Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

Epithelioid hemangioendothelioma, an ultra-rare cancer: a consensus paper from the community of experts

Epithelioid hemangioendothelioma (EHE) is an ultra-rare, translocated, vascular sarcoma. EHE clinical behavior is variable, ranging from that of a low-grade malignancy to that of a high-grade sarcoma and it is marked by a high propensity for systemic involvement. No active systemic agents are currently approved specifically for EHE, which is typically refractory to the antitumor drugs used in sarcomas. The degree of uncertainty in selecting the most appropriate therapy for EHE patients and the lack of guidelines on the clinical management of the disease make the adoption of new treatments inconsistent across the world, resulting in suboptimal outcomes for many EHE patients. To address the shortcoming, a global consensus meeting was organized in December 2020 under the umbrella of the European Society for Medical Oncology (ESMO) involving >80 experts from several disciplines from Europe, North America and Asia, together with a patient representative from the EHE Group, a global, disease-specific patient advocacy group, and Sarcoma Patient EuroNet (SPAEN). The meeting was aimed at defining, by consensus, evidence-based best practices for the optimal approach to primary and metastatic EHE. The consensus achieved during that meeting is the subject of the present publication.

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This consensus paper provides key recommendations on the management of epithelioid hemangioendothelioma (EHE).

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Recommendations followed a consensus meeting between experts and a representative of the EHE advocacy group and SPAEN.

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Authorship includes a multidisciplinary group of experts from different institutions from Europe, North America and Asia.

Tuning the excited-state intramolecular proton transfer (ESIPT)-based luminescence of metal-organic frameworks by metal nodes toward versatile photoluminescent applications

Here, using three metal cations (Mg2+, Al3+, and Zr4+) and an excited-state intramolecular proton transfer (ESIPT) active linker, 2,5-dihydroxyterephthalic acid (H2DHT), three luminescent metal-organic frameworks (LMOFs) were obtained. Importantly, their ESIPT-based luminescence originated from the linker was systematically tuned in emission profiles including intensity, emission color, and quantum efficiency in the solution as well as in the solid state, which is largely dependent on the composition and structural characteristics of these three LMOFs. Similar to the free linker, the Mg-based MOF possesses a relatively strong luminescence, the Al-based MOF has moderate luminescence due to the breathing effect, and the Zr-based MOF is very weakly luminescent, mainly caused by the LMCT process. Benefiting from unique emission behaviors of these three LMOFs, we further modulated their ESIPT-based luminescence through the interplay between guest species and components of LMOFs by combining with various photophysical processes, and successfully explored their potential applications as versatile photoluminescent platforms for target-triggered sensory materials, responsive fluorescent hydrogels, and white-light-emitting phosphors.

Polydopamine molecularly imprinted polymer coated on a biomimetic iron-based metal-organic framework for highly selective fluorescence detection of metronidazole

Molecular imprinting technology was used to coat polydopamine (PDA) onto MIL-53(Fe) surface by simple self-polymerization. The MIL-53(Fe)@MIP composite with enhanced peroxidase-like activity and specific target recognition function was synthesized and selected to construct a fluorescence sensor to detect metronidazole (MNZ). Since the substrate terephthalic acid was incorporated in the framework of MIL-53(Fe)@MIP, no additional luminescent substrate was required. This avoided the interference of the substrate on the enzymatic detection system and improved the accuracy of the assay. The characteristics of MIL-53(Fe)@MIP composite were investigated and confirmed by systematic analyses. The experimental results proved that the sensor provided satisfactory performances for quantitative determination of MNZ in wide linear range from 1 to 200 μM with low limit of detection as 53.4 nM. Potential interfering substances such as common cations and anions, amino acids, other antibiotics, sugars, and food additive were studied to show negligible effect on the assay, allowing the practical application to different fields including milk and human serum by the standard addition method. The recoveries were obtained between 93.2 and 102%, and the RSD was less than 3%.

Colorimetric determination of acid phosphatase activity and inhibitor screening based on in situ polymerization of aniline catalyzed by gold nanoparticles

A colorimetric assay for acid phosphatase (ACP) was constructed that is based on in situ polymerization of aniline catalyzed by gold nanoparticles (AuNPs). Aniline can be polymerized by ammonium persulfate (APS) in acidic condition and form gold-polyaniline core-shell nanoparticles (Au@PANI NPs) in the presence of AuNPs with the assistance of sodium dodecyl sulfate (SDS). AuNPs were also found to accelerate the polymerization process of aniline and thus shorten the reaction time. Upon the introduction of ascorbic acid (AA), the oxidant APS was consumed via the redox reaction. That led to the suppression of the formation of PANI. Consequently, ACP activity can be supervised on the basis of hydrolysis of 2-phospho-L-ascorbic acid trisodium salt (AAP) catalyzed by ACP to release AA. With the increase of ACP activity, the intensity ratio of the absorbance at λ₇₀₅ nm (A₇₀₅) and the absorbance at λ₅₃₀ nm (A₅₃₀) gradually decreased and the color gradually changed from dark-green to light-green to blue-gray to purple and eventually to pink. This method for ACP determination worked in the range 0.40 to 2.00 U·L^-1. The detection limit is 0.043 U·L^-1. The assay was applied to determine ACP in human serum. The recovery ranged from 81.0 to 104.6%. Relative standard deviation was less than 5%. This suits the request for biological sample analysis. Graphical abstract Schematic presentation of the colorimetric determination of acid phosphatase activity and inhibitor screening based on in situ polymerization of aniline catalyzed by gold nanoparticles. : acid phosphatase (ACP); : gold nanoparticles (AuNPs); : gold-polyaniline core-shell nanoparticles (Au@PANI NPs); ascorbic acid (AA); 2-phospho-L-ascorbic acid trisodium salt (AAP).

EpsR Negatively Regulates Streptococcus mutans Exopolysaccharide Synthesis

Streptococcus mutans is considered the primary etiological agent of human dental caries. Glucosyltransferases (Gtfs) from S. mutans play important roles in the formation of biofilm matrix and the development of cariogenic oral biofilm. Therefore, Gtfs are considered an important target to prevent the development of dental caries. However, the role of transcription factors in regulating gtf expression is not yet clear. Here, we identify a MarR (multiple antibiotic resistance regulator) family transcription factor named EpsR (exopolysaccharide synthesis regulator), which negatively regulates gtfB expression and exopolysaccharide (EPS) production in S. mutans. The epsR in-frame deletion strain grew slowly, aggregated more easily in the presence of dextran, and displayed different colony morphology and biofilm structure. Notably, epsR deletion resulted in altered 3-dimensional biofilm architecture, increased water-insoluble EPS production, and upregulated GtfB protein content and activity. In addition, global gene expression profiling revealed differences in the expression levels of 69 genes in which gtfB was markedly upregulated. The conserved DNA motif for EpsR binding was determined by electrophoretic mobility shift assay and DNase I footprinting assays. Moreover, analysis of β-galactosidase activity suggested that EpsR acted as a repressor and inhibited gtfB expression. Taken together, our findings indicate that EpsR is an important transcription factor that regulates gtfB expression and EPS production in S. mutans. These results add new aspects to the complexity of regulating the expression of genes involved in the cariogenicity of S. mutans, which might lead to novel strategies to prevent the formation of cariogenic biofilm that may favor diseases.

Concentration-dependent photoluminescence carbon dots for visual recognition and detection of three tetracyclines

Concentration-dependent photoluminescence carbon dots (CDs) have been successfully synthesized through the one-step hydrothermal treatment of o-phthalic acid and ethylenediamine. The CDs possessed higher fluorescence quantum yield, up to 39.22%, exhibiting distinguished optical property, water solubility, and stability. The CDs that emit strong blue-green fluorescence can visually identify and determine tetracycline (TC), oxytetracycline (OTC), and chlortetracycline (CTC). TC quenched the fluorescence of CDs at 500 nm owing to the inner filter effect; OTC behaved similarly, but the emission wavelength of CDs was red-shifted to 515 nm. Inversely, once CTC was introduced to CDs solution, the fluorescence increased and the emission peak was blue-shifted to 450 nm. Bandgap transition and electrostatic interaction were proposed to be the mechanisms for the detection of OTC and CTC by CDs. Wide linear relationships were established for TC, OTC, and CTC with the limits of detection to be 50 nM, 36 nM, and 373 nM, respectively. Furthermore, the nanoscale probe constructed by this system has been applied to detect tetracyclines (TCs) in complex samples with satisfying recoveries (93.2-114%) and was designed as a portable test strip sensor for visually on-site TCs of honey sample screening. Accordingly, the preparation process of the nano fluorescent probe is simple and environmentally friendly, and the probe has a specific recognition ability for tetracyclines. The synthesized CDs in this work provide a new orientation for fast, effective, and visual real-time detection of tetracycline in actual samples.

[Research Status of Postmortem MSCT Angiography in Forensic Science]

Abstract

Virtual autopsy is a new technique for investigating the morphological changes of cadaveric tissues and organs by medical imaging technology. It has been widely used in the identification of causes of death. Multislice spiral computed tomography （MSCT） has become a routine inspection method in some identification institutions, although it cannot completely replace traditional autopsy, it plays a key auxiliary or substitute role in the identification of certain abnormal causes of death. Plain MSCT scan cannot visualize cadaveric vessels, but can perform cadaveric angiography to determine vascular injury or disease. This technology has entered a rapid development period in recent years, and has made a considerable progress in contrast agent, perfusion methods and imaging methods. This article summarizes several common cadaveric MSCT angiography methods, such as systemic angiography, angiography through cardiopulmonary resuscitation, targeted angiography, and angiography by cardiac puncture, and analyzes and compares the application prospects.

Sarcopenia as a Risk Factor for Future Hip Fracture: A Meta-Analysis of Prospective Cohort Studies

OBJECTIVE

Our study aims to determine whether sarcopenia is a predictive factor of future hip fractures.

DESIGN

Systematic review and meta-analysis. Set: We searched for potentially suitable articles in PubMed, Cochrane library, Medline and EMBASE from inception to March 2020. The quality of the research was assessed by the Newcastle-Ottawa Scale (NOS). Finally, a meta-analysis was conducted with the Stata software.

PARTICIPANTS

Older community-dwelling residents.

MEASUREMENTS

Hip fracture due to sarcopenia.

RESULTS

We retrieved 2129 studies through our search strategy, and five studies with 23,359 individuals were analyzed in our pooled analyses. Sarcopenia increases the risk of future hip fractures with a pooled hazard ratio (HR) of 1.42 (95% CI: 1.18-1.71, P <0.001, I2 = 37.7%). In addition, in subgroup analyses based on different definitions of sarcopenia, sarcopenia was associated with the risk of future hip fractures with the Asian Working Group for Sarcopenia (AWGS) criteria with a pooled HR of 2.13(95% CI: 1.33-3.43). When subgroup analyses were conducted by sex, sarcopenia was associated with the risk for future hip fractures in females with pooled HRs of 1.69 (95% CI: 1.18-2.43). Sarcopenia was associated with the risk of future hip fractures in the group with a follow-up period of more than 5 years, with a pooled HR of 1.32 (95% CI: 1.08-1.61), and in the group with a follow-up period of less than 5 years, with a pooled HR of 2.13 (95% CI: 1.33-3.43).

CONCLUSIONS

Sarcopenia could significantly increase the risk of future hip fracture in old people; thus, it is necessary to prevent hip fractures in individuals with sarcopenia.

The Impact of Frailty on COVID-19 Outcomes: A Systematic Review and Meta-analysis of 16 Cohort Studies

BACKGROUND

Frail patients are increasingly vulnerable to stress, which is mainly manifested by a reduced physiologic reserve in metabolic and immune systems and neuromuscular system. Several studies found a significant association of frailty with COVID-19 severity to support the evidence for the application of frailty assessment. However, there were contradictory results in other studies. Thus we conducted a systematic review and meta-analysis to synthesize the current studies to investigate impact of frailty on COVID-19 outcomes and provide evidence-based decisions in clinical practice.

OBJECTIVE

We aimed to synthesize the current studies to investigate impact of frailty on COVID-19 outcomes and provide evidence-based decisions in clinical practice.

DESIGN

A systematic review and Meta-analysis of 16 cohort studies.

PARTICIPANTS

Patients with COVID-19.

METHODS

A systematic retrieving for potential literature was conducted in several public electronic databases, including Medline(OvidSP), EMBASE, Pubmed and Chinese databases(China National Knowledge Infrastructure,Wanfang and Weipu) on August 1, 2020.The literature research was updated on October 26, 2020. Newcastle Ottawa Scale for cohort studies was used for quality assessment. RevMan (Version 5.3) and Stata 14.0 were used to synthesize the pooled effects.

RESULTS

According to the predefined inclusion and exclusion criteria, sixteen studies of 4324 patients were included in the final analysis. Frailty was significantly associated with increased risk of all-cause mortality among patients with COVID-19, with pooled adjusted odds ratios of 1.81 (95% confidence intervals:1.48,2.21, I2=87.0%, P<0.001). The result was consistent in stratified analysis to according to age, patient source, definitions of frailty, study quality, and adjustment method. Frailty was significant associated with an increased risk of COVID-19 severity, admission to intensive care unit, application of invasive mechanical ventilation, long-length stay.

CONCLUSIONS

In this meta-analysis, we found frailty was significantly associated with an increased risk of clinical adverse events (all- cause mortality, COVID-19 severity, admission to the intensive care unit, application of invasive mechanical ventilation, long-length stay). Given the epidemic of COVID-19 and shortage of medical resources, paying more attention to screening frailty would contribute to disease management and resource allocation among patients with COVID-19.

Dose-response relationship between serum fibroblast growth factor 21 and liver fat content in non-alcoholic fatty liver disease

BACKGROUND & AIM

Although serum fibroblast growth factor 21 (FGF21) levels are associated with liver fat content in non-alcoholic liver fat disease (NAFLD), the precise nature of the association remains undetermined. Therefore, this study aimed to explore the potential dose-response relationship between FGF21 and liver fat content in NAFLD.

METHODS

For this exploratory study from a randomized trial, 220 NAFLD patients with central obesity were recruited via community-based screening and randomly assigned to either control, moderate or vigorous-moderate exercise groups for 12 months. After this exercise intervention, patients were followed-up for a further 12 months. Serum FGF21 levels were measured by ELISA. Intrahepatic triglyceride (IHTG) content was determined by proton magnetic resonance spectroscopy.

RESULTS

Of the 220 patients, 149 (67.7%) were female; mean age was 53.9 ± 7.1 years and mean BMI was 28.0 ± 2.9 kg/m² for all patients. Baseline IHGT increased gradually (P = 0.029 for trend) according to baseline serum FGF21 quartiles 1, 2, 3 and 4 (212.3, 358.9, 538.7 and 793.5 pg/mL, respectively). On grouping the distribution of serum FGF21 level changes into quartiles at month 12, the relative IHTG loss increased as serum FGF21 levels were reduced (P = 0.004 for trend). A similar trend was observed at month 24 (P = 0.006 for trend). Multivariate linear regression analysis revealed that changes in serum FGF21 levels were independently associated with changes in IHTG at both month 12 [β (SE), 0.136 (0.118); P = 0.048] and month 24 [β (SE), 0.152 (0.139); P = 0.041]. Using restricted cubic spline regression, changes in serum FGF21 were strongly and positively associated with their corresponding relative IHTG loss at both month 12 and follow-up (P_overall = 0.017, P_non-linear = 0.044 and P_overall = 0.020, P_non-linear = 0.361, respectively, for dose-response).

CONCLUSION

Serum FGF21 is strongly associated with liver fat content in a dose-response manner in centrally obese NAFLD patients. These findings support the use of serum FGF21 as a biomarker of liver fat content in NAFLD.

[Risk factors and prognosis of bronchopulmonary dysplasia associated pulmonary hypertension in preterm infants]

Objective: To analyze clinical features, prognosis and risk factors of bronchopulmonary dysplasia (BPD) associated pulmonary hypertension (PH). Methods: Clinical data of 338 infants with BPD were collected from the neonatal intensive care unit (NICU) in Shenzhen Maternity and Child Healthcare Hospital, Southern Medical University between January 2016 and December 2018. These infants were divided into PH group and non-PH group. The clinical features and prognosis were compared between these two groups by Chi-square test or nonparametric test. Risk factors for BPD-PH were analyzed with binary logistic regression model. Results: Among the 338 BPD infants, 314 had no PH (92.9%) and 24 had PH (7.1%), with an average gestational age of (27.1±1.8) weeks, and 206 were males and 132 females.PH infants had younger gestational age ((26.4±2.1) vs. (27.2±1.7) weeks, t=2.201, P=0.028) and lower birth weight ((798±255) vs. (1 003±240) g, t=4.030, P<0.01), compared to non-PH infants. Besides, duration of mechanical ventilation and non-invasive positive pressure ventilation were higher in PH group than that in non-PH group (14.3 (2.1, 43.7) vs. 0.5 (0, 4.7) d, Z=-4.553, P<0.01; 30.0 (22.5, 64.2) vs. 15.0 (7.0, 26.0) d, Z=-4.838, P<0.01). The proportions of maternal hypertension, small for gestational age (SGA), late onset sepsis, ventilator associated pneumonia, hemodynamically significant patent ductus arteriosus (hsPDA), patent ductus arteriosus (PDA) requiring ligation, severe BPD and severe extrauterine growth retardation (EUGR) were higher in PH group than those in non-PH group ((20.8% (5/24) vs. 6.4% (20/314), 33.3% (8/24) vs. 7.6% (24/314), 54.2% (13/24) vs. 7.3% (23/314), 25.0% (6/24) vs. 6.1% (19/314), 75.0% (18/24) vs. 39.2% (123/314), 45.8% (11/24) vs. 1.9% (6/314), 66.7% (16/24) vs. 7.3% (23/314), 75.0% (18/24) vs. 45.5% (143/314), all P<0.05). Multivariate logistic regression analysis showed that maternal hypertension (OR=12.950, 95%CI: 1.740-96.385), severe bronchopulmonary dysplasia (OR=10.160, 95%CI: 2.725-37.884), SGA (OR=4.992, 95%CI: 1.432-16.920), PDA requiring ligation (OR=19.802, 95%CI: 3.297-118.921), severe EUGR (OR=20.316, 95%CI: 2.221-185.853) were independent risk factors of BPD associated PH. In the 24 infants with PH, all 7 mild PH infants and 8 moderate PH infants survived, while 4 out of 9 severe PH infants died. Among the survivors, the longest duration of oxygen therapy was up to the corrected gestational age of 1 year and 2 months. Conclusions: PH is a severe complication of BPD, and associated with higher mortality and poor prognosis. Echocardiography screening and regular post-discharge follow up are recommended for BPD infants with risk factors of PH.

CDK8 is associated with RAP2.6 and SnRK2.6 and positively modulates abscisic acid signaling and drought response in Arabidopsis

CDK8 is a key subunit of Mediator complex, a large multiprotein complex that is a fundamental part of the conserved eukaryotic transcriptional machinery. However, the biological functions of CDK8 in plant abiotic stress responses remain largely unexplored. Here, we demonstrated CDK8 as a critical regulator in the abscisic acid (ABA) signaling and drought response pathways in Arabidopsis. Compared to wild-type, cdk8 mutants showed reduced sensitivity to ABA, impaired stomatal apertures and hypersensitivity to drought stress. Transcriptomic and chromatin immunoprecipitation analysis revealed that CDK8 positively regulates the transcription of several ABA-responsive genes, probably through promoting the recruitment of RNA polymerase II to their promoters. We discovered that both CDK8 and SnRK2.6 interact physically with an ERF/AP2 transcription factor RAP2.6, which can directly bind to the promoters of RD29A and COLD-REGULATED 15A (COR15A) with GCC or DRE elements, thereby promoting their expression. Importantly, we also showed that CDK8 is essential for the ABA-induced expression of RAP2.6 and RAP2.6-mediated upregulation of ABA-responsive genes, indicating that CDK8 could link the SnRK2.6-mediated ABA signaling to RNA polymerase II to promote immediate transcriptional response to ABA and drought signals. Overall, our data provide new insights into the roles of CDK8 in modulating ABA signaling and drought responses.

Somatostatin Neurons Govern Theta Oscillations Induced by Salient Visual Signals

Salient visual stimuli enhance theta oscillations and spike-phase locking in the theta band in the primary visual cortex (V1) of mice; however, the detailed mechanisms remain unknown. GABAergic neurons play a vital role in regulating these oscillations. Here, we use optogenetic recordings to tag cell-type-specific neurons in V1 of head-fixed mice and demonstrate that salient visual stimuli facilitate somatostatin (SOM)-expressing neuron responses and firing with theta band oscillations but suppress activities of parvalbumin (PV)-expressing neurons. Furthermore, inactivation of SOM neurons attenuates the enhancement of theta oscillations induced by salient visual stimuli and rhythmic activation of SOM neurons enhances theta oscillations. These results reveal a potential cortical theta oscillation mechanism governed by SOM neurons.

Association of placenta-derived extracellular vesicles with pre-eclampsia and associated hypercoagulability: a clinical observational study

OBJECTIVE

Pre-eclampsia (PE) is a pregnancy-associated condition initiated by placental factors. We have demonstrated that placental extracellular vesicles (pcEVs) cause hypertension and proteinuria in pregnant and non-pregnant mice.

STUDY DESIGN

An observational study with both case-control and longitudinal designs.

SETTING

A single centre at the Department of Obstetrics and Gynaecology, Tianjin Medical University.

POPULATION

We collected blood samples and clinical information from 54 PE patients, 33 normally pregnant women at 30-36 gestational weeks and on postpartum days 1 and 4 for the cross-sectional study, and at 22-31, 32-35 and 36-40 weeks for the longitudinal study. Non-pregnant women were also recruited.

METHODS

Blood samples were analysed using flow cytometry, coagulation tests and ELISA.

MAIN OUTCOME MEASURES

The primary outcome was plasma pcEV and other extracellular vesicles (EVs), and their expressions of anionic phospholipids and von Willebrand factor (VWF). Secondary variables included coagulation, ADAMTS-13 and the anionic phospholipid-binding proteins.

RESULTS

Plasma pcEVs progressively increased from pregnant women during non-menstrual period (NW) to PE patients (interquartile range [IQR] for NW: 206/microlitre [116-255], normal pregnancy [NP]: 1108/microlitre [789-1969] and PE: 8487/microlitre [4991-16 752]) and predicted PE. EVs from endothelial cells, platelets and erythrocytes accounted for <10% of pcEVs. VWF became hyper-adhesive in PE patients and contributed to the pregnancy-associated hypercoagulability.

CONCLUSION

Placental, platelet- and endothelial cell-derived EVs were significantly elevated in PE patients, but only pcEVs predicted PE. These EVs played a causal role in the pregnancy-induced hypercoagulability.

TWEETABLE ABSTRACT

Placenta-derived extracellular vesicles predict pre-eclampsia and the associated hypercoagulability.

Long-term systolic blood pressure and all-cause mortality in heart failure with preserved ejection fraction: an analysis of the TOPCAT trial

Background

Lower systolic blood pressure (SBP) at admission or discharge was associated with poor outcomes in patients with heart failure and preserved ejection fraction (HFpEF). However, the optimal long-term SBP for HFpEF was less clear.

Purpose

To examine the association of long-term SBP and all-cause mortality among patients with HFpEF.

Methods

We analyzed participants from the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist (TOPCAT) study. Participants had at least two SBP measurements of different times during the follow-up were included. Long-term SBP was defined as the average of all SBP measurements during the follow-up. We stratified participants into four groups according to long-term SBP: &lt;120mmHg, ≥120mmHg and &lt;130mmHg, ≥130mmHg and &lt;140mmHg, ≥140mmHg. Multivariable adjusted Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CI) for all-cause mortality associated with SBP level. To assess for nonlinearity, we fitted restricted cubic spline models of long-term SBP. Sensitivity analyses were conducted by confining participants with history of hypertension or those with left ventricular ejection fraction≥50%.

Results

The 3338 participants had a mean (SD) age of 68.5 (9.6) years; 51.4% were women, and 89.3% were White. The median long-term SBP was 127.3 mmHg (IQR 121–134.2, range 77–180.7). Patients in the SBP of &lt;120mmHg group were older age, less often female, less often current smoker, had higher estimated glomerular filtration rate, less often had history of hypertension, and more often had chronic obstructive pulmonary disease and atrial fibrillation. After multivariable adjustment, long-term SBP of 120–130mmHg and 130–140mmHg was associated with a lower risk of mortality during a mean follow-up of 3.3 years (HR 0.65, 95% CI: 0.49–0.85, P=0.001; HR 0.66, 95% CI 0.50–0.88, P=0.004, respectively); long-term SBP of &lt;120mmHg had similar risk of mortality (HR 1.03, 95% CI: 0.78–1.36, P=0.836), compared with long-term SBP of ≥140mmHg. Findings from restricted cubic spline analysis demonstrate that there was J-shaped association between long-term SBP and all-cause mortality (P=0.02). These association was essentially unchanged in sensitivity analysis.

Conclusions

Among patients with HFpEF, long-term SBP showed a J-shaped pattern with all-cause mortality and a range of 120–140 mmHg was significantly associated with better outcomes. Future randomized controlled trials need to evaluate optimal long-term SBP goal in patients with HFpEF.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): China Postdoctoral Science Foundation Grant (2019M660229 and 2019TQ0380)

An optimized acetylcholine sensor for monitoring in vivo cholinergic activity

The ability to directly measure acetylcholine (ACh) release is an essential step toward understanding its physiological function. Here we optimized the GRAB_ACh (GPCR-activation-based ACh) sensor to achieve substantially improved sensitivity in ACh detection, as well as reduced downstream coupling to intracellular pathways. The improved version of the ACh sensor retains the subsecond response kinetics, physiologically relevant affinity and precise molecular specificity for ACh of its predecessor. Using this sensor, we revealed compartmental ACh signals in the olfactory center of transgenic flies in response to external stimuli including odor and body shock. Using fiber photometry recording and two-photon imaging, our ACh sensor also enabled sensitive detection of single-trial ACh dynamics in multiple brain regions in mice performing a variety of behaviors.

Protease-activated receptor 1 inhibitor improves brain edema in rats with intracerebral hemorrhage

AIM

To investigate the changes of water content in brain tissue, the expression of AQP4mRNA after cerebral hemorrhage in rats, and the intervention effect of Protease activated receptor 1 inhibitor (PAR1 inhibitor) on both.

METHODS

Establish sham operation group (Sham group), ICH group, ICH+PAR1 inhibitor high-dose group (PI(H)group), ICH+PAR1 inhibitor low-dose group (PI(L)group), 25 in each group. Neural dysfunction scores were performed at 1d, 3d, 7d, 14d, and 21d after surgery, and brain water content and AQP4mRNA content were measured.

RESULTS

Results: The neurological dysfunction and cerebral edema of rats with cerebral hemorrhage reached the peak at 3 days after operation. With the increase of time, the water content and AQP4mRNA content in the PL(H)group were higher than those in the PI(L)group. The differences were statistically significant.

CONCLUSIONS

Appropriate inhibition of PAR1 can alleviate cerebral edema around the hematoma and play a role in improving the function of nerve defects. The mechanism may be realized by down-regulating the expression of AQP4mRNA in brain tissue (Tab. 3, Fig. 3, Ref. 25).

Colorimetric determination of tyrosinase based on in situ silver metallization catalyzed by gold nanoparticles

Gold nanoparticles (AuNPs) catalyze the mild reaction between the weak reducing agent kojic acid (KA) and silver ions (Ag⁺) to form Au@Ag bimetallic NPs by the combination of the intrinsic catalysis with plasmonic properties This is proposed as a novel optical assay to determine the tyrosinase (TYRase) concentration. The nanoparticles have been characterized by UV-vis spectroscopy, transmission electron microscope (TEM) images, and X-ray photoelectron spectroscopy (XPS). The sensing mechanism is based on the fact that KA binds to TYRase by chelating with dicopper active site of TYRase and the introduction of TYRase restrains the Au@Ag bimetallic NP formation by the precedent binding with KA. A clear color variation from yellow to pink and UV-vis spectral changes are observed at the optimal wavelength of 410 nm. The assay works in the range 0.13~0.73 U mL^-1 with a detection limit (LOD) of 0.019 U mL^-1. The impact from matrix interfering substances including glucose, uric acid, common oxidases, and amino acids is negligible. The applicability is demonstrated by quantitative determination of TYRase in human serum samples with 74 to 89% recovery and RSD less than 4.0%, which accords with the level for bio-sample analysis. Graphical abstract Schematic presentation of colorimetric assay for tyrosinase (TYRase) based on the inhibition effect on silver deposition onto catalytically active gold nanoparticles (AuNPs) and its application with a smartphone. Tyrosinase (TYRase); silver ions (Ag⁺); kojic acid (KA); gold nanoparticles (AuNPs); gold-silver core-shell nanoparticles (Au@Ag NPs).