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1.
Nature ; 585(7824): 256-260, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32848244

RESUMEN

Temperature controls plant growth and development, and climate change has already altered the phenology of wild plants and crops1. However, the mechanisms by which plants sense temperature are not well understood. The evening complex is a major signalling hub and a core component of the plant circadian clock2,3. The evening complex acts as a temperature-responsive transcriptional repressor, providing rhythmicity and temperature responsiveness to growth through unknown mechanisms2,4-6. The evening complex consists of EARLY FLOWERING 3 (ELF3)4,7, a large scaffold protein and key component of temperature sensing; ELF4, a small α-helical protein; and LUX ARRYTHMO (LUX), a DNA-binding protein required to recruit the evening complex to transcriptional targets. ELF3 contains a polyglutamine (polyQ) repeat8-10, embedded within a predicted prion domain (PrD). Here we find that the length of the polyQ repeat correlates with thermal responsiveness. We show that ELF3 proteins in plants from hotter climates, with no detectable PrD, are active at high temperatures, and lack thermal responsiveness. The temperature sensitivity of ELF3 is also modulated by the levels of ELF4, indicating that ELF4 can stabilize the function of ELF3. In both Arabidopsis and a heterologous system, ELF3 fused with green fluorescent protein forms speckles within minutes in response to higher temperatures, in a PrD-dependent manner. A purified fragment encompassing the ELF3 PrD reversibly forms liquid droplets in response to increasing temperatures in vitro, indicating that these properties reflect a direct biophysical response conferred by the PrD. The ability of temperature to rapidly shift ELF3 between active and inactive states via phase transition represents a previously unknown thermosensory mechanism.


Asunto(s)
Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Proteínas Priónicas/química , Temperatura , Factores de Transcripción/química , Factores de Transcripción/metabolismo , Aclimatación/fisiología , Arabidopsis/química , Calor , Modelos Moleculares , Péptidos/metabolismo , Transición de Fase , Dominios Proteicos , Proteínas Represoras/química , Proteínas Represoras/metabolismo
2.
Retina ; 43(1): 120-129, 2023 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-36165992

RESUMEN

PURPOSE: To investigate bilateral macular features on optical coherence tomography in patients with unilateral peripheral exudative hemorrhagic chorioretinopathy (PEHCR). METHODS: In this cross-sectional study, optical coherence tomography features of affected eyes (PEHCR group, n = 30) and unaffected contralateral eyes (contralateral group, n = 30) were investigated. Age-matched and sex-matched patients with polypoidal choroidal vasculopathy (PCV group, n = 51) and healthy controls (normal group, n = 50) were included to compare choroidal thickness, measured at six points apart from the fovea, with the PEHCR group. RESULTS: Subretinal drusenoid deposits were the most common feature in the PEHCR (20%) and contralateral (23%) groups, followed by soft drusen. Although the macular choroid was comparably thin in both the PEHCR and contralateral groups, pachyvessels were also observed. The choroids of the PEHCR group were significantly thinner than those of the normal group at the subfovea and 1-mm temporal to the fovea and considerably thinner than those of the polypoidal choroidal vasculopathy group from 3-mm nasal to 3-mm temporal to the fovea. CONCLUSION: In patients with unilateral PEHCR, bilateral choroidal thinning and drusenoid deposit accumulation were noted in the macula. The pathophysiology of PEHCR may be a rare peripheral complication of age-related macular degeneration with pathologic choroid.


Asunto(s)
Enfermedades de la Coroides , Drusas Retinianas , Humanos , Estudios Transversales , Angiografía con Fluoresceína , Enfermedades de la Coroides/diagnóstico , Enfermedades de la Coroides/patología , Coroides/patología , Drusas Retinianas/diagnóstico , Drusas Retinianas/etiología , Drusas Retinianas/patología , Tomografía de Coherencia Óptica , Estudios Retrospectivos
3.
BMC Musculoskelet Disord ; 24(1): 973, 2023 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-38102571

RESUMEN

BACKGROUND: The upper normoglycemic range has been proposed as a risk factor for degenerative rotator cuff tendon tear (RCT), and insulin resistance has been suggested as a risk factor for tendinopathy. However, no research has established their association with degenerative RCT in the general population. This study aimed to determine whether fasting glucose levels and insulin resistance are risk factors for degenerative RCT in the normoglycemic population and identify the risk range for fasting glucose. METHODS: This study included 418 normoglycemic participants from a rural cohort. Participants completed questionnaires, physical exams, blood tests, and MRI evaluations of both shoulders. Insulin resistance was assessed using a triglyceride/high-density-lipoprotein (TG/HDL) ≥ 3.5. Logistic regression analysis was used to determine the association between fasting glucose level, TG/HDL ≥ 3.5, and other factors and degenerative RCT. The study calculated the areas under the receiver operating characteristic curve (AUC) to determine the more appropriate predicting value between the scale and categorical values of fasting glucose levels, and compared the AUCs using the DeLong method. RESULTS: In the multivariable analyses, both scale and categorical values of fasting glucose levels, and TG/HDL ≥ 3.5 were significantly associated with degenerative RCT. Fasting glucose levels ≥ 90.5 mg/dL (OR: 3.87, 95% CI: 2.10-7.06) in scale value and 90-99 mg/dL (OR: 4.13, 95% CI: 2.87-8.12) in categorical value were significantly associated with degenerative RCT (P < .001). The AUC of the scale value of fasting glucose levels ≥ 90.5 mg/dL was 0.68. The AUC of the categorical value of fasting glucose levels of 90-99 mg/dL was 0.70. Because of the significantly larger AUC of the categorical value of fasting glucose levels of 90-99 mg/dL, those fasting glucose levels were determined to be independently associated with degenerative RCT (P < .001). CONCLUSIONS: High fasting glucose levels within the normal range may link to increase insulin resistance and risk of degenerative RCT. Normoglycemic levels of 90-99 mg/dL and insulin resistance may be risk factors for degenerative RCT. LEVEL OF EVIDENCE: Level III, prognostic study.


Asunto(s)
Resistencia a la Insulina , Lesiones del Manguito de los Rotadores , Humanos , Lesiones del Manguito de los Rotadores/diagnóstico por imagen , Lesiones del Manguito de los Rotadores/complicaciones , Hombro , Ayuno , Glucosa
4.
Proc Natl Acad Sci U S A ; 117(12): 6901-6909, 2020 03 24.
Artículo en Inglés | MEDLINE | ID: mdl-32165537

RESUMEN

The Evening Complex (EC), composed of the DNA binding protein LUX ARRHYTHMO (LUX) and two additional proteins EARLY FLOWERING 3 (ELF3) and ELF4, is a transcriptional repressor complex and a core component of the plant circadian clock. In addition to maintaining oscillations in clock gene expression, the EC also participates in temperature and light entrainment, acting as an important environmental sensor and conveying this information to growth and developmental pathways. However, the molecular basis for EC DNA binding specificity and temperature-dependent activity were not known. Here, we solved the structure of the DNA binding domain of LUX in complex with DNA. Residues critical for high-affinity binding and direct base readout were determined and tested via site-directed mutagenesis in vitro and in vivo. Using extensive in vitro DNA binding assays of LUX alone and in complex with ELF3 and ELF4, we demonstrate that, while LUX alone binds DNA with high affinity, the LUX-ELF3 complex is a relatively poor binder of DNA. ELF4 restores binding to the complex. In vitro, the full EC is able to act as a direct thermosensor, with stronger DNA binding at 4 °C and weaker binding at 27 °C. In addition, an excess of ELF4 is able to restore EC binding even at 27 °C. Taken together, these data suggest that ELF4 is a key modulator of thermosensitive EC activity.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crecimiento & desarrollo , Arabidopsis/metabolismo , Ritmo Circadiano , ADN de Plantas/metabolismo , Proteínas de Unión al ADN/metabolismo , Regulación de la Expresión Génica de las Plantas , Arabidopsis/genética , Proteínas de Arabidopsis/genética , ADN de Plantas/genética , Proteínas de Unión al ADN/genética
5.
Genomics ; 114(3): 110334, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35278618

RESUMEN

Despite extensive studies on blood pressure, its genetic risk factors remain uncertain. Even one of the most researched blood pressure-related traits - renin - is not fully understood genetically. Here, we determine the genetic relationship and associated predisposition between blood pressure and baseline renin. In 8840 Korean individuals, we observed a strong negative genome-wide genetic correlation (rg = -0.484) between systolic blood pressure (SBP) and plasma renin activity (PRA), suggesting that antagonistic genetic signals explain the variance in the two traits. We found 51 significant pleiotropic SNPs affecting the two traits, which could contribute to the Renin-Angiotensin-Aldosterone System (RAAS). Our findings provide insight into studies on RAAS by identifying the genome-wide relationship and susceptibility loci of SBP and PRA.


Asunto(s)
Aldosterona , Renina , Humanos , Renina/genética , Presión Sanguínea/genética , Aldosterona/genética , Sistema Renina-Angiotensina/genética , República de Corea
6.
Angew Chem Int Ed Engl ; 62(32): e202306879, 2023 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-37321976

RESUMEN

Designing multi-resonance (MR) emitters that can simultaneously achieve narrowband emission and suppressed intermolecular interactions is challenging for realizing high color purity and stable blue organic light-emitting diodes (OLEDs). Herein, a sterically shielded yet extremely rigid emitter based on a triptycene-fused B,N core (Tp-DABNA) is proposed to address the issue. Tp-DABNA exhibits intense deep blue emissions with a narrow full width at half maximum (FWHM) and a high horizontal transition dipole ratio, superior to the well-known bulky emitter, t-DABNA. The rigid MR skeleton of Tp-DABNA suppresses structural relaxation in the excited state, with reduced contributions from the medium- and high-frequency vibrational modes to spectral broadening. The hyperfluorescence (HF) film composed of a sensitizer and Tp-DABNA shows reduced Dexter energy transfer compared to those of t-DABNA and DABNA-1. Notably, deep blue TADF-OLEDs with the Tp-DABNA emitter display higher external quantum efficiencies (EQEmax =24.8 %) and narrower FWHMs (≤26 nm) than t-DABNA-based OLEDs (EQEmax =19.8 %). The HF-OLEDs based on the Tp-DABNA emitter further demonstrate improved performance with an EQEmax of 28.7 % and mitigated efficiency roll-offs.

7.
Chem Rec ; 22(6): e202200011, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35332649

RESUMEN

A detailed understanding of the dissociation of O2 molecules on metal surfaces induced by various excitation sources, electrons/holes, light, and localized surface plasmons, is crucial not only for controlling the reactivity of oxidation reactions but also for developing various oxidation catalysts. The necessity of mechanistic studies at the single-molecule level is increasingly important for understanding interfacial interactions between O2 molecules and metal surfaces and to improve the reaction efficiency. We review single-molecule studies of O2 dissociation on Ag(110) induced by various excitation sources using a scanning tunneling microscope (STM). The comprehensive studies based on the STM and density functional theory calculations provide fundamental insights into the excitation pathway for the dissociation reaction.

8.
Bioorg Med Chem Lett ; 55: 128451, 2022 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-34774741

RESUMEN

JAK inhibitors have been considered as useful targets for the treatment of related diseases. However, first-generation JAK inhibitors have side effects such as anemia, thrombocytopenia, neutropenia and headaches which have been suggested to result from high JAK2 inhibition. Second-generation JAK inhibitors with more specific JAK isozyme inhibition have been studied to eliminate these adverse effects. In this study, novel 4-(1,5- or 2,5-triazole)-pyrrolopyrimidine derivatives with aromatic moieties were synthesized as JAK1 inhibitors, and an in vitro enzyme assay was used to evaluate the JAK inhibitory effects. Among these JAK1 inhibitors, the compound 23a showed an IC50 level of 72 nM, as well as being selective against other JAKs by 12 times or more: the results of molecular docking studies suggested that the high JAK1 selectivity resulted from a key interaction between the iodine atom of compound 23a and His-885 of hJAK1.


Asunto(s)
Janus Quinasa 1/antagonistas & inhibidores , Inhibidores de las Cinasas Janus/farmacología , Pirimidinas/farmacología , Pirroles/farmacología , Triazoles/farmacología , Cristalografía por Rayos X , Relación Dosis-Respuesta a Droga , Humanos , Janus Quinasa 1/metabolismo , Inhibidores de las Cinasas Janus/síntesis química , Inhibidores de las Cinasas Janus/química , Modelos Moleculares , Estructura Molecular , Pirimidinas/síntesis química , Pirimidinas/química , Pirroles/síntesis química , Pirroles/química , Relación Estructura-Actividad , Triazoles/síntesis química , Triazoles/química
9.
Langenbecks Arch Surg ; 407(2): 491-499, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34322746

RESUMEN

PURPOSE: To evaluate the diagnostic accuracy of near-infrared autofluorescence-based identification in the identification of parathyroid glands during thyroidectomy or parathyroidectomy. METHODS: The clinical studies were retrieved from PubMed, the Cochrane Central Register of Controlled Trials, Embase, Web of Science, SCOPUS, and Google Scholar. The study protocol was registered on Open Science Framework ( https://osf.io/um8rj/ ). The search period ranged from the date of each database's inception to May 2021. Cohort studies dealing with patients of whom parathyroid glands were detected by near-infrared autofluorescence and confirmed clinically or pathologically during thyroidectomy or parathyroidectomy were included. Editorials, letters, "how-I-do-it" descriptions, other site head and neck tumors, and articles with lack of diagnostic identification data were excluded. True positive, true negative, false positive, and false negative were extracted. The QUDAS ver. 2 was used to evaluate the methodological quality. RESULTS: Seventeen studies with 1198 participants were evaluated in this analysis. Near-infrared autofluorescence-based identification of parathyroid glands showed a diagnostic odds ratio of 228.8759 (95% confidence interval, 134.1099; 390.6063). The area under the summary receiver operating characteristic curve was 0.967. The sensitivity, specificity, negative predictive value, and positive predictive value were 0.9693 (0.9491; 0.9816), 0.9248 (0.8885; 0.9499), 0.9517 (0.8981; 0.9778), and 0.9488 (0.9167; 0.9689), respectively. Subgroup analyses were performed to compare two autofluorescence detection methods, because there was high heterogeneity in the outcomes. The diagnostic accuracy was higher in probe-based detection than in image-based detection. CONCLUSIONS: Near-infrared autofluorescence-based identification is valuable for identifying the parathyroid glands of patients during thyroidectomy or parathyroidectomy.


Asunto(s)
Glándulas Paratiroides , Paratiroidectomía , Estudios de Cohortes , Humanos , Imagen Óptica/métodos , Glándulas Paratiroides/diagnóstico por imagen , Glándulas Paratiroides/cirugía , Paratiroidectomía/métodos , Tiroidectomía/métodos
10.
J Shoulder Elbow Surg ; 31(10): 2121-2127, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35447316

RESUMEN

BACKGROUND: Thyroid functional abnormalities are considered risk factors for idiopathic adhesive capsulitis (IAC) though that relationship remains uncertain. Although dyslipidemias are associated with IAC, no readily accessible study has reported associations between dyslipidemias and IAC patients with subclinical hypothyroidism. The purposes of this study were to investigate whether subclinical hypothyroidism is an independently associated factor for IAC and to determine the differences in prevalence of dyslipidemias between two groups of persons with subclinical hypothyroidism: one composed of IAC patients and the other of individuals without IAC. METHODS: This case-control study included a case group of 412 IAC patients without intrinsic shoulder lesions, extrinsic causes, or medication for thyroid dysfunction. The control group comprised 1236 age- and sex-matched persons seeking general checkups at the authors' health promotion center during the same period as the case group. Control subjects had normal shoulder function and no previously diagnosed adhesive capsulitis, no medication for thyroid dysfunction, and no history of trauma or of shoulder surgery. The studied variables were age, gender, obesity, diabetes, dyslipidemias, subclinical hypothyroidism, hypothyroidism, and hyperthyroidism. A conditional logistic regression analysis evaluated the matched sets of subjects to determine odds ratios and 95% confidence intervals for the studied variables. The differences in the prevalence of dyslipidemias between IAC patients with subclinical hypothyroidism and individuals with subclinical hypothyroidism but without IAC were determined with generalized estimating equations, using covariates of age, sex, and diabetes. The P values were set at < 0.05. RESULTS: Subclinical hypothyroidism (odds ratio, 2.10; 95% confidence interval, 1.36-3.15; P = .001) was significantly associated with IAC. Patients with IAC and subclinical hypothyroidism had a significantly higher prevalence of hyper-low-density lipoproteinemia, an inflammatory lipoproteinemia, than individuals with subclinical hypothyroidism but without IAC (P = .002). CONCLUSIONS: Subclinical hypothyroidism is significantly associated with IAC. Hyper-low-density lipoproteinemia, an inflammatory lipoproteinemia, is involved in IAC accompanied by subclinical hypothyroidism.


Asunto(s)
Bursitis , Diabetes Mellitus , Dislipidemias , Hipotiroidismo , Bursitis/complicaciones , Bursitis/epidemiología , Estudios de Casos y Controles , Diabetes Mellitus/epidemiología , Dislipidemias/complicaciones , Humanos , Hipotiroidismo/complicaciones , Hipotiroidismo/epidemiología
11.
Drug Dev Res ; 83(7): 1600-1612, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36124859

RESUMEN

µ-Opioid receptor (MOR) Gi-biased agonists with no recruitment of ß-arrestin were introduced as a new analgesic strategy to overcome the conventional undesirable side effects of opioid receptor-targeted drugs, such as tolerance, addiction, respiratory depression, and constipation. For the development of novel Gi-biased MOR agonists, the design, synthesis, and structure-activity relationship (SAR) analysis of the aminopyrazole core skeleton were conducted according to the current SAR data of PZM21 (2a) and its derivatives. New derivatives were biologically evaluated for their agonistic effects on cyclic adenosine monophosphate (cAMP) levels for the Gi pathway and ß-arrestin recruitment in MOR/κ-opioid receptor/δ opioid receptor. An optimized selective Gi-biased agonist, Compound 17a, was discovered with potent cAMP inhibitory activities, with a 50% efficacy concentration value of 87.1 nM and no activity in the MOR ß-arrestin pathway and other subtypes. The in vivo pain relief efficacy of Compound 17a was confirmed in a dose-dependent manner with spinal nerve ligation and cisplatin-induced peripheral neuropathy rodent neuropathic pain models.


Asunto(s)
Neuralgia , Receptores Opioides mu , Humanos , Receptores Opioides mu/agonistas , Analgésicos Opioides/farmacología , beta-Arrestinas/metabolismo , Receptores Opioides/metabolismo , Pirazoles
12.
Int J Mol Sci ; 23(2)2022 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-35055154

RESUMEN

Fluorescent molecular assembly systems provide an exciting platform for creating stimuli-responsive nano- and microstructured materials with optical, electronic, and sensing functions. To understand the relationship between (i) the plausible molecular structures preferentially adopted depending on the solvent polarity (such as N,N-dimethylformamide [DMF], tetrahydrofuran [THF], and toluene), (ii) the resulting spectroscopic features, and (iii) self-assembled nano-, micro-, and macrostructures, we chose a sterically crowded triangular azo dye (3Bu) composed of a polar molecular core and three peripheral biphenyl wings. The chromophore changed the solution color from yellow to pink-red depending on the solvent polarity. In a yellow DMF solution, a considerable amount of the twisted azo form could be kept stable with the help of favorable intermolecular interactions with the solvent molecules. By varying the concentration of the DMF solution, the morphology of self-assembled structures was transformed from nanoparticles to micrometer-sized one-dimensional (1D) structures such as sticks and fibers. In a pink-red toluene solution, the periphery of the central ring became more planar. The resulting significant amount of the keto-hydrazone tautomer grew into micro- and millimeter-sized 1D structures. Interestingly, when THF-H2O (1:1) mixtures were stored at a low temperature, elongated fibers were stacked sideways and eventually developed into anisotropic two-dimensional (2D) sheets. Notably, subsequent exposure of visible-light-irradiated sphere samples to solvent vapor resulted in reversible fluorescence off↔on switching accompanied by morphological restoration. These findings suggest that rational selection of organic dyes, solvents, and light is important for developing reusable fluorescent materials.


Asunto(s)
Compuestos Azo/química , Colorantes/química , Solventes/química , Cristalografía por Rayos X , Luz , Modelos Moleculares , Estructura Molecular , Nanoestructuras
13.
J Cell Physiol ; 236(2): 1362-1374, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-32749680

RESUMEN

The beneficial effects of light-emitting diode (LED) irradiation have been reported in various pathologies, including cancer. However, its effect in pancreatic cancer cells remains unclear. Herein, we demonstrated that blue LED of 460 nm regulated pancreatic cancer cell proliferation and apoptosis by suppressing the expression of apoptosis-related factors, such as mutant p53 and B-cell lymphoma 2 (Bcl-2), and decreasing the expression of RAC-ß serine/threonine kinase 2 (AKT2), the phosphorylation of protein kinase B (AKT), and mammalian target of rapamycin (mTOR). Blue LED irradiation also increased the levels of cleaved poly-(ADP-ribose) polymerase (PARP) and caspase-3 in pancreatic cancer cells, while it suppressed AKT2 expression and inhibited tumor growth in xenograft tumor tissues. In conclusion, blue LED irradiation suppressed pancreatic cancer cell and tumor growth by regulating AKT/mTOR signaling. Our findings indicated that blue LEDs could be used as a nonpharmacological treatment for pancreatic cancer.


Asunto(s)
Apoptosis/genética , Proliferación Celular/genética , Neoplasias Pancreáticas/radioterapia , Proteínas Proto-Oncogénicas c-akt/genética , Serina-Treonina Quinasas TOR/genética , Animales , Apoptosis/efectos de la radiación , Línea Celular Tumoral , Proliferación Celular/efectos de la radiación , Regulación Neoplásica de la Expresión Génica/genética , Regulación Neoplásica de la Expresión Génica/efectos de la radiación , Humanos , Luz , Ratones , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patología , Fosfatidilinositol 3-Quinasas/genética , Fosforilación/efectos de la radiación , Ensayos Antitumor por Modelo de Xenoinjerto
14.
Plant Physiol ; 182(1): 612-625, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31712305

RESUMEN

The Evening Complex (EC) is a core component of the Arabidopsis (Arabidopsis thaliana) circadian clock, which represses target gene expression at the end of the day and integrates temperature information to coordinate environmental and endogenous signals. Here we show that the EC induces repressive chromatin structure to regulate the evening transcriptome. The EC component ELF3 directly interacts with a protein from the SWI2/SNF2-RELATED (SWR1) complex to control deposition of H2A.Z-nucleosomes at the EC target genes. SWR1 components display circadian oscillation in gene expression with a peak at dusk. In turn, SWR1 is required for the circadian clockwork, as defects in SWR1 activity alter morning-expressed genes. The EC-SWR1 complex binds to the loci of the core clock genes PSEUDO-RESPONSE REGULATOR7 (PRR7) and PRR9 and catalyzes deposition of nucleosomes containing the histone variant H2A.Z coincident with the repression of these genes at dusk. This provides a mechanism by which the circadian clock temporally establishes repressive chromatin domains to shape oscillatory gene expression around dusk.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Cromatina/metabolismo , Histonas/metabolismo , Arabidopsis/genética , Arabidopsis/fisiología , Proteínas de Arabidopsis/genética , Relojes Circadianos/fisiología , Histonas/genética , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
15.
Nano Lett ; 20(3): 2107-2112, 2020 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-32053385

RESUMEN

We report a chemical route to synthesize centimeter-scale stoichiometric "graphenol (C6OH1)", a 2D crystalline alcohol, via vapor phase hydroxylation of epitaxial graphene on Cu(111). Atomic resolution scanning tunneling microscopy revealed this highly-ordered configuration of graphenol and low energy electron diffraction studies on a large-area single crystal graphene film demonstrated the feasibility of the same superstructure being achieved at the centimeter length scale. Periodic density functional theory (DFT) calculations about the formation of C6(OH)1 and its electronic structure are also reported.

16.
Medicina (Kaunas) ; 58(1)2021 Dec 30.
Artículo en Inglés | MEDLINE | ID: mdl-35056361

RESUMEN

Hypokalemic periodic paralysis (HPP) is a neuromuscular disorder associated with muscular dysfunction caused by hypokalemia. There are various causes of HPPs and rarely, HPP appears to be relevant to tenofovir or glucocorticoid treatment. There have been several case reports of tenofovir-related nephrotoxicity or tenofovir-induced HPP. However, a case report of glucocorticoid-induced HPP in a patient using tenofovir temporarily has not been reported. Herein, we report a case of glucocorticoid-induced HPP with short-term use of tenofovir. A 28-year-old man visited the emergency room with decreased muscle power in all extremities (2/5 grade). In their past medical history, the patient was treated with tenofovir for two months for a hepatitis B virus infection. At the time of the visit, the drug had been discontinued for four months. The day before visiting the emergency room, betamethasone was administered at a local clinic for herpes on the lips. Laboratory tests showed hypokalemia, hypophosphatemia, and mild metabolic acidosis. However, urinalysis revealed no abnormal findings. Consequently, it can be postulated that this patient developed HPP by glucocorticoids after taking tenofovir temporarily. This is the first case report of glucocorticoid-induced HPP in a patient using tenofovir. Clinicians who prescribe tenofovir should be aware of HPP occurring when glucocorticoids are used.


Asunto(s)
Hipopotasemia , Parálisis Periódica Hipopotasémica , Hipofosfatemia , Adulto , Glucocorticoides/efectos adversos , Humanos , Hipopotasemia/inducido químicamente , Parálisis Periódica Hipopotasémica/inducido químicamente , Parálisis Periódica Hipopotasémica/diagnóstico , Parálisis Periódica Hipopotasémica/tratamiento farmacológico , Hipofosfatemia/inducido químicamente , Masculino , Tenofovir/efectos adversos
17.
J Am Chem Soc ; 142(20): 9327-9336, 2020 05 20.
Artículo en Inglés | MEDLINE | ID: mdl-32325000

RESUMEN

Engineering of supramolecular topologies offers potential opportunities for tailoring their properties to various function and applications. However, the synthesis of interlocked or intertwined compounds, catenanes, links or knots, is a challenge. Previously, we used coordination-driven self-assembly and noncovalent interactions (NCIs) between metal-based acceptors and multipyridyl donors to create supramolecular topologies with increasing complexity. Self-assembling components of fixed length and geometry have been utilized for the production of topologies such as Borromean rings, Solomon links, Hopf's link, "rectangle in rectangle", and an 818 molecular knot. However, recent synthesis of a linear [3]catenane by us witnessed the importance of flexible ligands along with coordination-driven self-assembly and NCIs in self-assembling units. This flexibility provides distinctive angularity for the recognition of various NCIs and thus offers tremendous possibilities for realizing complex supramolecular topologies. This study proposed a selective and quantitative synthesis, and also the first X-ray characterization of a closed three-link chain (a prime link of [3]catenane with 6 crossings) via two component coordination-driven self-assembly. The experiments based upon concentration, guest template, and solvent effects were systematically presented. Furthermore, the experimental finding was supported by density functional theory calculations, which highlighted the necessity of the multiple NCIs along with appropriate geometry of the [2 + 2] rings.

18.
Plant Cell ; 29(11): 2817-2830, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29070509

RESUMEN

Stomata are epidermal openings that facilitate plant-atmosphere gas exchange during photosynthesis, respiration, and water evaporation. Stomatal differentiation and patterning are spatially and temporally regulated by the master regulators SPEECHLESS (SPCH), MUTE, and FAMA, which constitute a central gene regulatory network along with Inducer of CBF Expression (ICE) transcription factors for this developmental process. Stomatal development is also profoundly influenced by environmental conditions, such as light, temperature, and humidity. Light induces stomatal development, and various photoreceptors modulate this response. However, it is unknown how light is functionally linked with the master regulatory network. Here, we demonstrate that, under dark conditions, the E3 ubiquitin ligase CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1) degrades ICE proteins through ubiquitination pathways in leaf abaxial epidermal cells in Arabidopsis thaliana Accordingly, the ICE proteins accumulate in the nuclei of leaf abaxial epidermal cells in COP1-defective mutants, which constitutively produce stomata. Notably, light in the blue, red, and far-red wavelength ranges suppresses the COP1-mediated degradation of the ICE proteins to induce stomatal development. These observations indicate that light is directly linked with the ICE-directed signaling module, via the COP1-mediated protein surveillance system, in the modulation of stomatal development.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Luz , Estomas de Plantas/metabolismo , Factores de Transcripción/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Proteínas de Arabidopsis/genética , Regulación del Desarrollo de la Expresión Génica/efectos de la radiación , Regulación de la Expresión Génica de las Plantas/efectos de la radiación , Estomas de Plantas/genética , Estomas de Plantas/crecimiento & desarrollo , Plantas Modificadas Genéticamente , Proteolisis/efectos de la radiación , Transducción de Señal/genética , Transducción de Señal/efectos de la radiación , Factores de Transcripción/genética , Ubiquitina-Proteína Ligasas/genética
19.
Chemistry ; 26(70): 16793-16801, 2020 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-32779254

RESUMEN

Doubly boron-doped thermally activated delayed fluorescence (TADF) emitters based on a 9,10-diboraanthracene (DBA) acceptor decorated with ortho-donor groups (Cz2oDBA, 2; BuCz2oDBA, 3; DMAC2oDBA, 4) are prepared to realize high-efficiency green-to-red organic light-emitting diodes (OLEDs). X-ray diffraction analyses of 2 and 4 reveal the symmetrical and highly twisted ortho-donor-acceptor-donor (D-A-D) structure of the emitters. The twisted conformation leads to a very small energy splitting (ΔEST <0.08 eV) between the excited singlet and triplet states that gives rise to strong TADF, as supported by theoretical studies. Depending on the strength of the donor moieties, the emission color is fine-tuned in the visible region from green (2) to yellow (3) to red (4). Carbazole-containing 2 and 3 exhibit high photoluminescence quantum yields (PLQYs) approaching 100 %, whereas DMAC-substituted 4 is moderately emissive (PLQY=44 %) in a doped host film. Highly efficient green-to-red TADF-OLEDs are realized with the proposed ortho-D-A-D compounds as emitters. The green and yellow OLEDs incorporating Cz2oDBA (2) and BuCz2oDBA (3) emitters exhibit high external quantum efficiencies (EQEs) of 26.6 % and 21.6 %, respectively. In particular, the green device shows an excellent power efficiency above 100 lm W-1 . A red OLED fabricated with a DMAC2oDBA (4) emitter exhibits a maximum EQE of 10.1 % with an electroluminescence peak at 615 nm.

20.
Gynecol Obstet Invest ; 85(3): 252-258, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32268326

RESUMEN

BACKGROUND/OBJECTIVES: Mechanical micro-vibration remains insufficient for improving embryo culture conditions in human immature oocytes. This study compared the clinical outcomes and embryo development between germinal vesicle (GV) oocytes with the micro-vibration culture (MVC) system in in vitro maturation (IVM) cycles and in vivo-matured oocytes in controlled ovarian hyperstimulation (COH) cycles in polycystic ovarian syndrome (PCOS) patients. METHODS: This study investigated 152 PCOS patients who underwent 159 fresh embryo transfer cycles, including IVM cycles with embryos derived from GV oocytes and the COH cycles with embryos derived from in vivo-matured oocytes. The IVM cycles were divided into groups according to the culture system used: static culture (SC) and MVC: In the IVM-S group (n = 47), SC was applied during both IVM and in vitro culture (IVC), whereas in the IVM-MV group (n = 44), MVC was applied during both IVM and IVC. For the COH cycles, in the COH-S group (n = 68), SC was applied during IVC. RESULTS: The number of in vitro-matured oocytes was similar in the IVM-S and IVM-MV groups, but the good-quality embryo (GQE; ≥6-cells) rate was significantly higher in the IVM-MV group (p < 0.01). The GQE rate and clinical outcomes of the COH-S group were significantly better than those of the IVM-S group (p < 0.05) but similar to those of the IVM-MV group. CONCLUSION: Compared with the SC system, the MVC system in IVM cycles improves the embryonic quality of GV oocytes and clinical outcomes, resulting in development of potential equivalent to in vivo-matured oocytes.


Asunto(s)
Desarrollo Embrionario/fisiología , Técnicas de Maduración In Vitro de los Oocitos/métodos , Oocitos/fisiología , Inducción de la Ovulación/métodos , Síndrome del Ovario Poliquístico/fisiopatología , Adulto , Transferencia de Embrión , Femenino , Humanos , Embarazo , Resultado del Tratamiento , Vibración
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