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1.
BMC Public Health ; 24(1): 1448, 2024 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-38816734

RESUMEN

BACKGROUND: This study aimed to investigate the knowledge, attitudes, and practices (KAP) toward cardiovascular complications among end-stage renal disease patients undergoing maintenance hemodialysis. METHODS: This web-based cross-sectional study was conducted at Guangdong Provincial People's Hospital between December 2022, and May 2023. RESULTS: A total of 545 valid questionnaires were collected, with an average age of 57.72 ± 13.47 years. The mean knowledge, attitudes and practices scores were 8.17 ± 2.9 (possible range: 0-24), 37.63 ± 3.80 (possible range: 10-50), 33.07 ± 6.10 (possible range: 10-50) respectively. Multivariate logistic regression analysis showed that patients from non-urban area had lower knowledge compared to those from urban area (odds ratio (OR) = 0.411, 95% CI: 0.262-0.644, P < 0.001). Furthermore, higher levels of education were associated with better knowledge, as indicated by OR for college and above (OR = 4.858, 95% CI: 2.483-9.504), high school/vocational school (OR = 3.457, 95% CI: 1.930-6.192), junior high school (OR = 3.300, 95% CI: 1.945-5.598), with primary school and below as reference group (all P < 0.001). Besides, better knowledge (OR = 1.220, 95% CI: 1.132-1.316, P < 0.001) and higher educational levels were independently associated with positive attitudes. Specifically, individuals with a college degree and above (OR = 2.986, 95% CI: 1.411-6.321, P = 0.004) and those with high school/vocational school education (OR = 2.418, 95% CI: 1.314-4.451, P = 0.005) have more positive attitude, with primary school and below as reference group. Next, better attitude (OR = 1.174, 95% CI: 1.107-1.246, P < 0.001) and higher education were independently associated with proactive practices. Those with college and above (OR = 2.870, 95% CI: 1.359-6.059, P = 0.006), and those with high school/vocational school education (OR = 1.886, 95% CI: 1.032-3.447, P = 0.039) had more proactive practices, with primary school and below as reference group. CONCLUSIONS: End-stage renal disease patients undergoing maintenance hemodialysis demonstrated insufficient knowledge, positive attitudes, and moderate practices regarding cardiovascular complications. Targeted interventions should prioritize improving knowledge and attitudes, particularly among patients with lower educational levels and income, to enhance the management of cardiovascular complications in end-stage renal disease.


Asunto(s)
Enfermedades Cardiovasculares , Conocimientos, Actitudes y Práctica en Salud , Fallo Renal Crónico , Diálisis Renal , Humanos , Masculino , Femenino , Diálisis Renal/psicología , Estudios Transversales , Fallo Renal Crónico/terapia , Fallo Renal Crónico/psicología , Persona de Mediana Edad , Adulto , Anciano , Encuestas y Cuestionarios , China/epidemiología
2.
J Org Chem ; 88(19): 14210-14215, 2023 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-37703517

RESUMEN

An efficient synthesis of α-(1,3,5-triazinylthio)-ketones from 1,3-dicarbonyl compounds with 1,3,5-triazine-2-thiols has been developed. The reaction proceeds through the C-C bond cleavage and C-S bond reconstruction of 1,3-dicarbonyl compounds, and ß-keto esters, ß-keto amides, and 1,3-diones were tolerated. In addition, the annulation of 1,3,5-triazine-2-thiols with chalcones has been achieved for the synthesis of thiazolo[3,2-a][1,3,5]triazines. The method occurred in moderate to good yields and tolerated chalcone with a broad functional group.

3.
Optom Vis Sci ; 100(1): 111-116, 2023 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-36705721

RESUMEN

SIGNIFICANCE: These data demonstrate that defocus incorporated multiple segment (DIMS) lens reduces myopia progression in children during the first year of use. PURPOSE: This study aimed to investigate the efficacy of DIMS myopia control spectacle lens in Chinese myopic children aged 6 to 15 years. METHODS: This is a retrospective study of 1-year longitudinal data. A total of 180 Chinese myopic children were selected from patients at Zhongshan Ophthalmic Center, Sun Yat-sen University, from February 2018 to January 2021. One group consisted of 90 children aged 6 to 15 years, with spherical equivalent refraction -0.50 to -7.75 D (-3.82 ± 1.57 D) and fitted with the DIMS lens. The other group consisted of 90 children fitted with single-vision spectacle lenses and matched with the DIMS group for age, sex, refraction, and progression of myopia in the previous year. One-year myopia progression was measured retrospectively in two groups. Unpaired t test was used to compare the myopia progression between the DIMS group and the control group. Pearson correlation was used to explore the relationship between myopia progression, age, and baseline refraction. RESULTS: After 1 year of DIMS lens wear, myopia progression was significantly lower in the DIMS group (-0.51 ± 0.50 vs. -0.85 ± 0.51 D, P < .001). Myopia progression was positively correlated with age in both groups. The difference between the DIMS and control groups was more pronounced for children aged 10 to 15 years than for children aged 6 to 9 years. CONCLUSIONS: This study confirms that the DIMS lens reduces myopia progression during the first year of use. Efficacy seems to increase with age.


Asunto(s)
Pueblos del Este de Asia , Miopía , Humanos , Niño , Estudios Retrospectivos , Miopía/diagnóstico , Miopía/terapia , Ojo , Refracción Ocular , Progresión de la Enfermedad
4.
Adv Exp Med Biol ; 1431: 95-106, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37644289

RESUMEN

In recent years, many schools have cut back on their teaching and laboratory hours, and courses in the anatomical sciences are more integrated into the horizontal and longitudinal curriculums. Traditionally, teaching in anatomical science classes consists of lectures and laboratory sessions. Usually, gross anatomy and histology are the two main courses in pre-matriculation programs. The summer pre-matriculation program at the University of Mississippi Medical Center (UMMC) was designed to better prepare students for success in their first year of medicine and dentistry. The course provided these students with an opportunity to study gross anatomy and histology ahead of time and develop their learning skills for the coming academic year. Historically, gross anatomy and histology courses have been taught separately with a different emphasis. We have designed a new approach to implement gross anatomy, histology, and pathology-all three disciplines-in a single lecture in the organ section of the histology course. This triple-discipline (triple lecture) approach allows three professors in anatomy, histology, and pathology to work together in a two-and-a-half-hour review lecture. This approach allows students to develop their critical thinking skills and better prepares them to transfer basic anatomic knowledge into their future clinical practice. Students indicated this was their first experience with the triple-discipline approach, and they remarked that it helped them integrate anatomy and histology as well as demonstrate the clinical importance of the structures and organs. This approach can be used at different stages of medical education and helps faculty and students better integrate various disciplines and is more suitable in the modern curriculum. A similar approach was used in our fourth year course in medical histology.


Asunto(s)
Educación Médica , Medicina , Humanos , Curriculum , Estudiantes , Relevancia Clínica
5.
Adv Exp Med Biol ; 1431: 145-160, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37644291

RESUMEN

This chapter begins by exploring the current landscape of virtual and augmented reality technologies in a post-pandemic world and asserting the importance of virtual technologies that improve students' learning outcomes while also reducing costs. Next, the chapter describes clinical anatomy instruction concepts in medical education, including applied anatomy content knowledge, pedagogical anatomy content knowledge, and virtual stereoscopic visualization studies that exemplify these concept areas, respectively. The chapter then explores the concept of procedural training with a specific emphasis on virtual stereoscopic anatomy visualization studies that exemplify or have implications for procedural training in medical education. Subsequently, the chapter discusses the benefits and challenges as well as the potential future positive and negative implications of virtual stereoscopic visualizations in medical education before finally concluding with some pensive considerations for the present and future of anatomy education and training using virtual technologies.


Asunto(s)
Realidad Aumentada , Educación Médica , Humanos , Escolaridad , Estudiantes , Conocimiento
6.
Adv Exp Med Biol ; 1431: 161-175, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37644292

RESUMEN

Three-dimensional (3D) anatomy models have been used for education in health professional schools globally. Virtual technology has become more popular for online teaching since the COVID-19 pandemic. This chapter will describe a project in which a series of virtual anatomical models of organs and structures were developed for educational purposes, and it will describe in detail how to build three-dimensional (3D) movies using DemoMaker. Although setting up the 3D system was complicated and challenging, the process of reconstructing 3D models from radiographic images and the steps of creating animations and 3D movies are exponentially simpler. These efforts require minimal training, thus allowing most people to be able to engage in this modeling process and utilize the moviemaking steps. Amira® software and computed tomographic angiography (CTA) data were used to create 3D models of the lungs, heart, liver, stomach, kidney, etc. The anatomical locations of these structures within the body can be identified and visualized by recording information from multiple CTA slices using volume and surface segmentation. Ultimately, these virtual 3D models can be displayed via dual projectors onto a specialized silver screen and visualized stereoscopically by viewers as long as they wear 3D polarized glasses. Once these 3D movies are created, they can be played automatically on a computer screen, silver screen, 3D system playback screen, and video player, and they can be embedded into PowerPoint lecture slides. Both virtual models and movies are suitable for self-directed learning, face-to-face class teaching, and virtual anatomy education. Model animations and 3D movie displays offer students the opportunities to learn about anatomy and the anatomical positions of organs in the body and their 3D relationships to one another. By observing and studying these 3D models, students have the potential to be able to compartmentalize the anatomical information and retain it at a higher level than students learning corresponding anatomy without similar resources.


Asunto(s)
COVID-19 , Películas Cinematográficas , Humanos , Pandemias , Escolaridad , Estudiantes
7.
Adv Exp Med Biol ; 1431: 1-15, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37644285

RESUMEN

For over two centuries, the educational landscape both nationally and globally has changed tremendously. The more traditional teaching and learning resources and platforms, such as traditional textbooks, chalkboards and whiteboards, overhead transparency and carousel projectors, and traditional classroom settings, have been either replaced or supplemented in the anatomical sciences by integrated and virtual eBooks, online learning management (OLM) platforms, and virtual learning and meeting apps. Virtual teaching and learning, especially proliferated with the advent and aftermath of the COVID-19 pandemic, and institutions worldwide that had already been utilizing virtual class and lab sessions in their anatomy curricula expanded virtual course offerings. Many institutions have retained virtual course offerings even after the pandemic, given the distance learning benefits. The future of anatomy education holds many promising possibilities given the voracious speed with which technology is advancing. One such promising advancement is the full, seamless incorporation of virtual three-dimensional (3D) immersive and semi-immersive learning into anatomy laboratories and classroom settings globally as well as into students' laptops and handheld devices for easy use at home or anywhere.


Asunto(s)
COVID-19 , Pandemias , Humanos , Aprendizaje , Escolaridad , Curriculum
8.
Clin Anat ; 36(6): 915-925, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37194679

RESUMEN

Medical courses worldwide are undergoing significant curricular changes, including the teaching and learning of histology. In order to set international standards for the anatomical sciences, the International Federation of Associations of Anatomists (IFAA) is developing core anatomical syllabuses by means of Delphi panels. Already published is a core syllabus for the teaching of the cell and the basic tissues within medicine. Here, we record the deliberations of an IFAA Delphi panel commissioned to develop core subject matter for the teaching within a medical histology course of the cardiovascular and lymphatic circulatory system, the lymphoid, respiratory, and digestive systems, and the integument. The Delphi panel was comprised of academics from multiple countries who were required to review relevant histological topics/items by evaluating each topic as being either "Essential," "Important," "Acceptable," or "Not required." Topics that were rated by over 60% of the panelists as being "Essential" are reported in this paper as being core topics for the teaching of medical histology. Also reported are topics that, while not reaching the threshold for being designated as core material, may be recommended or not required within the curriculum.


Asunto(s)
Sistema Cardiovascular , Educación de Pregrado en Medicina , Humanos , Curriculum , Aprendizaje , Técnica Delphi
9.
Molecules ; 28(11)2023 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-37298814

RESUMEN

In this study, we report a selective approach for synthesizing N-([1,3,5]triazine-2-yl) α-ketoamides and N-([1,3,5]triazine-2-yl) amides from ketones with 2-amino[1,3,5]triazines through oxidation and oxidative C-C bond cleavage reaction, respectively. The transformation proceeds under mild conditions, provides good functional group tolerance and chemoselectivity, and will serve as a valuable tool for the synthesis of bioactive products.


Asunto(s)
Amidas , Cetonas , Cetonas/química , Amidas/química , Aminas/química , Triazinas , Oxidación-Reducción
10.
Angew Chem Int Ed Engl ; 62(4): e202215582, 2023 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-36418237

RESUMEN

Disentangled ultrahigh molecular weight polyethylene (dis-UHMWPE) has excellent processability but can be achieved under extreme conditions. Herein, we report ethylene polymerization with the binuclear half-sandwich scandium complexes C1-Sc2 and C2-Sc2 to afford UHMWPE. C1-Sc2 bearing a short linker shows higher activity and gives higher molecular weight PEs than C2-Sc2 containing a flexible spacer and the mononuclear Sc1 . Strikingly, all UHMWPEs isolated from C1-Sc2 under broad temperature range (25-120 °C) and wide ethylene pressures (2-13 bar) feature very low degree of entanglement as proved by rheological test, DSC annealing study and SEM. These dis-UHMWPEs are facilely mediated solid-state-process at 130 °C and their tensile strength and modulus reach up to 149.2 MPa and 1.5 GPa, respectively. DFT simulations reveal that the formation of dis-UHMWPE is attributed to the binuclear synergic effect and the agostic interaction between the active center and the growing chain.

11.
BMC Nephrol ; 23(1): 221, 2022 06 23.
Artículo en Inglés | MEDLINE | ID: mdl-35739470

RESUMEN

INTRODUCTION: The purpose of this study is to present the prevalence and effects of direct arterial puncture (DAP) for hemodialysis patients, and to introduce optimal option for the vascular access (VA) in certain hemodialysis patients with poor condition of vascular or cardiac function in a compelling situation. METHODS: This was a cross-sectional study. Demographic characteristics and laboratory data were extracted from the health care system. Relevant DAP information was collected by a questionnaire. Case-control matching was performed to compare the hemodialysis adequacy between DAP and other VAs. RESULTS: A total of 526 patients were selected for analysis by convenience sampling, of which 38 patients relied https://www.baidu.com/link?url=eaDh8Hn-yZGJyDB0_h4zBenKd7qY1yX-KNxO-qU49gktQOGTJJg3slTjIbG095st4hRfprQIHRjfhfeGOZyH73y8tvSUCwMmvWbUhyix2ZK on DAP for hemodialysis. The main reasons using DAP for hemodialysis included the cost of arteriovenous access creation or maintenance in 19(50%) patients and the poor condition of vascular or cardiac function in 14 (39.5%) patients. Some complications of DAP occurred, such as aneurysm or pseudoaneurysm in 16(42.1%) patients, infiltration in 12 (31.6%) patients. Differences in hemodialysis adequacy were not statistically significant between DAP and other types of VA. CONCLUSION: In conclusion, DAP can meet the need of prescription hemodialysis, yet it has several limitations. Although the patients in our study were long-term dependent on DAP for hemodialysis with various reasons, we do not recommend DAP as a long-term vascular access if better options are available. However, DAP should not be overlooked to be a supplemental VA for hemodialysis with adequate blood flow and availability for individuals with poor condition of vascular or cardiac function in a compelling situation.


Asunto(s)
Derivación Arteriovenosa Quirúrgica , Diálisis Renal , Derivación Arteriovenosa Quirúrgica/efectos adversos , Estudios Transversales , Hemodinámica , Humanos , Punciones , Procedimientos Quirúrgicos Vasculares
12.
Angew Chem Int Ed Engl ; 61(9): e202112966, 2022 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-34931421

RESUMEN

Syndioselective polymerization of unprotected polar styrenes has achieved great success via specially designed catalysts and the establishment of "self-assisted" theory. In contrast, isospecific polymerization of polar styrenes has remained less explored. Herein, we present new racemic ansa-bis(benz[e]indenyl) rare-earth metal complexes and their high activity and perfect isoselectivity (mmmm>99 %) for the polymerization of unmasked polar styrenes without any activators. Moreover, the copolymerizations of para- and meta-methoxystyrenes with styrene give gradient and random copolymers, respectively. The insertion rate of polar monomers could be readily tuned in the range of 0-100 mol % by changing their loading ratios. The resultant isotactic polar polystyrenes are quantitatively transformed into hydroxyl or methylsulfonyl polystyrenes with high Tg s. DFT calculations reveal the isospecific mechanism.

13.
Angew Chem Int Ed Engl ; 61(29): e202205894, 2022 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-35581680

RESUMEN

Many efforts have been devoted to preparing star polymers. Research into coordination polymerization, the most powerful stereoselective process to endow polymers with superb properties, lags far behind those achieved by radical polymerization and ionic polymerization. Herein, we propose a facile strategy to prepare star polymers with regular arms based on coordination polymerization via an insertion reaction between the carbon-heteroatom unsaturated bond and the metal-alkyl species. Terminating a living cis-1,4-selective isoprene polymerization by using isocyanate as cross-linker (CL), a star polyisoprene with low polydispersity was obtained in high yield (91.8 %). A kinetic study showed the star polymer was formed via a step-growth procedure. The types of CL and the ratio of [CL]0 : [Cat.]0 are key factors to determine the arm number and the yield of star polymer. Finally, synthetic IR rubber with a green strength up to 1.99 MPa superior to natural rubber (1.43 MPa) was prepared for the first time.

14.
Dev Biol ; 457(2): 206-214, 2020 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-30796893

RESUMEN

The choriocapillaris is an exceptionally high density, two-dimensional, sheet-like capillary network, characterized by the highest exchange rate of nutrients for waste products per area in the organism. These unique morphological and physiological features are critical for supporting the extreme metabolic requirements of the outer retina needed for vision. The developmental mechanisms and processes responsible for generating this unique vascular network remain, however, poorly understood. Here we take advantage of the zebrafish as a model organism for gaining novel insights into the cellular dynamics and molecular signaling mechanisms involved in the development of the choriocapillaris. We show for the first time that zebrafish have a choriocapillaris highly similar to that in mammals, and that it is initially formed by a novel process of synchronized vasculogenesis occurring simultaneously across the entire outer retina. This initial vascular network expands by un-inhibited sprouting angiogenesis whereby all endothelial cells adopt tip-cell characteristics, a process which is sustained throughout embryonic and early post-natal development, even after the choriocapillaris becomes perfused. Ubiquitous sprouting was maintained by continuous VEGF-VEGFR2 signaling in endothelial cells delaying maturation until immediately before stages where vision becomes important for survival, leading to the unparalleled high density and lobular structure of this vasculature. Sprouting was throughout development limited to two dimensions by Bruch's membrane and the sclera at the anterior and posterior surfaces respectively. These novel cellular and molecular mechanisms underlying choriocapillaris development were recapitulated in mice. In conclusion, our findings reveal novel mechanisms underlying the development of the choriocapillaris during zebrafish and mouse development. These results may explain the uniquely high density and sheet-like organization of this vasculature.


Asunto(s)
Coroides/irrigación sanguínea , Coroides/embriología , Neovascularización Fisiológica/fisiología , Retina/embriología , Animales , Diferenciación Celular/fisiología , Ratones , Ratones Endogámicos BALB C , Transducción de Señal/fisiología , Factor A de Crecimiento Endotelial Vascular/metabolismo , Receptor 2 de Factores de Crecimiento Endotelial Vascular/metabolismo , Pez Cebra , Proteínas de Pez Cebra/metabolismo
15.
Ophthalmic Physiol Opt ; 41(5): 1087-1096, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34382246

RESUMEN

PURPOSE: This study aims to reveal the relationship between the posterior ocular contour and the subsequent progression of myopia in children. METHODS: Children aged 8-12 years with myopia received baseline measurements and were instructed to wear their glasses every day and return for a follow-up visit after one year. Axial length and other ocular parameters were measured using a noncontact biometer. The contour of the posterior eye was calculated and analysed based on images from spectral domain optical coherence tomography (SD-OCT). Univariate and multivariate linear regression models were created to analyse the relationship between the contour of the posterior eye and the progression of myopia. RESULTS: Baseline posterior ocular contour measurements correlated with baseline axial length and spherical equivalent refraction (SER) (all p < 0.05). Eyes that were more myopic tended to have a more prolate posterior ocular contour. Although the baseline contour of the retinal pigment epithelium (RPE) and chorioscleral interface (CSI) showed no significant relationship with the progression of myopia (all p > 0.05), interestingly, when the baseline contour of the RPE was more prolate than that of the CSI, the axial length increased during the following year (R2  = 0.62; p < 0.01). The multivariate model, when adjusted for other variables, further validated the independent role of this variable. CONCLUSIONS: The difference between the RPE and CSI contours correlated with the subsequent progression of myopia in children. This finding can help inform clinicians regarding the management of children at the onset of myopia and potentially provide an avenue for experimental research on the mechanism of myopia development.


Asunto(s)
Miopía , Tomografía de Coherencia Óptica , Longitud Axial del Ojo , Niño , Humanos , Miopía/diagnóstico , Estudios Prospectivos , Refracción Ocular
16.
Clin Anat ; 34(3): 483-495, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33449424

RESUMEN

The International Federation of Associations of Anatomists (IFAA) are developing core syllabuses for the anatomical sciences by means of Delphi panels. In this article, we provide the core subject matter for the teaching of the cell and of basic tissues within a medical histology course. The goal is to set an international standard providing guidelines for such a core syllabus. The Delphi panel, composed of members across multiple countries, required two rounds to evaluate 257 relevant items/topics approved by the IFAA. Based on the perception of the core knowledge of histology, the items were to be rated by each member of the Delphi panel as being "Essential," "Important," "Acceptable," or "Not required." Topics that were rated by over 60% of the panelists as being "Essential" and "Important" are provided in this article and are recommended for the teaching of medical histology.


Asunto(s)
Anatomía/educación , Curriculum , Educación de Pregrado en Medicina , Histología/educación , Técnica Delphi , Humanos
17.
Molecules ; 26(14)2021 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-34299428

RESUMEN

Anilido-imine ligands o-C6H4(NHAr1)(CH=NAr2), in which Ar1 is 2,6-diisopropylbenzyl group and Ar2 contains fluorine (HL1) or methoxyl (HL2) group on ortho-position of phenyl substituent, were synthesized for constructing rare-earth metals based complexes of 1a-1c (HL1 based Sc, Lu, Y) and 2a-2c (HL2 based Sc, Lu, Y). Based on their NMR spectra and X-ray single-crystal structures, the side-arm group of -F and -OMe is identified to chelate to the corresponding central metal. The twisted angles between two planes formed by chelated heteroatoms (N, N, F for HL1 and N, N, O for HL2) are observed, in which the largest dihedral angle (53.3°) for HL1-Y and the smallest dihedral angle (44.32°) for HL2-Sc are detected. After being activated by AliBu3 and [Ph3C][B(C6F5)4], these catalysts showed great activity for isoprene polymerization. Bearing the same ligand HL1, smaller scandium based complex 1a and middle size of lutetium based 1b provided lower cis-1,4-selectivity (57.3% and 64.2%), larger yttrium complex 1c displayed high cis-1,4-selectivity (84%). Chelating by crowded HL2, small size of scandium complex 2a provided impressive trans-1,4-selectivity (93.0%), middle lutetium based 2b displayed non-selectivity and larger yttrium complex 2c showed clear cis-1,4-selectivity (83.3%). Moreover, 2a/AliBu3 system showed the quasi-living chain transfer capability.

18.
Molecules ; 26(11)2021 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-34200341

RESUMEN

Sinomenine is a morphinan alkaloid with a variety of biological activities. Its derivatives have shown significant cytotoxic activity against different cancer cell lines in many studies. In this study, two series of sinomenine derivatives were designed and synthesized by modifying the active positions C1 and C4 on the A ring of sinomenine. Twenty-three compounds were synthesized and characterized by spectroscopy (IR, 1H-NMR, 13C-NMR, and HRMS). They were further evaluated for their cytotoxic activity against five cancer cell lines, MCF-7, Hela, HepG2, SW480 and A549, and a normal cell line, Hek293, using MTT and CCK8 methods. The chlorine-containing compounds exhibited significant cytotoxic activity compared to the nucleus structure of sinomenine. Furthermore, we searched for cancer-related core targets and verified their interaction with derivatives through molecular docking. The chlorine-containing compounds 5g, 5i, 5j, 6a, 6d, 6e, and 6g exhibited the best against four core targets AKT1, EGFR, HARS and KARS. The molecular docking results were consistent with the cytotoxic results. Overall, results indicate that chlorine-containing derivatives might be a promising lead for the development of new anticancer agents.


Asunto(s)
Morfinanos/química , Morfinanos/farmacología , Células A549 , Antineoplásicos/química , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Línea Celular , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Diseño de Fármacos , Ensayos de Selección de Medicamentos Antitumorales/métodos , Células HEK293 , Células HeLa , Células Hep G2 , Humanos , Células MCF-7 , Simulación del Acoplamiento Molecular/métodos
19.
Angew Chem Int Ed Engl ; 60(49): 25735-25740, 2021 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-34559927

RESUMEN

Herein, we report copolymerizations of ethylene (E) and ortho-/meta-/para-fluorostyrenes (SF =oFS/mFS/pFS) by using quinolyl methylene fluorenyl scandium complex (Flu-CH2 -Qu)Sc(CH2 SiMe3 )2 . The copolymerizations proceed in a controlled fashion to afford copolymers composed of "soft" ethylene-fluorostyurene (E-SF ) random segments (Tg =-22.2-5.1 °C) and "hard" crystalline ethylene-ethylene (E-E) segments (Tm =42.3-130.2 °C). The copolymers behave like thermoplastic elastomers at room temperature by showing high stress values up to 39.5 MPa under elongation-at-break above 774 % with elastic recovery over 75 %. The excellent mechanical properties are mainly attributed to the microphase separation of the nanoscale crystalline E-E domain from the amorphous E-SF copolymer matrix proved by AFM, WAXD and SAXS. The mechanism investigation by the density functional theory (DFT) simulation reveals that the steric bulky and electron-withdrawing ligand of the catalytic precursor prefers E propagation to generate long E-E segments, while the incorporation of SF is thermodynamic control.

20.
Macromol Rapid Commun ; 41(10): e2000038, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32285525

RESUMEN

Streoregular poly(vinyl alcohol) is hard to obtain because vinyl alcohol is unstable relative to its tautomer acetaldehyde, and the monomer precursor vinyl ester is poisonous to the coordination catalyst. Herein, the coordination polymerization of 2-vinyl-2,1-borazanaphthalene (BN2VN) is reported by the linked or unlinked half-sandwich ligands attached scandium precursors ((FluSiMe3 )Sc(CH2 SiMe3 )2 (THF) (THF = tetrahydrofuran, 1), (FluCH2 CH2 -NHC-R)Sc(CH2 SiMe3 )2 (THF) (R = mesityl 2, i Pr 3, Me 4), and (FluCH2 Py)Sc(CH2 SiMe3 )2 (5) for the first time. Among these precursors, complex 5 converts 600 equivalents of BN2VN into polymer within 5 min to reach an activity as high as 8.99 × 105 g molSc -1 h-1 . The resultant products show excellent syndiotacticity and melting temperatures above 300 °C, which can be transferred to syndiotactic poly(vinyl alcohol) with 90% rr triad content by postpolymerization oxidation.


Asunto(s)
Naftalenos/química , Alcohol Polivinílico/síntesis química , Complejos de Coordinación/química , Estructura Molecular , Polimerizacion , Alcohol Polivinílico/química , Escandio/química , Estereoisomerismo
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