56 research outputs found

    ASASSN-13db 2014-2017 Eruption as an Intermediate Luminosity Optical Transient

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    The low mass star ASASSN-13db experienced an EXor outburst in 2013, which identified it as a Young Stellar Object (YSO). Then, from 2014 to 2017 it had another outburst, longer and more luminous than the earlier. We analyze the observations of the second outburst, and compare it to eruptions of Intermediate Luminosity Optical Transients (ILOTs). We show that the decline of the light curve is almost identical to that of the V838 Mon, a prototype of a type of ILOT known as Luminous Red Nova (LRN). This similarity becomes conspicuous when oscillations that are associated with rotation are filtered out from the light curve of ASASSN-13db. We suggest that the eruption was the result of accretion of a proto-planet of a few Earth masses. The proto-planet was shredded by tidal forces before it was accreted onto the YSO, releasing gravitational energy that powered the outburst for ≈800\approx 800 days, and ended in a ≈55\approx 55 days decline phase. When the accretion material started depleting the accretion rate lowered and the eruption light curve declined for almost two months. Then it exhausted completely, creating a sharp break in the light curve. Another possibility is that the mass was a result of an instability in the proto-planetary disk that lead to a large episode of accretion from an inner viscous disk. We find that the variation of the temperature of the outburst is consistent with the surface temperature expected from a depleted viscous accretion disk. The 2014-2017 outburst of ASASSN-13db may be the least energetic ILOT to have been discovered to date, with an energy budget of only ≈1042\approx 10^{42} erg.Comment: Accepted to Galaxie

    IMOS integrated photonics for free-space sensing and communications

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    Photonic integration in a thin InP membrane can offer optical antennas and interferometers monolithically integrated with lasers and detectors. Such approach, with high density and scalability, has shown high potential for applications of free-space sensing and communications.</p

    Collagenous Matrix Supported by A 3D-Printed Scaffold for Osteogenic Differentiation of Dental Pulp Cells

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    Objective A systematic characterization of hybrid scaffolds, fabricated based on combinatorial additive manufacturing technique and freeze-drying method, is presented as a new platform for osteoblastic differentiation of dental pulp cells (DPCs). Methods The scaffolds were consisted of a collagenous matrix embedded in a 3D-printed beta-tricalcium phosphate (β-TCP) as the mineral phase. The developed construct design was intended to achieve mechanical robustness owing to 3D-printed β-TCP scaffold, and biologically active 3D cell culture matrix pertaining to the Collagen extracellular matrix. The β-TCP precursor formulations were investigated for their flow-ability at various temperatures, which optimized for fabrication of 3D printed scaffolds with interconnected porosity. The hybrid constructs were characterized by 3D laser scanning microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and compressive strength testing. Results The in vitro characterization of scaffolds revealed that the hybrid β-TCP/Collagen constructs offer superior DPCs proliferation and alkaline phosphatase (ALP) activity compared to the 3D-printed β-TCP scaffold over three weeks. Moreover, it was found that the incorporation of TCP into the Collagen matrix improves the ALP activity. Significance The presented results converge to suggest the developed 3D-printed β-TCP/Collagen hybrid constructs as a new platform for osteoblastic differentiation of DPCs for craniomaxillofacial bone regeneration

    The possibility of access to the kidneys from posterior axillary line in supine position for percutaneous nephrolithotomy

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    Please cite this article as: Tabibi A, Kashi AH, Mirjalili SAM, Mahmoudnejad N, Kashani P, Salavatipour B, Soltani MH. The possibility of access to the kidneys from posterior axillary line in supine position for percutaneous nephrolithotomy. Novel Biomed 2013;1(2):43-47.Objectives: To evaluate the possibility of access to the kidneys from posterior axillary line (PAL) in supine position for percutaneous nephrolithotomy.Materials and Methods: 102 consecutive patients who were candidated for abdominal CT scan, enrolled in this study. In cases of impossible access, the point on the posterior surface of body which permitted safe access was determined and the percent of movement toward body midline (relative to PAL) was calculated (M.PER).Results: Percutaneous access was simulated from upper and middle calyces of the kidney in 13% and 75% of cases, respectively. Access to the lower region was possible in 90% of right and 79% of left lower calyces, respectively (p=0.03). In cases with impossible access from PAL, the M.PER for a safe access was 46-47% for upper region and 34- 38% for middle and lower calyces of the kidney (P = 0.0001).Conclusions: Access to upper calyces from PAL was limited in some cases regarding to the presence of solid organs. Presence of colon made access impossible in the lower right and left calyces in about 10% and 20% of cases, respectively. In upper region, more deviation toward midline was necessary to establish a safe access compared with middle and lower calyces

    Medical expulsive therapy for pediatric ureteral stones: A meta-analysis of randomized clinical trials

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    To evaluate the efficacy and safety of medical expulsive therapy (MET) for ureteral stones in pediatric patients, Cochrane, PubMed, Web of Science, Scopus, and the reference list of retrieved studies were searched up to September 2022 to identify RCTs on the efficacy of MET. The protocol was prospectively registered at PROSPERO (CRD42022339093). Articles were reviewed, data were extracted by two reviewers, and the differences were resolved by the third reviewer. The risk of bias was assessed using the RoB2. The outcomes, including the stone expulsion rate (SER), stone expulsion time (SET), episode of pain, analgesic consumption, and adverse effects, were evaluated. Six RCTs enrolling 415 patients were included in the meta-analysis. The duration of MET ranged from 19 to 28 days. The investigated medications included tamsulosin, silodosin, and doxazosin. The stone-free rate after 4 weeks in the MET group was 1.42 times that of the control group (RR: 1.42; 95% CI: 1.26–1.61, p < 0.001). The stone expulsion time also decreased by an average of 5.18 days (95% CI: −8.46/−1.89, p = 0.002). Adverse effects were more commonly observed in the MET group (RR: 2.18; 95% CI: 1.28–3.69, p = 0.004). The subgroup analysis evaluating the influence of the type of medication, the stone size, and the age of patients failed to reveal any impact of the aforementioned factors on the stone expulsion rate or stone expulsion time. Alpha-blockers as medical expulsive therapy among pediatric patients are efficient and safe. They increase the stone expulsion rate and decrease the stone expulsion time; however, this included a higher rate of adverse effects, which include headache, dizziness, or nasal congestion

    Importance of long non-coding RNAs in the pathogenesis, diagnosis, and treatment of prostate cancer

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    Long non-coding RNAs (lncRNAs) are regulatory transcripts with essential roles in the pathogenesis of almost all types of cancers, including prostate cancer. They can act as either oncogenic lncRNAs or tumor suppressor ones in prostate cancer. Small nucleolar RNA host genes are among the mostly assessed oncogenic lncRNAs in this cancer. PCA3 is an example of oncogenic lncRNAs that has been approved as a diagnostic marker in prostate cancer. A number of well-known oncogenic lncRNAs in other cancers such as DANCR, MALAT1, CCAT1, PVT1, TUG1 and NEAT1 have also been shown to act as oncogenes in prostate cancer. On the other hand, LINC00893, LINC01679, MIR22HG, RP1-59D14.5, MAGI2-AS3, NXTAR, FGF14-AS2 and ADAMTS9-AS1 are among lncRNAs that act as tumor suppressors in prostate cancer. LncRNAs can contribute to the pathogenesis of prostate cancer via modulation of androgen receptor (AR) signaling, ubiquitin–proteasome degradation process of AR or other important signaling pathways. The current review summarizes the role of lncRNAs in the evolution of prostate cancer with an especial focus on their importance in design of novel biomarker panels and therapeutic targets
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