Structural basis of a small monomeric Clivia fluorogenic RNA with a large Stokes shift.

RNA-based fluorogenic modules have revolutionized the spatiotemporal localization of RNA molecules. Recently, a fluorophore named 5-((Z)-4-((2-hydroxyethyl)(methyl)amino)benzylidene)-3-methyl-2-((E)-styryl)-3,5-dihydro-4H-imidazol-4-one (NBSI), emitting in red spectrum, and its cognate aptamer named Clivia were identified, exhibiting a large Stokes shift. To explore the underlying molecular basis of this unique RNA-fluorophore complex, we determined the tertiary structure of Clivia-NBSI. The overall structure uses a monomeric, non-G-quadruplex compact coaxial architecture, with NBSI sandwiched at the core junction. Structure-based fluorophore recognition pattern analysis, combined with fluorescence assays, enables the orthogonal use of Clivia-NBSI and other fluorogenic aptamers, paving the way for both dual-emission fluorescence and bioluminescence imaging of RNA molecules within living cells. Furthermore, on the basis of the structure-based substitution assay, we developed a multivalent Clivia fluorogenic aptamer containing multiple minimal NBSI-binding modules. This innovative design notably enhances the recognition sensitivity of fluorophores both in vitro and in vivo, shedding light on future efficient applications in various biomedical and research contexts.

Humans can sense small numbers of objects in a box by touch alone.

Everyday experiences suggest that a container, such as a box of chocolate sprinkles, can convey pertinent information about the nature of its content. Despite the familiarity of the experience, we do not know whether people can perceive the number of objects in the container from touch alone and how accurately they can do so. In three experiments, participants handled containers holding between one and five objects and verbally estimated their number. Containers were small cardboard jewelry boxes, and objects were round beads of varying diameter and weight. Any useful visual and auditory cues were precluded. Experiment 1 demonstrated very accurate performance, provided the objects were of sufficient weight. Experiment 2 demonstrated that withholding information about the possible number of objects inside the container does not affect accuracy at a group level but does produce occasional overestimations at an individual level. Experiment 3 demonstrated that removing the weight cue leads to systematic underestimations but does not eliminate people's ability to distinguish between different numbers of objects in the container. This study contributes to a growing picture that container haptics is surprisingly capable.

Large Stokes shift fluorescent RNAs for dual-emission fluorescence and bioluminescence imaging in live cells.

Fluorescent RNAs, aptamers that bind and activate small fluorogenic dyes, have provided a particularly attractive approach to visualizing RNAs in live cells. However, the simultaneous imaging of multiple RNAs remains challenging due to a lack of bright and stable fluorescent RNAs with bio-orthogonality and suitable spectral properties. Here, we develop the Clivias, a series of small, monomeric and stable orange-to-red fluorescent RNAs with large Stokes shifts of up to 108 nm, enabling the simple and robust imaging of RNA with minimal perturbation of the target RNA's localization and functionality. In combination with Pepper fluorescent RNAs, the Clivias enable the single-excitation two-emission dual-color imaging of cellular RNAs and genomic loci. Clivias can also be used to detect RNA-protein interactions by bioluminescent imaging both in live cells and in vivo. We believe that these large Stokes shift fluorescent RNAs will be useful tools for the tracking and quantification of multiple RNAs in diverse biological processes.

The influence of parenting style in childhood on adult depressed patients' interpersonal relationships in the period of youth.

Objective: The objective of this study was to explore the mediating effect of adolescent self and courage on the relationship between parenting style in childhood and adult depressed patients' interpersonal relationships in the period of youth. Methods: The study analyzed data from 651 depressed individuals using the Wang Weidong memory-tracing personality developmental inventory (WMPI) from the psychology department of Guang'anmen Hospital. Results: The results of the study show a significant positive correlation between parenting style in childhood, adolescent self, courage, and adult depressed patients' interpersonal relationships in the period of youth. Parenting style in childhood has a direct positive predictive effect on adult depressed patients' interpersonal relationships in the period of youth. It also has an indirect effect on interpersonal relationships in the period of youth through three indirect pathways: the independent mediating effect of adolescent self, the independent mediating effect of adolescent courage, and the chain mediating effect of adolescent self and courage. Conclusion: The findings of this study suggest that parenting style in childhood plays an important role in shaping adult depressed patients' interpersonal relationships in the period of youth. The relationship between parenting style in childhood and interpersonal relationships in the period of youth is influenced by the independent mediating effect of adolescent self and courage, as well as the chain mediating effect of adolescent self and courage. These findings have implications for the development of interventions and programs aimed at improving the mental health and well-being of depressed patients.

Transformation kinetics of exogenous lead in an acidic soil during anoxic-oxic alteration: Important roles of phosphorus and organic matter.

Lead (Pb) can enter soil environment during flooding events such as surface runoff and intensive rainfall. However, the key transformation processes of exogenous Pb during anoxic-oxic alteration remain poorly understood particularly how phosphorus and organic matter contribute to Pb immobilization/release. Here, a kinetic model was established to investigate the Pb transformation in an acidic soil with two levels of Pb contamination under alternating anoxic-oxic conditions, based on the results of seven-step sequential extraction, dissolved organic carbon, sulfate, iron, phosphorus, and surface sites. Results showed that the potentially available Pb, including dissolved, exchangeable, and specifically adsorbed fractions, was gradually transferred to the fulvic complex, Fe-Mn oxides bound, and sulfides bound Pb after 40-day incubation under anoxic conditions, while the fulvic complex Pb further increased after 20-day incubation under oxic conditions. The concentration of phosphorus that was extracted by 0.5 M HCl or 0.03 M NH4F in 0.025 M HCl increased under anoxic conditions and decreased under oxic conditions. When Pb-binding to phosphorus is considered during kinetic modeling, the simulated results of Pb transformation suggest that phosphorus is more important than organic matter for Pb immobilization under anoxic conditions, while the phosphates, Fe-Mn oxides, and sulfides immobilized Pb is slowly released and then complexed by fulvic acids during the re-immobilization of dissolved organic matter in soil under oxic conditions. The model established with low Pb level has been successfully applied to describe the Pb transformation with high Pb level. This study provides a comprehensive understanding of the roles of phosphorus and organic matter in controlling Pb transformation in soil from kinetic modeling.

Transformation kinetics of exogenous nickel in a paddy soil during anoxic-oxic alteration: Roles of organic matter and iron oxides.

Nickel is generally released from flooded soils; however, the key Ni transformation processes in soils that are freshly contaminated by Ni2+ during anoxic-oxic alteration remain unclear. We developed a kinetic model to investigate the Ni transformation in paddy soils under anoxic and oxic conditions based on the results of the seven-step sequential extraction, determination of dissolved and soil organic matter, and surface site quantification, which provide the kinetic data of different Ni fractions, organic matter, and reactive sites for modeling. The dissolved, exchangeable, and specifically adsorbed Ni was gradually transferred to fulvic complex, humic complex, Fe-Mn oxide bound, and sulfide bound Ni after 40 d of anoxic incubation due to the increase in pH and soil surface sites, which were mainly induced by Fe(III) oxide reduction and soil organic matter release. The introduction of oxygen triggered a rapid release of Ni, which was ascribed to the decrease in pH and soil surface sites caused by Fe(II) oxidation and carbon re-immobilization. Kinetic modeling demonstrated that complexation with soil organic matter dominated Ni immobilization under anoxic conditions, while organic matter and Fe-Mn oxides contributed similarly to Ni release under oxic conditions, although the majority of Ni remained complexed with soil organic matter. These findings are important for the evaluation and prediction of Ni behavior in paddy soils with exogenous Ni during flooding-drainage practices.

Structure-based investigation of fluorogenic Pepper aptamer.

Pepper fluorescent RNAs are a recently reported bright, stable and multicolor fluorogenic aptamer tag that enable imaging of diverse RNAs in live cells. To investigate the molecular basis of the superior properties of Pepper, we determined the structures of complexes of Pepper aptamer bound with its cognate HBC or HBC-like fluorophores at high resolution by X-ray crystallography. The Pepper aptamer folds in a monomeric non-G-quadruplex tuning-fork-like architecture composed of a helix and one protruded junction region. The near-planar fluorophore molecule intercalates in the middle of the structure and is sandwiched between one non-G-quadruplex base quadruple and one noncanonical G·U wobble helical base pair. In addition, structure-based mutational analysis is evaluated by in vitro and live-cell fluorogenic detection. Taken together, our research provides a structural basis for demystifying the fluorescence activation mechanism of Pepper aptamer and for further improvement of its future application in RNA visualization.

A clinical analysis of very and extremely low birth weight preterm infants.

OBJECTIVE: To investigate the clinical characteristics, treatment strategies, and outcomes of very low birth weight (VLBW)/extremely low birth weight (ELBW) preterm infants in Weihai from January 2017 to December 2019. METHODS: 107 VLBW/ELBW preterm infants admitted to our hospital were recruited as the study cohort and divided into three groups: the < 1000 g group (n = 11 cases), the ≥ 1000~1250 g group (n = 32 cases), and the ≥ 1250~1500 g group (n = 64 cases). The clinical characteristics of the VLBW/ELBW preterm infants in each group were analyzed, and the hospitalization duration times, the survival rates, the ventilator use, the main complications, and the follow-ups in each group were compared statistically. RESULTS: There were significant differences in the occurrences of maternal anemia during pregnancy, the birth weights, the gestational ages, the births of singletons, twins, or multiples, the hospitalization duration times, the occurrences of late-onset sepsis (LOS), and the occurrences of periventricular intraventricular hemorrhages (PIVH) among the three groups (P < 0.05). Our multivariate logistic regression and ROC curve analyses showed that the lower the gestational age (OR = 12.56, 95% CI: 2.45~14.63, P = 0.01), the lower the birth weight (OR = 8.69, 95% CI: 1.95~10.34, P = 0.03), and the premature rupture of membranes (OR = 6.44, 95% CI: 1.03~9.77, P = 0.04) and LOS (OR = 9.64, 95% CI: 1.67~18.99, P = 0.02) would induce a higher death rate among premature infants. Furthermore, after one year of follow-up, the psychomotor development indexes (PDI) of the different birth weight groups were increased along with the birth weight, and the differences were statistically significant (χ2 = 4.19, 4.99, P = 0.027, 0.01). CONCLUSION: Strengthening perinatal health care and actively preventing and treating various complications are of great significance in improving the survival rate and long-term quality of life of VLBW/ELBW premature infants.

Strategies for understanding RNA recognition by X-ray crystallography and NMR methods.

One class of non-coding RNA molecules, termed riboswitches, are the regulatory elements with ability to control gene expression by sensing different cellular metabolites. Specific recognition of the corresponding ligand induced the conformation rearrangement of riboswitch, and thus turned on/off the down-stream gene expression. In this chapter, we will focus on two principal methods that are currently used to investigate the recognition mechanism of riboswitches, including X-ray crystallography and NMR spectroscopy. First, we present that how to get the diffraction-quality crystals of riboswitches in specific functional states. Then we focus on how to use NMR spectroscopy as a tool to learn the dynamics of riboswitches. Detailed protocols are listed below.

Hatchet ribozyme structure and implications for cleavage mechanism.

Small self-cleaving ribozymes catalyze site-specific cleavage of their own phosphodiester backbone with implications for viral genome replication, pre-mRNA processing, and alternative splicing. We report on the 2.1-Å crystal structure of the hatchet ribozyme product, which adopts a compact pseudosymmetric dimeric scaffold, with each monomer stabilized by long-range interactions involving highly conserved nucleotides brought into close proximity of the scissile phosphate. Strikingly, the catalytic pocket contains a cavity capable of accommodating both the modeled scissile phosphate and its flanking 5' nucleoside. The resulting modeled precatalytic conformation incorporates a splayed-apart alignment at the scissile phosphate, thereby providing structure-based insights into the in-line cleavage mechanism. We identify a guanine lining the catalytic pocket positioned to contribute to cleavage chemistry. The functional relevance of structure-based insights into hatchet ribozyme catalysis is strongly supported by cleavage assays monitoring the impact of selected nucleobase and atom-specific mutations on ribozyme activity.

[Rapid determination of nine components in the first extraction process of Xingnaojing injection by using ultraviolet spectroscopy].

In this study, an analytical method based on ultraviolet spectroscopy was established for the rapid determination of nine components including isophorone, 4-methylene-isophorone, curcumenone, curcumenol, curdione, curzerenone, furanodienone, curcumol and germacrone in the first extraction process of Xingnaojing injection. 166 distillate samples of Gardeniae Fructus and Radix Curcumae were collected in the first extraction process of Xingnaojing injection. The ultraviolet spectra of these samples were collected, and the contents of the nine components in these samples were determined by high performance liquid chromatography. Least squares support vector machine and radial basis function artificial neural network were used to establish the multivariate calibration models between the ultraviolet spectra and the contents of the nine components. The results showed that the established ultraviolet spectrum analysis method can determine the contents of the nine components in the distillates accurately, with root mean square error of prediction of 0.068, 0.147, 0.215, 0.319, 1.01, 1.27, 0.764, 0.147, 0.610 mg•L⁻¹, respectively. This proposed method is a rapid, simple and low-cost tool for the monitoring and endpoint determination of the extraction process of Xingnaojing injection to reduce quality defects and variations.

Application of color-coded quantitative digital subtraction angiography in predicting the outcomes of immediate type I and type III endoleaks.

OBJECTIVE: Immediate type I and type III endoleaks after endovascular aneurysm repair (EVAR) could be persistent or temporary. Reintervention is necessary for persistent ones. Color-coded quantitative digital subtraction angiography (CQDSA) could provide a quantitative evaluation of the endoleak hemodynamics. We aimed to use CQDSA to quantify immediate type I and type III endoleaks after EVAR and to find a practical way to predict their outcomes. METHODS: Between January 2012 and December 2014, 485 consecutive patients with abdominal aortic aneurysms underwent EVAR at our institution. Thirty-five patients (31 men, four women) with slight immediate type I and type III endoleaks after EVAR were recruited in the prospective observational nested case-control study. After at least 6 months of follow-up, these patients were divided into two groups based on endoleak-related adverse events. Their final intraprocedure DSA images were collected and converted into a single polychromatic image for CQDSA measurements. The parameter time to peak (TTP) of the selected regions of interest in the endoleak area and a reference area at the same latitude within the stent graft were derived from the time-intensity curve. A receiver operating characteristic curve was generated to test the ability of TTP to predict endoleak-related adverse events and to identify the optimal cutoff value. RESULTS: Finally, two groups were identified: 12 patients with endoleak-related adverse events and 23 patients without endoleak-related adverse events. Median follow-up time for all patients was 24.0 months. Age, gender, and comorbidity were similar in these two groups. TTP was significantly lower in patients with endoleak-related adverse events (P = .002). The risk of endoleak-related adverse events was significantly higher in patients with mixed-type endoleak than in those with simple-type endoleak (P = .003). According to the receiver operating characteristic curves, TTP ≤5 seconds reached the maximal sum of sensitivity and specificity (sensitivity, 91.67%; specificity, 69.57%). Logistic regression analysis confirmed that TTP ≤5 seconds (P = .016) and mixed-type endoleak (P = .044) were associated with higher risk of endoleak-related adverse events. CONCLUSIONS: CQDSA could help predict the outcomes of immediate type I or type III endoleaks after EVAR. TTP ≤5 seconds and mixed-type endoleak were two potential predictors of endoleak-related adverse events. This approach may offer an objective assessment of such immediate endoleaks and reference for immediate reintervention or conservative therapy.

Flat-detector computed tomography PBV map in the evaluation of presurgical embolization for hypervascular brain tumors.

BACKGROUND: Preoperative embolization of hypervascular brain tumors is frequently used to minimize intraoperative bleeding. OBJECTIVE: To explore the efficacy of embolization using flat-detector CT (FDCT) parenchymal blood volume (PBV) maps before and after the intervention. MATERIALS AND METHODS: Twenty-five patients with hypervascular brain tumors prospectively received pre- and postprocedural FDCT PBV scans using a biplane system under a protocol approved by the institutional research ethics committee. Semiquantitative analysis, based on region of interest measurements of the pre- and post-embolization PBV maps, operating time, and blood loss, was performed to assess the feasibility of PBV maps in detecting the perfusion deficit and to evaluate the efficacy of embolization. RESULTS: Preoperative embolization was successful in 18 patients. The relative PBV decreased significantly from 3.98±1.41 before embolization to 2.10±2.00 after embolization. Seventeen patients underwent surgical removal of tumors 24 hours after embolization. The post-embolic tumor perfusion index correlated significantly with blood loss (ρ=0.55) and operating time (ρ=0.60). CONCLUSIONS: FDCT PBV mapping is a useful method for evaluating the perfusion of hypervascular brain tumors and the efficacy of embolization. It can be used as a supplement to CT perfusion, MRI, and DSA in the evaluation of tumor embolization.

Quantitative assessment of angiographic perfusion reduction using color-coded digital subtraction angiography during transarterial chemoembolization.

PURPOSE: The aim of this study was to develop a quantitative measurement of perfusion reduction using color-coded digital subtraction angiography (ccDSA) to monitor intra-procedural arterial stasis during TACE. MATERIALS AND METHODS: A total number of 35 patients with hepatocellular carcinoma who had undergone TACE were enrolled into the study. Pre- and post-two-dimensional digital subtraction angiography scans were conducted with same protocol and post-processed with ccDSA prototype software. Time-contrast-intensity (CI[t]) curve was obtained by region-of-interest (ROI) measurement on the generated ccDSA image. Quantitative 2D perfusion parameters time to peak, area under the curve (AUC), maximum upslope, and contrast intensity peak (CI-Peak) derived from the ROI-based CI[t] curve for pre- and post-TACE were evaluated to assess the reduction of antegrade blood flow and tumor blush. Relationships between 2D perfusion parameters, subjective angiographic chemoembolization endpoint (SACE) scale, and clinical outcomes were analyzed. RESULTS: Area normalized AUC and CI-Peak revealed significant reduction after the TACE (P < 0.0001). AUCnorm decreased from pre-procedure of 0.867 ± 0.242 to 0.421 ± 0.171 (P < 0.001) after completion of TACE. CI-Peaknorm was 0.739 ± 0.221 before TACE and 0.421 ± 0.174 (P < 0.001) after TACE. Tumor blood supply time slowed down obviously after embolization. A perfusion reduction either from AUCnorm or CI-Peaknorm ranging from 30% to 40% was associated with SACE level III and a reduction ranging from 60% to 70% was equivalent to SACE level IV. For intermediate reduction (SACE level III), better tumor response was found after TACE rather than a higher reduction (SACE level IV). CONCLUSION: ccDSA application provides an objective approach to quantify the perfusion reduction and subjectively evaluate the arterial stasis of antegrade blood flow and tumor blush caused by TACE.

Evaluation of Distal Hemodynamic Changes of Lower Extremity after Endovascular Treatment: Correlation between Measurements of Color-Coded Quantitative Digital Subtraction Angiography and Ankle-Brachial Index.

PURPOSE: To confirm the feasibility of using time-to-peak (TTP) measurements derived from color-coded digital subtraction angiography (ccDSA) imaging to assess improvements in distal circulation in relation to the ankle-brachial index (ABI). MATERIALS AND METHODS: Nineteen patients who underwent percutaneous transluminal angioplasty and/or stent placement (in 20 lower extremities) were evaluated. A region of interest (ROI) at the proximal superficial femoral artery (SFA) was selected for a reference TTP for quantitative assessments. The ROI measurements of the TTP interval between medial and lateral plantar/dorsalis pedis relative to the reference was regarded as the ΔTTP and used to assess distal hemodynamic improvement achieved by the revascularization. The ABI was obtained with a handheld Doppler ultrasound machine with a manually operated blood-pressure cuff. Correlation between the two methods was analyzed. RESULTS: The ABI improved significantly from 0.44 ± 0.18 to 0.79 ± 0.20 (t = 10.11; P < .0001) after the intervention. TTP, which reflected the blood flow time from the proximal SFA to the foot, became much faster, from 11.86 seconds ± 4.26 to 6.75 seconds ± 2.03 (t = 6.57; P < .001). A good correlation was observed between the improvement ratios of ΔTTP and ABI (r = 0. 863). CONCLUSIONS: TTP measurements derived from ccDSA provide an easy and objective method for assessment of distal hemodynamic changes after endovascular treatment of lower-extremity peripheral arterial disease (PAD). It may provide a quantitative method to assess the adequacy of endovascular interventions and provide more objective suggestions for procedure endpoints, with potentially better clinical outcomes for patients with PAD.

Spontaneous Rupture of Hepatocellular Carcinoma Mimicking ST-Segment Elevation Myocardial Infarction.

BACKGROUND: Several medical conditions that mimic ST-elevation myocardial infarction (STEMI) have been reported previously, but acute abdominal disease mimicking STEMI is rare. CASE REPORT: We report on a 72-year-old man who presented to the emergency department (ED) with epigastric pain. Meanwhile, STEMI with shock developed. Anticoagulation medication and emergent percutaneous coronary intervention (PCI) were arranged in a timely manner. However, hepatocellular carcinoma (HCC) rupture was the true cause of the ST-segment elevation. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case report highlights the fact that acute myocardial infarction is not the only cause of ST-segment elevation. HCC rupture should be one of the differential diagnoses.

[Studies on chemical constituents of Syringa veutina].

OBJECTIVE: To study the chemical constituents of Syringa veutina Kom. METHODS: The constituents were isolated and repeatedly purified on silica and Sephadex LH-20 column chromatography. They were dentified and structurally elucidated by spectral analysis. RESULTS: Seven compounds were obtained. They were identified as Syningin(1), Liriodendrin(2), (+) -Medioresinol di-O-beta-D-glucopyranosied (3), Rutin(4), Quercetin 3-O-beta-D-glucopyranoside (5), Kaempferol-3-O-beta-D-glucopyranosied (6), D-mannitol (7). CONCLUSION: Compound 2 and 3 were isolated from this genus for the first time. Compound 4, 5, 6 and 7 were isolated from this plant for the first time.