Ufmylation reconciles salt stress-induced unfolded protein responses via ER-phagy in Arabidopsis.

In plants, the endomembrane system is tightly regulated in response to environmental stresses for maintaining cellular homeostasis. Autophagosomes, the double membrane organelles forming upon nutrient deprivation or stress induction, degrade bulky cytosolic materials for nutrient turnover. Though abiotic stresses have been reported to induce plant autophagy, few receptors or regulators for selective autophagy have been characterized for specific stresses. Here, we have applied immunoprecipitation followed by tandem mass spectrometry using the autophagosome marker protein ATG8 as bait and have identified the E3 ligase of the ufmylation system Ufl1 as a bona fide ATG8 interactor under salt stress. Notably, core components in the ufmylation cascade, Ufl1 and Ufm1, interact with the autophagy kinase complexes proteins ATG1 and ATG6. Cellular and genetic analysis showed that Ufl1 is important for endoplasmic reticulum (ER)-phagy under persisting salt stress. Loss-of-function mutants of Ufl1 display a salt stress hypersensitive phenotype and abnormal ER morphology. Prolonged ER stress responses are detected in ufl1 mutants that phenocopy the autophagy dysfunction atg5 mutants. Consistently, expression of ufmylation cascade components is up-regulated by salt stress. Taken together, our study demonstrates the role of ufmylation in regulating ER homeostasis under salt stress through ER-phagy.

HHL1 and SOQ1 synergistically regulate nonphotochemical quenching in Arabidopsis.

Nonphotochemical quenching (NPQ) is an important photoprotective mechanism that quickly dissipates excess light energy as heat. NPQ can be induced in a few seconds to several hours; most studies of this process have focused on the rapid induction of NPQ. Recently, a new, slowly induced form of NPQ, called qH, was found during the discovery of the quenching inhibitor suppressor of quenching 1 (SOQ1). However, the specific mechanism of qH remains unclear. Here, we found that hypersensitive to high light 1 (HHL1)-a damage repair factor of photosystem II-interacts with SOQ1. The enhanced NPQ phenotype of the hhl1 mutant is similar to that of the soq1 mutant, which is not related to energy-dependent quenching or other known NPQ components. Furthermore, the hhl1 soq1 double mutant showed higher NPQ than the single mutants, but its pigment content and composition were similar to those of the wildtype. Overexpressing HHL1 decreased NPQ in hhl1 to below wildtype levels, whereas NPQ in hhl1 plants overexpressing SOQ1 was lower than that in hhl1 but higher than that in the wildtype. Moreover, we found that HHL1 promotes the SOQ1-mediated inhibition of plastidial lipoprotein through its von Willebrand factor type A domain. We propose that HHL1 and SOQ1 synergistically regulate NPQ.

Mycobacterium vaccae alleviates allergic airway inflammation and airway hyper-responsiveness in asthmatic mice by altering intestinal microbiota.

Host immunity can influence the composition of the gut microbiota and consequently affect disease progression. Previously, we reported that a Mycobacterium vaccae vaccine could ameliorate allergic inflammation in asthmatic mice by regulating inflammatory immune processes. Here, we investigated the anti-inflammatory effects of M. vaccae on allergic asthma via gut microbiota modulation. An ovalbumin (OVA)-induced asthmatic murine model was established and treated with M. vaccae. Gut microbiota profiles were determined in 18 BALB/c mice using 16S rDNA gene sequencing and metabolomic profiling was performed using liquid chromatography quadrupole time-of-flight mass spectrometry. Mycobacterium vaccae alleviated airway hyper-reactivity and inflammatory infiltration in mice with OVA-induced allergic asthma. The microbiota of asthmatic mice is disrupted and that this can be reversed with M. vaccae. Additionally, a total of 24 differential metabolites were screened, and the abundance of PI(14:1(9Z)/18:0), a glycerophospholipid, was found to be correlated with macrophage numbers (r = 0.52, p = 0.039). These metabolites may affect chemokine (such as macrophage chemoattractant protein-1) concentrations in the serum, and ultimately affect pulmonary macrophage recruitment. Our data demonstrated that M. vaccae might alleviate airway inflammation and hyper-responsiveness in asthmatic mice by reversing imbalances in gut microbiota. These novel mechanistic insights are expected to pave the way for novel asthma therapeutic strategies.

YTHDC1 promotes the malignant progression of gastric cancer by promoting ROD1 translocation to the nucleus.

RNA-binding proteins (RBPs) make vital impacts on tumor progression and are important potential targets for tumor treatment. Previous studies have shown that RBP regulator of differentiation 1 (ROD1), enriched in the nucleus, is abnormally expressed and functions as a splicing factor in tumors; however, the mechanism underlying its involvement in gastric cancer (GC) is unknown. In this study, ROD1 is found to stimulate GC cell proliferation and metastasis and is related to poor patient prognosis. In vitro experiments showed that ROD1 influences GC proliferation and metastasis through modulating the imbalance of the level of the oncogenic gene OIP5 and the tumor suppressor gene GPD1L. Further studies showed that the N6-methyladenosine (m6A) "reader" protein YTHDC1 can interact with ROD1 and regulate the balance of the expression of the downstream molecules OIP5/GPD1L by promoting the nuclear enrichment of ROD1. Therefore, YTHDC1 stimulates GC development and progression through modulating nuclear enrichment of the splicing factor ROD1.

Optimal strategy for stabilizing protein folding intermediates.

To manipulate the protein concentration at a certain functional state through chemical stabilizers is crucial for protein-related studies. It not only plays a key role in protein structure analysis and protein folding kinetics, but also affects protein functionality to a large extent and thus has wide applications in medicine, food industry, etc. However, due to concerns about side effects or financial costs of stabilizers, identifying optimal strategies for enhancing protein stability with a minimal amount of stabilizers is of great importance. Here, we prove that either for the fixed terminal time (including both finite and infinite cases) or for the free one, the optimal control strategy for stabilizing the folding intermediates with a linear strategy for stabilizer addition belongs to the class of bang-bang controls. The corresponding optimal switching time is derived analytically, whose phase diagram with respect to several key parameters is explored in detail. The bang-bang control will be broken when nonlinear strategies for stabilizer addition are adopted. Moreover, the above theory is applied to the stabilization of erythropoietin by ten different kinds of chemicals, providing theoretical guidance for the selection and rational usage of stabilizers. Our current study on optimal strategies for protein stabilizers not only offers deep insights into the general picture of protein folding kinetics but also provides valuable theoretical guidance on treatments for protein-related diseases in medicine.

Eupatilin ameliorates postmenopausal osteoporosis via elevating microRNA-211-5p and repressing JAK2/STAT3 pathway.

Postmenopausal osteoporosis (PMOP) poses a significant threat to women's health worldwide. Eupatilin is a key bioactive component of the Chinese herbal medicine Artemisia asiatica Nakai. Recent research reports have proved the inhibitory function of Eupatilin in many diseases. MicroRNAs (miRNAs) are 21-23 nucleotide-long, single-stranded, noncoding RNA molecules generated endogenously, and many studies have indicated that miRNAs are involved in the development of osteoporosis. This study explored the role and potential mechanism of Eupatilin underlying PMOP. First, rats were given intragastric administration of Eupatilin every day and subcutaneous injections of oligonucleotides or plasmids that interfered with miR-211-5p or janus kinase 2 (JAK2) once a week. After 4 weeks, the PMOP rat model was established. Then, serum alkaline phosphatase, calcium, and phosphorus levels, as well as femur bone mineral density and biomechanical parameters, were detected. Hematoxylin-eosin staining and Masson staining were applied for detecting the pathological condition of femur, and immunohistochemical staining was for detecting osteocalcin. MC3T3-E1 cells were transfected with plasmid vectors interfering with miR-211-5p or JAK2; and cell viability, lactate dehydrogenase cytotoxicity, and cell mineralization were subsequently examined. The relationship between miR-211-5p and JAK2/signal transducer and activator of transcription 3 (STAT3) pathway was analyzed. The targeting relation between miR-211-5p and JAK2 was also verified. The experimental results revealed that Eupatilin improved the pathological conditions of PMOP rats by promoting the proliferation and mineralization of osteoblasts. MiR-211-5p was down-regulated and JAK2/STAT3 was upregulated in PMOP rats. Upregulation of miR-211-5p further improved the pathological conditions of PMOP rats based on Eupatilin treatment. MiR-211-5p inhibited the JAK2/STAT3 pathway. JAK2 offset the effects of elevated miR-211-5p on PMOP rats. Overall, Eupatilin attenuates PMOP through elevating miR-211-5p and repressing JAK2/STAT3 pathway, which suggests the utility of Eupatilin as a potential drug for POMP treatment.

First report of Boeremia exigua causing spot blight on cowpea in China.

Cowpea or black-eyed pea [Vigna unguiculata (L.) Walp.] is a dual-purpose leguminous crop grown for food and fodder. In September 2022, cowpea plants exhibiting symptoms of a leaf spot and blight were observed in Renda Town located in Jingning County of Gansu Province, China, with the disease incidence in individual cowpea fields as high as 100%. Diseased leaves showed variable-sized, nearly circular brown blotches, large blotches with dark brown margins, and the adaxial surfaces of blotches had small black dots and whorls (Fig. 1). Multiple isolates with consistent colony characteristics were obtained from cowpea leaves with typical symptoms. The isolates were transferred to fresh potato dextrose agar medium (PDA) and then purified by transferring hyphal tips to PDA. Three isolates, JNJD-1, JNJD-2, and JNJD-3, were selected for subsequent identification and pathogenicity determination. After eight days at 25℃ on PDA, the colonies appeared irregular, aerial mycelium dense, cottony, atrovirens to olive brown, with white hyphae on the undulate margin (Fig. 2A and B). The pycnidia were globose to sub-globose, brown to dark brown, with 70-110 µm diameters. Single celled hyaline conidia were ellipsoidal to oblong with obtuse ends, and measured 6.6-9.3 × 2.8-4.1 µm (x̄ = 7.8 × 3.5 µm, n = 50) (Fig. 2C). Morphological characteristics are similar to the description of the genus Boeremia (Aveskamp et al, 2010). Primer pairs ITS1/ITS4, LR0R/LR5, fRPB2-5F2/fRPB2-7cR, and TUB2FD/TUB4RD were used to amplify portions of the ITS, LSU, RPB2, and TUB genes, respectively (Chen et al, 2015). The obtained sequences (Accession numbers: PP033662 to PP033664 for ITS, PP033667 to PP033669 for LSU, PP035531 to PP035533 for RPB2, and PP035534 to PP035536 for TUB) were 97% identical to that of a B. exigua strain CBS 431.74 (accession no. FJ427001, EU754183, GU371780, and FJ427112) (Table 1). The constructed maximum likelihood tree indicated close relationships between three isolates and B. exigua, which clustered together (Fig. 3). Cowpea plants (cultivar Junlintianxia) at the three-leaf stage were inoculated by spraying a spore suspension (1×106 conidia/ml) of JNJD-1, JNJD-2, and JNJD-3 until run off and incubated at greenhouse conditions (25°C and 12 h light). Inoculations with sterile water were used as a control and each treatment was repeated 3 times with five plants per replicate. Small brown spots appeared on the infected leaves at 2 dpi, followed by the appearance of large blotches, with dark brown at the margin and grayish-white in the center at 5 dpi (Fig. 4A). These lesions gradually increase and coalesce, causing leaf chlorosis and finally defoliation in serious cases. Disease incidence in inoculated cowpea plants treated with the isolates JNJD-1, JNJD-2, and JNJD-3 reached almost 100%. In contrast, control plants developed no symptoms (Fig. 4B). The pathogens were re-isolated from the inoculated leaves and identified as B. exigua using morphological and molecular analysis, whereas no fungus was isolated from control leaves. The experiment was repeated once under the same conditions, yielding similar results. B. exigua has a broad host range, infecting 19 families and 31 genera of plant species, and causing leaf spots, leaf blight, and tuber rot (Lan and Duan 2022). To our knowledge, this is the first report of the pathogen B. exigua causing spot blight on cowpeas. It has been reported that B. exigua infects leguminous crops from multiple genera, such as field pea, soybean, white clover, and Dumasia villosa (Liu et al, 2023). This study further enriches the host range of this pathogen and the pathogen species of cowpea leaf diseases.

Exploring microRNAs in craniofacial regenerative medicine.

microRNAs (miRs) have been reported over the decades as important regulators in bone development and bone regeneration. They play important roles in maintaining the stem cell signature as well as regulating stem cell fate decisions. Thus, delivering miRs and miR inhibitors to the defect site is a potential treatment towards craniofacial bone defects. However, there are challenges in translation of basic research to clinics, including the efficiency, specificity, and efficacy of miR manipulation methods and the safety of miR delivery systems. In this review, we will compare miR oligonucleotides, mimics and antagomirs as therapeutic reagents to treat disease and regenerate tissues. Newer technology will be discussed as well as the efficiency and efficacy of using these technologies to express or inhibit miRs in treating and repairing oral tissues. Delivery of these molecules using extracellular vesicles and nanoparticles can achieve different results and depending on their composition will elicit specific effects. We will highlight the specificity, toxicity, stability, and effectiveness of several miR systems in regenerative medicine.

Inhibition of Amyloid ß Aggregation and Cytotoxicity by Berbamine Hydrochloride.

Alzheimer's disease (AD) continues to be a major global health challenge, and the recent approval of Aduhelm and Leqembi has opened new avenues for its treatment. Small-molecule inhibitors targeting Aß aggregation hold promise as an alternative to monoclonal antibodies. In this study, we evaluated the ability of berbamine hydrochloride (BBMH), a member of the bisbenzylisoquinoline alkaloids, to reduce Aß aggregation and cytotoxicity. Thioflavin T kinetics, circular dichroism spectroscopy, and atomic force microscopy results indicated that BBMH effectively inhibited Aß aggregation. Surface plasmon resonance and molecular docking results further revealed that BBMH could bind to Aß fibrils, thereby hindering the aggregation process. This physical picture has been confirmed in a quantitative way by chemical kinetics analysis, which showed BBMH tends to bind with the fibril ends and thus prevents the transition from protofibrils to mature fibrils as well as the elongation process. Additionally, our MTT results showed that BBMH was able to reduce the cytotoxicity of Aß40 on N2a cells. Our results demonstrate, for the first time, the potential of BBMH to inhibit Aß aggregation and cytotoxicity, offering a promising direction for further research and drug development efforts in the fight against Alzheimer's disease.

Log odds of positive lymph nodes as a novel prognostic predictor for gastric cancer: a systematic review and meta-analysis.

BACKGROUND: We conducted a systematic review and meta-analysis to summarize the predictive and prognostic ability of the log odds of positive lymph nodes (LODDS) staging system and compare it with pathological N (pN) classification and the ratio-based lymph node system (rN) for the overall survival (OS) of gastric cancer (GC). METHODS: Through a systematic review till March 7, 2022, we identified population-based studies that reported the prognostic effects of LODDS in patients with GC. We compare the predictive effectiveness of the LODDS staging system with that of the rN and pN classification systems for the OS of GC. RESULTS: Twelve studies comprising 20,312 patients were included in this systematic review and meta-analysis. The results showed that LODDS1, LODDS2, LODDS3, and LODDS4 in GC patients were correlated with poor OS compared with LODDS0 (LODDS1 vs. LODDS0: HR = 1.62, 95% CI (1.42, 1.85); LODDS2 vs. LODDS0: HR = 2.47, 95% CI (2.02, 3.03); LODDS3 vs. LODDS0: HR = 3.15, 95% CI (2.50, 3.97); LODDS4 vs. LODDS0: HR = 4.55, 95% CI (3.29, 6.29)). Additionally, significant differences in survival were observed among patients with different LODDS classifications (all P-values were < 0.001) with the same rN and pN classifications. Meanwhile, for patients with different pN or rN classifications with the same LODDS classification, prognosis was highly similar. CONCLUSION: The findings show that LODDS is correlated with the prognosis of GC patients and is superior to the pN and rN classifications for prognostic assessment.

Eupatilin ameliorates postmenopausal osteoporosis via elevating microRNA-211-5p and repressing Janus kinase 2/Signal transducer and activator of transcription 3 pathway.

This study explored the effect of Eupatilin on postmenopausal osteoporosis and explored the mechanisms associated with miR-211-5p. First, the rats were given intragastric administration of Eupatilin every day and subcutaneously injected once a week with oligonucleotides or plasmids that interfered with the expression of miR-211-5p or Janus kinase 2 (JAK2). After 4 weeks, a rat model of osteoporosis was established. Then, serum alkaline phosphatase, calcium and phosphorus levels were detected, as well as femur bone mineral density and biomechanical parameters. HE staining and Masson staining were applied for detecting the pathological condition of femur while immunohistochemical staining was for detecting the positive expression of osteocalcin. In addition, MC3T3-E1 cells were transfected with plasmid vectors interfering with miR-211-5p or JAK2, and cell viability, lactate dehydrogenase cytotoxicity, and cell mineralization were subsequently examined. The relationship between miR-211-5p and JAK2/Signal transducer and activator of transcription 3 (STAT3) pathway was analyzed, and the targeting of miR-211-5p and JAK2 was also verified. The experimental results found that Eupatilin improved the pathological conditions of osteoporotic rats by promoting the proliferation and mineralization of osteoblasts. miR-211-5p was down-regulated and JAK2/STAT3 were up-regulated in osteoporotic rats. Upregulation of miR-211-5p further improved the pathological conditions of osteoporotic rats based on Eupatilin treatment. MiR-211-5p inhibited the JAK2/STAT3 pathway. Upregulation of JAK2 reversed the effects of elevated miR-211-5p on osteoporotic rats. Overall, Eupatilin attenuates postmenopausal osteoporosis through elevating miR-211-5p and repressing JAK2/STAT3 pathway.

Germination of aged oat seeds associated with changes in antioxidant enzyme activity and storage compounds mobilization.

Germination of aged seeds may be associated with specific metabolic changes. The objective of this study was to examine physiological and metabolic alterations before and after germination of control and aged oat (Avena sativa) seeds. The activity of antioxidant enzymes and the level of storage compounds were measured in the embryo and endosperm at 0, 4, 16, and 32 h of imbibition for control seeds and 0, 4, 16, 32, and 60 h of imbibition for medium vigor seeds after artificially accelerated aging; metabolomic changes were determined in embryos at 16 and 32 h of seed imbibition. In aged oat seeds, superoxide dismutase activity and catalase activity increased in the late imbibition stage. The content of soluble sugars decreased significantly in the later stages of imbibition, while the content of proteins increased in 32 h of seed imbibition eventually producing mannitol and proline. The mobilization of fat in deteriorated seeds was mainly through the sphingolipid metabolic pathway generated by cell growth-promoting dihydrosphingosine-1-phosphate. Ascorbic acid, avenanthramide and proline levels increased significantly at 60 h of imbibition, playing an important role in the germination of aged oat seeds.

Towards Optimal Control of Amyloid Fibrillation.

Epigallocatechin-3-gallate, as a representative amyloid inhibitors, has shown a promising ability against A[Formula: see text] fibrillation by directly degradating the mature fibrils. Most previous studies have been focusing on its functional mechanisms, meanwhile its optimal dosage has been seldom considered. To solve this critical issue, we refer to the generalized Logistic model for amyloid fibrillation and inhibition and adopt the optimal control theory to balance the effectiveness and cost (or toxicity) of inhibitors. The optimal control trajectory of inhibitors is analytically solved, based on which the influence of model parameters, the difference between the optimal control strategy and several other traditional drug dosing strategies are systematically compared and validated through experiments. It is found that the strategy of multiple-times adding is more suitable for a long-term disease treatment, while single high-dose therapy is preferred for a short-term treatment. We hope our findings can shed light on the rational usage of amyloid inhibitors in clinic.

An in vitro and in vivo study on extracorporeal transducer optimization for high-intensity focused ultrasound to improve the safety and efficacy of breast tumor ablation.

OBJECTIVE: To observe the characteristics of a new extracorporeal high intensity focused ultrasound transducer, titled Haifu system JCQ-B, and to compare its safety and efficacy for breast ablation with the standard Haifu system JC transducer. MATERIALS AND METHODS: Ox liver with pig skin and pork ribs were prepared in a semi-sphere shape, served as in vitro acoustic model. The udders of female goats were used as in vivo acoustic model. Both in vitro and in vivo models were ablated by either JCQ-B or JC transducer. The morphology of biological focal region (BFR), the coagulative necrosis volume, and the temperature increase were observed and compared. RESULTS: The BFR morphology of JCQ-B transducer was circular both in vitro and in vivo, with a length-width ratio close to one. Under the same sonication parameters (sonication power, time and depth in tissue), coagulation necrosis volume caused by JCQ-B transducer was larger than that caused by JC transducer both in vitro and in vivo. The increase in temperature in the near and far acoustic pathways with JCQ-B transducer was significantly lower than that of JC transducer in vitro. After receiving high sonication energy during in vivo experimentation, there were no complications observed after the ablation of JCQ-B transducer, while small skin damage was observed after the ablation of JC transducer. CONCLUSIONS: The JCQ-B transducer improved the safety and efficacy of treatment by optimizing BFR morphology and ablation efficiency, which could be applied in the treatment of breast tumor.

Burden of gastroesophageal reflux disease in 204 countries and territories, 1990-2019: a systematic analysis for the Global Burden of disease study 2019.

INTRODUCTION: For effective preventive strategies against GORD (gastro-esophageal reflux disease), we assessed the GORD burden from 1990 to 2019. METHODS: The burden of GORD between 1990 and 2019 was evaluated globally, regionally, and nationally. Using ASIR (age-standardized incidence), ASYLDs (age-standardized years lived with disabilitys), we compared them to the GBD world population per 100,000. The estimates were based on 95% uncertainty intervals (UIs). The AAPC (average annual percent change) in incidence, YLDs, along with prevalence rates with associated 95% CIs were estimated. RESULTS: Data to estimate the burden of GORD are scarce till now. The global ASIR of GORD in 2019 was 3792.79 per 100,000, an increase AAPC of 0.112% from 1990. The prevalence of GORD increased with a AAPC of 0.096% to 9574.45 per 100,000. Global ASYLDs in 2019 was 73.63, an increase AAPC of 0.105% from 1990. The GORD burden varies greatly depending on the development level and geographical location. USA demonstrated the most obvious decreasing trend in burden of GORD, while Sweden had an increasing trend. That the increase in GORD YLDs was mediated primarily by the growth and aging of population, was revealed by decomposition analyses. There was an inverse relationship between SDI (socio-demographic index) and GORD-burden. Frontier analyses revealed significant scope of improvement in the status of development at all levels. CONCLUSION: GORD is a public health challenge, especially in Latin America. Some SDI quintiles had declining rates, while some countries experienced increased rates. Thus, resources should be allocated for preventative measures based on country-specific estimates.

Evaluation of characteristic metabolites of aromatic amino acids in patients with HIV infection at different stages of disease.

BACKGROUND: Acquired immune deficiency syndrome (AIDS), human immunodeficiency virus (HIV) infection, and antiretroviral therapy are usually associated with metabolic disorders. Screening for biomarkers to evaluate the progression of metabolic disorders is important for the diagnosis and treatment of HIV infection. This study aimed to establish and validate a method to quantify serum aromatic amino acid (AAA) metabolites as biomarkers of metabolic disorders in patients with HIV. METHODS: The AAAs and metabolites were analyzed using high-performance liquid chromatography-tandem mass spectrometry. Pearson's correlation, heatmap, and receiver operating characteristic curve analyses were used for statistical analysis. RESULTS: Under optimal detection conditions, the lower limits of phenylalanine (Phe), tryptophan (Trp), kynurenine (Kyn), tyrosine, phenylacetylglutamine (PAGln), and 5-hydroxytryptamine quantification reached 0.02, 0.02, 0.01, 0.02, 0.01, and 0.002 µg/ml, respectively, and the precision of intra- and inter-day was stay below 10.30%. Serum samples were stable for at least 6 months when stored at -80°C. The inter-group differences and associations between the biomarkers exhibited a particular volatility trend in PAGln, Trp, and Kyn metabolism in HIV-infected patients with metabolic syndrome. CONCLUSIONS: The developed method can be used for rapid and sensitive quantification of the AAA metabolism profile in vivo to further appraise the process of HIV infection, evaluate intervening measures, conduct mechanistic investigations, and further study the utility of PAGln, a characteristic metabolite of AAA, as a biomarker of HIV infection coupled with metabolic syndrome.

Kinetics of the conformational cycle of Hsp70 reveals the importance of the dynamic and heterogeneous nature of Hsp70 for its function.

Hsp70 is a conserved molecular chaperone that plays an indispensable role in regulating protein folding, translocation, and degradation. The conformational dynamics of Hsp70 and its regulation by cochaperones are vital to its function. Using bulk and single-molecule fluorescence resonance energy transfer (smFRET) techniques, we studied the interdomain conformational distribution of human stress-inducible Hsp70A1 and the kinetics of conformational changes induced by nucleotide and the Hsp40 cochaperone Hdj1. We found that the conformations between and within the nucleotide- and substrate-binding domains show heterogeneity. The conformational distribution in the ATP-bound state can be induced by Hdj1 to form an "ADP-like" undocked conformation, which is an ATPase-stimulated state. Kinetic measurements indicate that Hdj1 binds to monomeric Hsp70 as the first step, then induces undocking of the two domains and closing of the substrate-binding cleft. Dimeric Hdj1 then facilitates dimerization of Hsp70 and formation of a heterotetrameric Hsp70-Hsp40 complex. Our results provide a kinetic view of the conformational cycle of Hsp70 and reveal the importance of the dynamic nature of Hsp70 for its function.

An approach for accessibility assessment and vulnerability analysis of national multimodal transport systems.

A series of ambitious accessibility-oriented policies have been launched in the world, which center around improving accessibility via the national multimodal transport systems including road, airline, and railway. The national multimodal transport accessibility assessment is one of the "basic" analyses for the design and implementation of these policies, whereas existing national-scale accessibility studies either focus on single-mode or two-mode transport or ignore the schedule-dependent nature of railway and airline. This article models the integrated road, railway, airline, and walking transport as a four-layer network with the consideration of their interdependencies. An algorithm is then developed to accurately assess the travel time-based accessibility on the four-layer network with the consideration of the daily schedule of trains and flights. The proposed approach is applied to map accessibility to 363 cities in mainland China and analyze the optimal travel modes. In addition, this article investigates the travel time-based vulnerability of the national multimodal transport system in mainland China under the extreme storm recently occurred in Zhengzhou (July 2021). The findings in this work provide insightful suggestions for transport planners to design the national multimodal transport systems and for stakeholders to schedule travels.

Boundary effects on topological characteristics of urban road networks.

Urban road networks (URNs), as simplified views and important components of cities, have different structures, resulting in varying levels of transport efficiency, accessibility, resilience, and many socio-economic indicators. Thus, topological characteristics of URNs have received great attention in the literature, while existing studies have used various boundaries to extract URNs for analysis. This naturally leads to the question of whether topological patterns concluded using small-size boundaries keep consistent with those uncovered using commonly adopted administrative boundaries or daily travel range-based boundaries. This paper conducts a large-scale empirical analysis to reveal the boundary effects on 22 topological metrics of URNs across 363 cities in mainland China. Statistical results show that boundaries have negligible effects on the average node degree, edge density, orientation entropy of road segments, and the eccentricity for the shortest or fastest routes, while other metrics including the clustering coefficient, proportion of high-level road segments, and average edge length together with route-related metrics such as average angular deviation show significant differences between road networks extracted using different boundaries. In addition, the high-centrality components identified using varied boundaries show significant differences in terms of their locations, with only 21%-28% of high-centrality nodes overlapping between the road networks extracted using administrative and daily travel range-based boundaries. These findings provide useful insights to assist urban planning and better predict the influence of a road network structure on the movement of people and the flow of socio-economic activities, particularly in the context of rapid urbanization and the ever-increasing sprawl of road networks.

Night-time surgery for type a aortic dissection: Immediate or delaying?

OBJECTIVES: This study aims to investigate whether surgery performed during night compared with daytime were associated with an increased risk of operative mortality of type A aortic dissection (TAAD) patients. METHODS: A total of 2015 TAAD patients who underwent surgical repair were collected from two cardiovascular centers from Jan 2015 to Jan 2021. According to the start time of surgery, patients were divided into daytime group (06:01 a.m. to 06:00 p.m.) and night-time group (06:01 p.m. to 06:00 a.m.), and retrospective analyses were performed between them. RESULTS: The operative mortality of night-time group (12.2%, 43/352) was dramatically higher than daytime group (6.9%, 115/1663; p = 0.001). There was significant difference between night-time and daytime groups in terms of 30-days mortality (5.8% vs 10.8%; p = 0.001) and in-hospital mortality (3.5% vs 6.0%; p = 0.03). The night-time group had a longer duration of intensive care unit stay (4 vs two; days; p < 0.001) and ventilation support (34 vs 19; hours; p < 0.001), compared with daytime group. The risk factors for operative mortality were night-time surgery (odds ratio [OR], 1.545; p = 0.027), age (odds ratio, 1.152; p < 0.001), total arch replacement (OR, 2.265; p < 0.001) and previous aortic surgery (OR, 2.376; p = 0.003). CONCLUSION: Night-time surgical repair may be associated with higher operative mortality of patients with TAAD. Nevertheless, it is reasonable to offer emergency surgery at night-time for such patients who were more likely to present disastrous complications with delayed surgical intervention, as outcomes indicate acceptable operative mortality.