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1.
Nature ; 625(7994): 253-258, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38200292

RESUMEN

Neutron stars and stellar-mass black holes are the remnants of massive star explosions1. Most massive stars reside in close binary systems2, and the interplay between the companion star and the newly formed compact object has been theoretically explored3, but signatures for binarity or evidence for the formation of a compact object during a supernova explosion are still lacking. Here we report a stripped-envelope supernova, SN 2022jli, which shows 12.4-day periodic undulations during the declining light curve. Narrow Hα emission is detected in late-time spectra with concordant periodic velocity shifts, probably arising from hydrogen gas stripped from a companion and accreted onto the compact remnant. A new Fermi-LAT γ-ray source is temporally and positionally consistent with SN 2022jli. The observed properties of SN 2022jli, including periodic undulations in the optical light curve, coherent Hα emission shifting and evidence for association with a γ-ray source, point to the explosion of a massive star in a binary system leaving behind a bound compact remnant. Mass accretion from the companion star onto the compact object powers the light curve of the supernova and generates the γ-ray emission.

2.
Nature ; 623(7989): 927-931, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37968403

RESUMEN

In recent years, certain luminous extragalactic optical transients have been observed to last only a few days1. Their short observed duration implies a different powering mechanism from the most common luminous extragalactic transients (supernovae), whose timescale is weeks2. Some short-duration transients, most notably AT2018cow (ref. 3), show blue optical colours and bright radio and X-ray emission4. Several AT2018cow-like transients have shown hints of a long-lived embedded energy source5, such as X-ray variability6,7, prolonged ultraviolet emission8, a tentative X-ray quasiperiodic oscillation9,10 and large energies coupled to fast (but subrelativistic) radio-emitting ejecta11,12. Here we report observations of minutes-duration optical flares in the aftermath of an AT2018cow-like transient, AT2022tsd (the 'Tasmanian Devil'). The flares occur over a period of months, are highly energetic and are probably nonthermal, implying that they arise from a near-relativistic outflow or jet. Our observations confirm that, in some AT2018cow-like transients, the embedded energy source is a compact object, either a magnetar or an accreting black hole.

3.
Sci Adv ; 9(23): eadi1405, 2023 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-37285439

RESUMEN

Long-duration gamma-ray bursts (GRBs) are powerful cosmic explosions, signaling the death of massive stars. Among them, GRB 221009A is by far the brightest burst ever observed. Because of its enormous energy (Eiso ≈ 1055 erg) and proximity (z ≈ 0.15), GRB 221009A is an exceptionally rare event that pushes the limits of our theories. We present multiwavelength observations covering the first 3 months of its afterglow evolution. The x-ray brightness decays as a power law with slope ≈t-1.66, which is not consistent with standard predictions for jetted emission. We attribute this behavior to a shallow energy profile of the relativistic jet. A similar trend is observed in other energetic GRBs, suggesting that the most extreme explosions may be powered by structured jets launched by a common central engine.

4.
Nature ; 617(7961): 477-482, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-37198310

RESUMEN

Type Ia supernovae (SNe Ia) are thermonuclear explosions of degenerate white dwarf stars destabilized by mass accretion from a companion star1, but the nature of their progenitors remains poorly understood. A way to discriminate between progenitor systems is through radio observations; a non-degenerate companion star is expected to lose material through winds2 or binary interaction3 before explosion, and the supernova ejecta crashing into this nearby circumstellar material should result in radio synchrotron emission. However, despite extensive efforts, no type Ia supernova (SN Ia) has ever been detected at radio wavelengths, which suggests a clean environment and a companion star that is itself a degenerate white dwarf star4,5. Here we report on the study of SN 2020eyj, a SN Ia showing helium-rich circumstellar material, as demonstrated by its spectral features, infrared emission and, for the first time in a SN Ia to our knowledge, a radio counterpart. On the basis of our modelling, we conclude that the circumstellar material probably originates from a single-degenerate binary system in which a white dwarf accretes material from a helium donor star, an often proposed formation channel for SNe Ia (refs. 6,7). We describe how comprehensive radio follow-up of SN 2020eyj-like SNe Ia can improve the constraints on their progenitor systems.

5.
Nature ; 617(7959): 55-60, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-37138107

RESUMEN

Planets with short orbital periods (roughly under 10 days) are common around stars like the Sun1,2. Stars expand as they evolve and thus we expect their close planetary companions to be engulfed, possibly powering luminous mass ejections from the host star3-5. However, this phase has never been directly observed. Here we report observations of ZTF SLRN-2020, a short-lived optical outburst in the Galactic disk accompanied by bright and long-lived infrared emission. The resulting light curve and spectra share striking similarities with those of red novae6,7-a class of eruptions now confirmed8 to arise from mergers of binary stars. Its exceptionally low optical luminosity (approximately 1035 erg s-1) and radiated energy (approximately 6.5 × 1041 erg) point to the engulfment of a planet of fewer than roughly ten Jupiter masses by its Sun-like host star. We estimate the Galactic rate of such subluminous red novae to be roughly between 0.1 and several per year. Future Galactic plane surveys should routinely identify these, showing the demographics of planetary engulfment and the ultimate fate of planets in the inner Solar System.

8.
Indian J Dermatol ; 68(6): 634-641, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38371584

RESUMEN

Introduction: Spongiosis is defined as intercellular edema and vesicles in the epidermis. Histopathology is the gold standard for the diagnosis of spongiotic disorders. Clinical diagnosis of eczema is sometimes unclear and confused with other dermatoses; histopathology often shows spongiotic tissue reaction patterns; such conditions are called spongiotic disorders. It is challenging for a dermatologist to make the correct diagnosis noninvasively with a dermoscope and thus we have taken up the study to correlate the dermoscopic and histopathological findings in spongiotic disorders to set dermoscopic criteria for the diagnosis. Objective: To study the dermoscopic features of spongiotic disorders and correlate clinical, dermoscopic, and histopathological findings. Materials and Methods: Two hundred fifty two patients, with history and clinical presentation suggesting eczema were enrolled. They were classified as Acute (<6 weeks), Subacute (6 weeks to 3 months), and Chronic (>3 months) eczemas based on duration. Dermoscopy and skin biopsy were performed on representative lesions. Data were compiled and statistically analyzed using frequency distribution and Chi-square test. Results: We correlated the diagnosis based on acute, subacute, and chronic with three modalities, clinical examination, dermoscopy, and histopathology. On clinical examination, acute (27.4%), subacute (42.9%), and chronic (29.7%) dermatitis. On dermoscopy, acute (28.5%), subacute (40.4%), and chronic (31.1%) dermatitis. On histopathology, acute (29.5%), subacute (44.2%), and chronic (26.3%) spongiosis. A positive correlation of 99%, 96.2%, and 95% was observed on dermoscopy and histopathology, in acute, subacute, and chronic eczemas, respectively. Dermoscopy of acute eczemas showed linear vessels (100%) and red background (100%). White-Clods (98.9%) and excoriation marks (70.1%). Dermoscopy of subacute eczemas showed white scales (99.1%), irregular pigment network (98.3%), vascular changes with irregular dots (97.4%), a brown-white background (93.1%), and black/brown/grey dots (91.4%). Dermoscopy of chronic eczema showed brown-white background (100%), irregular pigment network (100%), and black/brown/grey blotches (100%). Conclusion: Definitive dermoscopic patterns are observed consistently with spongiotic diseases and these can be used additionally to set dermoscopic criteria and confirm the diagnosis. Also, dermoscopic findings are well correlated with the already established histopathological features.

9.
Artículo en Inglés | MEDLINE | ID: mdl-38394424

RESUMEN

ABSTRACT: The breast can be affected by a variety of specific and unique disorders during pregnancy and lactation. One of these disorders is spontaneous infarction of the breast which is a rare condition seen in physiologically hyperplastic mammary tissue associated with pregnancy and lactation. The causes and mechanism of the development of breast infarct remain largely unknown. Only 25 cases of breast infarct have been reported in the English literature. Phyllodes tumor is uncommon in pregnant women, and to date, only one report of spontaneous infarction of the phyllodes tumor has been reported in a postpartum woman. In this report, we describe the first case of coexistent infarction of the hyperplastic breast parenchyma with infarction of phyllodes tumor in a 25-year-old female.

10.
Artículo en Inglés | MEDLINE | ID: mdl-38391384

RESUMEN

ABSTRACT: Appendicitis is the most common cause of the acute abdomen and usually occurs because of the fecalith in adults and lymphoid hyperplasia in childhood. Gastric cancer metastasis to the appendix is a rare condition that might be present with symptoms of acute appendicitis. The English literature describes only thirteen cases of gastric carcinoma metastasizing to the appendix and presenting as acute appendicitis. In this report, we describe the first case of metastatic signet ring cell carcinoma of appendix presenting with clinical features of acute appendicitis.

11.
Nature ; 612(7940): 430-434, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36450988

RESUMEN

Tidal disruption events (TDEs) are bursts of electromagnetic energy that are released when supermassive black holes at the centres of galaxies violently disrupt a star that passes too close1. TDEs provide a window through which to study accretion onto supermassive black holes; in some rare cases, this accretion leads to launching of a relativistic jet2-9, but the necessary conditions are not fully understood. The best-studied jetted TDE so far is Swift J1644+57, which was discovered in γ-rays, but was too obscured by dust to be seen at optical wavelengths. Here we report the optical detection of AT2022cmc, a rapidly fading source at cosmological distance (redshift z = 1.19325) the unique light curve of which transitioned into a luminous plateau within days. Observations of a bright counterpart at other wavelengths, including X-ray, submillimetre and radio, supports the interpretation of AT2022cmc as a jetted TDE containing a synchrotron 'afterglow', probably launched by a supermassive black hole with spin greater than approximately 0.3. Using four years of Zwicky Transient Facility10 survey data, we calculate a rate of [Formula: see text] per gigapascals cubed per year for on-axis jetted TDEs on the basis of the luminous, fast-fading red component, thus providing a measurement complementary to the rates derived from X-ray and radio observations11. Correcting for the beaming angle effects, this rate confirms that approximately 1 per cent of TDEs have relativistic jets. Optical surveys can use AT2022cmc as a prototype to unveil a population of jetted TDEs.

13.
J Ayurveda Integr Med ; 13(3): 100619, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36027804

RESUMEN

BACKGROUND: In routine, Ayurveda practitioners prefer classical pharmaceutical form of herbal medicines in compare to modern extracts. OBJECTIVE: To explore the difference of efficiency between whole drug powder of Phyllanthus niruri plus root decoction of Sida cordifolia and modern extracts of the same in compared to placebo in patients of diabetic poly-neuropathy. MATERIAL AND METHODS: A randomized, partly-double-blinded, placebo-controlled trial evaluated the efficacy of two different pharmaceutical forms of herbal medicines over placebo in 90 patients (30 in each group) of diabetic sensory polyneuropathy for first three weeks period. After three weeks, active herbal medication groups were continued with their assigned medicaments for next 5 weeks period and all placebo-patients were randomized again into 2 groups of active medication and treated for next 8 weeks. Patients were assessed with Neuropathy Total Symptom Score 6 and sensation thresholds. RESULTS: Significant effect of both form of herbal medicines over placebo was found in aching pain [F (2, 49) = 6.79, p = 0.002], allodynia [F (2, 59) = 6.74, p = 0.002], burning pain [F (2, 82) = 14.66, p < 0.0001], numbness [F (2, 77) = 16.37, p < 0.0001] and pricking pain [F (2, 50) = 14.23, p < 0.0001]. After the 8 weeks period, no significant difference was identified between the effect of both the herbal treatment on aching pain (U = 220, p = 0.03), allodynia (U = 421.5, p = 0.29), burning pain (U = 881.5, p = 0.846), numbness (U = 778, p = 0.92) and pricking pain (U = 260, p = 0.15). CONCLUSION: Both herbal groups have significant effect to reduce NTSS-6 score in compare to placebo. No significant difference found between the effect of two different pharmaceutical forms of Phyllanthus niruri and S. cordifolia.

14.
Phys Rev Lett ; 128(22): 221101, 2022 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-35714251

RESUMEN

The origins of the high-energy cosmic neutrino flux remain largely unknown. Recently, one high-energy neutrino was associated with a tidal disruption event (TDE). Here we present AT2019fdr, an exceptionally luminous TDE candidate, coincident with another high-energy neutrino. Our observations, including a bright dust echo and soft late-time x-ray emission, further support a TDE origin of this flare. The probability of finding two such bright events by chance is just 0.034%. We evaluate several models for neutrino production and show that AT2019fdr is capable of producing the observed high-energy neutrino, reinforcing the case for TDEs as neutrino sources.

15.
Am J Clin Exp Urol ; 9(6): 435-455, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34993264

RESUMEN

For organ-confined prostate cancer, socioeconomic factors influencing Magnetic Resonance Imaging (MRI)-guided biopsy utilization and downstream prostate cancer patients' care are unknown. This retrospective, observational cohort study used the New York Statewide Planning and Research Cooperative System (SPARCS) billing-code driven database to examine the impact of prostate patients' socioeconomic characteristics on prostate cancer care defined as initial biopsy, 2-month post-biopsy cancer diagnoses, and within 1-year cancer-related intervention, controlling for other risk factors. From 2011-2017, the population studied (n = 18,253) included all New York State-based, male, residents aged 18 to 75 without a prior prostatectomy receiving a first-time biopsy; 760 such patient records in 2016 were removed due to data quality concerns. Major exposures included patient age, race, ethnicity and insurance. The major outcome included receipt of MRI biopsy versus standard biopsy and for these sub-populations, subsequent 2-month post-biopsy metastatic versus non-metastatic prostate cancer diagnosis and within 1-year prostate cancer treatment (prostatectomy with or without radiation versus prostatectomy-only) were compared using dichotomous (primary) and time-to-event (secondary) endpoints. Of 17,493 patients with a first-time prostate biopsy, 3.89% had MRI guided biopsies; of the 17,128 patients with no pre-biopsy cancer diagnosis, the subsequent prostate cancer diagnosis rate was 42.59%. For 6,754 non-metastatic prostate cancer patients with 1-year follow-up, 1,674 (24.79%) received surgery (with or without radiation) and 495 (7.33%) received radiation-only. Holding other factors constant, multivariable regression models identified that race-insurance was a primary predictor of MRI-guided biopsy use. Compared to commercially insured White patients, Black patients across all insurance categories received MRI-guided biopsies less frequently; Commercially insured and self-pay Black patients also had increased chance of prostate cancer diagnosis. Across all insurers, Black patients had lower likelihood of prostatectomies. In contrast, Black and White patients with government insurance were more likely to have within 1-year radiation-only treatments versus commercially insured White patients. Thus, across the prostate cancer care continuum, race-insurance affected prostate cancer-related service utilization. Future research should evaluate the generalizability of these New York State findings.

16.
Heliyon ; 5(7): e02021, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31312733

RESUMEN

Antimicrobial resistance (AMR) is a serious concern in pathogenic bacteria. As a new approach to addressing AMR, we report here the green synthesis of vanillin capped gold nanoparticles (VAuNPs) using the popular flavouring molecule vanillin (C8H8O3) as a reducing and capping agent. Physicochemical characterization revealed that the synthesised VAuNPs were stable and crystalline in nature. VAuNPs were non-bactericidal even at high concentration (>2000 µg/ml). The antibiotic potentiation activity was studied in combination with seven widely used antibiotics against extremely drug resistant (XDR) Pseudomonas aeruginosa. Major reductions in minimum inhibitory concentrations (MIC, 10-14-folds) of the antibiotics meropenem (10 fold) and trimethoprim (14 fold) were observed in the presence of VAuNPs (50 µg/ml). Furthermore, it was found that VAuNPs in combination with meropenem or trimethoprim provided 1.5-3-fold better potentiation effects than that of vanillin alone. Use of an ethidium bromide agar cart wheel assay indicated that VAuNPs can block the activity of efflux pumps. High reduction in the MIC of antibiotics was therefore attributed to the efflux pump repression activity of VAuNPs. Further, RT-qPCR of clinically relevant MexAB-OprM efflux pump components showed down-regulation in mexB and OprM transcripts in VAuNPs treated P. aeruginosa clinical isolates. Our results reveal that VAuNPs impart susceptibility to the last line antibiotics meropenem, trimethoprim and few widely used antibiotics in XDR P. aeruginosa clinical isolates that display resistance to these antibiotics. Therefore, this study indicate the ability of VAuNPs and vanillin to be used as antibiotic adjuvants for inhibiting bacterial efflux pumps to potentiate antibiotics for addressing AMR problem affecting human health and environment.

17.
J Indian Prosthodont Soc ; 19(2): 180-183, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31040553

RESUMEN

This paper describes indigenously developed digital Gothic arch tracer for the acquisition of centric jaw relation in patient. The developed tracer eliminates disadvantages of intra-oral tracing and makes it more suitable for recording centric relation in patients. The system also makes real-time monitoring of tracing possible in intraoral tracing. This also opens various avenues for research in removable prosthodontics.

18.
Hypertens Pregnancy ; 37(4): 204-211, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30257118

RESUMEN

OBJECTIVE: To assess brachial artery distensibility and associated factors in healthy primigravidas. METHODS: We assessed brachial artery distensibility using the DynaPulse 5,000A in 37 women each trimester, and 6-8 weeks and 1-5 years postpartum. Associations with physical and cardiometabolic measures were considered. RESULTS: Mean (SE) brachial artery distensibility (%Δ/mmHg) decreased (stiffened) from 7.50 (0.20) 12-14 weeks to 6.93 (0.22) 36-38 weeks (p < .01) and returned to baseline 7.52 (0.44) at 2.7 years postpartum. Weight gain and greater cardiac output were significantly related to greater stiffness. CONCLUSION: Increased weight and cardiac output of pregnancy were associated with brachial artery stiffening.


Asunto(s)
Presión Sanguínea/fisiología , Arteria Braquial/fisiología , Gasto Cardíaco/fisiología , Rigidez Vascular/fisiología , Aumento de Peso/fisiología , Adulto , Femenino , Humanos , Embarazo , Adulto Joven
19.
J Ayurveda Integr Med ; 9(1): 61-63, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29395893

RESUMEN

Severe knee flexion contracture greater than 80° is rare and challenging to manage. It is a common complication which occurs after a prolonged course of the rheumatoid arthritis. The case was a 45 year old female patient of Ama vata (rheumatoid arthritis) with sandhijadya and sankoca (contracture deformity) who was hospitalized for 2 months. She was unable to walk since 1 year due to contracture of both knee joints. The patient came on a wheel chair and was unable to walk even with support. She was advised for contracture repair surgery which she refused. After hospitalization she was treated with Nadi svedana twice a day for 20 min each. Simultaneously, passive stretching for 45 s in every 5 min interval was done. She was treated for 2 months. The patient was instructed to continue other Ayurvedic remedies given as the Ama vata (rheumatoid arthritis) treatment. After Nadi svedana, goniometric assessment of the knees contracture was performed every week. She got satisfactory result in stiffness and pain and has been able to walk with support. Extension of both knee joints has improved up to 20° with increased range of motion. Her height has also been increased up to 1.5 cm due to improvement in the extension of the knee joints with better feeling in daily activities during 3 months of follow-up period.

20.
Blood ; 131(14): 1532-1544, 2018 04 05.
Artículo en Inglés | MEDLINE | ID: mdl-29437554

RESUMEN

Chronic myeloid leukemia (CML) stem/progenitor cells (SPCs) express a transcriptional program characteristic of proliferation, yet can achieve and maintain quiescence. Understanding the mechanisms by which leukemic SPCs maintain quiescence will help to clarify how they persist during long-term targeted treatment. We have identified a novel BCR-ABL1 protein kinase-dependent pathway mediated by the upregulation of hsa-mir183, the downregulation of its direct target early growth response 1 (EGR1), and, as a consequence, upregulation of E2F1. We show here that inhibition of hsa-mir183 reduced proliferation and impaired colony formation of CML SPCs. Downstream of this, inhibition of E2F1 also reduced proliferation of CML SPCs, leading to p53-mediated apoptosis. In addition, we demonstrate that E2F1 plays a pivotal role in regulating CML SPC proliferation status. Thus, for the first time, we highlight the mechanism of hsa-mir183/EGR1-mediated E2F1 regulation and demonstrate this axis as a novel, critical factor for CML SPC survival, offering new insights into leukemic stem cell eradication.


Asunto(s)
Factor de Transcripción E2F1/biosíntesis , Proteína 1 de la Respuesta de Crecimiento Precoz/metabolismo , Regulación Leucémica de la Expresión Génica , Leucemia Mielógena Crónica BCR-ABL Positiva/metabolismo , MicroARNs/metabolismo , Proteínas de Neoplasias/metabolismo , Células Madre Neoplásicas/metabolismo , ARN Neoplásico/metabolismo , Regulación hacia Arriba , Animales , Proliferación Celular , Supervivencia Celular , Factor de Transcripción E2F1/genética , Proteína 1 de la Respuesta de Crecimiento Precoz/genética , Femenino , Humanos , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Leucemia Mielógena Crónica BCR-ABL Positiva/patología , Masculino , Ratones Noqueados , MicroARNs/genética , Proteínas de Neoplasias/genética , Células Madre Neoplásicas/patología , ARN Neoplásico/genética , Transducción de Señal
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