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Iodide-adduct time-of-flight chemical ionization mass spectrometry (I-CIMS) has been developed as a powerful tool for detecting the oxidation products of volatile organic compounds. However, the accurate quantification of species that do not have generic standards remains a challenge for I-CIMS application. To accurately quantify aromatic hydrocarbon oxidation intermediates, both quantitative and semi-quantitative methods for I-CIMS were established for intermediate species. The direct quantitative experimental results reveal a correlation between sensitivity to iodide addition and the number of polar functional groups (keto groups, hydroxyl groups, and acid groups) present in the species. Leveraging the selectivity of I-CIMS for species with diverse functional groups, this study established semi-quantitative equations for four distinct categories: monophenols, monoacids, polyphenol or diacid species, and species with multiple functional groups. The proposed classification method offers a pathway to enhancing the accuracy of the semi-quantitative approach, achieving an improvement in R2 values from 0.52 to beyond 0.88. Overall, the categorized semi-quantitative method was utilized to quantify intermediates formed during the oxidation of toluene under both low-NO and high-NO conditions, revealing the differential variations in oxidation products with varying levels of NO x concentration. [ABSTRACT FROM AUTHOR]

As a main extraction compound from Scutellaria baicalensis Georgi, Baicalin exhibits various biological activities. However, the underlying mechanism of Baicalin on hypertension‐induced heart injury remains unclear. In vivo, mice were infused with angiotensin II (Ang II; 500 ng/kg/min) or saline using osmotic pumps, followed by intragastrically administrated with Baicalin (5 mg/kg/day) for 4 weeks. In vitro, H9C2 cells were stimulated with Ang II (1 μM) and treated with Baicalin (12.5, 25 and 50 μM). Baicalin treatment significantly attenuated the decrease in left ventricular ejection fraction and left ventricular fractional shortening, increase in left ventricular mass, left ventricular systolic volume and left ventricular diastolic volume of Ang II infused mice. Moreover, Baicalin treatment reversed 314 differentially expressed transcripts in the cardiac tissues of Ang II infused mice, and enriched multiple enriched signalling pathways (including apoptosis, autophagy, AMPK/mTOR signalling pathway). Consistently, Baicalin treatment significantly alleviated Ang II‐induced cell apoptosis in vivo and in vitro. Baicalin treatment reversed the up‐regulation of Bax, cleaved‐caspase 3, cleaved‐caspase 9, and the down‐regulation of Bcl‐2. Meanwhile, Baicalin treatment alleviated Ang II‐induced increase of autophagosomes, restored autophagic flux, and down‐regulated LC3II, Beclin 1, as well as up‐regulated SQSTM1/p62 expression. Furthermore, autophagy inhibitor 3‐methyladenine treatment alleviated the increase of autophagosomes and the up‐regulation of Beclin 1, LC3II, Bax, cleaved‐caspase 3, cleaved‐caspase 9, down‐regulation of SQSTM1/p62 and Bcl‐2 expression after Ang II treated, which similar to co‐treatment with Baicalin. Baicalin treatment reduced the ratio of p‐AMPK/AMPK, while increased the ratio of p‐mTOR/mTOR. Baicalin alleviated Ang II‐induced cardiomyocyte apoptosis and autophagy, which might be related to the inhibition of the AMPK/mTOR pathway. [ABSTRACT FROM AUTHOR]

Rational delineation of ecological functional areas and clarification of their driving factors are of significance for maintaining regional ecosystem stability. We assessed six ecosystem services of Sihu Lake Basin located in Jianghan Plain using InVEST and RUSLE models and recreational scoring methods. By using K-means clustering, we identified the ecosystem service bundles, and delineated the ecological functional areas in combination with ecological sensitivity and ecosystem service bundles. The dominant driving factors of different ecological functional areas were analyzed by Geodetector. The results showed that the spatial distributions of habitat quality and carbon sequestration services were similar, with high values being mainly concentrated in Changhu Lake Basin and Honghu Lake Basin. However, the spatial distributions of crop production and soil conservation services were different, with high-value areas concentrated in the northwest area with mountains. The high values of water production service were mainly concentrated in the eastern part of Honghu Lake Basin, while the high-value areas of ecological recreation service were mainly concentrated in the northwest area and the southern part of Honghu Lake Basin. The Sihu Lake Basin could be classified into crop production bundle, habitat quality bundle, and urban living bundle according to cluster analysis. The low ecological sensitivity areas accounted for 59.0% of the Sihu Lake Basin. We classified the study area into ecological restoration areas, ecological conservation areas, ecological transition areas, ecological development areas, and comprehensive use areas by combination of ecological sensitivity and ecosystem service bundles. The geodetector results indicated that the driving factors of each ecological function zone were significantly different. The natural factors significantly influenced the ecological restoration zone, while the normalized vegetation index and population density were the main influencing factors in the ecological conservation zone and the ecological development zone, respectively. Land use type was the main influencing factor in the ecological transition zone and the comprehensive use zone. The results could provide important support for coordinated regional social development and environmental protection. [ABSTRACT FROM AUTHOR]

The structure and stability of grassland ecosystems have a significant impact on biodiversity, material cycling and productivity for ecosystem services. However, the issue of the structure and stability of grassland ecosystems has not been systematically reviewed. Based on the Web of Science (WOS) and China National Knowledge Infrastructure (CNKI) databases, we used the systematic-review method and screened 133 papers to describe and analyze the frontiers of research into the structure and stability of grassland ecosystems. The research results showed that: (1) The number of articles about the structure and stability of grassland ecosystems is gradually increasing, and the research themes are becoming increasingly diverse. (2) There is a high degree of consistency between the study area and the spatial distribution of grassland. (3) Based on the changes in ecosystem patterns and their interrelationships with ecosystem processes, we reviewed the research progress and landmark results on the structure, stability, structure–stability relationship and their influencing factors of grassland ecosystems; among them, the study of structure is the main research focus (51.12%), followed by the study of the influencing factors of structure and stability (37.57%). (4) Key scientific questions on structural optimization, stability enhancement and harmonizing the relationship between structure and stability are explored. (5) Based on the background of karst desertification control (KDC) and its geographical characteristics, three insights are proposed to optimize the spatial allocation, enhance the stability of grassland for rocky desertification control and coordinate the regulation mechanism of grassland structure and stability. This study provided some references for grassland managers and relevant policy makers to optimize the structure and enhance the stability of grassland ecosystems. It also provided important insights to enhance the service capacity of grassland ecosystems in KDC. [ABSTRACT FROM AUTHOR]

Karst desertification control of grasslands balances the ecological and economic benefits of ecological restoration and rural ecological animal husbandry development. In the context of global changes and intensified human activities, the fragility of grassland ecosystems under karst desertification control is becoming increasingly evident, and enhancing the ecological resilience and ecosystem services of grasslands is an issue that urgently needs to be addressed. In this paper, the CNKI literature, WOS core databases and Goolgle scholar were used as search sources, identifying 179 articles related to the study of grassland ecosystem vulnerability and ecological resilience. This research systematically reviewed the progress of grassland ecosystem vulnerability research and analyzed the relationship between grassland ecosystem services (GESs) and grassland ecosystem vulnerability and resilience. The direction of enhancing GESs in karst areas is indicated in terms of the reciprocal feedback, synergistic relationship, and mechanism of action of GESs, vulnerability, and resilience. It is also emphasized that the karst desertification area should provide an ecological foundation for the sustainable development of the regional environment around the supply-and-demand relationship of GESs, the trade-off synergy of service flow, and the enhancement of ecological resilience, thereby consolidating the effectiveness of karst desertification control, enhancing GESs, and helping rural revitalization. [ABSTRACT FROM AUTHOR]

Temporal lobe epilepsy, a chronic disease of the brain characterized by degeneration of the hippocampus, has impaired risk assessment. Risk assessment is vital for survival in complex environments with potential threats. However, the underlying mechanisms remain largely unknown. The intricate balance of gene regulation and expression across different brain regions is related to the structure and function of specific neuron subtypes. In particular, excitation/inhibition imbalance caused by hyperexcitability of glutamatergic neurons and/or dysfunction of GABAergic neurons, have been implicated in epilepsy. First, we estimated the risk assessment (RA) by evaluating the behavior of mice in the center of the elevated plus maze, and found that the kainic acid-induced temporal lobe epilepsy mice were specifically impaired their RA. This experiment evaluated approach-RA, with a forthcoming approach to the open arm, and avoid-RA, with forthcoming avoidance of the open arm. Next, results from free-moving electrophysiological recordings showed that in the hippocampus, ∼7% of putative glutamatergic neurons and ∼15% of putative GABAergic neurons were preferentially responsive to either approach-risk assessment or avoid-risk assessment, respectively. In addition, ∼12% and ∼8% of dorsal lateral septum GABAergic neurons were preferentially responsive to approach-risk assessment and avoid-risk assessment, respectively. Notably, during the impaired approach-risk assessment, the favorably activated dorsal dentate gyrus and CA3 glutamatergic neurons increased (∼9%) and dorsal dentate gyrus and CA3 GABAergic neurons decreased (∼7%) in the temporal lobe epilepsy mice. Then, we used RNA sequencing and immunohistochemical staining to investigate which subtype of GABAergic neuron loss may contribute to excitation/inhibition imbalance. The results show that temporal lobe epilepsy mice exhibit significant neuronal loss and reorganization of neural networks. In particular, the dorsal dentate gyrus and CA3 somatostatin-positive neurons and dorsal lateral septum cholecystokinin-positive neurons are selectively vulnerable to damage after temporal lobe epilepsy. Optogenetic activation of the hippocampal glutamatergic neurons or chemogenetic inhibition of the hippocampal somatostatin neurons directly disrupts RA, suggesting that an excitation/inhibition imbalance in the dHPC dorsal lateral septum circuit results in the impairment of RA behavior. Taken together, this study provides insight into epilepsy and its comorbidity at different levels, including molecular, cell, neural circuit, and behavior, which are expected to decrease injury and premature mortality in patients with epilepsy. [ABSTRACT FROM AUTHOR]

The ongoing coronavirus disease 2019 (COVID‐19) epidemic has made a huge impact on health, economies, and societies all over the world. Although reverse transcription‐polymerase chain reaction (RT‐PCR)‐based nucleic acid detection has been primarily used in the diagnosis of COVID‐19, it is time‐consuming with limited application scenarios and must be operated by qualified personnel. Antibody test, particularly point‐of‐care antibody testing, is a suitable complement to nucleic acid test as it provides rapid, portable, and cost‐effective detection of infections. In this study, a Rapid Antibody Test Kit was developed based on fluorescence immunochromatography for the sensitive, accurate, and automated detection of immunoglobulin M (IgM) and IgG antibodies against severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) in human serum, plasma, and whole blood samples within 10 min. The sensitivity, specificity, precision, and stability of the test kit were of good performance. No cross‐activity and no interference was observed. In the multiple‐center parallel study, 223 samples from hospitalized patients were used to evaluate the clinical specificity of the test. Both SARS‐CoV‐2 IgM and IgG achieved a clinical specificity of 98.21%. The clinical sensitivities of SARS‐CoV‐2 IgM and IgG were 79.54% and 87.45%, respectively, among 733 reverse transcription‐polymerase chain reaction (RT‐PCR) confirmed SARS‐CoV‐2 samples. For the combined IgM and IgG assays, the sensitivity and specificity were 89.22% and 96.86%, respectively. Our results demonstrate that the combined use of IgM and IgG could serve as a more suitable alternative detection method for patients with COVID‐19, and the developed kit is of great public health significance for the prevention and control of the COVID‐19 pandemic. Highlights: We developed a rapid SARS‐CoV‐2 IgM and IgG test, which could be easy‐use and automatic for prevention and control of the COVID‐19 pandemic.The test showed good performance in evaluation of sensitivity, specificity, precision, and stability, and no cross‐activity and interference was observed.The combined use of IgM and IgG showed could be more suitable for COVID‐19 patients. [ABSTRACT FROM AUTHOR]

An appropriate balance between explorative and defensive behavior is essential for the survival and reproduction of prey animals in risky environments. However, the neural circuit and mechanism that allow for such a balance remains poorly understood. Here, we use a semi-naturalistic predator threat test (PTT) to observe and quantify the defense-exploration balance, especially risk exploration behavior in mice. During the PTT, the activity of the putative dorsal CA3 glutamatergic neurons (dCA3Glu) is suppressed by predatory threat and risk exploration, whereas the neurons are activated during contextual exploration. Moreover, optogenetic excitation of these neurons induces a significant increase in risk exploration. A circuit, comprising the dorsal CA3, dorsal lateral septal, and dorsomedial hypothalamic (dCA3Glu-dLSGABA-DMH) areas, may be involved. Moreover, activation of the dCA3Glu-dLSGABA-DMH circuit promotes the switch from defense to risk exploration and suppresses threat-induced increase in arousal. [Display omitted] • dCA3Glu neurons are suppressed by predatory threat and risk exploration • A disynaptic dCA3Glu-dLSGABA-DMH circuit is identified • This circuit controls the switch between defense and risk exploration • Activating this circuit inhibits defense by decreasing predator-evoked arousal Zhong et al. show that dCA3Glu neurons respond positively to contextual exploration but negatively to potential threat. A dCA3Glu-dLSGABA-DMH circuit controlling exploration and defense balances in complex environments is identified. Activation or inhibition of this circuit bidirectionally regulates an animal's arousal level and promotes the switch between defense and risk exploration. [ABSTRACT FROM AUTHOR]