Recent timing observation constrained the braking index of the X-ray pulsar PSR J1640-4631 to be n = 3.15 ± 0.03, which is the highest value of all pulsars with measured braking indices so far. In ...this Letter, we investigate whether pulsar braking by combined between the magnetic dipole emission and the gravitational radiation might have a braking index greater than three. For conventional neutron star and low mass quark star candidates, the inferred ellipticities derived by the observed braking index are obviously much larger than the theoretical estimated maximum value. If PSR J1640-4631 is a low-mass neutron star with a mass of 0.1 M⊙, the inferred ellipticity can be approximately equal to the theoretical estimated maximum value. Because of the radio-quiet nature of this source, we employ the vacuum gap model developed by Ruderman and Sutherland to constrain the inclination angle to be 87.2 − 90°. Based on this, we propose that a low-mass neutron star with a large inclination angle can interpret the high braking index and the radio-quiet nature of this source. Future observations such as gravitational wave detection and long-term timing for this source are required to confirm or confute our scenario.
Recently, the black hole X-ray binary (BHXB) Nova Muscae 1991 has been reported to be experiencing an extremely rapid orbital decay. So far, three BHXBs have anomalously high orbital-period ...derivatives, which cannot be interpreted by the standard stellar evolution theory. In this work, we investigate whether the resonant interaction between the binary and a surrounding circumbinary (CB) disk could produce the observed orbital-period derivatives. Analytical calculations indicate that the observed orbital-period derivatives of XTE J1118+480 and A0620-00 can originate from the tidal torque between the binary and a CB disk with a mass of 10−9 M , which is approximately in agreement with the dust disk mass detected in these two sources. However, Nova Muscae 1991 was probably surrounded by a heavy CB disk with a mass of 10−7 M . Based on the CB disk model and the anomalous magnetic braking theory, we simulate the evolution of the three BHXBs with intermediate-mass donor stars by using the MESA code. Our simulated results are approximately consistent with the observed donor-star masses, orbital periods, and orbital-period derivatives. However, the calculated effective temperatures of the donor stars are higher than indicated by the observed spectral types of two sources.
Some short-period, detached binary systems have recently been reported as experiencing very rapid orbital decay, much faster than is expected from the angular-momentum loss caused by gravitational ...radiation alone. As these systems contain fully convective stars, magnetic braking is not believed to be operative, making the large orbital-period derivative puzzling. Here, we explore whether a resonant interaction between the binary and a surrounding circumbinary (CB) disk could account for the observed orbital decay. Our calculations indicate that the observed orbital-period derivatives in seven detached binaries can be produced by the resonant interaction between the binary and a CB disk if the latter has a mass in the range of , which is of the same order as the inferred disk mass ( ) in the post-common-envelope binary NN Ser.
Current antiangiogenic therapy is limited by its cytostatic property, scarce drug delivery to the tumor, and side toxicity. To address these limitations, we unveiled the role of ZEB1, a tumor ...endothelium-enriched zinc-finger transcription factor, during tumor progression. We discovered that the patients who had lung adenocarcinomas with high ZEB1 expression in tumor endothelium had increased prevalence of metastases and markedly reduced overall survival after the diagnosis of lung cancer. Endothelial ZEB1 deletion in tumor-bearing mice diminished tumor angiogenesis while eliciting persistent tumor vascular normalization by epigenetically repressing TGF-β signaling. This consequently led to improved blood and oxygen perfusion, enhanced chemotherapy delivery and immune effector cell infiltration, and reduced tumor growth and metastasis. Moreover, targeting vascular ZEB1 remarkably potentiated the anticancer activity of nontoxic low-dose cisplatin. Treatment with low-dose anti-programmed cell death protein 1 (anti-PD-1) antibody elicited tumor regression and markedly extended survival in ZEB1-deleted mice, conferring long-term protective anticancer immunity. Collectively, we demonstrated that inactivation of endothelial ZEB1 may offer alternative opportunities for cancer therapy with minimal side effects. Targeting endothelium-derived ZEB1 in combination with conventional chemotherapy or immune checkpoint blockade therapy may yield a potent and superior anticancer effect.
Abstract The fallback disk model is widely accepted to explain long-period neutron stars (NSs) that cannot be simulated by magnetic dipole radiation. However, there was no confirmed detection of ...disks from the newly discovered long-period pulsars GLEAM-X 162759.5-523504.3 and GPM J1839-10 and the slowest known isolated NS 1E 161348-5055. This might be because the disks have either been in a noninteracting/inactive state where their emission is too weak to be detected or have been disrupted. In this work, we conduct simulations to examine the lifetime of supernova fallback disks around isolated NSs. We assume that the disks' mass varies in a self-similar way, and their interaction with the NS occurs only in an interacting/active state. Our results reveal that nearly all the interacting lifetimes for the disks are shorter than 10 5 yr, while the existence lifetimes are considerably longer.
ABSTRACT
Ultracompact X-ray binaries (UCXBs) are low-mass X-ray binaries with hydrogen-deficient mass donors and ultrashort orbital periods. They have been suggested to be the potential Laser ...Interferometer Space Antenna (LISA) sources in the low-frequency region. Several channels for the formation of UCXBs have been proposed so far. In this paper, we carried out a systematic study on the He star donor channel, in which a neutron star (NS) accretes matter from a He main-sequence (MS) star through Roche lobe overflow, where the mass transfer is driven by the gravitational wave radiation. First, we followed the long-term evolution of the NS+He MS binaries by employing the stellar evolution code Modules for Experiments in Stellar Astrophysics (mesa
), and thereby obtained the initial parameter spaces for the production of UCXBs. We then used these results to perform a detailed binary population synthesis approach to obtain the Galactic rates of UCXBs through this channel. We estimate the Galactic rates of UCXBs appearing as LISA sources to be ${\sim} 3.1\!-\!11.9\, \rm Myr^{-1}$ through this channel, and the number of such UCXB-LISA sources in the Galaxy can reach about 1–26 calibrated by observations. This work indicates that the He star donor channel may contribute significantly to the Galactic UCXB formation rate. We found that the evolutionary tracks of UCXBs through this channel can account for the location of the five transient sources with relatively long orbital periods quite well. We also found that such UCXBs can be identified by their locations in the mass-transfer rate versus the orbital period diagram.
The reaction of 4/5-carbonyl-cycloalkenone 1 or its achiral isomer 1′ with organoboronic acid 2 in the presence of a chiral diene (S,S)-Fc-tfb-rhodium catalyst gave disubstituted trans-cycloalkanone ...3 with high diastereo- and enantioselectivity. This highly efficient dynamic kinetic resolution is achieved by fast racemization of 1 through the formation of a dienolate followed by kinetic resolution with the chiral catalyst. The utility is demonstrated by the synthesis of key intermediates en route to (−)-cannabidiol.
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•A mathematic model was first developed to describe mass transfer process in RPB.•The outlet SO2 concentration was ultra-low, below 35 mg/m3.•The predicted desulfurization efficiency ...agreed well with the experimental result.•The HTU for RPB is one order of magnitude lower than that of conventional reactors.
In order to reduce SO2 emissions and achieve green utilization of sulfur resources, a desulfurization method of SO2 removal using hydrogen peroxide (H2O2) in rotating packed bed (RPB) is proposed. It can not only achieve the efficient removal of SO2, but also lead to the effective utilization of sulfur resources. A mathematic model was first developed to describe the reaction and mass transfer process between H2O2 and SO2 in RPB. The influences of different operating conditions including RPB rotating speed, H2O2 mass fraction, gas–liquid volumetric flow rate ratio, gas flux, and inlet SO2 concentration on desulfurization performance were studied. Under the optimized conditions, it turned out that the desulfurization efficiency was above 99% and the outlet SO2 concentration was ultra-low, below 35 mg/m3. The validity of the model was confirmed by the fact that most of the predicted desulfurization efficiency agreed well with the experimental result with a deviation within 5%. The height of mass transfer unit HTU for RPB is calculated to be 1.60–2.07 cm, which is one order of magnitude lower than that of conventional reactors, indicating the investment of the desulfurization reactor can be greatly reduced by using RPB.
β-Adrenergic receptor (β-AR) overactivation is a major pathological factor associated with cardiac diseases and mediates cardiac inflammatory injury. Glibenclamide has shown anti-inflammatory effects ...in previous research. However, it is unclear whether and how glibenclamide can alleviate cardiac inflammatory injury induced by β-AR overactivation. In the present study, male C57BL/6J mice were treated with or without the β-AR agonist isoprenaline (ISO) with or without glibenclamide pretreatment. The results indicated that glibenclamide alleviated ISO-induced macrophage infiltration in the heart, as determined by Mac-3 staining. Consistent with this finding, glibenclamide also inhibited ISO-induced chemokines and proinflammatory cytokines expression in the heart. Moreover, glibenclamide inhibited ISO-induced cardiac fibrosis and dysfunction in mice. To reveal the protective mechanism of glibenclamide, the NLRP3 inflammasome was further analysed. ISO activated the NLRP3 inflammasome in both cardiomyocytes and mouse hearts, but this effect was alleviated by glibenclamide pretreatment. Furthermore, in cardiomyocytes, ISO increased the efflux of potassium and the generation of ROS, which are recognized as activators of the NLRP3 inflammasome. The ISO-induced increases in these processes were inhibited by glibenclamide pretreatment. Moreover, glibenclamide inhibited the cAMP/PKA signalling pathway, which is downstream of β-AR, by increasing phosphodiesterase activity in mouse hearts and cardiomyocytes. In conclusion, glibenclamide alleviates β-AR overactivation-induced cardiac inflammation by inhibiting the NLRP3 inflammasome. The underlying mechanism involves glibenclamide-mediated suppression of potassium efflux and ROS generation by inhibiting the cAMP/PKA pathway.
Background
Microvascular invasion (MVI) is associated with poor postoperative survival outcomes in patients with hepatocellular carcinoma (HCC). An Eastern Hepatobiliary Surgery Hospital (EHBH) MVI ...scoring system was established to predict prognosis in patients with HCC with MVI after R0 liver resection (LR) and to supplement the most commonly used classification systems.
Materials and Methods
Patients with HCC with MVI who underwent R0 LR as an initial therapy were included. The EHBH‐MVI score was developed from a retrospective cohort from 2003 to 2009 to form the training cohort. The variables associated with overall survival (OS) on univariate analysis were subsequently investigated using the log‐rank test, and the EHBH‐MVI score was developed using the Cox regression model. It was validated using an internal prospective cohort from 2011 to 2013 as well as three independent external validation cohorts.
Results
There were 1,033 patients in the training cohort; 322 patients in the prospective internal validation cohort; and 493, 282, and 149 patients in the three external validation cohorts, respectively. The score was developed using the following factors: α‐fetoprotein level, tumor encapsulation, tumor diameter, hepatitis B e antigen positivity, hepatitis B virus DNA load, tumor number, and gastric fundal/esophageal varicosity. The score differentiated two groups of patients (≤4, >4 points) with distinct long‐term prognoses outcomes (median OS, 55.8 vs. 19.6 months; p < .001). The predictive accuracy of the score was greater than the other four commonly used staging systems for HCC.
Conclusion
The EHBH‐MVI scoring system was more accurate in predicting prognosis in patients with HCC with MVI after R0 LR than the other four commonly used staging systems. The score can be used to supplement these systems.
Implications for Practice
Microvascular invasion (MVI) is a major determinant of survival outcomes after curative liver resection for patients with hepatocellular carcinoma (HCC). Currently, there is no scoring system aiming to predict prognosis of patients with HCC and MVI after R0 liver resection (LR). Most of the widely used staging systems for HCC do not use MVI as an independent risk factor, and they cannot be used to predict the prognosis of patients with HCC and MVI after surgery. In this study, a new Eastern Hepatobiliary Surgery Hospital (EHBH) MVI scoring system was established to predict prognosis of patients with HCC and MVI after R0 LR. Based on the results of this study, postoperative adjuvant therapy may be recommended for patients with HCC and MVI with an EHBH‐MVI score >4. This score can be used to supplement the currently used HCC classifications to predict postoperative survival outcomes in patients with HCC and MVI.
This article reports a new EHBH‐MVI scoring system, based on preoperative serological and postoperative pathological data, that was developed with the goal of predicting long‐term survival in patients with hepatocellular carcinoma with microvascular tumor invasion and to identify patients who may benefit from adjuvant therapy based on the prediction of poor postoperative prognosis using the new scoring system.
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