Establishment of a platform based on dual RPA combined with CRISPR/Cas12a for the detection of Klebsiella pneumoniae and its KPC resistance gene.

Carbapenem resistant Klebsiella pneumoniae (CRKP) can cause serious hospital- and community-acquired infections. Treatment for CRKP infection is limited, resulting in prolonged hospitalization and high consultation costs. The KPC genotype has the highest detection rate of CRKP, and its mortality rate is higher than the overall mortality rate of CRKP. However, traditional testing methods have disadvantages such as long time and reliance on complex and sophisticated instruments, which are not conducive to rapid screening for CRKP. Therefore, this study aimed to establish a detection platform for early screening of CRKP so that effective antimicrobial therapy could be administered promptly to prevent the widespread spread of CRKP. We integrated dual RPA with CRISPR/Cas12a to establish a dual platform for the detection of K. pneumoniae (Kp) rcsA-specific gene and KPC resistance gene. Four result reading methods were established, including fluorescence detection (FD), blue light irradiation detection (BLID), ultraviolet irradiation detection (UID), and lateral flow test strips (LFTS). For the rcsA gene, the LOD of FD was 1 × 10 pg/µL, and the other three methods could detect 1 × 101 pg/µL of bacterial DNA. As for the KPC gene, four resultant readout methods were able to detect 1 × 102 pg/µL of bacterial DNA. In 59 clinical strains tested, the dual RPA-CRISPR/Cas12a detection of the rcsA had 100% sensitivity, specificity, and accuracy compared to the culture method. Compared with the drug sensitivity test, the sensitivity of dual RPA-CRISPR/Cas12a detection for the KPC was 85.71%, the specificity was 100%, and the accuracy was 94.92%. In summary, our dual RPA-CRISPR/Cas12a platform proved to be rapid, precise, and convenient for the efficient detection of Kp with KPC in the laboratory or at the point of care.

Neuroprotective Effects of AER-271 in a tMCAO Mouse Model: Modulation of Autophagy, Apoptosis, and Inflammation.

Following ischemic stroke, aquaporin 4 (AQP4) expression modifications have been associated with increased inflammation. However, the underlying mechanisms are not fully understood. This study aims to elucidate the mechanistic basis of post-cerebral ischemia-reperfusion (I/R) inflammation by employing the AQP4-specific inhibitor, AER-271. The middle cerebral artery occlusion (MCAO) model was used to induce ischemic stroke in mice. C57BL/6 mice were randomly allocated into four groups: sham operation, I/R, AER-271, and 2-(nicotinamide)-1,3,4-thiadiazole (TGN-020) treatment, with observations recorded at 1 day, 3 days, and 7 days post-tMCAO. Each group consisted of 15 mice. Procedures included histological examination through HE staining, neurological scoring, Western blot analysis, and immunofluorescence staining. AER-271 treatment yielded significant improvements in post-stroke weight recovery and neurological scores, accompanied by a reduction in cerebral infarction volume. Moreover, AER-271 exhibited a noticeable influence on autophagic and apoptotic pathways, affecting the activation of both pro-inflammatory and anti-inflammatory cytokines. Alterations in the levels of inflammatory biomarkers MCP-1, NLRP3, and caspase 1 were also detected. Finally, a comparative assessment of the effects of AER-271 and TGN-020 in mitigating apoptosis and microglial polarization in ischemic mice revealed neuroprotective effects with no significant difference in efficacy. This study provides essential insights into the neuroprotective mechanisms of AER-271 in cerebral ischemia-reperfusion injury, offering potential clinical applications in the treatment of ischemic cerebrovascular disorders.

Biochar Improves Yield by Reducing Saline-Alkaline Stress, Enhancing Filling Rate of Rice in Soda Saline-Alkaline Paddy Fields.

Soda saline-alkaline stress significantly impedes the rice grain filling process and ultimately impacts rice yield. Biochar has been shown to mitigate the negative impacts of saline-alkaline stress on plants. However, the exact mechanism by which biochar influences the rice grain-filling rate in soda saline-alkaline soil is still not fully understood. A two-year field experiment was conducted with two nitrogen fertilizer levels (0 and 225 kg ha-1) and five biochar application rates [0% (B0), 0.5% (B1), 1.5% (B2), 3.0% (B3), and 4.5% (B4) biochar, w/w]. The results demonstrated that biochar had a significant impact on reducing the Na+ concentration and Na+/K+ ratio in rice grown in soda saline-alkaline lands, while also improving its stress physiological conditions. B1, B2, B3, and B4 showed a notable increase in the average grain-filling rate by 5.76%, 6.59%, 9.80%, and 10.79%, respectively, compared to B0; the time to reach the maximum grain-filling rate and the maximum grain weight saw increases ranging from 6.02% to 12.47% and from 7.85% to 14.68%, respectively. Meanwhile, biochar, particularly when used in conjunction with nitrogen fertilizer, notably enhanced the activities of sucrose synthase (SuSase), ADPG pyrophosphorylase (AGPase), starch synthase (StSase), and starch branching enzyme (SBE) of rice grains in soda saline-alkaline lands. Furthermore, rice yield increased by 11.95-42.74% in the B1, B2, B3, and B4 treatments compared to the B0 treatment. These findings showed that biochar improves yield by regulating ionic balance, physiological indicators, starch synthesis key enzyme activities, and the grain-filling rate in soda saline-alkaline paddy fields.

A rapid and ultra-sensitive dual readout platform for Klebsiella pneumoniae detection based on RPA-CRISPR/Cas12a.

The bacterium Klebsiella pneumoniae (Kp) was the primary pathogen of hospital-acquired infection, but the current detection method could not rapidly and conveniently identify Kp. Recombinase polymerase amplification (RPA) was a fast and convenient isothermal amplification technology, and the clustered regularly interspaced short palindromic repeats (CRISPR) system could rapidly amplify the signal of RPA and improve its limit of detection (LOD). In this study, we designed three pairs of RPA primers for the rcsA gene of Kp, amplified the RPA signal through single-strand DNA reporter cleavage by CRISPR/Cas12a, and finally analyzed the cleavage signal using fluorescence detection (FD) and lateral flow test strips (LFTS). Our results indicated that the RPA-CRISPR/Cas12a platform could specifically identify Kp from eleven common clinical pathogens. The LOD of FD and LFTS were 1 fg/µL and 10 fg/µL, respectively. In clinical sample testing, the RPA-CRISPR/Cas12a platform was consistent with the culture method and qPCR method, and its sensitivity and specificity were 100% (16/16) and 100% (9/9), respectively. With the advantages of detection speed, simplicity, and accuracy, the RPA-CRISPR/Cas12a platform was expected to be a convenient tool for the early clinical detection of Kp.

Integrated Analysis Construct a Tumor-Associated Macrophage Novel Signature with Promising Implications in Predicting the Prognosis and Immunotherapeutic Response of Gastric Cancer Patients.

BACKGROUND: Gastric cancer (GC) remains one of the most prevalent malignant tumors worldwide. At present, tumor-associated macrophages (TAMs) are essential in the progression, metastasis, and drug resistance of tumors. Therefore, TAMs can be a crucial target for tumor treatment. AIMS: We intended to investigate the TAM characteristics in GC and develop a risk signature based on TAM to predict the prognosis of GC patients. METHODS: The single-cell RNA sequencing (scRNA-seq) and bulk RNA-seq data were acquired from a publicly available database. We utilized the Seurat pipeline to process the scRNA-seq data and determine TAM cell types using marker genes. Univariate Cox regression analysis was utilized to examine TAM-related prognostic genes, and then we employed Lasso-Cox regression analysis, and Multivariate Cox regression analysis established a novel risk profile to forecast the clinical value of the model with a new nomogram combining risk profiles and clinicopathological characteristics. RESULTS: The current study employed scRNA-seq data to identify five TAM clusters in GC, among which four were significantly associated with GC prognosis. Accordingly, we further developed a TAM-related risk signature utilizing nine genes. After evaluation, our model accurately predicted the prognosis of gastric cancer. Generally, GC patients with low TAMS scores exhibited a more favorable prognosis, greater benefits from immunotherapy, and higher levels of immune cell infiltration. CONCLUSIONS: The prognosis of GC can be effectively predicted by TAM-based risk signatures, and the signature may provide a new perspective for comprehensively guiding clinical diagnosis, prediction, and immunotherapy for gastric cancer.

Migration Inhibition Factor Secreted by Peripheral Blood Memory B Cells Binding to CD74-CD44 Receptor Complex Drives Macrophage Behavior in Alzheimer's Disease.

Dysregulation of the peripheral immune system is be involved in the neuroinflammation in Alzheimer disease (AD) and accelerate the disease progression. The contribution of immune cells, particularly B cells, to AD pathogenesis has gained attention in recent research. In this study, we investigated the role of Peripheral Blood Memory B cells (PBMBs) and their secreted Migration Inhibition Factor (MIF) in driving macrophage behavior in AD based on the scRNA-seq technique, immunofluorescence and flow cytometry. We discovered that MIF binds to the CD74-CD44 receptor complex on macrophages, influencing their behavior. The dysregulated macrophage response hampers the clearance of amyloid-beta (Aß) plaques, exacerbating AD pathology. Targeting the MIF-CD74-CD44 signal pathway may hold therapeutic potential in modulating macrophage activity and mitigating neuroinflammation in AD. This study provides a further understanding of peripheral immune cells dysregulated in AD.

A dual RPA-LFD assay for the simultaneous detection of Salmonella typhimurium and Salmonella enteritidis.

Introduction: Salmonella was one of the most common bacteria that caused foodborne illness, with S. typhimurium (Salmonella typhimurium) and S. enteritidis (Salmonella enteritidis) infections accounting for more than 75% of human salmonella infections. Methods: In this study, we developed a method of dual recombinase polymerase amplification (RPA) combined with a lateral flow dipstick for the rapid detection of S. typhimurium and S. enteritidis in clinical specimens (stool). Results: The entire reaction process, including amplification and result reading, could be completed within 65 min. The detection limits of S. typhimurium and S. enteritidis in pure culture samples were 5.23 × 101 CFU/mL and 3.59 × 101 CFU/mL, respectively. The detection limits of S. typhimurium and S. enteritidis in artificially contaminated samples were 8.30 × 101 CFU/mL and 2.70 × 102 CFU/mL, respectively. In addition, the method had no cross-reaction with other pathogenic microorganisms. The results in clinical samples were fully consistent with those obtained using Bacterial Analysis Manual, with sensitivity and specificity were 100% (8/8) and 100% (17/17) for S. typhimurium and 100% (4/4) and 100% (21/21) for S. enteritidis, respectively. Discussion: The detection limits of S. typhimurium and S. enteritidis in artificially contaminated samples were higher than those in pure culture samples, which might be attributed to the inherent complex composition of artificially contaminated samples. In addition, the detection limits of S. typhimurium and S. enteritidis in the same sample were also different, which might be attributed to different amplification efficiency of two target genes in the same reaction system. Conclusion: This assay had potential application outdoors, as it could be performed within 1 h at 38°C without a complex instrument, and the results could be observed with the naked eye. In conclusion, the dual RPA-LFD assay established in this study had practical significance for the rapid detection of S. typhimurium and S. enteritidis in the future.

A multiplex RPA coupled with CRISPR-Cas12a system for rapid and cost-effective identification of carbapenem-resistant Acinetobacter baumannii.

Background: Carbapenem-resistant Acinetobacter baumannii (CRAB) poses a severe nosocomial threat, prompting a need for efficient detection methods. Traditional approaches, such as bacterial culture and PCR, are time-consuming and cumbersome. The CRISPR-based gene editing system offered a potential approach for point-of-care testing of CRAB. Methods: We integrated recombinase polymerase amplification (RPA) and CRISPR-Cas12a system to swiftly diagnose CRAB-associated genes, OXA-51 and OXA-23. This multiplex RPA-CRISPR-Cas12a system eliminates bulky instruments, ensuring a simplified UV lamp-based outcome interpretation. Results: Operating at 37°C to 40°C, the entire process achieves CRAB diagnosis within 90 minutes. Detection limits for OXA-51 and OXA-23 genes are 1.3 × 10-6 ng/µL, exhibiting exclusive CRAB detection without cross-reactivity to common pathogens. Notably, the platform shows 100% concordance with PCR when testing 30 clinical Acinetobacter baumannii strains. Conclusion: In conclusion, our multiplex RPA coupled with the CRISPR-Cas12a system provides a fast and sensitive CRAB detection method, overcoming limitations of traditional approaches and holding promise for efficient point-of-care testing.

Inulin alters gut microbiota to alleviate post-stroke depressive-like behavior associated with the IGF-1-mediated MAPK signaling pathway.

INTRODUCTION: Gut microbiota dysbiosis is a key factor of the pathogenesis of post-stroke depression (PSD). PSD is associated with increased hippocampal neuronal apoptosis and decreased synaptic connectivity. Inulin can be involved in hippocampal neuron protection through the microbiome-gut-brain axis. However, the neuroprotective effects of inulin in PSD are still to be further investigated. METHODS: By utilizing the GEO public database, we identify differentially expressed genes in the hippocampus following inulin intake. This can help us discover key signaling pathways through functional enrichment analysis. Furthermore, we validate the expression levels of signaling molecules in a rat model of PSD and examine the effects of inulin on behavioral changes and body weight. Additionally, conducting a microbiome analysis to identify significantly different microbial populations and perform correlation analysis. RESULTS: The intake of inulin significantly up-regulated mitogen-activated protein kinase signaling pathway in the hippocampus. Inulin changed in the gut microbiota structure, leading to an increase in the abundance of Lactobacillus and Clostridium_sensu_stricto_1 in the intestines of PSD rats, while decreasing the abundance of Ruminococcus UCG_005, Prevotella_9, Oscillospiraceae, and Clostridia UCG_014. Furthermore, the inulin diet elevated levels of insulin-like growth factor 1 in the serum, which showed a positive correlation with the abundance of Lactobacillus. Notably, the consumption of inulin-enriched diet increased activity levels and preference for sugar water in PSD rats, while also reducing body weight. CONCLUSION: These findings highlight the potential therapeutic benefits of inulin in the management of depression and emphasize the importance of maintaining a healthy gut microbiota for PSD.

Factors affecting medical students' intention to use Rain Classroom: a cross-sectional survey.

BACKGROUND: Rain Classroom was one of the most popular online learning platforms in Chinese higher education during the pandemic. However, there is little research on user intention under the guidance of technology acceptance and unified theory (UTAUT). OBJECTIVE: This research aims to determine factors influencing students' behavioural intention to use Rain Classroom. METHODS: In this cross-sectional and correlational investigation, 1138 medical students from five medical universities in Guangxi Province, China, made up the sample. This study added self-efficacy (SE), motivation (MO), stress (ST), and anxiety (AN) to the UTAUT framework. This study modified the framework by excluding actual usage variables and focusing only on intention determinants. SPSS-26 and AMOS-26 were used to analyze the data. The structural equation modelling technique was chosen to confirm the hypotheses. RESULTS: Except for facilitating conditions (FC), all proposed factors, including performance expectancy (PE), effort expectancy (EE), social influence (SI), self-efficacy (SE), motivation (MO), anxiety (AN), and stress (ST), had a significant effect on students' behavioural intentions to use Rain Classroom. CONCLUSIONS: The research revealed that the proposed model, which was based on the UTAUT, is excellent at identifying the variables that influence students' behavioural intentions in the Rain Classroom. Higher education institutions can plan and implement productive classrooms.

The records of 239+240Pu and 137Cs of global fallout in Lake East Dongting Sediments and Responses to watershed environmental changes.

Plutonium-239 + 240 and 137Cs in the environment can usually be used to track the impact of nuclear activities on the environment, and have become important tools in environmental geochemical studies. In this study, nine sediment cores (E1-E9) in Lake East Dongting were collected and measured for the activity concentration of 239+240Pu, 137Cs and the atomic ratio of 240Pu/239Pu, and then their vertical distribution characteristics were analyzed. The results show that: the activity concentrations of 137Cs and 239+240Pu in Lake East Dongting ranged from 5.26 ± 0.43 to 28.6 ± 2.23 Bq kg-1 and 0.29 ± 0.02 to 1.37 ± 0.09 Bq kg-1, with an average of 7.48 ± 0.68 Bq kg-1 and 0.39 ± 0.03 Bq kg-1, respectively. The atomic ratios of 240Pu/239Pu are 0.168 ± 0.012-0.211 ± 0.015, which are basically consistent with the global atmospheric deposition. The vertical profiles of 137Cs and 239+240Pu in sediment cores show obvious single-peak distribution in E1-E6 and bimodal distribution in E7-E9. The results of sedimentation rates calculated by 137Cs and 239+240Pu method ranged from 0.59 cm y-1 to 1.99 cm y-1 with a mean of 1.18 cm y-1 and 0.61 cm y-1 to 2.18 cm y-1 with a mean of 1.26 cm y-1. The inventories of 137Cs and 239+240Pu in nine sediment cores are 5.87-10.8 kBq m-2 and 307-545 Bq m-2, which are about 8-14 and 9-15 times the inventory in the global average atmospheric deposition at the same latitude respectively. Comparing the results of the sedimentation rates and the inventories from different sampling points indicates that extreme climatic events and human activities have a significant impact on sediment environment of Lake East Dongting.

Changes in vegetation in China's drylands are closely related to afforestation compared with climate change.

The response of vegetation to climate change and human activities has attracted considerable attention. However, quantitative studies on the effects of climate change and human activities on dryland vegetation in different seasons remain unclear. This study investigated the impacts of precipitation, temperature, soil water storage (SWS) (top [0-7 cm], shallow [7-28 cm], and middle [28-100 cm] layers), vapor pressure deficit (VPD), and afforestation on vegetation as well as their relative contribution rates during the rainy season ([RS], June to September), dry season ([DS], November to April), transition season ([TS], May and October), and all year period (AY) in China's drylands from 2001 to 2020 using the first-difference method. Areas with precipitation and SWS showing significant positive correlation with dryland vegetation (p < 0.05) were found to be larger in RS than in DS and TS, and the positive effect of SWS increased with soil depth in the 0-28 cm interval. Increasing VPD induced a significant negative effect on vgetation during RS but it was not predominant in DS and TS. Afforestation showed an extremely significant positive correlated with dryland vegetation across >60 % of China's dryland areas (p < 0.01), but this improvement was found to be limited to regions with the highest afforestation area. Moreover, dryland vegetation dynamics were driven by afforestation in all seasons, with contribution rates of 64.23 %-71.46 %. The effects of SWS and VPD on vegetation driven by precipitation and temperature exceeded the direct effects of precipitation and temperature. Among climatic factors, VPD showed a major regulating effect on dryland vegetation at the top and shallow soil layers in almost all seasons, whereas the relative contribution rate of SWS increased with soil layer. The findings can provide a scientific reference for the sustainable development and protection of drylands under global warming.

Soil microbial community characteristics and the influencing factors at different elevations on the eastern slope of Helan Mountain, Northwest China.

As an important bridge connecting aboveground communities and belowground biological processes, soil microorganisms play an important role in regulating belowground ecological processes. The altitudinal changes and driving factors of soil microbial community in mountain ecosystem in arid region are still unclear. We measured soil physicochemical properties at seven altitudes in the range of 1300-2800 m in Helan Mountains, and investigated the understory community composition, soil physicochemical properties, and soil microbial community. The driving factor for soil microbial community was explored by variance partitioning analysis and redundancy analysis. The results showed that the total amount of soil microorganisms and bacterial biomass first increased and then decreased with the increases of altitude, fungi, actinomyces, arbuscular mycorrhizal fungi, Gram-positive bacteria, and Gram-negative bacteria groups showed a gradual increase. The variation of fungal-to-bacterial ratio (F/B) along the altitude showed that the cumulative ability of soil bacteria was stronger than that of fungi at low altitudes, while the pattern is opposite at high altitudes. The ratio of Gram-positive bacteria to Gram-negative bacteria (GP/GN) showed an overall decreasing trend with the increases of altitude, indicating that soil bacteria and organic carbon availability changed from "oligotrophic" to "eutrophication" and from "low" to "high" transition as the altitude increased. Vegetation properties, soil physical and chemical properties jointly accounted for 95.7% of the variation in soil microbial community. Soil organic carbon (SOC), soil water content (SWC), and total nitrogen (TN) were significantly correlated with soil microbial community composition. Our results revealed the distribution pattern and driving factors of soil microbial communities at different elevations on the eastern slope of Helan Mountain, which would provide theoretical basis and data support for further understanding the interaction between plant-soil-microorganisms in arid areas.

Effect of data spatial vertical resolution on the estimation of vertical profiles of the refractive index structure constant.

The vertical profile of optical turbulence is a key factor in the performance design of astronomical telescopes and adaptive optics instruments. As site-testing campaigns are extremely expensive, the selection of appropriate spatial resolution data and estimation methods is extremely important. This study investigated the effect of using different methods (Dewan, HMNSP99, Thorpe method) to estimate the refractive index structure constant (C n2) using different resolution data (5 m, 25 m, ERA5 data) in Huaihua, Hunan. Compared with Dewan, HMNSP99 for estimating C n2 using 5 m and 25 m resolution data, the Thorpe method almost always shows the best performance, with RXY above 0.75 and lower RMSE and MRE between estimated and measured C n2. The results of C n2 estimation using HMNSP99 at different resolution data varied widely, indicating that HMNSP99 is more sensitive to the data resolution and the temperature gradient is more sensitive to the resolution. Using ERA5 data, the two methods of estimating C n2 using Dewan and HMNSP99 have close results. It indicates that the wind shear is the main factor when the spatial resolution of the data is reduced to a certain degree, and the contribution of temperature gradient is small in the high altitude turbulence.

Chinese expert consensus on the construction of the fluoroless cardiac electrophysiology laboratory and related techniques.

Transcatheter radiofrequency ablation has been widely introduced for the treatment of tachyarrhythmias. The demand for catheter ablation continues to grow rapidly as the level of recommendation for catheter ablation. Traditional catheter ablation is performed under the guidance of X-rays. X-rays can help display the heart contour and catheter position, but the radiobiological effects caused by ionizing radiation and the occupational injuries worn caused by medical staff wearing heavy protective equipment cannot be ignored. Three-dimensional mapping system and intracardiac echocardiography can provide detailed anatomical and electrical information during cardiac electrophysiological study and ablation procedure, and can also greatly reduce or avoid the use of X-rays. In recent years, fluoroless catheter ablation technique has been well demonstrated for most arrhythmic diseases. Several centers have reported performing procedures in a purposefully designed fluoroless electrophysiology catheterization laboratory (EP Lab) without fixed digital subtraction angiography equipment. In view of the lack of relevant standardized configurations and operating procedures, this expert task force has written this consensus statement in combination with relevant research and experience from China and abroad, with the aim of providing guidance for hospitals (institutions) and physicians intending to build a fluoroless cardiac EP Lab, implement relevant technologies, promote the standardized construction of the fluoroless cardiac EP Lab.

Mismatch between primary and secondary growth and its consequences on wood formation in Qinghai spruce.

The connections between the primary and secondary growth of trees allows better understanding of the dynamics of carbon sequestration in forest ecosystems. The relationship between primary and secondary growth of trees could change due to the diverging responses of meristems to climate warming. In this study, the bud phenology and radial growth dynamics of Qinghai spruce (Picea crassifolia) in arid and semi-arid areas of China in 2019 and 2020 were weekly monitored to analyze their response to different weather conditions and their links with carbon sink. Xylem anatomical traits (i.e. lumen radial diameter and cell wall thickness) were quantified along cell radial files after the end of xylem lignification to calculate the early-to-latewood transition date. Winter and early spring (January-March) were warmer in 2020 with a colder April compared with 2019. Precipitation in April-June was lower in 2020 than in 2019. In 2019, bud phenology occurred earlier, while the onset of xylem formation and the early-to-latewood transition date were delayed. The duration from the beginning of split bud and exposed shoot to the early-to-latewood transition date was positively correlated with the radial width of earlywood (accounting for ~80% of xylem width) and total xylem width. The longer duration of xylem cell division did not increase xylem cell production and radial width. Moreover, the duration from bud burst to the early-to-latewood transition date in 2020 was negatively linked with early phloem cell production as compared with 2019. Our findings suggest that warm conditions in winter and early spring promote the xylogenesis of Qinghai spruce, but might delay bud burst. However, the xylem width increments largely depend on the duration from bud burst to the start of latewood cell division rather than on the earlier xylogenesis and longer duration of xylem cell differentiation induced by warm conditions.

Case report: Unusual cause of refractory hypoxemia after pacemaker lead extraction.

A 59-year-old woman with a history of a pacemaker implanted for III-degree atrioventricular block was admitted due to pocket infection. The atrial and ventricular leads were removed via the right femoral vein using a needle's eye snare. Hypoxemia was observed immediately after the removal of the lead. It was refractory to oxygen therapy. The pulse oxygen saturation (SpO2) showed 89% in the supine position and 77% in the upright position. However, the CTPA and pulmonary perfusion SPECT/CT imaging did not reveal any signs of pulmonary embolism. Pulmonary function tests and chest CT showed normal results. Transthoracic contrast echocardiography revealed a patent foramen ovale (PFO) and a right-to-left intracardiac shunt, no significant tricuspid regurgitation, without any signs of elevated right heart pressure or pulmonary hypertension. Hypoxemia was considered to be associated with the right-to-left shunt through PFO. The condition was relieved by percutaneous closure of the PFO. Refractory hypoxemia resulting from an intracardiac right-to-left shunt following pacemaker lead extraction is a rare but serious complication. Transthoracic contrast echocardiography helps in diagnosis. If the right-to-left intracardiac shunt through PFO persists irreversibly and the associated hypoxemic symptoms are significant, closure of the PFO is necessary. Transesophageal echocardiography also revealed the presence of a left-to-right shunt through PFO during cardiac systole. The closure of the PFO is also necessary to avoid long-term complications, such as chronic pulmonary hypertension and right heart failure.

Microstructure, Characterization and Mechanical Properties of Coal and Coal-like Materials.

Energy is the most basic driving force for world development and economic growth and the basis for human survival [...].

The association between C-peptide and atrial cardiomyopathy in nondiabetic adults: results from NHANES III.

Serum C-peptide exhibits various biological activities. The relationship between C-peptide and atrial cardiomyopathy remains unknown. We aimed to investigate the association between C-peptide level and atrial cardiomyopathy in nondiabetic adults. Our study enrolled 4578 participants without diagnosed diabetes from the Third National Health and Nutrition Examination Survey (NHANES III). Atrial cardiomyopathy was defined as a deep terminal negative P wave in V1 below - 100 µV (more negative), according to the electrocardiogram. The participants were categorized into low C-peptide (≤ 1.46 nmol/L) and high C-peptide (> 1.46 nmol/L) groups, according to the receiver operating characteristic analysis. Odds ratio (OR) and 95% confidence interval (CI) for the association between C-peptide level and atrial cardiomyopathy were generated using multivariate logistic regression analysis. The prevalence of atrial cardiomyopathy was higher in the high C-peptide group than in the low C-peptide group (5.62% vs. 2.31%, P < 0.001, respectively). Multivariate logistic regression analysis showed that participants in the high C-peptide group had a 3.60-fold (95% CI 1.81-6.99) higher risk of atrial cardiomyopathy than those in the low C-peptide group. Per standard deviation increase in C-peptide was linked to a 1.20-fold (95% CI 1.00-1.41) higher risk in atrial cardiomyopathy. High C-peptide level might be an independent risk factor for atrial cardiomyopathy in nondiabetic adults.

Estimation and characterization of atmospheric turbulence in the free atmosphere above the Tibetan Plateau using the Thorpe method.

Understanding turbulence in the free atmosphere is important for analyzing atmospheric pollution, forecasting weather, and light transmission. In this paper, we have tried to estimate the atmospheric refractive index structure constant C n2, the turbulent dissipation rate ε, and the turbulent diffusion coefficient K simultaneously during the experiment time over Lhasa, using the sounding data coupled with the Thorpe method. The result shows that the C n2 estimation gives a better performance with the correlation coefficients and the average relative error when compared with C n2 estimated by Dewan and HMNSP99. Besides this, the measured and estimated C n2, estimated ε, and K all show larger values in the troposphere, especially near the tropopause. It is worth noting that C n2 and ε are similar in terms of height distribution. These attempts at estimation all suggest that the Thorpe method can be used to estimate the intensity of turbulence in the free atmosphere over Lhasa.