The Kepler observations indicate that many exoplanets are super-Earths, which brings about a puzzle for the core-accretion scenario. Since observed super-Earths are in the range of critical mass, ...they accrete gas efficiently and become gas giants. Theoretically, super-Earths are predicted to be rare in the core-accretion framework. To resolve this contradiction, we propose that the tidally forced turbulent diffusion may affect the heat transport inside the planet. Thermal feedback induced by turbulent diffusion is investigated. We find that the tidally forced turbulence generates pseudo-adiabatic regions within radiative zones, which pushes the radiative-convective boundaries inward. This decreases the cooling luminosity and enhances the Kelvin-Helmholtz (KH) timescale. For a given lifetime of protoplanetary disks (PPDs), there exists a critical threshold for the turbulent diffusivity, critical. If turb > critical, the KH timescale is longer than the disk lifetime and the planet becomes a super-Earth, rather than a gas giant. We find that even a small value of turbulent diffusion has influential effects on the evolution of super-Earths. The critical increases with the core mass. We further ascertain that, within the minimum-mass extrasolar nebula, critical increases with the semimajor axis. This may explain the feature that super-Earths are common in inner PPD regions, while gas giants are common in outer PPD regions. The predicted envelope mass fraction is not fully consistent with observations. We discuss physical processes, such as late core assembly and mass-loss mechanisms, that may be operating during super-Earth formation.
Bushen-Tiaojing-Fang (BSTJF) is commonly used to treat infertility. This study investigated the effects of BSTJF on the pregnancy outcomes of patients with repeated controlled ovarian stimulation ...(COS), on mitochondrial function, and on oxidative stress in ovarian granulosa cells (GCs) and follicular fluid (FF). The samples and clinical data of 97 patients, including 35 in the control group, 29 in the placebo group and 33 in the BSTJF group, were collected for this study. The mitochondrial ultrastructure, ATP content, mitochondrial DNA (mtDNA) number, 8-hydroxy-2-deoxyguanosine (8-OHdG), Mn-superoxide dismutase (Mn-SOD), glutathione peroxidase (GSH-Px) activity levels, and mRNA expression levels of Mn-SOD, GSH-Px, and nuclear factor erythroid-derived factor 2-related factor 2 (Nrf2) were analyzed. The high-grade embryo (P < 0.001), implantation (P = 0.033), and clinical pregnancy (P = 0.031) rates, as well as the ATP content (P = 0.014), mtDNA number (P = 0.035), GSH-Px activity (P = 0.004 in GCs and P = 0.008 in FF) and mRNA expression levels (P = 0.019), were significantly lower in the placebo group than in the control group, whereas the 8-OHdG content was significantly (P = 0.006 in FF) higher in the placebo group than in the control group. Compared with those in the placebo group, the high-grade embryo rate (P = 0.007), antioxidant enzyme activity (P = 0.037 and 0.036 in Mn-SOD; P = 0.047 and 0.030 in GSH-Px) and mRNA level (P < 0.001 in Nrf2, P = 0.039 in Mn-SOD and P = 0.002 in GSH-Px) were significantly higher in the BSTJF group, as were changes in mitochondrial ultrastructure, ATP (P = 0.040) and mtDNA number (P = 0.013). In conclusion, BSTJF can improve oxidative stress in patients with repeated COS and pregnancy outcomes.
Abstract
We investigate novel transport properties of chiral continuous-time quantum walks (CTQWs) on graphs. By employing a gauge transformation, we demonstrate that CTQWs on chiral chains are ...equivalent to those on non-chiral chains, but with additional momenta from initial wave packets. This explains the novel transport phenomenon numerically studied in (Khalique
et al
2021
New J. Phys.
23
083005). Building on this, we delve deeper into the analysis of chiral CTQWs on the Y-junction graph, introducing phases to account for the chirality. The phase plays a key role in controlling both asymmetric transport and directed complete transport among the chains in the Y-junction graph. We systematically analyze these features through a comprehensive examination of the chiral CTQW on a Y-junction graph. Our analysis shows that the CTQW on Y-junction graph can be modeled as a combination of three wave functions, each of which evolves independently on three effective open chains. By constructing a lattice scattering theory, we calculate the phase shift of a wave packet after it interacts with the potential-shifted boundary. Our results demonstrate that the interplay of these phase shifts leads to the observed enhancement and suppression of quantum transport. The explicit condition for directed complete transport or
100
%
efficiency is analytically derived. Our theory has applications in building quantum versions of binary tree search algorithms.
AbstractObjectiveTo examine the protective effects of appropriate personal protective equipment for frontline healthcare professionals who provided care for patients with coronavirus disease 2019 ...(covid-19).DesignCross sectional study.SettingFour hospitals in Wuhan, China.Participants420 healthcare professionals (116 doctors and 304 nurses) who were deployed to Wuhan by two affiliated hospitals of Sun Yat-sen University and Nanfang Hospital of Southern Medical University for 6-8 weeks from 24 January to 7 April 2020. These study participants were provided with appropriate personal protective equipment to deliver healthcare to patients admitted to hospital with covid-19 and were involved in aerosol generating procedures. 77 healthcare professionals with no exposure history to covid-19 and 80 patients who had recovered from covid-19 were recruited to verify the accuracy of antibody testing.Main outcome measuresCovid-19 related symptoms (fever, cough, and dyspnoea) and evidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, defined as a positive test for virus specific nucleic acids in nasopharyngeal swabs, or a positive test for IgM or IgG antibodies in the serum samples.ResultsThe average age of study participants was 35.8 years and 68.1% (286/420) were women. These study participants worked 4-6 hour shifts for an average of 5.4 days a week; they worked an average of 16.2 hours each week in intensive care units. All 420 study participants had direct contact with patients with covid-19 and performed at least one aerosol generating procedure. During the deployment period in Wuhan, none of the study participants reported covid-19 related symptoms. When the participants returned home, they all tested negative for SARS-CoV-2 specific nucleic acids and IgM or IgG antibodies (95% confidence interval 0.0 to 0.7%).ConclusionBefore a safe and effective vaccine becomes available, healthcare professionals remain susceptible to covid-19. Despite being at high risk of exposure, study participants were appropriately protected and did not contract infection or develop protective immunity against SARS-CoV-2. Healthcare systems must give priority to the procurement and distribution of personal protective equipment, and provide adequate training to healthcare professionals in its use.
Telomerase plays a pivotal role in tumorigenesis by both telomere‐dependent and telomere‐independent activities, although the underlying mechanisms are not completely understood. Using single‐sample ...gene set enrichment analysis (ssGSEA) across 9,264 tumour samples, we observe that expression of telomerase reverse transcriptase (TERT) is closely associated with immunosuppressive signatures. We demonstrate that TERT can activate a subclass of endogenous retroviruses (ERVs) independent of its telomerase activity to form double‐stranded RNAs (dsRNAs), which are sensed by the RIG‐1/MDA5‐MAVS signalling pathway and trigger interferon signalling in cancer cells. Furthermore, we show that TERT‐induced ERV/interferon signalling stimulates the expression of chemokines, including CXCL10, which induces the infiltration of suppressive T–cell populations with increased percentage of CD4+ and FOXP3+ cells. These data reveal an unanticipated role for telomerase as a transcriptional activator of ERVs and provide strong evidence that TERT‐mediated ERV/interferon signalling contributes to immune suppression in tumours.
Synopsis
Expression of telomerase reverse transcriptase is closely associated with immunosuppressive signatures in tumours. TERT induces dsRNAs by bidirectional transcription of ERVs, which triggers interferon response and attracts suppressive T cell populations.
TERT activates a subclass of ERVs to form dsRNAs independent of its telomerase activity by interacting with Sp1.
dsRNAs transcribed from TA‐ERVs trigger interferon response via RIG‐1/MDA5‐MAVS signalling.
Increased chemokine secretion attracts suppressive T cells and establishes an immunosuppressed microenvironment.
Expression of telomerase reverse transcriptase is closely associated with immunosuppressive signatures in tumours. TERT induces dsRNAs by bidirectional transcription of ERVs, which triggers interferon response and attracts suppressive T cell populations.
Sensitivity that won't break the bank: The addition of an anti‐lysozyme DNA aptamer (a polyanion) to a cationic perylene probe that exists in aqueous solution as a mixture of the fluorescent free ...monomer and aggregate forms shifted the equilibrium and resulted in fluorescence quenching (see schematic representation). The subsequent introduction of lysozyme weakened DNA binding to the perylene aggregates and led to fluorescence recovery.
Triaxial loading and unloading tests on marble specimens under different stress paths were conducted to investigate the characteristics of energy evolution in rock deformation process. Results show ...that tensile failure occurred in rock specimens under uniaxial compression, while shear failure dominated under triaxial loading and unloading. The energy storage limit of rock specimens under triaxial loading was higher than that under uniaxial compression or triaxial unloading. A nonlinear energy evolution model of rock was established based on the interaction mechanism of energy accumulation and energy dissipation. Results from the theoretical model are in good agreement with the test results. Since the evolution of energy was characterised by bifurcation and chaos, a strain value corresponding to the energy iterative growth factor at the first bifurcation of the energy equation was chosen as the initiation criterion for rock failure. The critical strain accounted for 77%, 72–76%, and 72–81% of the peak strain under uniaxial compression, triaxial loading, and unloading, respectively.
Cup‐shaped molecules are of great interest due to their appealing architectures and properties. Compared with widely studied calixarenes, polyoxometalate‐based cup‐shaped molecules currently remain a ...virgin land waiting for exploration. In this work, we report the first discovery of two giant cup‐shaped inorganic–organic hybrid polyoxoniobates (PONbs) of {Cu12Nb120} and {Cd16Nb128}. The former integrates three tricyclic Nb24 clusters and a hexacyclic Nb48 cluster into a cup‐shaped molecule via a Cu12 metallacalixarene, while the latter unifies two tricyclic Nb24 clusters and a brand‐new pentacyclic Nb40 cluster into another cup‐shaped molecule via a hybrid Cd16 unit. With 132 and 144 metal centers, {Cu12Nb120} and {Cd16Nb128} show the largest two inorganic–organic hybrid PONbs known to date.
Calixarene‐like polyoxoniobates: Two unprecedented giant calixarene‐like polyoxoniobate (PONb) nanocups based on multiple macrocyclic clusters have been made, showing the fusion of two areas of metallacalixarene and PONb chemistry. The two molecular nanocups are by far the largest two inorganic–organic hybrid PONbs and hold promise for developing largely unexplored inorganic–organic hybrid PONb chemistry.
Telomerase plays a pivotal role in the pathology of aging and cancer by controlling telomere length and integrity. However, accumulating evidence indicates that telomerase reverse transcriptase may ...have fundamental biological functions independent of its enzymatic activity in telomere maintenance. In this study, the ectopic expression of human telomerase reverse transcriptase (hTERT) and its catalytic mutant hTERT K626A induced cancer cell invasion accompanied by the up‐regulation of the metalloproteinases (MMPs) MMP1, ‐3, ‐9, and ‐10. Both hTERT and hTERT K626A induced MMP9 mRNA expression and promoter activity in an NF‐κB‐dependent manner. hTERT and hTERT K626A also regulated the expression of several NF‐κB target genes in cancer cell lines. Furthermore, both hTERT and hTERT K626A interacted with NF‐κB p65 and increased NF‐κB p65 nuclear accumulation and DNA binding. A mammalian 1‐hybrid assay showed a functional interplay between hTERT and NF‐κB p65 that may mediate NF‐κB‐dependent transcription activation in cells. Together, these data reveal a telomere‐independent role for telomerase as a transcriptional modulator of the NF‐κB signaling pathway and a possible contributor to cancer development and progression.—Ding, D., Xi, P., Zhou, J., Wang, M., Cong, Y.‐S. Human telomerase reverse transcriptase regulates MMP expression independently of telomerase activity via NF‐κB‐dependent transcription. FASEB J. 27, 4375–4383 (2013). www.fasebj.org
In this study, we examine the effectiveness of operational-level environmental management (EM) practices and their long-term impacts. Using data from the U.S. Environmental Protection Agency (EPA)'s ...Toxic Release Inventory, we assess how different source reduction practices utilised at the operational processes of U.S. industrial facilities affect their environmental performance. We find that those operational-level EM practices have varying impacts on immediate and long-term environmental improvements. Practices such as good operating practices, inventory control, process modification, spill/leak prevention, and cleaning/degreasing procedures are found to be able to help facilities improve their efficiency in pollution and waste reduction in the year of implementation. Additionally, good operating practices and spill/leak prevention can generate continuous improvement in pollution and waste reduction even after the implementation year. But at the facilities that adopt process modifications and cleaning/degreasing procedures, the improvements achieved from initial adoption can only be maintained at the same level afterwards. Moreover, the EM practice of inventory control only possesses temporary effectiveness limited to the implementation year while the efficiency of pollution and waste reduction at the facilities that applied this practice fell back to the level before the implementation. The implications of the results are discussed.
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