171 research outputs found

    Electromagnetic counterparts of high-frequency gravitational waves in a rotating laboratory frame system and their detection

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    We consider the perturbative photon flows (PPFs, i.e., electromagnetic (EM) counterparts) generated by the EM resonance response to high-frequency gravitational waves (HFGWs) with additional polarization states in a rotating laboratory frame system. It is found that when the propagating direction of the HFGWs and the symmetrical axis of the laboratory frame system are the same, the PPFs have the maximum value. In this case, using the rotation (the rotation of azimuth ϕ\phi) of the EM detection system, all six possible polarization states of the HFGWs can be separated and displayed. For the current experimental conditions, it is quite prospective to detect the PPFs generated by the HFGWs predicted in the braneworld models, the primordial black hole theories and the interaction mechanism between astrophysical plasma and intense EM radiation, etc., due to the large amplitudes (or high spectral densities) and spectral characteristics of these HFGWs. Detecting the primordial HFGWs from inflation faces great challenges at present, but it is not impossible.Comment: 29 pages, 8 figures, 1 table; corrected some minor typos; added reference

    Low-intensity pulsed ultrasound of different intensities differently affects myocardial ischemia/reperfusion injury by modulating cardiac oxidative stress and inflammatory reaction

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    IntroductionThe prevalence of ischemic heart disease has reached pandemic levels worldwide. Early revascularization is currently the most effective therapy for ischemic heart diseases but paradoxically induces myocardial ischemia/reperfusion (MI/R) injury. Cardiac inflammatory reaction and oxidative stress are primarily involved in the pathology of MI/R injury. Low-intensity pulsed ultrasound (LIPUS) has been demonstrated to reduce cell injury by protecting against inflammatory reaction and oxidative stress in many diseases, including cardiovascular diseases, but rarely on MI/R injury.MethodsThis study was designed to clarify whether LIPUS alleviates MI/R injury by alleviating inflammatory reaction and oxidative stress. Simultaneously, we have also tried to confirm which intensity of the LIPUS might be more suitable to ameliorate the MI/R injury, as well as to clarify the signaling mechanisms. MI/R and simulated ischemia/reperfusion (SI/R) were respectively induced in Sprague Dawley rats and human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs). LIPUS treatment, biochemical measurements, cell death assay, estimation of cardiac oxidative stress and inflammatory reaction, and protein detections by western blotting were performed according to the protocol.ResultsIn our study, both in vivo and in vitro, LIPUS of 0.1 W/cm2 (LIPUS0.1) and 0.5 W/cm2 (LIPUS0.5) make no significant difference in the cardiomyocytes under normoxic condition. Under the hypoxic condition, MI/R injury, inflammatory reaction, and oxidative stress were partially ameliorated by LIPUS0.5 but were significantly aggravated by LIPUS of 2.5 W/cm2 (LIPUS2.5) both in vivo and in vitro. The activation of the apoptosis signal-regulating kinase 1 (ASK1)/c-Jun N-terminal kinase (JNK) pathway in cardiomyocytes with MI/R injury was partly rectified LIPUS0.5 both in vivo and in vitro.ConclusionOur study firstly demonstrated that LIPUS of different intensities differently affects MI/R injury by regulating cardiac inflammatory reaction and oxidative stress. Modulations on the ASK1/JNK pathway are the signaling mechanism by which LIPUS0.5 exerts cardioprotective effects. LIPUS0.5 is promising for clinical translation in protecting against MI/R injury. This will be great welfare for patients suffering from MI/R injury

    Deep learning of heart-sound signals for efficient prediction of obstructive coronary artery disease

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    Background Due to the limitations of current methods for detecting obstructive coronary artery disease (CAD), many individuals are mistakenly or unnecessarily referred for coronary angiography (CAG). Objectives Our goal is to create a comprehensive database of heart sounds in CAD and develop accurate deep learning algorithms to efficiently detect obstructive CAD based on heart sound signals. This will enable effective screening before undergoing CAG. Methods We included 320 subjects suspected of CAD who underwent CAG. We employed advanced filtering techniques and state-of-the-art deep learning models (VGG-16, 1D CNN, and ResNet18) to analyze the heart sound signals and identify obstructive CAD (defined as at least one ≥50 % stenosis). To assess the performance of our models, we prospectively recruited an additional 80 subjects for testing. Results In the test set, VGG-16 exhibited the highest performance with an area under the ROC curve (AUC) of 0.834 (95 % CI, 0.736–0.930), while ResNet-18 and CNN-7 achieved AUCs of only 0.755 (95 % CI, 0.614–0.819) and 0.652 (95 % CI, 0.554–0.770) respectively. VGG-16 demonstrated a sensitivity of 80.4 % and specificity of 86.2 % in the test set. The combined diagnostic model of VGG and DF scores achieved an AUC of 0.915 (95 % CI: 0.855–0.974), and the AUC for VGG combined with PTP scores was 0.908 (95 % CI: 0.845–0.971). The sensitivity and specificity of VGG-16 exceeded 0.85 in patients with coronary artery occlusion and those with 3 vascular lesions. Conclusions Our deep learning model, based on heart sounds, offers a non-invasive and efficient screening method for obstructive CAD. It is expected to significantly reduce the number of unnecessary referrals for downstream screening

    Frequent occurrence of unreduced gametes in Triticum turgidum-Aegilops tauschii hybrids.

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    Abstract Spontaneous chromosome doubling via union of unreduced (2n) gametes has been thought to be the way that common wheat (Triticum aestivum L.) was originated from the hybridization of T. turgidum L. with Ae. tauschii Cosson. Previous works have observed unreduced gametes in F 1 hybrids of Ae. tauschii with six of the eight T. turgidum subspecies. It is not clear, however, whether the formation of these unreduced gametes is a norm in the F 1 hybrids. In the present study, we tried to answer this question by assessing the occurrence frequency of unreduced gametes in 115 T. turgidum-Ae. tauschii hybrid combinations, involving 76 genotypes of seven T. turgdium subspecies and 24 Ae. tauschii accessions. Our data show that these hybrid combinations differed significantly (P B 0.01, F = 11.40) in selfed seedset, an indicator for production of unreduced gametes. This study clearly showed that meiotic restitution genes are widely distributed within T. turgidum. However, significant differences were found between as well as within T. turgidum subspecies and in the interaction of the T. turgidum genotypes with those of Ae. taushii. The possible application of the meiotic restitution genes from T. turgidum in production of double haploids is also discussed

    Mechanistic aspects of photo-induced formation of peroxide ions on the surface of cubic Ln(2)O(3) (Ln = Nd, Sm, Gd) under oxygen

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    National Basic Research Program of China [2010CB732303]; National Natural Science Foundation of China [21173173, 21033006, 20923004]; Program for Changjiang Scholars and Innovative Research Team in University [IRT1036]The photo-induced formation of peroxide ions on the surface of cubic Ln(2)O(3) (Ln = Nd, Sm, Gd) was studied by in situ microprobe Raman spectroscopy using a 325 nm laser as excitation source. It was found that the Raman bands of peroxide ions at 833-843 cm(-1) began to grow at the expense of the Ln(3+)-O-2 bands at 333-359 cm(-1) when the Ln(2)O(3) samples under O-2 were continuously irradiated with a focused 325 nm laser beam at temperatures between 25-150 degrees C. The intensity of the peroxide Raman band was found to increase with increasing O-2 partial pressure, whereas no peroxide band was detected on the Ln(2)O(3) under N-2 as well as on the samples first irradiated with laser under Ar or N-2 followed by exposure to O-2 in the dark. The experiments using O-18 as a tracer further confirmed that the peroxide ions are generated by a photo-induced reaction between O-2 and the lattice oxygen (O2-) species in Ln(2)O(3). Under the excitation of 325 nm UV light, the transformation of O-2 to peroxide ions on the surface of the above lanthanide sesquioxides can even take place at room temperature. Basicity of the lattice oxygen species on Ln(2)O(3) also has an impact on the peroxide formation. Higher temperature or laser irradiation power is required to initiate the reaction between O-2 and O2- species of weaker basicity

    Genomewide association study of leprosy.

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    BACKGROUND: The narrow host range of Mycobacterium leprae and the fact that it is refractory to growth in culture has limited research on and the biologic understanding of leprosy. Host genetic factors are thought to influence susceptibility to infection as well as disease progression. METHODS: We performed a two-stage genomewide association study by genotyping 706 patients and 1225 controls using the Human610-Quad BeadChip (Illumina). We then tested three independent replication sets for an association between the presence of leprosy and 93 single-nucleotide polymorphisms (SNPs) that were most strongly associated with the disease in the genomewide association study. Together, these replication sets comprised 3254 patients and 5955 controls. We also carried out tests of heterogeneity of the associations (or lack thereof) between these 93 SNPs and disease, stratified according to clinical subtype (multibacillary vs. paucibacillary). RESULTS: We observed a significant association (P<1.00x10(-10)) between SNPs in the genes CCDC122, C13orf31, NOD2, TNFSF15, HLA-DR, and RIPK2 and a trend toward an association (P=5.10x10(-5)) with a SNP in LRRK2. The associations between the SNPs in C13orf31, LRRK2, NOD2, and RIPK2 and multibacillary leprosy were stronger than the associations between these SNPs and paucibacillary leprosy. CONCLUSIONS: Variants of genes in the NOD2-mediated signaling pathway (which regulates the innate immune response) are associated with susceptibility to infection with M. leprae

    Environmental inhibitors of 11β-hydroxysteroid dehydrogenase type 2

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    11β-Hydroxysteroid dehydrogenase (11β-HSD) regulates glucocorticoid action by catalyzing the interconversion of active cortisol and inactive cortisone in glucocorticoid and mineralocorticoid target tissues. Two distinct isoforms, 11β-HSD1 and 11β-HSD2, have been characterized. 11β-HSD1 is widely expressed, uses NADP+/NADPH as cofactors, and contributes to the metabolic syndrome and related conditions by increasing cortisol level. 11β-HSD2 is an NAD^+-dependent oxidase, converting cortisol to cortisone to lower active glucocorticoid level. The inhibition of 11β-HSD2 activity is generally detrimental to health because the buildup of local cortisol concentration can cause symptoms of apparent mineralocorticoid excess, fetal developmental defect and lower testosterone level in males. In this review, we focus on many environmental inhibitors of 11β-HSD2 including licorice components, gossypol, phthalates, organotins, alkylphenols and perfluorinated substances

    Regulation of blood-testis barrier dynamics by the mTORC1/rpS6 signaling complex: An in vitro study

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    During spermatogenesis, developing germ cells that lack the cellular ultrastructures of filopodia and lamellipodia generally found in migrating cells, such as macrophages and fibroblasts, rely on Sertoli cells to support their transport across the seminiferous epithelium. These include the transport of preleptotene spermatocytes across the blood-testis barrier (BTB), but also the transport of germ cells, in particular developing haploid spermatids, across the seminiferous epithelium, that is to and away from the tubule lumen, depending on the stages of the epithelial cycle. On the other hand, cell junctions at the Sertoli cell–cell and Sertoli–germ cell interface also undergo rapid remodeling, involving disassembly and reassembly of cell junctions, which, in turn, are supported by actin- and microtubule-based cytoskeletal remodeling. Interestingly, the underlying mechanism(s) and the involving biomolecule(s) that regulate or support cytoskeletal remodeling remain largely unknown. Herein, we used an in vitro model of primary Sertoli cell cultures that mimicked the Sertoli BTB in vivo overexpressed with the ribosomal protein S6 (rpS6, the downstream signaling protein of mammalian target of rapamycin complex 1 [mTORC1]) cloned into the mammalian expression vector pCI-neo, namely, quadruple phosphomimetic and constitutively active mutant of rpS6 (pCI-neo/p-rpS6-MT) versus pCI-neo/rpS6-WT (wild-type) and empty vector (pCI-neo/Ctrl) for studies. These findings provide compelling evidence that the mTORC1/rpS6 signal pathway exerted its effects to promote Sertoli cell BTB remodeling. This was mediated through changes in the organization of actin- and microtubule-based cytoskeletons, involving changes in the distribution and/or spatial expression of actin- and microtubule-regulatory proteins

    Phthalate-induced testicular dysgenesis syndrome: Leydig cell influence

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    Phthalates, the most abundantly produced plasticizers, leach out from polyvinyl chloride plastics and disrupt androgen action. Male rats that are exposed to phthalates in utero develop symptoms characteristic of the human condition referred to as testicular dysgenesis syndrome (TDS). Environmental influences have been suspected to contribute to the increasing incidence of TDS in humans (i.e. cryptorchidism and hypospadias in newborn boys and testicular cancer and reduced sperm quality in adult males). In this review, we discuss the recent findings that prenatal exposure to phthalates affects Leydig cell function in the postnatal testis. This review also focuses on the recent progress in our understanding of how Leydig cell factors contribute to phthalate-mediated TDS

    Regulation of BTB dynamics in spermatogenesis—Insights from the adjudin model

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    During spermatogenesis, cell organelles, and germ cells, most notably haploid spermatids, are transported across the seminiferous epithelium so that fully developed spermatids line-up at the edge of the tubule lumen to undergo spermiation at stage VIII of the cycle. Studies have suggested that the microtubule (MT)-based cytoskeleton is necessary to support these cellular events. However, the regulatory molecule(s) and underlying mechanism(s) remain poorly understood. Herein, we sought to better understand this event by using an adjudin-based animal model. Adult rats were treated with adjudin at low-dose (10 mg/kg b.w.) which by itself had no notable effects on spermatogenesis. Rats were also treated with low-dose adjudin combined with overexpression of 2 endogenously produced blood-testis barrier (BTB) modifiers, namely rpS6 (ribosomal protein S6, the downstream signaling protein of mammalian target of rapamycin complex 1 [mTORC1]) and F5-peptide (a biological active peptide released from laminin-γ3 chain at the Sertoli-spermatid interface) versus the 2 BTB modifiers alone. Overexpression of these 2 BTB modifiers in the testis was shown to enhance delivery of adjudin to the testis, effectively inducing disruptive changes in MT cytoskeletons, causing truncation of MT conferred tracks that led to their collapse across the epithelium. The net result was massive germ cell exfoliation in the tubules, disrupting germ cell transport and cell adhesion across the seminiferous epithelium that led to aspermatogenesis. These changes were the result of disruptive spatial expression of several MT-based regulatory proteins. In summary, MT cytoskeleton supported by the network of MT regulatory proteins is crucial to maintain spermatogenesis
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