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1.
Nature ; 616(7957): 452-456, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36858074

RESUMEN

Some active asteroids have been proposed to be formed as a result of impact events1. Because active asteroids are generally discovered by chance only after their tails have fully formed, the process of how impact ejecta evolve into a tail has, to our knowledge, not been directly observed. The Double Asteroid Redirection Test (DART) mission of NASA2, in addition to having successfully changed the orbital period of Dimorphos3, demonstrated the activation process of an asteroid resulting from an impact under precisely known conditions. Here we report the observations of the DART impact ejecta with the Hubble Space Telescope from impact time T + 15 min to T + 18.5 days at spatial resolutions of around 2.1 km per pixel. Our observations reveal the complex evolution of the ejecta, which are first dominated by the gravitational interaction between the Didymos binary system and the ejected dust and subsequently by solar radiation pressure. The lowest-speed ejecta dispersed through a sustained tail that had a consistent morphology with previously observed asteroid tails thought to be produced by an impact4,5. The evolution of the ejecta after the controlled impact experiment of DART thus provides a framework for understanding the fundamental mechanisms that act on asteroids disrupted by a natural impact1,6.

2.
Nature ; 583(7816): 379-384, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32669697

RESUMEN

Magic-angle twisted bilayer graphene (TBG), with rotational misalignment close to 1.1 degrees, features isolated flat electronic bands that host a rich phase diagram of correlated insulating, superconducting, ferromagnetic and topological phases1-6. Correlated insulators and superconductivity have been previously observed only for angles within 0.1 degree of the magic angle and occur in adjacent or overlapping electron-density ranges; nevertheless, the origins of these states and the relation between them remain unclear, owing to their sensitivity to microscopic details. Beyond twist angle and strain, the dependence of the TBG phase diagram on the alignment4,6 and thickness of the insulating hexagonal boron nitride (hBN)7,8 used to encapsulate the graphene sheets indicates the importance of the microscopic dielectric environment. Here we show that adding an insulating tungsten diselenide (WSe2) monolayer between the hBN and the TBG stabilizes superconductivity at twist angles much smaller than the magic angle. For the smallest twist angle of 0.79 degrees, superconductivity is still observed despite the TBG exhibiting metallic behaviour across the whole range of electron densities. Finite-magnetic-field measurements further reveal weak antilocalization signatures as well as breaking of fourfold spin-valley symmetry, consistent with spin-orbit coupling induced in the TBG via its proximity to WSe2. Our results constrain theoretical explanations for the emergence of superconductivity in TBG and open up avenues towards engineering quantum phases in moiré systems.

3.
Reprod Biol Endocrinol ; 22(1): 80, 2024 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-38997724

RESUMEN

BACKGROUND: In recent years, with benefits from the continuous improvement of clinical technology and the advantage of fertility preservation, the application of embryo cryopreservation has been growing rapidly worldwide. However, amidst this growth, concerns about its safety persist. Numerous studies have highlighted the elevated risk of perinatal complications linked to frozen embryo transfer (FET), such as large for gestational age (LGA) and hypertensive disorders during pregnancy. Thus, it is imperative to explore the potential risk of embryo cryopreservation and its related mechanisms. METHODS: Given the strict ethical constraints on clinical samples, we employed mouse models in this study. Three experimental groups were established: the naturally conceived (NC) group, the fresh embryo transfer (Fresh-ET) group, and the FET group. Blastocyst formation rates and implantation rates were calculated post-embryo cryopreservation. The impact of FET on fetal growth was evaluated upon fetal and placental weight. Placental RNA-seq was conducted, encompassing comprehensive analyses of various comparisons (Fresh-ET vs. NC, FET vs. NC, and FET vs. Fresh-ET). RESULTS: Reduced rates of blastocyst formation and implantation were observed post-embryo cryopreservation. Fresh-ET resulted in a significant decrease in fetal weight compared to NC group, whereas FET reversed this decline. RNA-seq analysis indicated that the majority of the expression changes in FET were inherited from Fresh-ET, and alterations solely attributed to embryo cryopreservation were moderate. Unexpectedly, certain genes that showed alterations in Fresh-ET tended to be restored in FET. Further analysis suggested that this regression may underlie the improvement of fetal growth restriction in FET. The expression of imprinted genes was disrupted in both FET and Fresh-ET groups. CONCLUSION: Based on our experimental data on mouse models, the impact of embryo cryopreservation is less pronounced than other in vitro manipulations in Fresh-ET. However, the impairment of the embryonic developmental potential and the gene alterations in placenta still suggested it to be a risky operation.


Asunto(s)
Criopreservación , Transferencia de Embrión , Placenta , Criopreservación/métodos , Femenino , Embarazo , Animales , Ratones , Transferencia de Embrión/métodos , Placenta/metabolismo , Embrión de Mamíferos , Implantación del Embrión/genética , Desarrollo Fetal/genética , Blastocisto/metabolismo
4.
Gynecol Oncol ; 181: 125-132, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38159362

RESUMEN

OBJECTIVE: To determine the maximum tolerated dose (MTD) of paclitaxel combined with a fixed dose of cisplatin (75 mg/m2) delivered via hyperthermic intraperitoneal chemotherapy (HIPEC) to patients with ovarian cancer. METHODS: This multicenter Phase I trial employed a Bayesian Optimal Interval (BOIN) design. The MTD was determined to have a target dose-limiting toxicity (DLT) rate of 25%. The starting dose was 175 mg/m2. The Data and Safety Monitoring Board made decisions regarding dose escalation or de-escalation in increments of 25 mg/m2 for subsequent patient cohorts, up to a maximum sample size of 30 or 12 patients treated at a given dose. RESULTS: Twenty-one patients participated in this study. Among the three evaluable patients who received 150 mg/m2 paclitaxel, no DLTs were observed. Among the 12 evaluable patients who received 175 mg/m2 paclitaxel, two reported DLTs: one had grade 4 neutropenia and one had grade 4 anemia, neutropenia, and leukopenia. Four of the six evaluable patients who received 200 mg/m2 paclitaxel reported DLTs: one patient had grade 4 diarrhea, one had grade 3 kidney injury, and two had grade 4 anemia. The isotonic estimate of the DLT rate in the 175 mg/m2 dose group was 0.17 (95% confidence interval, 0.02-0.42), and this dose was selected as the MTD. CONCLUSION: Paclitaxel, when combined with a fixed dose of cisplatin (75 mg/m2), can be safely administered intraperitoneally at a dose of 175 mg/m2 in patients with ovarian cancer who received HIPEC (43 °C, 90 min) following cytoreductive surgery.


Asunto(s)
Anemia , Neutropenia , Neoplasias Ováricas , Humanos , Femenino , Cisplatino , Paclitaxel , Quimioterapia Intraperitoneal Hipertérmica , Dosis Máxima Tolerada , Teorema de Bayes , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias Ováricas/terapia , Neutropenia/inducido químicamente , Anemia/etiología , Relación Dosis-Respuesta a Droga
5.
BJOG ; 131(7): 952-960, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38168494

RESUMEN

OBJECTIVE: To assess pelvic floor muscle (PFM) strength and influencing factors among healthy women at different life stages. DESIGN: Multicentre cross-sectional study. SETTING: Fourteen hospitals in China. POPULATION: A total of 5040 healthy women allocated to the following groups (with 1680 women per group): premenopausal nulliparous, premenopausal parous and postmenopausal. METHODS: The PFM strength was evaluated by vaginal manometry. Multivariate logistic regression was used to determine the influencing factors for low PFM strength. MAIN OUTCOME MEASURES: Maximum voluntary contraction pressure (MVCP). RESULTS: The median MVCP values were 36, 35 and 35 cmH2O in premenopausal nulliparous (aged 19-51 years), premenopausal parous (aged 22-61 years), and postmenopausal (aged 40-86 years) women, respectively. In the premenopausal nulliparous group, physical work (odds ratio, OR 2.05) was the risk factor for low PFM strength, which may be related to the chronic increased abdominal pressure caused by physical work. In the premenopausal parous group, the number of vaginal deliveries (OR 1.28) and diabetes (OR 2.70) were risk factors for low PFM strength, whereas sexual intercourse (<2 times per week vs. none, OR 0.55; ≥2 times per week vs. none, OR 0.56) and PFM exercise (OR 0.50) may have protective effects. In the postmenopausal group, the number of vaginal deliveries (OR 1.32) and family history of pelvic organ prolapse (POP) (OR 1.83) were risk factors for low PFM strength. CONCLUSIONS: Physical work, vaginal delivery, diabetes and a family history of POP are all risk factors for low PFM strength, whereas PFM exercises and sexual life can have a protective effect. The importance of these factors varies at different stages of a woman's life.


Asunto(s)
Manometría , Fuerza Muscular , Diafragma Pélvico , Posmenopausia , Premenopausia , Vagina , Humanos , Femenino , Persona de Mediana Edad , Estudios Transversales , Diafragma Pélvico/fisiología , Adulto , Manometría/métodos , Fuerza Muscular/fisiología , Anciano , Posmenopausia/fisiología , Premenopausia/fisiología , Vagina/fisiología , Factores de Riesgo , Anciano de 80 o más Años , Adulto Joven , Paridad , China/epidemiología , Contracción Muscular/fisiología , Embarazo
6.
Mol Ther ; 31(7): 2077-2088, 2023 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-37060176

RESUMEN

OBP-301 is an oncolytic adenovirus modified to replicate within cancer cells and lyse them. This open-label, non-comparative, phase I dose-escalation trial aimed to assess its safety and optimal dosage in 20 patients with advanced hepatocellular carcinoma. Good tolerance was shown with a maximum tolerated dose of 6 × 1012 viral particles. The most common treatment-emergent adverse events were influenza-like illness, pyrexia, fatigue, decreased platelet count, abdominal distension, and anemia. Cohorts 4 and 5 had approximately 50% higher levels of CD8+ T cells in the peripheral blood after injection. The best target response occurred in 14 patients, 4 of whom had progressive disease. Multiple intratumoral injections of OBP-301 were well tolerated in patients with advanced hepatocellular carcinoma. The stable disease rate for the injected tumors was greater than the overall response rate, even with no obvious tumor response. OBP-301 might have a greater impact on local response as histological examination revealed that the presence of OBP-301 was consistent with the necrotic area at the injection site. Increased infiltration of CD8+ T cells and <1% PD-L1 expression were observed in tumors after injection. Improved antitumor efficacy might be achieved in future studies via viral injection with volume adjustment and in combination with other immuno-therapeutics.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Viroterapia Oncolítica , Virus Oncolíticos , Telomerasa , Humanos , Adenoviridae/genética , Carcinoma Hepatocelular/etiología , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/terapia , Línea Celular Tumoral , Viroterapia Oncolítica/efectos adversos , Virus Oncolíticos/genética
7.
Retina ; 44(6): 1021-1025, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38194676

RESUMEN

PURPOSE: To assess the impact of bilateral vision status on vision-related quality of life (VR-QOL) in patients with Type 2 diabetes in a Chinese cohort. METHODS: Patients with presenting visual acuity (PVA) and VR-QOL data from the Fushun Diabetic Retinopathy Cohort Study were included. Vision-related quality of life was assessed using the National Eye Institute Visual Function Questionnaire-25. Monocular PVA (Snellen) was categorized into three levels for both the better-seeing eye and worse-seeing eye: 1) high PVA (H, > 6/18); 2) moderate PVA (M, 6/18-6/60); and 3) low PVA (L, < 6/60). Based on the monocular PVAs, six categories of bilateral vision status were defined (H-H, H-M, H-L, M-M, M-L, and L-L). The parameters of VR-QOL were analyzed between the groups. RESULTS: A total of 1,717 patients were enrolled. For better-seeing eyes in the same PVA level, the Visual Function Questionnaire-25 composite score decreased significantly with declining PVA in the worse-seeing eye (H-M vs. H-L: 80.5 ± 17.9 vs. 73.6 ± 22.5, P = 0.01; M-M vs. M-L: 78.7 ± 19.6 vs. 69.1 ± 26.4, P = 0.01). Conversely, for worse-seeing eyes in the same PVA level, there was no significant difference in the Visual Function Questionnaire-25 composite score as PVA changed in the better-seeing eye (H-M vs. M-M, 80.5 ± 17.9 vs. 78.7 ± 19.6, P = 0.30; H-L vs. M-L: 73.6 ± 22.5 vs. 69.1 ± 26.4, P = 0.25). CONCLUSION: The PVA of the worse-seeing eye in bilateral vision has a greater impact on VR-QOL in diabetic patients. Priority treatment may be considered for the worse-seeing eye for diabetic patients with different bilateral vision statuses, to better improve VR-QOL.


Asunto(s)
Diabetes Mellitus Tipo 2 , Retinopatía Diabética , Calidad de Vida , Agudeza Visual , Humanos , Masculino , Agudeza Visual/fisiología , Femenino , Persona de Mediana Edad , Retinopatía Diabética/fisiopatología , Retinopatía Diabética/complicaciones , Retinopatía Diabética/psicología , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/fisiopatología , Encuestas y Cuestionarios , Anciano , Visión Binocular/fisiología , China/epidemiología
8.
Retina ; 44(10): 1649-1654, 2024 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-39151180

RESUMEN

PURPOSE: To summarize the causes of retinal arterial microaneurysm combined with branch retinal artery occlusion. METHODS: The case reports of retinal arterial microaneurysm combined with branch retinal artery occlusion were searched in PubMed, Web of Science, and CNKI databases before May 1, 2024. A total of nine participants from nine case reports were included to analyze factors leading to complications. RESULTS: The reasons for this complication are as follows: complications during photocoagulation therapy. Intraretinal hemorrhage and exudation result in compression of adjacent or distal arteries, resulting in branch retinal artery occlusion. Embolus dislodgement or intraarterial embolus formation can block the artery, damage the wall, and provide conditions for the development of retinal arterial microaneurysm. In addition, it is necessary to be alert to the optic disk macroaneurysm, if hemorrhage or embolus formation in the macroaneurysm will affect the blood supply of the downstream artery, affecting a large range of the retina. CONCLUSION: Based on the review of case reports, we found that retinal arterial microaneurysm and branch retinal artery occlusion can cause each other. Acute vision loss can result when a complication occurs. In addition, retinal vascular diseases can reflect the whole body, suggesting that ophthalmologists need to pay attention not only to the patient's fundus but also to the patient's systemic diseases.


Asunto(s)
Macroaneurisma Arterial de Retina , Oclusión de la Arteria Retiniana , Arteria Retiniana , Humanos , Oclusión de la Arteria Retiniana/diagnóstico , Oclusión de la Arteria Retiniana/etiología , Macroaneurisma Arterial de Retina/diagnóstico , Macroaneurisma Arterial de Retina/complicaciones , Arteria Retiniana/diagnóstico por imagen , Angiografía con Fluoresceína/métodos , Fondo de Ojo , Agudeza Visual , Hemorragia Retiniana/diagnóstico , Hemorragia Retiniana/etiología , Tomografía de Coherencia Óptica
9.
BMC Ophthalmol ; 24(1): 333, 2024 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-39123164

RESUMEN

PURPOSE: To investigate whether intravitreal antiviral injection (IAI) during vitrectomy reduces the postsurgical retinal detachment (RD) rate and improves the visual prognosis of patients with acute retinal necrosis (ARN). METHODS: This retrospective cohort study included ARN patients treated at a tertiary hospital between January 2013 and December 2020. Patients who underwent pars plana vitrectomy (PPV) alone or combined with intraoperative IAI were classified in PPV-only group and PPV + IAI group, respectively. The incidence of postsurgical RD and the best corrected visual acuity (BCVA) between the groups was compared. A multivariate Cox hazard analysis was employed to explore the risk factors of postsurgical RD. A multivariate logistic regression analysis was applied to assess the impact of intraoperative IAI on preventing severe vision loss (SVL). RESULTS: Fifty-seven eyes with ARN with a median follow-up of 18.5 months were included in the study. There was no significant association between intraoperative IAI during vitrectomy and a reduced risk of postsurgical RD (hazard ratio [HR], 2.65; 95% CI, 0.71-9.89) or SVL at the 6-month follow-up visit (odds ratio [OR], 0.92; 95% confidence interval [CI], 0.25-3.35). Better baseline best-corrected visual acuity (BCVA) was identified to associate with a higher risk of postsurgical RD (HR, 0.33; 95% CI, 0.14-0.81) and a lower risk of SVL at 6 months (OR, 2.28; 95% CI, 1.10-4.89). CONCLUSION: We did not observe a significant effect of intraoperative IAI on the anatomic and visual outcomes of ARN patients in this study. Intraoperative IAI may not be a necessary treatment option for ARN patients who receive vitrectomy.


Asunto(s)
Antivirales , Inyecciones Intravítreas , Síndrome de Necrosis Retiniana Aguda , Agudeza Visual , Vitrectomía , Humanos , Vitrectomía/métodos , Síndrome de Necrosis Retiniana Aguda/cirugía , Estudios Retrospectivos , Masculino , Femenino , Persona de Mediana Edad , Agudeza Visual/fisiología , Antivirales/administración & dosificación , Antivirales/uso terapéutico , Infecciones Virales del Ojo/cirugía , Anciano , Estudios de Seguimiento , Adulto , Desprendimiento de Retina/cirugía
10.
BMC Ophthalmol ; 24(1): 398, 2024 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-39243038

RESUMEN

PURPOSE: To investigate the effectiveness of anti-vascular endothelial growth factor (VEGF) therapy on post-vitrectomy macular edema (PVME) and determine the risk factors for PVME recovery. METHODS: This retrospective study included 179 eyes of 179 patients who underwent pars plana vitrectomy for proliferative diabetic retinopathy and developed PVME within 3 months after surgery. Eyes were grouped according to postoperative anti-VEGF treatment. RESULTS: Central retinal thickness (CRT) decreased significantly from baseline to 3-month follow-up in groups with (509.9 ± 157.2 µm vs. 401.2 ± 172.1 µm, P < 0.001) or without (406.1 ± 96.1 µm vs. 355.1 ± 126.0 µm, P = 0.008) postoperative anti-VEGF treatment. Best-corrected visual acuity (BCVA) did not differ between the two groups during follow-up. In the group not receiving anti-VEGF therapy, BCVA was significantly improved at 1, 2, and 3 months (P = 0.007, P < 0.001, and P < 0.001, respectively), while in the anti-VEGF group, BCVA was significantly improved at 1 and 3 months (P = 0.03 and P < 0.001). A thicker baseline CRT (ß = 0.44; 95% confidence interval, 0.26-0.61; P < 0.001) was significantly associated with decreasing CRT. CONCLUSION: PVME tends to spontaneously resolve in the early postoperative period. The effect of anti-VEGF therapy in the first 3 months after diagnosis appears to be limited.


Asunto(s)
Inhibidores de la Angiogénesis , Retinopatía Diabética , Edema Macular , Factor A de Crecimiento Endotelial Vascular , Vitrectomía , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Inhibidores de la Angiogénesis/uso terapéutico , Bevacizumab/uso terapéutico , Bevacizumab/administración & dosificación , Retinopatía Diabética/tratamiento farmacológico , Retinopatía Diabética/cirugía , Estudios de Seguimiento , Inyecciones Intravítreas , Edema Macular/etiología , Edema Macular/tratamiento farmacológico , Edema Macular/diagnóstico , Complicaciones Posoperatorias , Ranibizumab/administración & dosificación , Ranibizumab/uso terapéutico , Estudios Retrospectivos , Tomografía de Coherencia Óptica , Factor A de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Agudeza Visual , Vitrectomía/métodos
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