Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 403
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Proc Natl Acad Sci U S A ; 120(14): e2215153120, 2023 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-36989301

RESUMEN

Supercooled liquids undergo complicated structural relaxation processes, which have been a long-standing problem in both experimental and theoretical aspects of condensed matter physics. In particular, past experiments widely observed for many types of molecular liquids that relaxation dynamics separated into two distinct processes at low temperatures. One of the possible interpretations is that this separation originates from the two-scale hierarchical topography of the potential energy landscape; however, it has never been verified. Molecular dynamics simulations are a promising approach to tackle this issue, but we must overcome laborious difficulties. First, we must handle a model of molecular liquids that is computationally demanding compared to simple spherical models, which have been intensively studied but show only a slower process: α relaxation. Second, we must reach a sufficiently low-temperature regime where the two processes become well-separated. Here, we handle an asymmetric dimer system that exhibits a faster process: Johari-Goldstein ß relaxation. Then, we employ the parallel tempering method to access the low-temperature regime. These laborious efforts enable us to investigate the potential energy landscape in detail and unveil the first direct evidence of the topographic hierarchy that induces the ß relaxation. We also successfully characterize the microscopic motions of particles during each relaxation process. Finally, we study the correlation between low-frequency modes and two relaxation processes. Our results establish a fundamental and comprehensive understanding of experimentally observed relaxation dynamics in supercooled liquids.

2.
Gastrointest Endosc ; 99(4): 629-632, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37952682

RESUMEN

BACKGROUND AND AIMS: Perforation during esophageal endoscopic submucosal dissection (ESD) typically results from electrical damage. However, there are cases in which perforation occurs because of segmental absence of intestinal musculature (SAIM) without iatrogenic muscular injury. We investigated the occurrence rate and clinical course of SAIM during esophageal ESD. METHODS: We conducted a retrospective review of esophageal ESDs performed between 2013 and 2019 at 10 centers in Japan. RESULTS: Five of 1708 (0.29%) patients received ESD for esophageal cancer and had SAIM. The median muscular defect size was 20 mm. All lesions were resected without discontinuation. After resection, 3 patients were closed with Endoloop. Four patients had mediastinal emphysema. All patients were managed conservatively. CONCLUSIONS: SAIM is a very rare condition that is usually only diagnosed during ESD. Physicians performing esophageal ESD should be aware of SAIM. When SAIM is detected, the ESD technique should be modified to prevent full-thickness perforation.


Asunto(s)
Carcinoma de Células Escamosas , Resección Endoscópica de la Mucosa , Neoplasias Esofágicas , Humanos , Resección Endoscópica de la Mucosa/métodos , Resultado del Tratamiento , Neoplasias Esofágicas/cirugía , Neoplasias Esofágicas/patología , Carcinoma de Células Escamosas/patología , Estudios Retrospectivos
3.
Soft Matter ; 20(7): 1583-1602, 2024 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-38273794

RESUMEN

Understanding glass formation by quenching remains a challenge in soft condensed matter physics. Recent numerical studies on steepest descent dynamics, which is one of the simplest models of quenching, revealed that quenched liquids undergo slow relaxation with a power law towards mechanical equilibrium and that the late stage of this process is governed by local rearrangements of particles. These advances motivate the detailed study of instantaneous normal modes during the relaxation process because the glassy dynamics is considered to be governed by stationary points of the potential energy landscape. Here, we performed a normal mode analysis of configurations during the steepest descent dynamics and found that the dynamics is driven by almost flat directions of the potential energy landscape at long times. These directions correspond to localized modes and we characterized them in terms of their statistics and structure using methods developed in the study of local minima of the potential energy landscape.

4.
Int J Clin Oncol ; 29(3): 318-324, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38265529

RESUMEN

BACKGROUND: To identify the prognostic impact of treatment centralization in patients with testicular germ cell tumors (TGCT). METHODS: We used a hospital-based cancer registry data in Japan to extract seminoma and non-seminoma cases that were diagnosed in 2013, histologically confirmed, and received the first course of treatment. To compare the 5-years overall survival (OS) rates of patients stratified by institutional care volume, we performed a Cox proportional hazards regression analysis using inverse probability of treatment weighting (IPTW) method to adjust patient backgrounds. RESULTS: A total of 1767 TGCT patients were identified. The 5-years OS rates for stage II and III TGCT patients treated at low-volume institutions (< 7 cases) were significantly worse than high-volume institutions (≥ 7 cases) (91.2% vs. 83.4%, p = 0.012). Histological stratification revealed that 5-year OS rates for stage II and III seminoma patients in the low-volume group were significantly worse than the high-volume group (93.5% vs. 84.5%, p = 0.041). Multivariate OS analysis using an IPTW-matched cohort showed that institutional care volume was an independent prognostic factor (hazard ratio 2.13 [95% confidence interval: 1.23-3.71], p = 0.0072). CONCLUSION: Our results indicate that stage II and III TGCT patients experience lower survival rates at low-volume institutions and would benefit from treatment centralization.


Asunto(s)
Neoplasias de Células Germinales y Embrionarias , Seminoma , Neoplasias Testiculares , Masculino , Humanos , Pronóstico , Estadificación de Neoplasias , Japón/epidemiología , Seminoma/terapia , Seminoma/patología , Datos de Salud Recolectados Rutinariamente , Neoplasias Testiculares/patología , Neoplasias de Células Germinales y Embrionarias/terapia , Hospitales
5.
Echocardiography ; 41(1): e15755, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38284667

RESUMEN

BACKGROUND: Heart failure with preserved ejection fraction (HFpEF) is a group of diseases classified by left ventricular (LV) EF, a measure of pump function. However, LVEF does not reflect LV contractility. Previous studies have shown that tissue Doppler-derived LV isovolumic contraction velocity (IVCv) correlates well with the LV peak dP/dt, an index of LV contractility. We explored whether LV IVCv is associated with 1-year post-discharge outcomes in HFpEF. METHODS: We enrolled 113 patients (median age, 86 years, 45 male) with HFpEF (EF on admission ≥ 50%) who were admitted to our hospital for the treatment of acute HF. Clinical characteristics including echocardiographic data were obtained before discharge. IVCv was obtained from the tissue Doppler waveforms of both the septal and lateral mitral annulus of the apical 4-chamber view and averaged data were used. Primary outcomes were all-cause death or unplanned hospitalization due to HF within the first year. RESULTS: Among all patients, median LVEF was 61%, left atrial diameter was 47 mm, E/e' was 17.5, and IVCv was 4.5 cm/sec; mean tricuspid regurgitation velocity was 2.6 m/sec. Regarding laboratory data, the median plasma B-type natriuretic peptide level was 185 pg/mL. Thirty-four events occurred (15 deaths, 19 unplanned hospitalizations due to HF) within the first year. In multivariate Cox proportional hazards analyses, IVCv was significantly associated with outcomes (hazard ratio .68, 95% confidence interval .50-.89, p = .0095), independent of general characteristics, echocardiographic measures and pertinent laboratory parameters. CONCLUSION: LV IVCv was independently associated with 1-year outcomes in patients with HFpEF.


Asunto(s)
Insuficiencia Cardíaca , Humanos , Masculino , Anciano de 80 o más Años , Volumen Sistólico , Cuidados Posteriores , Alta del Paciente , Ecocardiografía , Función Ventricular Izquierda , Pronóstico
6.
Chem Pharm Bull (Tokyo) ; 72(1): 98-101, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38233138

RESUMEN

A novel tricyclic polyketide, curvulanone (1), was isolated from the marine-derived fungus Curvularia aeria. The structure of 1 was determined by NMR and single-crystal X-ray crystallography. 1 had a cyclopentabenzopyranone with 3-acetic acid structure that is rarely found in natural compounds. Monoamine oxidase and sirtuin 1 inhibitory test was exhibited and 1 showed their inhibitory activity.


Asunto(s)
Policétidos , Policétidos/farmacología , Policétidos/química , Hongos , Curvularia , Estructura Molecular
7.
Int J Urol ; 31(8): 906-912, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38695571

RESUMEN

OBJECTIVES: In a primary analysis of data from the BRIGHT study (UMIN000035712), photodynamic diagnosis-assisted transurethral resection of bladder tumor (PDD-TURBT) using oral 5-aminolevulinic acid hydrochloride reduced residual tumors in high-risk non-muscle invasive bladder cancer (NMIBC). We aimed to evaluate the effectiveness of PDD-TURBT for intravesical recurrence after a second transurethral resection for high-risk NMIBC. METHODS: High-risk NMIBC patients initially treated with PDD-TURBT (PDD group) were prospectively registered between 2018 and 2020. High-risk patients with NMIBC who were initially treated with white-light TURBT (WL group) were retrospectively registered. Intravesical recurrence-free survival after the second transurethral resection was compared between the PDD and WL groups using propensity score matching analysis. RESULTS: In total, 177 patients were enrolled in the PDD group, and 306 patients were registered in the WL group. After propensity score matching (146 cases in each group), intravesical recurrence within 1 year was significantly less frequent in the PDD group than in the WL group (p = 0.004; hazard ratio [HR] 0.44, 95% confidence interval [CI]: 0.25-0.77). In subgroup analysis, PDD-TURBT showed a particularly high efficacy in reducing intravesical recurrence within 1 year, especially in cases of tumors measuring less than 3 cm (p = 0.003; HR 0.31, 95% CI: 0.14-0.67), absence of residual tumor at second transurethral resection (p = 0.020; HR 0.37, 95% CI: 0.16-0.86), and no postoperative intravesical Bacillus Calmette-Guérin therapy (p < 0.001; HR 0.27, 95% CI: 0.13-0.58). CONCLUSIONS: PDD-TURBT may reduce short-term intravesical recurrence in patients with high-risk NMIBC.


Asunto(s)
Ácido Aminolevulínico , Recurrencia Local de Neoplasia , Fármacos Fotosensibilizantes , Neoplasias de la Vejiga Urinaria , Humanos , Neoplasias de la Vejiga Urinaria/patología , Neoplasias de la Vejiga Urinaria/cirugía , Neoplasias de la Vejiga Urinaria/mortalidad , Neoplasias de la Vejiga Urinaria/terapia , Masculino , Femenino , Ácido Aminolevulínico/administración & dosificación , Anciano , Recurrencia Local de Neoplasia/prevención & control , Recurrencia Local de Neoplasia/epidemiología , Fármacos Fotosensibilizantes/administración & dosificación , Persona de Mediana Edad , Invasividad Neoplásica , Cistectomía/métodos , Estudios Retrospectivos , Supervivencia sin Enfermedad , Neoplasia Residual , Puntaje de Propensión , Anciano de 80 o más Años , Estudios Prospectivos , Resección Transuretral de la Vejiga , Neoplasias Vesicales sin Invasión Muscular
8.
Cleft Palate Craniofac J ; 61(1): 155-158, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-36377243

RESUMEN

Ankyloblepharon filiforme adnatum (AFA) is a rare, benign congenital anomaly. Notably, it is characterized by the adhesion of the ciliary edges of the upper and lower eyelids at the trabecular line. AFA is usually a solitary malformation of sporadic occurrence; however, it can occur in conjunction with other congenital diseases. Herein, we report a case of cleft lip with AFA. A patient was referred to the ophthalmology department of our hospital. The ophthalmic diagnosis was AFA in both the eyes. The left eye was observed to have a fibrous adhesion in the center, and she underwent surgery to excise the fibrous adhesion of tissue with scissors. The right eye was observed to have a fibrous adhesion in the external canthus and was excised during lip plasty. After surgery, her eyes were able to fully open, and no other apparent disease was diagnosed. AFA is thought to be caused by an ectodermal-derived developmental abnormality. Notably, cases of AFA with a cleft lip are rare. Diagnosis and surgery should be performed promptly to minimize any risk of amblyopia and for the early detection of congenital diseases, including glaucoma.


Asunto(s)
Labio Leporino , Fisura del Paladar , Anomalías del Ojo , Anomalías de la Boca , Humanos , Femenino , Labio Leporino/cirugía , Labio Leporino/diagnóstico , Fisura del Paladar/cirugía , Fisura del Paladar/diagnóstico , Anomalías del Ojo/diagnóstico , Anomalías del Ojo/cirugía , Adherencias Tisulares
9.
Reprod Med Biol ; 23(1): e12584, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38807752

RESUMEN

Purpose: To investigate whether seminal plasma (SP)/serum ratios of multiple trace elements (TEs) can classify patients with male subfertility. Methods: SP/serum ratios of 20 TEs (lithium, sodium, magnesium, phosphorus, sulfur, potassium, calcium, manganese, iron, cobalt, copper, zinc, arsenic, selenium, rubidium, strontium, molybdenum, cesium, barium, and thallium) were calculated for healthy volunteers (n = 4) and those consulting for male subfertility (n = 245). Volunteer semen samples were collected by split ejaculation into early and subsequent fractions, and SP/serum ratio data were compared between fractions. The patients' SP/serum ratio data were used in an unsupervised clustering analysis and qualitatively compared with the data from the fractions of ejaculation from the volunteers. Semen quality parameters and pregnancy outcomes were compared between patient clusters. Results: The early fraction of volunteers was characterized by lower phosphorus and arsenic and 18 other higher TEs than the subsequent fraction. Cluster analysis classified patients into four distinct clusters, one sharing characteristics with the early fraction and another with the subsequent fraction. One cluster with the early fraction characteristics had significantly lower semen volume and higher pregnancy rates from spontaneous pregnancies or intrauterine insemination. Conclusions: Classification of patients based on SP/serum ratios of multiple TEs represents the dominance of fractions of ejaculation samples.

10.
Hinyokika Kiyo ; 70(4): 101-106, 2024 Apr.
Artículo en Japonés | MEDLINE | ID: mdl-38965909

RESUMEN

Case 1 : A 75-year-old man was emergently admitted to our hospital with a complaint of continuous bleeding from the ileal conduit. The conduit was constructed by a total pelvic resection for sigmoid colon cancer that invaded the urinary bladder 24 years ago. Swollen cutaneous mucosa was seen around the ileal conduit, but no obvious bleeding spot was observed. The contrast-enhanced computed tomographic (CT) scan and 3D visualization revealed varices extending to the abdominal wall. Percutaneous transhepatic embolization successfully stopped the bleeding, but it was needed again after two years. Case 2 : A 72-yearold man with a history of open cystectomy and ileal conduit for bladder cancer came to our hospital two years after the surgery, complaining of continuous bleeding from the conduit. The skin around the stoma site was discolored purple, but no obvious bleeding site or bloody urine was observed. The CT scan similar to Case 1 revealed varices in the ileal conduit, and percutaneous transhepatic embolization successfully stopped the bleeding, but it was needed again after five months. After that, three months passed without recurrence.


Asunto(s)
Derivación Urinaria , Várices , Humanos , Masculino , Anciano , Várices/cirugía , Várices/diagnóstico por imagen , Embolización Terapéutica , Tomografía Computarizada por Rayos X , Neoplasias de la Vejiga Urinaria/cirugía , Neoplasias de la Vejiga Urinaria/complicaciones , Hemorragia/etiología , Hemorragia/cirugía , Hemorragia/diagnóstico por imagen
11.
Esophagus ; 2024 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-39068303

RESUMEN

BACKGROUND: Repeat endoscopic submucosal dissection for metachronous recurrence of esophageal squamous cell carcinoma close to previous endoscopic submucosal dissection scars is challenging. Therefore, this study evaluated the efficacy and safety of repeat endoscopic submucosal dissection for recurrent esophageal squamous cell carcinoma. METHODS: The study included 1680 patients. After propensity score matching, esophageal endoscopic submucosal dissection-related outcomes were compared between the post-endoscopic submucosal dissection scar group (n = 91) and first endoscopic submucosal dissection group (n = 910). The Kaplan-Meier method and log-rank tests were used to compare both groups' survival and local recurrence curves. RESULTS: After propensity score matching, the two groups showed no significant difference in en bloc resection rate (97.80% vs. 99.56%, p = 0.096), treatment time (64.75 min vs 61.33 min, p = 0.448), recurrence rate (3.30% vs. 2.20%, p = 0.458), and stricture rate (7.69% vs. 4.07%, p = 0.110). However, the perforation rate was higher in the post-endoscopic submucosal dissection scar group than in the first endoscopic submucosal dissection group (4.40% vs. 1.10%, p = 0.031). The 5-year overall survival rates in the post-endoscopic submucosal dissection scar and first endoscopic submucosal dissection groups were 88.6% and 89.0%, respectively. CONCLUSIONS: Repeated esophageal endoscopic submucosal dissection for recurrent esophageal squamous cell carcinoma yielded satisfactory clinical outcomes and survival rates. Therefore, repeat endoscopic submucosal dissection may effectively treat esophageal squamous cell carcinoma recurrence close to the initial endoscopic submucosal dissection scars.

12.
Chembiochem ; 24(21): e202300455, 2023 11 02.
Artículo en Inglés | MEDLINE | ID: mdl-37497578

RESUMEN

For the development of delivery systems, the solubilization of hydrophobic guest molecules in water is an important yet challenging task. This can be achieved by preparing stable aqueous solutions with a high concentration of guest molecules using a natural product as a solubilizing agent and a mechanochemical high-speed vibration milling apparatus as a solubilizing method. Various solubilizing agent-guest molecule complexes can be obtained via the exchange between solubilizing agents, which enables the "on-off" switching of the properties of functional guest molecules, such as fluorescence intensity, and photodynamic activity. In the exchange method, guest molecules can transfer into cell membranes such as lysosomes and exosomes. Therefore, the exchange method of the solubilizing agents not only creates novel solubilizing agent-guest molecule complexes but also is applied to drug delivery systems.


Asunto(s)
Sistemas de Liberación de Medicamentos , Agua , Agua/química
13.
Chembiochem ; 24(15): e202300186, 2023 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-37069129

RESUMEN

Minimally invasive boron neutron capture therapy (BNCT) is an elegant approach for cancer treatment. The highly selective and efficient deliverability of boron agents to cancer cells is the key to maximizing the therapeutic benefits of BNCT. In addition, enhancement of the frequencies to achieve boron neutron capture reaction is also significant in improving therapeutic efficacy by providing a highly concentrated boron agent in each boron nanoparticle. As the density of the thermal neutron beam remains low, it is unable to induce high-efficiency cell destruction. Herein, we report phospholipid-coated boronic oxide nanoparticles as agents for BNCT that can provide a highly concentrated boron atom in each nanoparticle. The current system exhibited in vitro BNCT activity seven times higher than that of commercial boron agents. Furthermore, the system could penetrate cancer spheroids deeply, efficiently suppressing thermal neutron irradiation-induced growth.


Asunto(s)
Terapia por Captura de Neutrón de Boro , Nanopartículas , Boro , Fosfolípidos , Compuestos de Boro/uso terapéutico , Óxidos
14.
Chemistry ; 29(10): e202203071, 2023 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-36415055

RESUMEN

Herein, trimethyl-ß-cyclodextrin (TMe-ß-CDx) and γ-cyclodextrin (γ-CDx) could dissolve a tetraphenylethylene derivative (TPE-OH4 ) in water through high-speed vibration milling. The fluorescence intensity of the TMe-ß-CDx-TPE-OH4 complex was much higher than that of the γ-CDx-TPE-OH4 complex, as the rotation of the central C=C double bond of TPE-OH4 after photoactivation was inhibited in a smaller TMe-ß-CDx cavity in comparison with the γ-CDx cavity. In contrast, the fluorescence intensity of the γ-CDx-TPE-OH4 complex was very weak; nevertheless, it increased after the addition of liposomes due to the transfer of TPE-OH4 from the γ-CDx cavity to the lipid membrane as a "turn-on" phenomenon. Furthermore, to apply temperature sensor, it was demonstrated that the fluorescence intensity in the liposomes depended on the phase-transition temperature. By using the fluorescence turn-on phenomenon, TPE-OH4 could detect the presence of HeLa cells and E. coli by fluorescence.


Asunto(s)
Ciclodextrinas , Humanos , Ciclodextrinas/química , Liposomas , Escherichia coli , Células HeLa
15.
Chemistry ; 29(47): e202301385, 2023 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-37334625

RESUMEN

Tetrakis(4-aminophenyl)porphyrin (1) and tetrakis(4-acetamidophenyl)porphyrin (2) were dissolved in water with the incorporation of a polysaccharide (λ-carrageenan (CGN)) as a water-solubilizing agent. Although the photodynamic activity of the CGN-2 complex was considerably lower than that of the CGN-1 complex, the selectivity index (SI; IC50 in a normal cell/IC50 in a cancer cell) of the CGN-2 complex was considerably higher than that of the CGN-1 complex. This is because the photodynamic activity of the CGN-2 complex was significantly affected by the intracellular uptakes by the normal and cancer cells. During in vivo experiments, the CGN-2 complex inhibited tumor growth under light irradiation with high blood retention compared with the CGN-1 complex and Photofrin, which exhibited lower blood retention. This study showed that the photodynamic activity and SI are influenced by substituent groups of arene in the meso-positions of porphyrin analogs.


Asunto(s)
Neoplasias , Animales , Humanos , Ratones , Acetilación , Línea Celular Tumoral , Liposomas , Neoplasias/química , Neoplasias/terapia , Fotoquímica/métodos , Fotoquimioterapia , Fármacos Fotosensibilizantes/uso terapéutico , Porfirinas/química
16.
Chemistry ; 29(72): e202302486, 2023 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-37792507

RESUMEN

Boron neutron capture therapy (BNCT) is a promising modality for cancer treatment because of its minimal invasiveness. To maximize the therapeutic benefits of BNCT, the development of efficient platforms for the delivery of boron agents is indispensable. Here, carborane-integrated immunoliposomes were prepared via an exchanging reaction to achieve HER-2-targeted BNCT. The conjugation of an anti-HER-2 antibody to carborane-integrated liposomes successfully endowed these liposomes with targeting properties toward HER-2-overexpressing human ovarian cancer cells (SK-OV3); the resulting BNCT activity toward SK-OV3 cells obtained using the current immunoliposomal system was 14-fold that of the l-BPA/fructose complex, which is a clinically available boron agent. Moreover, the growth of spheroids treated with this system followed by thermal neutron irradiation was significantly suppressed compared with treatment with the l-BPA/fructose complex.


Asunto(s)
Boranos , Terapia por Captura de Neutrón de Boro , Humanos , Liposomas , Terapia por Captura de Neutrón de Boro/métodos , Boro , Compuestos de Boro , Fructosa
17.
Soft Matter ; 19(31): 6046-6056, 2023 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-37525927

RESUMEN

The jamming transition is a nonequilibrium critical phenomenon, which governs characteristic mechanical properties of jammed soft materials, such as pastes, emulsions, and granular matters. Both experiments and theory of jammed soft materials have revealed that the complex modulus measured by conventional macrorheology exhibits a characteristic frequency dependence. Microrheology is a new type of method to obtain the complex modulus, which transforms the microscopic motion of probes to the complex modulus through the generalized Stokes relation (GSR). Although microrheology has been applied to jammed soft materials, its theoretical understanding is limited. In particular, the validity of the GSR near the jamming transition is far from obvious since there is a diverging length scale lc, which characterizes the heterogeneous response of jammed particles. Here, we study the microrheology of jammed particles by theory and numerical simulation. First, we develop a linear response formalism to calculate the response function of the probe particle, which is transformed to the complex modulus via the GSR. Then, we apply our formalism to a numerical model of jammed particles and find that the storage and loss modulus follow characteristic scaling laws near the jamming transition. Importantly, the observed scaling law coincides with that in macrorheology, which indicates that the GSR holds even near the jamming transition. We rationalize this equivalence by asymptotic analysis of the obtained formalism and numerical analysis on the displacement field of jammed particles under a local perturbation.

18.
Soft Matter ; 19(32): 6074-6087, 2023 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-37491980

RESUMEN

Although glass phases are ubiquitously found in various soft matter systems, we are still far from a complete understanding of them. The concept of marginal stability predicted by infinite-dimensional mean-field theories is drawing attention as a candidate for a universal and distinguishing unique feature of glasses. While among theoretical predictions, the non-Debye scaling has indeed been observed universally over various classes of glasses, the Gardner phase is found only in a limited portion of them. In this work, we numerically demonstrate that plastic events observed in two-dimensional Lennard-Jones glasses under quasistatic shear exhibit statistical properties that are qualitatively consistent with the picture of an infinitely hierarchical energy landscape associated with the Gardner phase.

19.
Org Biomol Chem ; 21(23): 4810-4816, 2023 06 14.
Artículo en Inglés | MEDLINE | ID: mdl-37248815

RESUMEN

Porphyrin-fullerene composite systems are attracting great attention as photodynamic agents; however, water-soluble derivatives are still scarce. Herein, we prepared noncovalently a lipid membrane-incorporated porphyrin-fullerene composite system with relative stability in aqueous solution. As in the case of porphyrin-fullerene composite systems in nonpolar solvents, efficient formation of singlet oxygen occurred via photoinduced energy transfer between porphyrin and fullerene as the predominant pathway in the photodynamic activity under the hydrophobic conditions of the lipid membranes, resulting in enhanced photodynamic activity toward Colon26 and HeLa cells compared with the individual porphyrin and fullerene components. Furthermore, the porphyrin-fullerene composite system exhibited high selectivity toward HeLa cells over normal mouse fibroblast L929 cells.


Asunto(s)
Fulerenos , Porfirinas , Animales , Ratones , Humanos , Porfirinas/farmacología , Porfirinas/química , Fulerenos/farmacología , Fulerenos/química , Células HeLa , Transferencia de Energía , Lípidos
20.
Org Biomol Chem ; 21(25): 5194-5202, 2023 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-37161772

RESUMEN

Phenazine-2,3-diol-based dyes, KY-1Na and KY-2Na bearing one and two carboxylic acid sodium salts, respectively, have been newly developed as water-soluble photosensitizers (PSs) possessing the ability to generate singlet oxygen (1O2). In order to evaluate the solubility of KY-1Na and KY-2Na in water, the hydrophobicity/hydrophilicity of the two PSs was investigated by experimental measurement of the logarithms (log Po/w) of the 1-octanol/water partition coefficient (Po/w) for the PS. The log Po/w values of both KY-1Na and KY-2Na were determined to be -0.9, indicating that both the PSs are more hydrophilic than Rose Bengal (-0.6) and have hydrophilicity equivalent to methylene blue (-0.9). Both the PSs in water show a broad photoabsorption band in the range of 500 to 600 nm. Thus, we estimated the 1O2 quantum yields (ΦΔ) of KY-1Na and KY-2Na in water by using 9,10-anthracenediyl-bis(methylene)dimalonic acid (ABDA) as a water-soluble 1O2 scavenger. It was found that in water the ΦΔ value (0.19) of KY-2Na is higher than that of KY-1Na (0.06). Density functional theory (DFT) calculations suggested that the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) distributions for the molecular structure of KY-2Na are adequately separated, leading to a decrease in the energy gap (ΔEST) between the singlet state (S1) and the triplet state (T1) that causes efficient intersystem crossing (ISC), compared to that for the molecular structure of KY-1Na. Indeed, time-dependent DFT (TD-DFT) calculations demonstrated that the ΔEST(S1-T1) value (0.82 eV) of KY-2Na is smaller than that (0.98 eV) of KY-1Na, resulting in a relatively high ΦΔ value of KY-2Na. Consequently, we demonstrate that phenazine-2,3-diol-based PSs bearing carboxylic acid salts possess high solubility and moderate 1O2 generation ability in water.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA