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Lanthanide complexes with judiciously designed ligands have been extensively studied for their potential applications as single-molecule magnets. With the influence of ligands on their magnetic properties generally established, recent research has unearthed certain effects inherent to site differentiation due to the different types and varying numbers of substituents on the same ligand platform. Using two new sandwich-type Er(III) complexes with cyclooctatetraenyl (COT) ligands featuring two differently positioned trimethylsilyl (TMS) substituents, namely, [Li(DME)Er(COT1,5-TMS2)2]n (Er1) and [Na(DME)3][Er(COT1,3-TMS2)2] (Er2) [COT1,3-TMS2 and COT1,5-TMS2 donate 1,3- and 1,5-bis(trimethylsilyl)-substituted cyclooctatetraenyl ligands, respectively; DME = 1,2-dimethoxyethane], and with reference to previously reported [Li(DME)3][Er(COT1,4-TMS2)2] (A) and [K(DME)2][Er(COT1,4-TMS2)2] (B), any possible substituent position effects have been explored for the first time. The rearrangement of the TMS substituents from the starting COT1,4-TMS2 to COT1,3-TMS2 and COT1,5-TMS2, by way of formal migration of the TMS group, was thermally induced in the case of Er1, while for the formation of Er2, the use of Na+ in the placement of its Li+ and K+ congeners is essential. Both Er1 and Er2 display single-molecule magnetic behaviors with energy barriers of 170(3) and 172(6) K, respectively. Magnetic hysteresis loops, butterfly-shaped for Er1 and wide open for Er2, were observed up to 12 K for Er1 and 13 K for Er2. Studies of magnetic dynamics reveal the different pathways for relaxation of magnetization below 10 K, mainly by the Raman process for Er1 and by quantum tunneling of magnetization for Er2, leading to the order of magnitude difference in magnetic relaxation times and sharply different magnetic hysteresis loops.
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PURPOSE: The removal of small foreign bodies embedded within the deep soft tissues of the maxillofacial region is a complex and challenging task for maxillofacial surgeons. The purpose of this study was to explore the efficacy of the combination of intraoperative CT and surgical navigation for the removal of small foreign objects in the maxillofacial region. METHODS: A serial case study was conducted involving all consecutive patients who underwent surgical removal of small foreign bodies in the maxillofacial region. The combination of intraoperative CT and a surgical navigation system was used at a single medical institution from January 2018 to December 2022. Comprehensive data, including patient demographics, characteristics of the foreign bodies, previous surgical interventions, duration of the surgical procedure, and removal success rate were collected for this study. Relevant data were recorded into Microsoft Excel sheet and analyzed using SPSS version 22.0. RESULTS: Nine patients (6 males and 3 females) were included in this study, with an average age of 37 years. Each patient had previously undergone an unsuccessful removal attempt utilizing conventional surgical methods based on preoperative CT imaging or C-arm guidance at a local healthcare facility. Four patients also experienced unsuccessful attempts with preoperative CT image-based navigation systems. However, by employing the combined approach of intraoperative CT and surgical navigation, the foreign bodies were successfully removed in all 9 patients. The mean duration of the surgical procedure was 59 min, and the average size of the foreign bodies was approximately 26 mm³. Postoperative follow-up exceeding 6 months revealed no complications. CONCLUSION: The combined use of a surgical navigation system and intraoperative CT represents a potent and effective strategy for the precise localization and subsequent removal of small foreign bodies from the soft tissue structures of the maxillofacial region. This integrative approach appears to increase the success rate of surgical interventions in such cases.
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Two-electron oxidations are ubiquitous and play a key role in the synthesis and catalysis. For transition metals and actinides, two-electron oxidation often takes place at a single-metal site. However, redox reactions at rare-earth metals have been limited to one-electron processes due to the lack of accessible oxidation states. Despite recent advancements in nontraditional oxidation state chemistry, the low stability of low-valent compounds and large disparity among different oxidation states prevented the implementation of two-electron processes at a single rare-earth metal center. Here we report two-electron oxidations at a cerium(II) center to yield cerium(IV) terminal oxo and imido complexes. A series of cerium(II-IV) complexes supported by a tripodal tris(amido)arene ligand were synthesized and characterized. Experimental and theoretical studies revealed that the cerium(II) complex is best described as a 4f2 ion stabilized by δ-backdonation to the anchoring arene, while the cerium(IV) oxo and imido complexes exhibit multiple bonding characters. The accomplishment of two-electron oxidations at a single cerium center brings a new facet to molecular rare-earth metal chemistry.
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Manipulating the radical concentration to modulate the properties in solid multifunctional materials is an attractive topic in various frontier fields. Viologens have the unique redox capability to generate radical states through reversible electron transfer (ET) under external stimuli. Herein, taking the viologens as the model, two kinds of crystalline compounds with different molecule-conjugated systems were designed and synthesized. By subjecting the specific model viologens to pressure, the cross-conjugated 2-X all exhibit much higher radical concentrations, along with more sensitive piezochromic behaviors, compared to the linear-conjugated 1-X. Unexpectedly, we find that the electrical resistance (R) of 1-NO3 decreased by three orders of magnitude with the increasing pressure, while that in high-radical-concentration 2-NO3 remained almost unchanged. To date, such unusual invariant conductivity has not been documented in molecular-based materials under high pressure, breaking the conventional wisdom that the generations of radicals are beneficial to improve conductivity. We highlight that adjusting the molecular conjugation modes can be used as an effective way to regulate the radical concentrations and thus modulate properties rationally.
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Inkless and erasable printing (IEP) based on chromic materials holds great promise to alleviate environmental and sustainable problems. Metal-organic polymers (MOPs) are bright platforms for constructing IEP materials. However, it is still challenging to design target MOPs with excellent specific functions rationally due to the intricate component-structure-property relationships. Herein, an effective strategy was proposed for the rational design IEP-MOP materials. The stimuli-responsive viologen moiety was introduced into the construction of MOPs to give it potential chromic behaviors and two different coordination models (i. e. bilateral coordination model, M1 ; unilateral coordinated model, M2 ) based on the same viologen ligand were designed. Aided by theoretical calculations, model M1 was recommended secondarily as a more suitable system for IEP materials. Along this line, two representative viologen-ZnII MOPs 1 and 2 with models M1 and M2 were synthesized successfully. Experiments exhibit that 1 does have quicker stimuli response, stronger color contrast and longer radical lifetime compared to 2. Significantly, the obtained 1-IEP media brightly inherits the excellent chromic characteristics of 1 and the flexibility of the paper at the same time, which achieves most daily printing requirements, as well as enough resolution and durability to be used in identification by smart device.
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Herein, DyIII and ErIII, the typical oblate and prolate Kramers Ln ions, were employed to synthesize a series of isostructural pairs: 2-5Ln (Ln = Dy and Er). In the [(COT)Ln(THF)4]+ cationic fragments of 2Ln, central ions were coordinated by the equatorial ligand cyclooctatetraenyl (COT) and THF solvents, while in the heteroleptic complexes 3Ln ((COT)Ln(OAr')), 4Ln ((COT)Ln(OArâ³)), and 5Ln ((COT)Ln(N)), the coordination geometries were formed by the cooperation of COT and bulky aryloxides OAr' (2,6-bis(diphenylmethyl)-4-methylphenyl), OArâ³ (2,6-bis(1-adamantyl)-4-methylphenyl), and amide N (bis(triisopropylsilyl) amide) for 3Ln, 4Ln, and 5Ln, respectively. Among these complexes, with the combinations of varying coordination geometries and different anisotropies of f orbitals, 2Er, 3Dy, and 4Dy were found to be zero-field SIMs with effective energy barriers of 181.9, 527.7, and 622.0 K, respectively, which are consistent with the structural analyses and ab initio calculations. The blocking temperatures (TB) of 3Dy and 4Dy are 4 and 7 K, respectively, as confirmed by the hysteresis loops at varying temperatures. The structures of 5Ln exhibit an almost perfect umbrella-shaped geometry, characterized by N-Ln-Centroid (COT) angles measuring 178.9 and 179.3° for 5Dy and 5Er, respectively. Crystallographic data from these structures were utilized to investigate the impact of ligand alignment on the magnetic properties of the compounds.
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Two pairs of homochiral Dy(III) tetranuclear cluster complexes derived from (+)/(-)-3-trifluoroacetyl camphor (D-Htfc/L-Htfc), [Dy4(OH)2(L1)4(D-tfc)2(DMF)2]·4DMF (D-1) [H2L1 = (E)-2-(2-hydroxy-3-methoxybenzylideneamino)phenol)]/[Dy4(OH)2(L1)4(L-tfc)2(DMF)2]·4DMF (L-1) and [Dy4(OH)2(L2)4(D-tfc)2(DMF)2]·2H2O·3MeCN (D-2) [H2L2 = (E)-3-(2-hydroxy-3-methoxybenzylideneamino)naphthalen-2-ol]/[Dy4(OH)2(L2)4(L-tfc)2(DMF)2]·2H2O·3MeCN (L-2), were synthesized at room temperature, which have a Dy4 parallelogram-like core. The magnetic studies revealed that D-1 exhibits single-molecule magnet (SMM) behavior under zero dc magnetic field, and its magnetic relaxation has a distinct Raman process in addition to the Orbach process, with the Ueff/k value of 57.5 K and the C value of 28.27 s-1K-2.14; while D-2 displays dual magnetic relaxation behavior at 0 Oe field, with the Ueff/k value 114.8 K for the slow relaxation process (SR) and the C value of 10.656 s-1K-5.80 for the fast relaxation process (FR), respectively. Theoretical calculations indicated that the conjugated groups (phenyl vs naphthyl) of the Schiff base bridging ligands (H2L1 and H2L2) significantly affect the intramolecular magnetic interactions between the Dy3+ ions and ultimately lead to different relaxations. Furthermore, magnetic circular dichroism (MCD) measurements showed that these two pairs of Dy4 enantiomers exhibit strong room temperature magneto-optical Faraday effects; notably, increasing the conjugated group on the Schiff base bridging ligand is beneficial to enhancing the magneto-optical Faraday effects.
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The current study evaluated the efficacy and safety of a denosumab biosimilar, QL1206 (60 mg), compared to placebo in postmenopausal Chinese women with osteoporosis and high fracture risk. At 31 study centers in China, a total of 455 postmenopausal women with osteoporosis and high fracture risk were randomly assigned to receive QL1206 (60 mg subcutaneously every 6 months) or placebo. From baseline to the 12-month follow-up, the participants who received QL1206 showed significantly increased bone mineral density (BMD) values (mean difference and 95% CI) in the lumbar spine: 4.780% (3.880%, 5.681%), total hip :3.930% (3.136%, 4.725%), femoral neck 2.733% (1.877%, 3.589%) and trochanter: 4.058% (2.791%, 5.325%) compared with the participants who received the placebo. In addition, QL1206 injection significantly decreased the serum levels of C-terminal crosslinked telopeptides of type 1 collagen (CTX): -77.352% (-87.080%, -66.844%), and N-terminal procollagen of type l collagen (P1NP): -50.867% (-57.184%, -45.217%) compared with the placebo over the period from baseline to 12 months. No new or unexpected adverse events were observed. We concluded that compared with placebo, QL1206 effectively increased the BMD of the lumbar spine, total hip, femoral neck and trochanter in postmenopausal Chinese women with osteoporosis and rapidly decreased bone turnover markers. This study demonstrated that QL1206 has beneficial effects on postmenopausal Chinese women with osteoporosis and high fracture risk.
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Biosimilares Farmacéuticos , Conservadores de la Densidad Ósea , Osteoporosis Posmenopáusica , Osteoporosis , Femenino , Humanos , Biosimilares Farmacéuticos/efectos adversos , Densidad Ósea , Conservadores de la Densidad Ósea/uso terapéutico , Remodelación Ósea , Denosumab/uso terapéutico , Denosumab/farmacología , Método Doble Ciego , Pueblos del Este de Asia , Osteoporosis/tratamiento farmacológico , Osteoporosis Posmenopáusica/complicaciones , Osteoporosis Posmenopáusica/tratamiento farmacológico , PosmenopausiaRESUMEN
By changing the counterions (ClO4- and CF3SO3-) and the coordination anions (Cl- and Br-), we investigated their influences on the structures and performances of a class of Zn2Dy chiral single-molecule magnets (SMMs), which are based on a pair of chiral Schiff bases R,R-H2LSchiff and S,S-H2LSchiff {R,R-H2LSchiff = 2-((E)-((1R,2R)-2-((E)-2-hydroxy-3-methoxybenzylideneamino)cyclohexylimino)methyl)-6-methoxyphenol and S,S-H2LSchiff = 2-((E)-((1S,2S)-2-((E)-2-hydroxy-3-methoxybenzylideneamino)cyclohexylimino)methyl)-6-methoxyphenol}. Three pairs of chiral Zn2Dy Schiff base complexes were obtained by directed synthesis, which are [DyZn2(R,R-LSchiff)Cl2(H2O)](ClO4)·0.5MeOH·0.25H2O (R-1) and [DyZn2(S,S-LSchiff)Cl2(H2O)][DyZn2(S,S-LSchiff)Cl2(MeOH)](ClO4)2·MeOH·0.5H2O (S-1), [DyZn2(R,R-LSchiff)Cl2(H2O)](CF3SO3)·0.5MeOH (R-2) and [DyZn2(S,S-LSchiff)Cl2(H2O)][DyZn2(S,S-LSchiff)Cl2(MeOH)](CF3SO3)2·MeOH (S-2), and [DyZn2(R,R-LSchiff)Br2(H2O)](CF3SO3)·0.25MeOH (R-3) and [DyZn2(S,S-LSchiff)Br2(H2O)][DyZn2(S,S-LSchiff)Br2(MeOH)](CF3SO3)2 (S-3). They all exhibit good SMM behaviors, and their magnet relaxation is regulated by not only the counterions (ClO4- and CF3SO3-) but also the coordination anions (Cl- and Br-); these anions also have important effects on the second-harmonic generation (SHG) and third harmonic generation (THG) nonlinear optical properties. Interestingly, in the S-configuration complexes, the coordination solvent molecule of the Dy3+ ion on half of the molecules is the methanol molecule instead of the water molecule. This change in the coordinating solvent molecule can also significantly affect the SMM behaviors and the SHG and THG nonlinear optical properties. Moreover, ab initio calculations were applied to rationally explain the SMM properties.
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The fibroblast growth factor receptor (FGFR) belongs to the tyrosine kinase family consisting of four members (FGFR1-4). This study involved identification and characterization of FGFR1 and FGFR3 from mud crab Scylla paramamosain for the first time. The obtained cDNAs of SpFGFR1 and SpFGFR3 were 2,380 bp and 2,982 bp in length with a 1,503 bp and 2,310 bp open reading frame, respectively. The predicted SpFGFR1 protein included three immunoglobulin domains and a transmembrane region, while SpFGFR3 protein possessed a typical TyrKc (Tyrosine kinase, catalytic) domain. Real-time PCR analysis showed that SpFGFR1 and SpFGFR3 were highly expressed in the hepatopancreas. Furthermore, the expression levels of SpFGFR1 and SpFGFR3 in the hepatopancreas were enhanced following challenges with Vibro alginolyticus, Staphylococcus aureus, Poly (I:C) and White spot syndrome virus, which shows the involvement of SpFGFR1 and SpFGFR3 in innate immune response to infections from bacteria and virus. There was significant suppression of six antimicrobial peptide genes (SpALF1-5 and SpCrustin) and three NF-κB members (SpDorsal, SpIKK and SpRelish) when SpFGFR1 and SpFGFR3 was interfered in vivo. Also, treatment of the hemocytes with specific inhibitor of SpFGFR for 24 h consistently down-regulated SpDorsal, SpRelish and AMPs. These results suggested that SpFGFR1 and SpFGFR3 played important roles in regulating the Toll signaling pathway and immune deficiency (IMD) pathway through NF-κB signaling pathway. These findings may provide new insights into the role of FGFRs in the innate immune function of crustaceans.
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Braquiuros , Animales , FN-kappa B/metabolismo , Proteínas de Artrópodos , Receptores de Factores de Crecimiento de Fibroblastos/genética , Filogenia , Inmunidad Innata/genética , Transducción de Señal , Poli I-C/farmacología , Proteínas Tirosina Quinasas/genéticaRESUMEN
Organic-inorganic hybrid perovskites (OIHPs) have gained tremendous interest for their rich functional properties. However, the coexistence of more than one of ferroelectricity, ferromagnetism and ferroelasticity has been rarely found in OIHPs. Herein, we report a two-dimensional Cr2+ -based OIHP, [3,3-difluorocyclobutylammonium]2 CrCl4 ([DFCBA]2 CrCl4 ), which shows both ferroelectricity and ferromagnetism. It undergoes a 4/mmmFm type ferroelectric phase transition at a temperature as high as 387â K and shows multiaxial ferroelectricity with a saturate polarization of 2.1â µC cm-2 . It acts as a soft ferromagnet with a Curie temperature of 32.6â K. This work throws light on the exploration of OIHPs with the coexistence of ferroelectricity and ferromagnetism for applications in future multifunctional smart devices.
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Photodynamic therapy (PDT) is a non-invasive treatment modality against a range of cancers and nonmalignant diseases, however one must be aware of the risk of causing phototoxic reactions after treatment. We herein report a bioinspired design of next-generation photosensitizers (PSs) that not only effectively produce ROS but undergo fast metabolism after treatment to overcome undesirable side effects. We constructed a series of ß-pyrrolic ring-opening seco-chlorins, termed beidaphyrin (BP), beidapholactone (BPL), and their zinc(II) derivatives (ZnBP and ZnBPL), featuring intense near-infrared absorption and effective O2 photosensitization. Irradiation of ZnBPL led to a non-cytotoxic, metabolizable beidaphodiacetamide (ZnBPD) via in situ generated O2.- but not 1 O2 , as revealed by mechanistic studies including time-resolved absorption, kinetics, and isotope labeling. Furthermore, water-soluble ZnBPL showed an effective therapeutic outcome, fast metabolism, and negligible phototoxic reactions.
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Neoplasias , Fotoquimioterapia , Porfirinas , Humanos , Neoplasias/tratamiento farmacológico , Fármacos Fotosensibilizantes/farmacología , Fármacos Fotosensibilizantes/uso terapéutico , Porfirinas/farmacología , Porfirinas/uso terapéuticoRESUMEN
Planktonic microorganisms play a key role in the biogeochemical processes of the aquatic system, and they may be affected by many factors. High-throughput sequencing technology was used in this study to investigate and study the bacterioplankton community of water bodies in the upper reaches of the Heihe River Basin in Qinghai Plateau. Results showed that Proteobacteria, Firmicutes, Bacteroidetes and Actinobacteria are the predominant phyla in this river section, while the main genera are Thiomonas, Acidibacillus, Acidocella, Rhodanobacter, Acidithiobacter and Gallionella, which are autochthonous in the acid-mine drainage. Additionally, total nitrogen, total phosphorus, permanganate index and pH are significantly correlated with the bacterioplankton abundance and are the main limiting factors for the spatial distribution of the bacterioplankton. PICRUSt inferred that the mainstream microbial assemblages had a higher abundance of KOs belong to metabolism of terpenoids and polyketides, while the tributary had higher abundance of KOs belong to the immune system. The relationship between bacterioplankton community composition and environmental factors in the Heihe River basin was discussed for the first time in this study, which provides a theoretical basis for the healthy, orderly development of the water environment in the Heihe River Basin.
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Bacterias/aislamiento & purificación , Microbiota , Plancton/aislamiento & purificación , Ríos/química , Ríos/microbiología , Bacterias/clasificación , Bacterias/genética , China , Concentración de Iones de Hidrógeno , Compuestos de Manganeso/análisis , Redes y Vías Metabólicas/genética , Nitrógeno/análisis , Óxidos/análisis , Fósforo/análisis , Plancton/clasificación , Plancton/genéticaRESUMEN
By the bridging action of the 6-chloro-2-hydroxypyridine (Hchp) ligand and the terminal coordination role of the homochiral ligand, (-)/(+)-3-trifluoroacetyl camphor (l-Htfc/d-Htfc), a pair of enantiomerically pure dysprosium(III) dinuclear complexes, [Dy2(l-tfc)4(chp)2(MeOH)2] (l-1) and [Dy2(d-tfc)4(chp)2(MeOH)2] (d-1), was obtained. Their circular dichroism (CD) spectra verified their enantiomeric nature. Magnetic investigation indicated that they exhibit ferromagnetic interaction and good zero field single-molecule magnet (SMM) properties. The Ueff/k values of l-1 and d-1 at 0 Oe are 180.5 and 181.3 K, respectively, which are large values for homochiral Dy(III) SMMs. A reasonable explanation for the magnetic properties of l-1 and d-1 was supplied by ab initio calculations. Remarkably, magnetic circular dichroism (MCD) investigation revealed that the chiral Dy2 enantiomers show a strong magneto-optical Faraday effect at room temperature, suggesting potential applications in magneto-optical devices.
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Oxidative stress is one of the hallmarks of ischemic stroke. Catalase-based (CAT) biomimetic complexes are emerging as promising therapeutic candidates that are expected to act as neuroprotectants for ischemic stroke by decreasing the damaging effects from H2O2. Unfortunately, these molecules result in the unwanted production of the harmful hydroxyl radical, HOâ¢. Here, we report a series of salen-based tri-manganese (Mn(III)) metallocryptands (1-3) that function as catalase biomimetics. These cage-like molecules contain a unique "active site" with three Mn centers in close proximity, an arrangement designed to facilitate metal cooperativity for the effective dismutation of H2O2 with minimal HO⢠production. In fact, significantly greater oxygen production is seen for 1-3 as compared to the monomeric Mn(Salen) complex, 1c. The most promising system, 1, was studied in further detail and found to confer a greater therapeutic benefit both in vitro and in vivo than the monomeric control system, 1c, as evident from inter alia studies involving a rat model of ischemic stroke damage and supporting histological analyses. We thus believe that metallocryptand 1 and its analogues represent a new and seemingly promising strategy for treating oxidative stress related disorders.
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Antioxidantes/farmacología , Isquemia Encefálica/tratamiento farmacológico , Complejos de Coordinación/farmacología , Accidente Cerebrovascular Isquémico/tratamiento farmacológico , Fármacos Neuroprotectores/farmacología , Animales , Antioxidantes/síntesis química , Antioxidantes/química , Apoptosis/efectos de los fármacos , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patología , Catalasa/metabolismo , Células Cultivadas , Complejos de Coordinación/síntesis química , Complejos de Coordinación/química , Modelos Animales de Enfermedad , Etilenodiaminas/química , Etilenodiaminas/farmacología , Humanos , Accidente Cerebrovascular Isquémico/metabolismo , Accidente Cerebrovascular Isquémico/patología , Masculino , Manganeso/química , Manganeso/farmacología , Conformación Molecular , Fármacos Neuroprotectores/síntesis química , Fármacos Neuroprotectores/química , Imagen Óptica , Oxígeno/metabolismo , Ratas , Ratas Sprague-DawleyRESUMEN
Based on the high self-renewal ability and osteoblastic differentiation capacity, dental pulp stem cells (DPSCs) are suggested to be promising cell source for osteogenesis. Therefore, illustrating the mechanism of osteoblastic differentiation of DPSCs is required. This current study aims to illustrate the role and mechanism of Sp1 in regulating osteoblastic differentiation of DPSCs. In this study, we downregulated Sp1 in DPSCs and evaluated the osteoblastic differentiation by measuring Runx2 and OCN expression with Western blot analysis and by Alizarin red staining. Furthermore, we investigated the mechanism of Sp1 regulating noggin with Firefly luciferase reporter gene assay and ChIP assay, and correspondingly evaluated the function of noggin in Sp1-regulated osteoblastic differentiation of DPSCs. We found that knockdown of Sp1 inhibits the expression of ALP, Runx2, COL1A1 and OCN, and decreases ALP staining, Alizarin red staining. Sp1 binds to noggin promoter and inhibits noggin expression, thus correspondingly regulates DPSCs osteoblastic differentiation. In conclusion, our study revealed that Sp1 regulates DPSCs osteoblastic differentiation through noggin and that Sp1/noggin can provide new perspective for enhancing DPSCs osteogenesis.
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Proteínas Portadoras/genética , Diferenciación Celular , Pulpa Dental/citología , Osteoblastos/citología , Osteoblastos/metabolismo , Factor de Transcripción Sp1/genética , Proteínas Portadoras/metabolismo , Diferenciación Celular/genética , Regulación hacia Abajo/genética , Técnicas de Silenciamiento del Gen , Humanos , Regiones Promotoras Genéticas/genética , Factor de Transcripción Sp1/metabolismo , Células Madre/citología , Células Madre/metabolismo , Transcripción Genética , Regulación hacia Arriba/genéticaRESUMEN
In the series of the adducts of tris(alkyl) HoIII complexes, Ho(CH2SiMe3)3(THF)2 (1Ho-THF, Me = methyl) can exhibit slow magnetic relaxation under a zero applied direct current (DC) field with the energy barrier Δ/kB of 76 K, which is one of the highest in the non-Kramers ion HoIII-based single-ion magnets (SIMs). The DC field-dependence of relaxation time for 1Ho-THF indicates the occurrence of direct relaxation process at low temperature under certain DC fields. 1Ho-THF stands out in the series of 1Ln-THF (Ln = Tb, Dy, Ho, Er, Tm), wherein Dy congener is another SIM in the absence of a DC field with the relaxation barrier of 40 K, while Tb and Er congeners are field-induced SIMs. Further substitutions of the two trans-THF in 1Ho-THF by other neutral ligands such as quinuclidine, tricyclohexylphosphine oxide, and 3,5-lutidine afforded Ho(CH2SiMe3)3(quinuclidine)2 (2Ho-QN), Ho(CH2SiMe3)3(OPCy3)2 (3Ho-OPCy3), and Ho(CH2SiMe3)3(lutidine)3 (4Ho-Lut), respectively. The former two possess analogous structures to 1Ho-THF with two trans-arranged neutral ligands, and the latter one has three cis-lutidine coordinated. The fast quantum tunneling effect swamps the magnetic relaxation for the above three derivatives, so slow relaxation could not be observed under experimental conditions, even when a certain DC field was applied.
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Transforming growth factor-ß type III receptor (TßR3), as a co-receptor of TGF-ß superfamily, plays critical roles in development and growth as well as some disease pathogeneses by presenting ligands to other receptors in vertebrates. However, the identification and functional characterization of TßR3 had not been reported yet in invertebrates. In the present study, TßR3 was first identified and characterized in mud crab Scylla paramamosain. The obtained cDNA length of SpTßR3 was 2, 424 bp with a 1, 854 bp open reading frame, which encoded a putative peptide of 617 amino acids containing a typical transmembrane region and a Zona pellucida (ZP) domain. Real-time PCR results showed that SpTßR3 was predominantly expressed at early embryonic development stage and early postmolt stage, suggesting its participation in development and growth. We report, for the first time in invertebrates, the challenge of both Vibro alginolyticus and Poly (I:C) could alter the expression patterns of SpTßR3. Notably, the expression levels of SpIKK, two NF-κB members (SpRelish and SpDorsal), and five antimicrobial peptide genes (SpCrustin and SpALF1-4) were significantly suppressed when SpTßR3 was interfered in vivo. Secondly, the overexpression of SpTßR3 in vitro could activate NF-κB signaling through the dual-luciferase reporter assays. Furthermore, the bacterial clearance assay after SpTßR3 was silenced in vivo highlighted the potential of SpTßR3 in activating the innate immune responses. These results implied the involvement of SpTßR3 in the innate immune responses by regulating the NF-κB pathway. This study first indicated that TßR3 was present in invertebrate, and it participated in not only the development and growth but also the innate immunity of S. paramamosain. It also provided new insights into the origin or evolution of TGF-ß receptors in crustacean species and even in invertebrates.
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Braquiuros/genética , Braquiuros/inmunología , Regulación de la Expresión Génica/inmunología , Inmunidad Innata/genética , Receptores de Factores de Crecimiento Transformadores beta/genética , Receptores de Factores de Crecimiento Transformadores beta/inmunología , Transducción de Señal/genética , Secuencia de Aminoácidos , Animales , Proteínas de Artrópodos/química , Proteínas de Artrópodos/genética , Proteínas de Artrópodos/inmunología , Secuencia de Bases , Perfilación de la Expresión Génica , Filogenia , Poli I-C/farmacología , Receptores de Factores de Crecimiento Transformadores beta/química , Alineación de Secuencia , Vibrio alginolyticus/fisiologíaRESUMEN
Targeting-induced local lesions in genomes (TILLING) is a powerful reverse-genetics tool that enables high-throughput screening of genomic variations in plants. Although TILLING has been developed for many diploid plants, the technology has been used in very few polyploid species due to their genomic complexity. Here, we established an efficient capillary electrophoresis-based TILLING platform for allotetraploid cultivated tobacco (Nicotiana tabacum L.) using an ethyl methanesulfonate (EMS)-mutagenized population of 1,536 individuals. We optimized the procedures for endonuclease preparation, leaf tissue sampling, DNA extraction, normalization, pooling, PCR amplification, heteroduplex formation, and capillary electrophoresis. In a test screen using seven target genes with eight PCR fragments, we obtained 118 mutants. The mutation density was estimated to be approximately one mutation per 106 kb on average. Phenotypic analyses showed that mutations in two heavy metal transporter genes, HMA2S and HMA4T, led to reduced accumulation of cadmium and zinc, which was confirmed independently using CRISPR/Cas9 to generate knockout mutants. Our results demonstrate that this powerful TILLING platform (available at http://www.croptilling.org) can be used in tobacco to facilitate functional genomics applications.
Asunto(s)
Nicotiana/metabolismo , Sistemas CRISPR-Cas , Cadmio/metabolismo , Electroforesis Capilar , Metanosulfonato de Etilo/metabolismo , Mutagénesis/genética , Mutagénesis/fisiología , Hojas de la Planta/genética , Hojas de la Planta/metabolismo , Reacción en Cadena de la Polimerasa , Poliploidía , Nicotiana/genética , Zinc/metabolismoRESUMEN
We investigate a family of dinuclear dysprosium metallocene single-molecule magnets (SMMs) bridged by methyl and halogen groups [Cp'2 Dy(µ-X)]2 (Cp'=cyclopentadienyltrimethylsilane anion; 1: X=CH3 - ; 2: X=Cl- ; 3: X=Br- ; 4: X=I- ). For the first time, the magnetic easy axes of dysprosium metallocene SMMs are experimentally determined, confirming that the orientation of them are perpendicular to the equatorial plane which is made up of dysprosium and bridging atoms. The orientation of the magnetic easy axis for 1 deviates from the normal direction (by 10.3°) due to the stronger equatorial interactions between DyIII and methyl groups. Moreover, its magnetic axes show a temperature-dependent shifting, which is caused by the competition between exchange interactions and Zeeman interactions. Studies of fluorescence and specific heat as well as abâ initio calculations reveal the significant influences of the bridging ligands on their low-lying exchange-based energy levels and, consequently, low-temperature magnetic properties.