E93 is indispensable for reproduction in ametabolous and hemimetabolous insects.

Ecdysone-induced protein 93 (E93), known as the 'adult-specifier' transcription factor in insects, triggers metamorphosis in both hemimetabolous and holometabolous insects. Although E93 is conserved in ametabolous insects, its spatiotemporal expression and physiological function remain poorly understood. In this study, we first discover that, in the ametabolous firebrat Thermobia domestica, the previtellogenic ovary exhibits cyclically high E93 expression, and E93 mRNA is broadly distributed in previtellogenic ovarioles. E93 homozygous mutant females of T. domestica exhibit severe fecundity deficiency due to impaired previtellogenic development of the ovarian follicles, likely because E93 induces the expression of genes involved in ECM (extracellular matrix)-receptor interactions during previtellogenesis. Moreover, we reveal that in the hemimetabolous cockroach Blattella germanica, E93 similarly promotes previtellogenic ovarian development. In addition, E93 is also essential for vitellogenesis that is necessary to guarantee ovarian maturation and promotes the vitellogenesis-previtellogenesis switch in the fat body of adult female cockroaches. Our findings deepen the understanding of the roles of E93 in controlling reproduction in insects, and of E93 expression and functional evolution, which are proposed to have made crucial contributions to the origin of insect metamorphosis.

A spatiotemporal barrier formed by Follistatin is required for left-right patterning.

How left-right (LR) asymmetry emerges in a patterning field along the anterior-posterior axis remains an unresolved problem in developmental biology. Left-biased Nodal emanating from the LR organizer propagates from posterior to anterior (PA) and establishes the LR pattern of the whole embryo. However, little is known about the regulatory mechanism of the PA spread of Nodal and its asymmetric activation in the forebrain. Here, we identify bilaterally expressed Follistatin (Fst) as a regulator blocking the propagation of the zebrafish Nodal ortholog Southpaw (Spaw) in the right lateral plate mesoderm (LPM), and restricting Spaw transmission in the left LPM to facilitate the establishment of a robust LR asymmetric Nodal patterning. In addition, Fst inhibits the Activin-Nodal signaling pathway in the forebrain thus preventing Nodal activation prior to the arrival, at a later time, of Spaw emanating from the left LPM. This contributes to the orderly propagation of asymmetric Nodal activation along the PA axis. The LR regulation function of Fst is further confirmed in chick and frog embryos. Overall, our results suggest that a robust LR patterning emerges by counteracting a Fst barrier formed along the PA axis.

The role of KLF2 in regulating hepatic lipogenesis and blood cholesterol homeostasis via the SCAP/SREBP pathway.

Liver steatosis is a common metabolic disorder resulting from imbalanced lipid metabolism, which involves various processes such as de novo lipogenesis, fatty acid uptake, fatty acid oxidation, and VLDL secretion. In this study, we discovered that KLF2, a transcription factor, plays a crucial role in regulating lipid metabolism in the liver. Overexpression of KLF2 in the liver of db/db mice, C57BL/6J mice, and Cd36-/- mice fed on a normal diet resulted in increased lipid content in the liver. Additionally, transgenic mice (ALB-Klf2) that overexpressed Klf2 in the liver developed liver steatosis after being fed a normal diet. We found that KLF2 promotes lipogenesis by increasing the expression of SCAP, a chaperone that facilitates the activation of SREBP, the master transcription factor for lipogenic gene expression. Our mechanism studies revealed that KLF2 enhances lipogenesis in the liver by binding to the promoter of SCAP and increasing the expression of genes involved in fatty acid synthesis. Reduction of KLF2 expression led to a decrease in SCAP expression and a reduction in the expression of SREBP1 target genes involved in lipogenesis. Overexpression of KLF2 also increased the activation of SREBP2 and the mRNA levels of its downstream target SOAT1. In C57BL/6J mice fed a high-fat diet, overexpression of Klf2 increased blood VLDL secretion, while reducing its expression decreased blood cholesterol levels. Our study emphasizes the novelty that hepatic KLF2 plays a critical role in regulating lipid metabolism through the KLF2/SCAP/SREBPs pathway, which is essential for hepatic lipogenesis and maintaining blood cholesterol homeostasis.

Environmental exposure to per- and polyfluoroalkyl substances mixture and asthma in adolescents.

BACKGROUND: Previous epidemiological studies about the relationship between per- and polyfluoroalkyl substances (PFAS) concentrations and adolescent asthma have typically examined single PFAS, without considering the mixtures effects of PFAS. METHODS: Using data from the 2013-2018 National Health and Nutrition Examination Survey (NHANES), 886 adolescents aged 12-19 years were included in this study. We explored the association between PFAS mixture concentrations and adolescent asthma using weighted quantile sum (WQS) regression and Bayesian kernel machine regression (BKMR) models, respectively. RESULTS: After adjusting for confounders, the results of the WQS regression and BKMR models were consistent, with mixed exposure to the five PFAS not significantly associated with asthma in all adolescents. The association remained nonsignificant in the subgroup analysis by sex. CONCLUSIONS: Our study demonstrated no significant association between mixed exposure to PFAS and adolescent asthma, and more large cohort studies are needed to confirm this in the future.

Transfer-Imprinting-Assisted Growth of 2D/3D Perovskite Heterojunction for Efficient and Stable Flexible Inverted Perovskite Solar Cells.

2D/3D perovskite heterostructures show great potential to boost efficiency and stability of perovskite solar cells (PSCs). Here, a solvent-free transfer-imprinting-assisted growth (TIAG) method is employed to in situ grow 2D/3D perovskite heterojunctions. The solid-state transfer of spacer cation by the TIAG process enables a spatially confined growth of the 2D perovskite interlayer with uniform morphology between the 3D perovskites and charge transport layer. Meanwhile, the pressure associated with the TIAG process promotes the crystalline orientation, which is beneficial to carrier transport. As a result, the inverted PSC achieved a PCE of 23.09% (with certified 22.93%) and maintained 90% of their initial PCE after aging at 85 °C for 1200 h or operating for 1100 h under continuous AM 1.5 illumination. Flexible inverted PSCs achieved a PCE of 21.14% with mechanical robustness by maintaining above 80% of their initial PCE after 10000 bending cycles under a 3 mm bending radius.

Dynamic biomechanical changes of clear aligners during extraction space closure: Finite element analysis.

INTRODUCTION: Clear aligners (CAs) have recently become popular and widely used orthodontic appliances. Research on CA biomechanics has become a focal point in orthodontics to improve the efficiency of CA treatment and address challenging issues, such as extraction. The biomechanical characteristics of CAs in space closure have been reported. However, previous studies have mainly focused on static biomechanical analysis that cannot demonstrate the dynamic biomechanical changes in CAs during space-closing. Given that these biomechanical changes can be significant and have considerable clinical value, this study aimed to investigate these characteristics. METHODS: Sequential extraction space-closing models were derived from included patient data and refined using modeling and CA design software. A finite element analysis was performed to obtain biomechanical raw data. This study introduced a dual coordinate system and space geometry analysis to demonstrate the biomechanical properties accurately. RESULTS: As space closure progressed, the instantaneous tooth displacements increased, indicating an enhanced space closure force because of the increased strain in the CA extraction area. Meanwhile, the central axis of rotation of the anterior teeth continuously moved toward the labial-apical direction, showing a gradually enhanced vertical and torque control effect. CONCLUSIONS: During space closure, CAs undergo specific biomechanical changes, including increased contraction and control forces on both sides of the gap. These biomechanical effects are beneficial to alleviate the roller coaster effect gradually. Meanwhile, more reasonable staging design strategies can be proposed on the basis of this biomechanical mechanism.

[Value of single-phase gonadotropin-releasing hormone stimulation test in diagnosis of central precocious puberty in girls with different levels of body mass index]. / 单时相GnRHæ¿€å‘è¯•éªŒå¯¹ä¸åŒä½“é‡æŒ‡æ•°å¥³ç«¥ä¸­æž¢æ€§æ€§æ—©ç†Ÿè¯Šæ–­ä»·å€¼çš„ç ”ç©¶.

OBJECTIVES: To investigate the value of single-phase gonadotropin releasing hormone (GnRH) stimulation test in the diagnosis of central precocious puberty (CPP) in girls with different levels of body mass index (BMI). METHODS: A retrospective analysis was performed for the data of 760 girls with breast development before 7.5 years of age who attended the Third Affiliated Hospital of Zhengzhou University from January 2017 to August 2023. According to the results of GnRH stimulation test and clinical manifestations, they were divided into a CPP group (297 girls) and a non-CPP group (463 girls). According to the values of BMI, the girls were divided into a normal weight group (540 girls), an overweight group (116 girls), and an obese group (104 girls). The receiver operating characteristic (ROC) curve was used to investigate the value of single-phase GnRH stimulation test in the diagnosis of CPP in girls with different levels of BMI. RESULTS: Luteinizing hormone (LH)/follicle-stimulating hormone at 30 minutes after GnRH stimulation had an area under the curve (AUC) of 0.985 in the diagnosis of CPP, which was higher than the AUC at 0, 60, and 90 minutes (P<0.05). LH at 30 minutes had a similar diagnostic value to LH at 60 minutes (P>0.05). LH at 30 minutes was negatively correlated with BMI and BMI-Z value (P<0.05).The AUC for diagnosing CPP in normal weight, overweight, and obese girls at 30 minutes LH was 0.952, 0.965, and 0.954, respectively (P<0.05). CONCLUSIONS: The 30-minute GnRH stimulation test has a good value in the diagnosis of CPP in girls with different levels of BMI and is expected to replace the traditional GnRH stimulation test, but the influence of BMI on LH level should be taken seriously.

Microbiota-derived tryptophan metabolites indole-3-lactic acid is associated with intestinal ischemia/reperfusion injury via positive regulation of YAP and Nrf2.

BACKGROUND: Lactobacillus has been demonstrated to serve a protective role in intestinal injury. However, the relationship between Lactobacillus murinus (L. murinus)-derived tryptophan metabolites and intestinal ischemia/reperfusion (I/R) injury yet to be investigated. This study aimed to evaluate the role of L. murinus-derived tryptophan metabolites in intestinal I/R injury and the underlying molecular mechanism. METHODS: Liquid chromatograph mass spectrometry analysis was used to measure the fecal content of tryptophan metabolites in mice undergoing intestinal I/R injury and in patients undergoing cardiopulmonary bypass (CPB) surgery. Immunofluorescence, quantitative RT-PCR, Western blot, and ELISA were performed to explore the inflammation protective mechanism of tryptophan metabolites in WT and Nrf2-deficient mice undergoing intestinal I/R, hypoxia-reoxygenation (H/R) induced intestinal organoids. RESULTS: By comparing the fecal contents of three L. murinus-derived tryptophan metabolites in mice undergoing intestinal I/R injury and in patients undergoing cardiopulmonary bypass (CPB) surgery. We found that the high abundance of indole-3-lactic acid (ILA) in the preoperative feces was associated with better postoperative intestinal function, as evidenced by the correlation of fecal metabolites with postoperative gastrointestinal function, serum I-FABP and D-Lactate levels. Furthermore, ILA administration improved epithelial cell damage, accelerated the proliferation of intestinal stem cells, and alleviated the oxidative stress of epithelial cells. Mechanistically, ILA improved the expression of Yes Associated Protein (YAP) and Nuclear Factor erythroid 2-Related Factor 2 (Nrf2) after intestinal I/R. The YAP inhibitor verteporfin (VP) reversed the anti-inflammatory effect of ILA, both in vivo and in vitro. Additionally, we found that ILA failed to protect epithelial cells from oxidative stress in Nrf2 knockout mice under I/R injury. CONCLUSIONS: The content of tryptophan metabolite ILA in the preoperative feces of patients is negatively correlated with intestinal function damage under CPB surgery. Administration of ILA alleviates intestinal I/R injury via the regulation of YAP and Nrf2. This study revealed a novel therapeutic metabolite and promising candidate targets for intestinal I/R injury treatment.

Multimode Quasinormal Spectrum from a Perturbed Black Hole.

When two black holes merge, the late stage of gravitational wave emission is a superposition of exponentially damped sinusoids. According to the black hole no-hair theorem, this ringdown spectrum depends only on the mass and angular momentum of the final black hole. An observation of more than one ringdown mode can test this fundamental prediction of general relativity. Here, we provide strong observational evidence for a multimode black hole ringdown spectrum using the gravitational wave event GW190521, with a maximum Bayes factor of 56±1 (1σ uncertainty) preferring two fundamental modes over one. The dominant mode is the ℓ=m=2 harmonic, and the subdominant mode corresponds to the ℓ=m=3 harmonic. The amplitude of this mode relative to the dominant harmonic is estimated to be A_{330}/A_{220}=0.2_{-0.1}^{+0.2}. We estimate the redshifted mass and dimensionless spin of the final black hole as 330_{-40}^{+30}M_{⊙} and 0.86_{-0.11}^{+0.06}, respectively. We find that the final black hole is consistent with the no-hair theorem and constrain the fractional deviation from general relativity of the subdominant mode's frequency to be -0.01_{-0.09}^{+0.08}.

A rare presentation of central pontine myelinolysis secondary to hyperglycaemia.

BACKGROUND: Central pontine myelinolysis (CPM) is a rare demyelinating disorder caused by the loss of myelin in the center of the basis pontis. CPM typically occurs with rapid correction of severe chronic hyponatremia and subsequent disturbances in serum osmolality. Although hyperglycaemia is recognized as a pathogenetic factor in serum osmolality fluctuations, CPM is rarely seen in the context of diabetes. CASE PRESENTATION: A 66-year-old Chinese male presented with a history of gait imbalance, mild slurred speech and dysphagia for two weeks. MRI showed the mass lesions in the brainstem, and laboratory examinations showed high blood glucose and HbA1c, as well as increased serum osmolality. The patient was diagnosed with CPM secondary to hyperosmolar hyperglyceamia and received insulin treatment as well as supportive therapy. After six weeks of followup, the patient had fully recovered to a normal state. CONCLUSION: CPM is a potentially fatal neurological condition and can occur in uncontrolled diabetes mellitus. Early diagnosis and timely treatment are crucial for improving the prognosis.

Serum perfluoroalkyl substances and growth and development in US adolescents: a nationally representative cross-sectional study.

Per- and polyfluoroalkyl substances (PFAS), synthetic organic chemicals, have been discovered in the blood of both humans and animals throughout the world. This has raised widespread concerns about its toxicity, especially for growing children and adolescents. Most research on growth and development to date has concentrated on children at birth and during the first two years, while few studies have analyzed weight, height, and Body Mass Index (BMI) changes in children later in life. The present study aims to assess the association between serum PFAS levels and growth and development in adolescents. Through multiple linear regression, we explored the relationship between serum PFAS levels and weight, height, and BMI in adolescents (aged 12 to 19 years) participating in the 2015-2018 National Health and Nutrition Examination Survey (NHANES). After covariate adjustment, serum perfluorooctane sulfonic acid (PFOS) was associated with decreased weight-for-age z-score in females (tertile 2 of PFOS: ß = - 0.22, 95% CI: -0.68, 0.23; tertile 3 of PFOS: ß = - 0.78, 95% CI: -1.20, - 0.36; P for trend = 0.009), while serum perfluorononanoic acid (PFNA) was associated with decreased weight-for-age z-score in males (tertile 2 of PFNA: ß = 0.09, 95% CI: -0.40, 0.58; tertile 3 of PFNA: ß = - 0.44, 95% CI: -0.86, - 0.03; P for trend = 0.018).In addition, serum PFOS was associated with decreased BMI z-score in all participants (tertile 2 of PFOS: ß = - 0.15, 95% CI: -0.46, 0.16; tertile 3 of PFOS: ß = - 0.63, 95% CI: -1.06, - 0.20; P for trend = 0.013). CONCLUSION: Our findings indicate a negative association between serum PFAS levels and weight, and BMI among adolescents, and we observed that the negative association was sex-specific in weight. WHAT IS KNOWN: • Wide exposure to PFAS has led to concerns about its adverse effects, especially for children during their growth and development. • So far, much research has evaluated the effects of prenatal PFAS exposures on children, and the current results are mixed, with some research showing that there are sex differences. WHAT IS NEW: • This study investigated the relationship between serum PFAS levels and height and weight in adolescents and is a good addition to current research. • Our study found that exposure to PFAS negatively affects adolescent growth and development and that this effect is sex-specific.

Compounds isolated from the pericarp of Zanthoxylum bungeanum and inhibitory activity against LPS-induced NO production in RAW264.7.

Seventeen compounds were isolated and identified from the ethyl acetate part of Zanthoxylum bungeanum Maxim., including one new compound 18-acetyloxyneocryptotanshinone (1) and 16 known compounds (2-17). Their structures were elucidated by extensive spectroscopy. The absolute configuration of 1 was confirmed by electronic circular dichroism (ECD). All compounds were evaluated for the inhibition of LPS-induced nitric oxide (NO) production in RAW264.7 macrophages, of which 1 and 10 exhibited the most significant inhibitory effect, with IC50 of 17.29 and 10.27 µM, respectively.

Association between PFAS congeners exposure and asthma among US children in a nationally representative sample.

Over the past few decades, contamination with perfluorinated and polyfluoroalkyl substances (PFAS) has gradually become a worldwide problem. Now that common PFAS such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are being phased out and replaced, people may be exposed to other PFAS congeners, and their potential hazards should be fully studied. We assessed the association of serum PFAS levels (as biomarkers of exposure) with asthma, including 2-(N-methyl-perfluorooctane sulfonamido) acetic acid (Me-PFOSA-AcOH), pefluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUnDA), using data from participants aged 3-11 from the 2013-2014 National Health and Nutrition Examination Surveys (n = 525), where PFAS was modeled as a binary variable.Me-PFOSA-AcOH (1.36; 95% CI 0.77, 2.38), PFDA (1.33; 95% CI 0.76, 2.33), and PFUnDA (1.89; 95% CI 0.83, 4.35) were nonsignificantly associated with increased odds of asthma. Age, sex, and race/ethnicity modified associations between serum PFUnDA, not other serum PFAS congeners exposure, and odds of asthma. Specifically, for male participants, the OR = 3.06 and 95% CI 1.23-7.62 for serum PFUnDA exposure; for participants aged 3-7 years old, the OR = 3.55 and 95% CI 1.04-12.10 for serum PFUnDA exposure; for non-Hispanic White participants, the OR = 3.44 and 95% CI 1.14-10.36 for serum PFUnDA exposure, all of which exhibited a significantly positive relationship. This cross-sectional study provides some evidence for associations between exposure to PFAS congeners and asthma in children. We believe this relationship deserves further exploration. More large-scale epidemiologic studies are needed to evaluate the association of serum PFAS congeners, especially for PFUnDA exposure, with asthma among children.

[Value of basal luteinizing hormone level combined with uterine volume measurement in the early diagnosis of central precocious puberty in girls with different Tanner stages]. / é»„ä½“ç”Ÿæˆç´ åŸºç¡€å€¼è”åˆå­å®«ä½“ç§¯å¯¹ä¸åŒTanneråˆ†æœŸå¥³ç«¥ä¸­æž¢æ€§æ€§æ—©ç†Ÿæ—©æœŸè¯Šæ–­ä»·å€¼çš„ç ”ç©¶.

OBJECTIVES: To study the value of basal luteinizing hormone (LH) level combined with uterine volume measurement in the early diagnosis of central precocious puberty (CPP) in girls with different Tanner stages. METHODS: A retrospective analysis was performed on the girls who presented with breast development before the age of 8 years and attended the Third Affiliated Hospital of Zhengzhou University from January 2017 to September 2022. According to the results of gonadotropin-releasing hormone (GnRH) agonist test, the girls with peak LH ≥5.0 IU/L and peak LH/follicle stimulating hormone ≥0.6 were enrolled as the positive group, and the other girls were enrolled as the negative group. The two groups were compared in terms of the basal LH level and uterine volume. The receiver operating characteristic (ROC) curve was used to analyze their value in the early diagnosis of CPP. RESULTS: For the girls with Tanner B2 and B3 stages, the positive group had significantly higher basal LH level and uterine volume than the negative group (P<0.05). The basal LH level had an optimal cut-off value of 0.325 IU/L and 0.505 IU/L respectively in the diagnosis of Tanner stage B2/B3 CPP, while uterine volume had an optimal cut-off value of 1.639 mL and 2.158 mL respectively. Basal LH level combined with uterine volume measurement had a significantly larger area under the ROC curve than uterine volume measurement alone (P<0.001), but with no significant difference compared with that of basal LH level measurement alone (P>0.05). CONCLUSIONS: Basal LH level combined with uterine volume measurement is valuable in the early diagnosis of CPP in girls with different Tanner stages, which provides a basis and guiding significance for clinical diagnosis of CPP.

Asymmetric Hydrosilylation of ß-Silyl Styrenes Catalyzed by a Chiral Palladium Complex.

A palladium complex coordinated with a chiral SIPHOS ligand was evaluated as an efficient catalyst for asymmetric hydrosilylation of ß-silyl styrenes with trichlorosilane and 23 1,2-bis(silyl) chiral compounds were produced. Good to excellent enantioselectivities were observed with 1-aryl-2-silyl ethanols, where the trichlorosilyl groups of the hydrosilylation products were selectively converted into a hydroxyl group in the presence of pre-installed trialkylsilyl groups. Asymmetric hydrosilylation of ß-silyl styrenes followed by methylation of the trichlorosilyl group gave stable 1,2-bis(silyl) chiral compounds 4 with excellent yields. DFT calculations of hydridopalladium B coordinated with a SIPHOS ligand, an intermediate of the hydrosilylation reaction, established the optical structures to be energy minima, and the structural information could well illustrate the enantioselectivity for the hydrosilylation reaction.

Implications of p53 in mitochondrial dysfunction and Parkinson's disease.

Purpose: To study the underlying molecular mechanisms of p53 in the mitochondrial dysfunction and the pathogenesis of Parkinson's disease (PD), and provide a potential therapeutic target for PD treatment.Methods: We review the contributions of p53 to mitochondrial changes leading to apoptosis and the subsequent degeneration of dopaminergic neurons in PD.Results: P53 is a multifunctional protein implicated in the regulation of diverse cellular processes via transcription-dependent and transcription-independent mechanisms. Mitochondria are vital subcellular organelles for that maintain cellular function, and mitochondrial defect and impairment are primary causes of dopaminergic neuron degeneration in PD. Increasing evidence has revealed that mitochondrial dysfunction-associated dopaminergic neuron degeneration is tightly regulated by p53 in PD pathogenesis. Neurodegenerative stress triggers p53 activation, which induces mitochondrial changes, including transmembrane permeability, reactive oxygen species production, Ca2+ overload, electron transport chain defects and other dynamic alterations, and these changes contribute to neurodegeneration and are linked closely with PD occurrence and development. P53 inhibition has been shown to attenuate mitochondrial dysfunction and protect dopaminergic neurons from degeneration under conditions of neurodegenerative stress.Conclusions: p53 appears to be a potential target for neuroprotective therapy of PD.

Stereodivergent Synthesis of Tertiary Fluoride-Tethered Allenes via Copper and Palladium Dual Catalysis.

Herein we describe a protocol for the unprecedented stereodivergent synthesis of tertiary fluoride-tethered allenes bearing a stereogenic center and stereogenic axis via Cu/Pd synergistic catalysis. A broad scope of conjugated enynes are coupled with various α-fluoroesters in high yields with high diastereoselectivities and generally >99% ee. In addition, the four stereoisomers of the allene products ensure precise access to the corresponding four stereoisomers of the fluorinated hydrofurans via a novel stereodivergent axial-to-central chirality transfer process.

Omnidirectional light absorption enhancement of perovskite solar cells by an antireflection film with holographic lithography microstructures.

We report an omnidirectional light absorption enhancement of a perovskite solar cell (PSC) using antireflection (AR) film with soft imprinted microstructures from master molds via holographic lithography technology, which has high throughput and repeatability. The PSC's omnidirectional power conversion efficiency (PCE) enhancement is achieved by reducing Fresnel surface reflections and enhancing the optical path length. The maximum PCE of PSCs with AR film is up to 20.27%, corresponding to an absolute increase of 0.93% compared to 19.34% of control devices. Significantly, the enhancements of PCE increase with incident angle enlargement, which attributes to more effective Fresnel surface reflection suppression. Moreover, AR films exhibit water and dust repellent properties due to hydrophobicity, which is beneficial for PSC's long-term stability and light harvesting.

Search for Gravitational Waves from the Coalescence of Subsolar-Mass Binaries in the First Half of Advanced LIGO and Virgo's Third Observing Run.

We present a search for gravitational waves from the coalescence of subsolar-mass black hole binaries using data from the first half of Advanced LIGO and Virgo's third observing run. The observation of a subsolar-mass black hole merger may be an indication of primordial origin; primordial black holes may contribute to the dark matter distribution. We search for black hole mergers where the primary mass is 0.1-7 M_{⊙} and the secondary mass is 0.1-1 M_{⊙}. A variety of models predict the production and coalescence of binaries containing primordial black holes; some involve dynamical assembly, which may allow for residual eccentricity to be observed. For component masses >0.5 M_{⊙}, we also search for sources in eccentric orbits, measured at a reference gravitational-wave frequency of 10 Hz, up to e_{10}∼0.3. We find no convincing candidates and place new upper limits on the rate of primordial black hole mergers. The merger rate of 0.5-0.5 (1.0-1.0) M_{⊙} sources is <7100(1200) Gpc^{-3} yr^{-1}. Our limits are ∼3-4 times more constraining than prior analyses. Finally, we demonstrate how our limits can be used to constrain arbitrary models of the primordial black hole mass distribution and merger rate.

Search for Gravitational Waves from High-Mass-Ratio Compact-Binary Mergers of Stellar Mass and Subsolar Mass Black Holes.

We present the first search for gravitational waves from the coalescence of stellar mass and subsolar mass black holes with masses between 20-100 M_{⊙} and 0.01-1 M_{⊙}(10-10^{3} M_{J}), respectively. The observation of a single subsolar mass black hole would establish the existence of primordial black holes and a possible component of dark matter. We search the ∼164 day of public LIGO data from 2015-2017 when LIGO-Hanford and LIGO-Livingston were simultaneously observing. We find no significant candidate gravitational-wave signals. Using this nondetection, we place a 90% upper limit on the rate of 30-0.01 M_{⊙} and 30-0.1 M_{⊙} mergers at <1.2×10^{6} and <1.6×10^{4} Gpc^{-3} yr^{-1}, respectively. If we consider binary formation through direct gravitational-wave braking, this kind of merger would be exceedingly rare if only the lighter black hole were primordial in origin (<10^{-4} Gpc^{-3} yr^{-1}). If both black holes are primordial in origin, we constrain the contribution of 1(0.1)M_{⊙} black holes to dark matter to <0.3(3)%.