During Attention Modes Induced Dynamic Module Reconfiguration in Brain Networks

The interaction between dorsal and ventral attention networks (VANs) is mediated by the middle frontal gyrus (MFG), which is functionally connected to both networks. However, the direct role of the MFG in selective and sustained attention remains controversial. In the current study, we used transcranial magnetic stimulation (TMS) and electroencephalography (EEG) to probe the connectivity dynamic changes of MFG-associated regions during different attention modes. The participants underwent visual, selective, and sustained attention tasks to observe TMS-induced network changes. Twenty healthy participants received single-pulse TMS over the left or right MFG during tasks, while synchronous EEG data was acquired. Behavioral results were recorded and time-varying brain network analyses were performed. We found that the MFG is involved in attention processing and that sustained attention was preferentially controlled by the right MFG. Moreover, compared with the right hemisphere, the left hemisphere was associated with selective attention tasks. Visual and selective attention tasks induced MFG-related changes in network nodes were within the left hemisphere; however, sustained attention induced changes in network nodes were in the bilateral posterior MFG. Our findings indicated that the MFG plays a crucial role in regulating attention networks. In particular, TMS-induced MFG alterations influenced key nodes of the time-varying brain network, leading to the reorganization of brain network modules

The Combination of Human Urinary Kallidinogenase and Mild Hypothermia Protects Adult Rats Against Hypoxic-Ischemic Encephalopathy-Induced Injury by Promoting Angiogenesis and Regeneration

Objectives: Human Urinary Kallidinogenase (HUK) is a tissue kallikrein that plays neuroprotective role in ischemic conditions via different mechanisms. Mild hypothermia (MH) is another robust neuroprotectant that reduces mortality but does not profoundly ameliorate the neurological outcome in hypoxic-ischemic encephalopathy (HIE) patients. However, whether the combination of HUK and MH can be used as a promising neuroprotective treatment in HIE is unknown.Methods: One-hundred and forty-four adult Wistar rats were randomly divided into five groups: Sham, HIE, HUK, MH and a combination of HUK and MH treatment. The HIE rat model was established by right carotid dissection followed by hypoxia aspiration. The survival curve was created within 7 days, and the neurological severity scores (NSS) were assessed at days 0, 1, 3, and 7. Nissl staining, Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL), immunofluorescent staining and western blotting were used to evaluate neuronal survival, apoptosis and necrosis, tight-junction proteins Claudin-1 and Zonula occludens-1 (ZO-1), vascular endothelial growth factor (VEGF), doublecortex (DCX), bradykinin receptor B1 (BDKRB1), BDKRB2 and Ki67 staining.Results: The combined treatment rescued all HIE rats from death and had a best survival curve compared to HIE. The Combination also reduced the NSS scores after HIE at days 7, better than HUK or MH alone. The combination of HUK and MH reserved more cells in Nissl staining and inhibited neuronal apoptosis and necrosis as well as significantly attenuated HIE-induced decreases in claudin-1, ZO-1, cyclin D1 and BDKRB1/B2 in comparison to HUK or MH treatment alone. Moreover, the combined treatment increased the expression of VEGF and DCX as well as the number of Ki67-labeled cells.Conclusions: This study demonstrates that both HUK and MH are neuroprotective after HIE insult; however, the combined therapy with HUK and MH enhanced the efficiency and efficacy of either therapy alone in the treatment of HIE, at least partially by promoting angiogenesis and regeneration and rescuing tight-junction loss. The combination of HUK and MH seems to be a feasible and promising clinical strategy to alleviate cerebral injury following HIE insult.Highlights: -The combination of HUK and MH distinctly reduces neurological dysfunction in HIE rats.-HUK enhances the neuroprotective effects of MH in HIE.-MH attenuates tight-junction disruption, upregulates the BDKR B1/2, DCX and cyclin D1.-The combination of MH and HUK enhances the expressions of MH/HUK mediated-BDKR B1/2, DCX, cyclin D1 and Ki67 positive cells

Primary urachal leiomyosarcoma: a case report and literature review of clinical, pathological, and medical imaging features

BackgroundUrachal tumors are exceedingly rare, and adenocarcinoma is the most common malignant urachal neoplasm. Here, an especially rare patient of primary urachal leiomyosarcoma from our hospital was reported, and only five patients have been reported thus far since 1981.Case descriptionA 24-year-old man was admitted due to urinary tract symptoms. Both urogenital ultrasonography and contrast-enhanced computed tomography showed a mass at the dome of the urinary bladder. Laparoscopic surgical resection was performed, and histopathologic examination of the mass confirmed the diagnosis of urachal leiomyosarcoma. No recurrence was noted after one and a half years.ConclusionsBecause the leiomyosarcoma located in the extraperitoneal space of Retzius and may manifest with nonspecific abdominal or urinary symptoms, early and definitive preoperative diagnosis is challenging. Partial cystectomy with complete excision of the urachus is recommended. Because only a few patients have been recorded, clinical outcomes and recurrence risks are difficult to assess