Abstract
We develop a physical framework for interpreting complex circumstellar patterns whorled around asymptotic giant branch (AGB) stars by investigating stable, coplanar triple systems using ...hydrodynamic and particle simulations. The introduction of a close tertiary body causes an additional periodic variation in the orbital velocity and trajectory of the AGB star. As a result, the circumstellar outflow builds a fine non-Archimedean spiral pattern superimposed upon the Archimedean spiral produced by the outer binary alone. This fine spiral can be approximated by off-centered circular rings that become tangent to each other at the location of the Archimedean spiral. The superimposed fine pattern fades out relatively quickly as a function of distance from the center of the system, in contrast to the dominant Archimedean spiral pattern, which presents a much slower fractional density decrease with radius. The different rates of radial decrease of the density contrast in the two superimposed patterns, coupled with their different time and spatial scales, lead to an apparent, but illusory radial change in the observed pattern interval, as has been reported, for example, in CW Leo. The function describing the detailed radial dependence of the expansion velocity is different in the two patterns, which may be used to distinguish them. The shape of the circumstellar whorled pattern is further explored as a function of the orbital eccentricity and the inner companion’s mass. Although this study is confined to stable, coplanar triple systems, the results are likely applicable to moderately noncoplanar systems and open interesting avenues for studying noncoplanar systems.
Abstract
Although episodic star formation (SF) has been suggested for nearby SF regions, a panoramic view of the recent episodic SF history in the solar neighborhood is still missing. By uniformly ...constraining the slope
α
of infrared spectral energy distributions (SEDs) of young stellar objects (YSOs) in the 13 largest Gould’s Belt (GB) protoclusters surveyed by the Spitzer Space Telescope, we have constructed a cluster-averaged histogram of
α
representing the YSO evolution lifetime as a function of the
α
value. Complementary to the traditional SED classification scheme (
0
,
i
,
f
,
ii
, and
iii
) that is based on different
α
values, a staging scheme (A, B, C, D, and E) of SED evolution is proposed on the basis of the
α
statistical features that can be better matched to the physical stages of disk dissipation and giant planet formation. This has also allowed us to unravel the fluctuations of SF rate (SFR) in the 3 Myr history of these GB protoclusters. Diverse evolutionary patterns such as single peaks, double peaks, and ongoing acceleration of SFR are revealed. The SFR fluctuations are between 20% and 60% (∼40% on average) and no dependence on the average SFR or the number of SFR episodes is found. However, spatially close protoclusters tend to have similar SFR fluctuation trends, indicating that the driving force of the fluctuations should be at size scales beyond the typical cluster sizes of several parsecs.
Hyssopus cuspidatus Boriss has been used to treat bronchial asthma for many years in Uighur medicine. JAX2, an ethanol extract from this plant, has effectiveness against bronchial asthma. However, ...the molecular basis for the anti-inflammatory effects of JAX2 remains unclear.
This study aimed to evaluate the mechanism of JAX2 against bronchial asthma.
We established an asthma model in rats using ovalbumin (OVA), and an inflammatory model in RAW264.7 cells using lipopolysaccharide (LPS) stimulation. To evaluate the anti-inflammatory effects of JAX2, the concentrations of tumor necrosis factor (TNF)-α, interleukin (IL)-4, IL-6, IL-17, eotaxin and immunoglobulin (Ig)E were measured by enzyme-linked immunosorbent assay (ELISA). Cell viability was investigated by the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)2H-tetrazolium, inner salt (MTS) assay. Further, nitric oxide (NO) and reactive oxygen species (ROS) were determined using Griess reagent and 2,7-dichlorofluorescein diacetate. The phosphorylation of p-extracellular signal-regulated kinase (ERK), p-Jun-NH2-terminal kinase (JNK), p38 kinases (p38) and p-inhibitor of nuclear factor kappa-B kinase (IKK), and nuclear translocation of p-p65 kinases (p-p65) were determined by immunofluorescence to uncover the effects of JAX2 on the Mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) signaling pathways.
After JAX2 administration to rats, Interferon (IFN)-γ concentrations in BALF increased significantly. Further, the concentrations of TNF-α, IL-4, IL-6, IL-17 and eotaxin in BALF, and IgE in serum decreased. JAX2 decreased TNF-α, IL-6 and NO in cell supernatant, and reduced ROS intracellularly. Concurrently, IFN-γ concentrations increased in cell supernatant significantly. In LPS-induced RAW264.7 cells, JAX2 inhibited phosphorylation of p-ERK, p-JNK and p-38 MAPK. The subsequent phosphorylation of p-IKK and nuclear translocation of the p-p65 subunit of NF-κB were also suppressed.
Based on these findings, we believe that JAX2 has both preventive and treatment effects in bronchial asthma. Furthermore, in the RAW264.7 cell inflammatory model, JAX2 also inhibited NF-κB and MAPK signaling pathways.
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ABSTRACT
We present a statistical study of a sample of 17 hub-filament-system (HFS) clouds of high-mass star formation using high-angular resolution (∼1–2 arcsec) ALMA 1.3 and 3 mm continuum data. ...The sample includes eight infrared (IR)-dark and nine IR-bright types, which correspond to an evolutionary sequence from the IR-dark to IR-bright stage. The central massive clumps and their associated most massive cores are observed to follow a trend of increasing mass (M) and mass surface density (Σ) with evolution from the IR-dark to IR-bright stage. In addition, a mass-segregated cluster of young stellar objects (YSOs) are revealed in both IR-dark and IR-bright HFSs with massive YSOs located in the hub and the population of low-mass YSOs distributed over larger areas. Moreover, outflow feedback in all HFSs are found to escape preferentially through the inter-filamentary diffuse cavities, suggesting that outflows would render a limited effect on the disruption of the HFSs and ongoing high-mass star formation therein. From the above observations, we suggest that high-mass star formation in the HFSs can be described by a multiscale mass accretion/transfer scenario, from hub-composing filaments through clumps down to cores, which can naturally lead to a mass-segregated cluster of stars.
Dexmedetomidine (DEX) is known to provide neuroprotection against cerebral ischemia and reperfusion injury (CIRI), but the exact mechanisms remain unclear. This study was conducted to investigate ...whether DEX pretreatment conferred neuroprotection against CIRI by inhibiting neuroinflammation through the JAK2/STAT3 signaling pathway. Middle cerebral artery occlusion (MCAO) was performed to establish a cerebral ischemia/reperfusion (I/R) model. Specific-pathogen-free male Sprague-Dawley rats were randomly divided into Sham, I/R, DEX, DEX + IL-6, and AG490 (a selective inhibitor of JAK2) groups. The Longa score, TTC staining, and HE staining were used to evaluate brain damage. ELISA was used to exam levels of TNF-alpha. Western blotting was used to assess the levels of JAK2, phosphorylated-JAK2 (p-JAK2), STAT3, and phosphorylated-STAT3 (p-STAT3). Our results suggested that both pretreatment with DEX and AG490 decreased the Longa score and cerebral infarct areas following cerebral I/R. After treatment with IL-6, the effects of DEX on abrogating these pathological changes were reduced. HE staining revealed that I/R-induced neuronal pathological changes were attenuated by DEX application, consistent with the AG490 group. However, these effects of DEX were abolished by IL-6. Furthermore, TNF-alpha levels were significantly increased in the I/R group, accompanied by an increase in the levels of the p- JAK2 and p-STAT3. DEX and AG490 pretreatment down-regulated the expressions of TNF-alpha, p-JAK2, and p-STAT3. In contrast, the down-regulation of TNF-alpha, p-JAK2, and p-STAT3 induced by DEX was reversed by IL-6. Collectively, our results indicated that DEX pretreatment conferred neuroprotection against CIRI by inhibiting neuroinflammation via negatively regulating the JAK2/STAT3 signaling pathway. Key words: Dexmedetomidine; Cerebral ischemia/reperfusion injury; Neuroprotection; JAK2/STAT3 signaling pathway; Inflammation
In recent years, the diagnosis and treatment of colorectal cancer (CRC) have been continuously improved, but the mortality rate continues to be high, especially in advanced patients. CRC patients ...usually have no obvious symptoms in the early stage and are already in the advanced stage when they are diagnosed. The 5-year survival rate is only 10%. The blood markers currently used to screen for CRC, such as carcinoembryonic antigen and carbohydrate antigen 19-9, have low sensitivity and specificity, whereas other methods are invasive or too expensive. As a result, recent research has shifted to the development of minimally invasive or noninvasive biomarkers in the form of body fluid biopsies. Non-coding RNA molecules are composed of microRNAs, long non-coding RNAs, small nucleolar RNAs, and circular RNAs, which have important roles in the occurrence and development of diseases and can be utilized for the early diagnosis and prognosis of tumors. In this review, we focus on the latest findings of mRNA-ncRNA as biomarkers for the diagnosis and prognosis of CRC, from fluid to tissue level.
Abstract Background Postoperative delirium (POD) is a common complication among elderly patients after surgery. The Naples Prognostic Score (NPS), a novel prognostic marker based on ...immune-inflammatory and nutritional status, was widely used in the assessment of the prognosis of surgical patients. However, no study has evaluated the relationship between NPS and POD. The aim of this article was to investigate the association between NPS and POD and test the predictive efficacy of preoperative NPS for POD in elderly patients with gastrointestinal tumors. Materials and methods In the present study, we retrospectively collected perioperative data of 176 patients (≥ 60 years) who underwent elective gastrointestinal tumor surgery from June 2022 to September 2023. POD was defined according to the chart-based method and the NPS was calculated for each patient. We compared all the demographics and laboratory data between POD and non-POD groups. Univariate and multivariate logistic regression analysis was used to explore risk factors of POD. Moreover, the accuracy of NPS in predicting POD was further assessed by utilizing receiver operating characteristic (ROC) curves. Results 20 had POD (11.4%) in a total of 176 patients, with a median age of 71 (65–76). The outcomes by univariate analysis pointed out that age, ASA status ≥ 3, creatinine, white blood cell count, fasting blood glucose (FBG), and NPS were associated with the risk of POD. Multivariate logistic regression analysis further showed that age, ASA grade ≥ 3, FBG and NPS were independent risk factors of POD. Additionally, the ROC curves revealed that NPS allowed better prognostic capacity for POD than other variables with the largest area under the curve (AUC) of 0.798, sensitivity of 0.800 and specificity of 0.667, respectively. Conclusion Age, ASA grade ≥ 3, and FBG were independent risk factors for POD in the elderly underwent gastrointestinal tumor surgery. Notably, the preoperative NPS was a more effective tool in predicting the incidence of POD, but prospective trials were still needed to further validate our conclusion. Trial registration The registration information for the experiment was shown below. (date: 3rd January 2024; number: ChiCTR2400079459)
As a novel class of endogenous non-coding RNAs discovered in recent years, circular RNAs (circRNAs) are highly conserved and stable covalently closed ring structures with no 5'-end cap or 3'-end ...poly(A) tail. CircRNAs are formed by reverse splicing, mainly by means of a noose structure or intron complementary pairing. Exosomes are tiny discoid vesicles with a diameter of 40-100 nm that are secreted by cells under physiological and pathological conditions. Exosomes play an important role in cell-cell communication by carrying DNA, microRNAs, mRNAs, proteins and circRNAs. In this review, we summarize the biological functions of circRNAs and exosomes, and further reveal the potential roles of exosomal circRNAs in different diseases, providing a scientific basis for the diagnosis, treatment, and prognosis of a wide variety of diseases.
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