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1.
J Am Chem Soc ; 146(9): 6377-6387, 2024 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-38385755

RESUMEN

We present comprehensive computational and experimental studies on the mechanism of an asymmetric photoredox/Pd dual-catalytic reductive C(sp3)-C(sp3) homocoupling of allylic electrophiles. In stark contrast to the canonical assumption that photoredox promotes bond formation via facile reductive elimination from high-valent metal-organic species, our computational analysis revealed an intriguing low-valent allylpalladium pathway that features tandem operation of Pd(0/II/I)-Pd(0/II/I/II) cycles. Specifically, we propose that (i) the photoredox/Pd system enables the in situ generation of allyl radicals from low-valent Pd(I)-allyl species, and (ii) effective interception of the fleeting allyl radical by the chiral Pd(I)-allyl species results in the formation of an enantioenriched product. Notably, the cooperation of the two pathways highlights the bifunctional role of Pd(I)-allyl species in the generation and interception of transient allyl radicals. Moreover, the mechanism implies divergent substrate-activation modes in this homocoupling reaction, suggesting a theoretical possibility for cross-coupling. Combined, the current study offers a novel mechanistic hypothesis for photoredox/Pd dual catalysis and highlights the use of low-valent allylpalladium as a means to efficiently intercept radicals for selective asymmetric bond constructions.

2.
J Transl Med ; 22(1): 278, 2024 03 14.
Artículo en Inglés | MEDLINE | ID: mdl-38486250

RESUMEN

BACKGROUND: LILRB3, a member of the leukocyte immunoglobulin-like receptor B (LILRB) family, has immunosuppressive functions and directly regulates cancer development, which indicates that LILRB3 is an attractive target for cancer diagnosis and therapy. Novel therapeutic treatments for acute myeloid leukemia (AML) are urgent and important, and RNA therapeutics including microRNAs (miRNAs) could be an effective option. Here, we investigate the role of dysregulated miRNA targeting LILRB3 in the AML microenvironment. METHODS: Potential miRNAs binding to the 3'-untranslated region (3'-UTR) of the LILRB3 mRNA were predicted by bioinformatics websites. Then, we screened miRNAs targeting LILRB3 by quantitative real-time PCR, and the dual luciferase reporter assay. The expression of LILRB3 and microRNA (miR)-103a-2-5p in AML were determined and then their interactions were also analyzed. In vitro, the effects of miR-103a-2-5p were determined by CCK8, colony formation assay, and transwell assay, while cell apoptosis and cell cycle were analyzed by flow cytometry. Cationic liposomes (CLPs) were used for the delivery of miR-103a-2-5p in the AML mouse model, which was to validate the potential roles of miR-103a-2-5p in vivo. RESULTS: LILRB3 was upregulated in AML cells while miR-103a-2-5p was dramatically downregulated. Thus, a negative correlation was found between them. MiR-103a-2-5p directly targeted LILRB3 in AML cells. Overexpressed miR-103a-2-5p significantly suppressed the mRNA and protein levels of LILRB3, thereby inhibiting AML cell growth and reducing CD8 + T cell apoptosis. In addition, overexpressed miR-103a-2-5p reduced both the relative expression of Nrf2/HO-1 pathway-related proteins and the ratio of GSH/ROS, leading to the excessive intracellular ROS that may promote AML cell apoptosis. In the mouse model, the delivery of miR-103a-2-5p through CLPs could inhibit tumor growth. CONCLUSIONS: MiR-103a-2-5p serves as a tumor suppressor that could inhibit AML cell proliferation and promote their apoptosis by downregulating LILRB3 expression, suppressing the Nrf2/HO-1 axis, and reducing the ratio of GSH/ROS. Besides, our findings indicate that miR-103a-2-5p may enhance the CD8 + T cell response by inhibiting LILRB3 expression. Therefore, the delivery of miR-103a-2-5p through CLPs could be useful for the treatment of AML.


Asunto(s)
Leucemia Mieloide Aguda , MicroARNs , Animales , Ratones , Liposomas , Factor 2 Relacionado con NF-E2 , Especies Reactivas de Oxígeno , Leucemia Mieloide Aguda/genética , Regiones no Traducidas 3'/genética , Apoptosis/genética , Linfocitos T CD8-positivos , Proliferación Celular/genética , Modelos Animales de Enfermedad , MicroARNs/genética , Microambiente Tumoral
3.
Opt Lett ; 49(17): 4975-4978, 2024 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-39208012

RESUMEN

High-quality three-dimensional computer-generated holograms (3D-CGHs) are crucial for programmable 3D femtosecond laser parallel recording (3D-FLPR). In this study, we introduced an innovative feedback approach for the rapid optimization of 3D-CGHs by incorporating the superposition of the calculated lens phases (CLPs) onto the 3D-CGHs within a feedback system. This feedback system, governed by coordinated control of a spatial light modulator (SLM) and a camera, served to avoid the poor quality of the ordinary CGH system. As a result, we successfully demonstrated coaxial 3D-FLPR in Ag-doped phosphate glass solely using a single fs laser pulse. Additionally, we regulated the energy distribution of the generated 3D multi-focus (3D-MF) to compensate the laser energy losses inside the glass. The presented single-pulse 3D parallel recording indicated the significant advancement facilitated by our method, particularly in enhancing the writing efficiency of optical storage.

4.
Sensors (Basel) ; 24(18)2024 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-39338721

RESUMEN

Compressive sensing (CS) is a notable technique in signal processing, especially in multimedia, as it allows for simultaneous signal acquisition and dimensionality reduction. Recent advancements in deep learning (DL) have led to the creation of deep unfolding architectures, which overcome the inefficiency and subpar quality of traditional CS reconstruction methods. In this paper, we introduce a novel CS image reconstruction algorithm that leverages the strengths of the fast iterative shrinkage-thresholding algorithm (FISTA) and modern Transformer networks. To enhance computational efficiency, we employ a block-based sampling approach in the sampling module. By mapping FISTA's iterative process onto neural networks in the reconstruction module, we address the hyperparameter challenges of traditional algorithms, thereby improving reconstruction efficiency. Moreover, the robust feature extraction capabilities of Transformer networks significantly enhance image reconstruction quality. Experimental results show that the FusionOpt-Net model surpasses other advanced methods on various public benchmark datasets.

5.
Nano Lett ; 23(9): 3803-3809, 2023 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-37103954

RESUMEN

Designing an active, stable, and nonprecious metal catalyst substitute for Pt in the oxygen reduction reaction (ORR) is highly demanded for energy-efficient and cost-effective prototype devices. Single-atomic-site catalysts (SASCs) have been widely concerning because of their maximum atomic utilization and precise structural regulation. Despite being challenging, the controllable synthesis of SASCs is crucial for optimizing ORR activity. Here, we demonstrate an ultrathin organometallic framework template-assisted pyrolysis strategy to synthesize SASCs with a unique two-dimensional (2D) architecture. Electrochemical measurements revealed that Fe-SASCs displayed an excellent ORR activity in an alkaline media, having a half-wave potential and a diffusion-limited current density comparable to those of commercial Pt/C. Remarkably, the durability and methanol tolerance of Fe-SASCs were even superior to those of Pt/C. Furthermore, Fe-SASCs displayed a maximum power density of 142 mW cm-2 with a current density of 235 mA cm-2 as a cathode catalyst in a zinc-air battery, showing its great potential for practical applications.

6.
Angew Chem Int Ed Engl ; 63(3): e202311053, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-37917574

RESUMEN

With the rapid development of asymmetric catalysis, the demand for the enantioselective synthesis of complex and diverse molecules with different chiral elements is increasing. Owing to the unique features of atropisomerism, the catalytic asymmetric synthesis of atropisomers has attracted a considerable interest from the chemical science community. In particular, introducing additional chiral elements, such as carbon centered chirality, heteroatomic chirality, planar chirality, and helical chirality, into atropisomers provides an opportunity to incorporate new properties into axially chiral compounds, thus expanding the potential applications of atropisomers. Thus, it is important to perform catalytic asymmetric transformations to synthesize atropisomers bearing multiple chiral elements. In spite of challenges in such transformations, in recent years, chemists have devised powerful strategies under asymmetric organocatalysis or metal catalysis, synthesizing a wide range of enantioenriched atropisomers bearing multiple chiral elements. Therefore, the catalytic asymmetric synthesis of atropisomers bearing multiple chiral elements has become an emerging field. This review summarizes the rapid progress in this field and indicates challenges, thereby promoting this field to a new horizon.

7.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 49(1): 40-46, 2024 Jan 28.
Artículo en Inglés, Zh | MEDLINE | ID: mdl-38615164

RESUMEN

OBJECTIVES: There are a variety of minimally invasive interventional treatments for trigeminal neuralgia, and the efficacy evaluation is different. The preferred treatment scheme is still controversial. This study aims to investigate the differences in treatment effects between patients with primary trigeminal neuralgia (PTN) treated with percutaneous balloon compression (PBC) for the first intervention and patients with pain recurrence after radiofrequency thermocoagulation (RT) who then received PBC for PTN, and to offer clinicians and patients more scientifically grounded and precise treatment alternatives. METHODS: We retrospectively analyzed 103 patients with PTN admitted to the Department of Pain Management of the Second Affiliated Hospital of Guangxi Medical University from January 2020 to December 2021, including 49 patients who received PBC for the first time (PBC group) and 54 patients who received PBC for pain recurrence after RT (RT+PBC group). General information, preoperative pain score, intraoperative oval foramen morphology, oval foramen area, balloon volume, duration of compression, and postoperative pain scores and pain recurrence at each time point on day 1 (T1), day 7 (T2), day 14 (T3), 1 month (T4), 3 months (T5), and 1 year (T6) were collected and recorded for both groups. The differences in treatment effect, complications and recurrence between the 2 groups were compared, and the related influencing factors were analyzed. RESULTS: The differences of general information, preoperative pain scores, foramen ovale morphology, foramen ovale area, T1 to T3 pain scores between the 2 groups were not statistically different (all P>0.05). The balloon filling volume in the PBC group was smaller than that in the RT+PBC group, the pain scores at T4 to T6 and pain recurrence were better than those in the RT+PBC group (all P<0.05). Pain recurrence was positively correlated with pain scores of T2 to T6 (r=0.306, 0.482, 0.831, 0.876, 0.887, respectively; all P<0.01). CONCLUSIONS: The choice of PBC for the first intervention in PTN patients is superior to the choice of PBC after pain recurrence after RT treatment in terms of treatment outcome and pain recurrence.


Asunto(s)
Neuralgia del Trigémino , Humanos , Neuralgia del Trigémino/cirugía , Estudios Retrospectivos , China , Electrocoagulación , Dolor Postoperatorio
8.
Acc Chem Res ; 55(18): 2562-2580, 2022 09 20.
Artículo en Inglés | MEDLINE | ID: mdl-36053083

RESUMEN

Catalytic atroposelective syntheses of axially chiral compounds have stimulated extensive interest in multiple communities, such as synthetic chemistry, biochemistry, and materials science, because of the intriguing characteristics of atropisomerism. In particular, atropisomeric indole derivatives, which contain a kind of five-membered heterocyclic framework, are widely distributed in a number of natural alkaloids, biologically relevant compounds, chiral ligands, and chiral organocatalysts. Hence, the catalytic atroposelective synthesis of indole derivatives bearing axial chirality is of considerable importance and has become an emerging focus of research. However, there are substantial challenges associated with the atroposelective synthesis of indole derivatives, including remote ortho-substituents around the chiral axis, a lower barrier for rotation, and a weaker configurational stability than that of atropisomeric six-membered biaryls. Therefore, the development of effective strategies toward the catalytic atroposelective synthesis of indole derivatives has become an urgent task.In order to tackle these challenges and to accomplish the task, our group devised a unique strategy of designing indole-derived platform molecules and developing organocatalytic enantioselective transformations of such platform molecules to synthesize atropisomeric indole derivatives; asymmetric organocatalysis has tremendous advantages and was the research area recognized by the Nobel Prize in Chemistry in 2021. This Account summarizes our endeavors in the organocatalytic atroposelective synthesis of indole derivatives bearing axial chirality. In brief, we devised and developed a series of indole-derived platform molecules, such as indolylmethanols, (hetero)aryl indoles, oxindole-based styrenes, N-aminoindoles, and indole-based homophthalic anhydrides, by introducing different functional groups onto the indole ring to achieve new reactivity and modulate the reactive site of the indole ring. As a result, these indole-derived platform molecules possess versatile and unique reactivity and are capable of undergoing a variety of organocatalytic enantioselective transformations for preparing structurally diversified indole derivatives with axial chirality.We used these strategies to accomplish the atroposelective synthesis of plenty of indole derivatives with axial chirality, including (hetero)aryl indoles, alkene-indoles, oxindole-based styrenes, N-pyrrolylindoles, and isochromenone-indoles. In addition, we gave a thorough and detailed understanding of the designed reaction by investigating the reaction pathway and activation mode. More importantly, we studied the biological activity of some products and performed catalyst design on the basis of atropisomeric indole moieties, which are helpful for disclosing more applications of indole derivatives bearing axial chirality.In the future, the organocatalytic atroposelective synthesis of indole derivatives bearing axial chirality will indubitably remain a frontier topic in the research area of asymmetric catalysis and chiral indole chemistry despite challenging issues, for instance, the atroposelective synthesis of novel indole derivatives bearing an unconventional chiral axis, the development of atropisomeric indole derivatives into powerful catalysts or ligands, and the discovery of atroposelective indole derivatives as potent drug candidates. We hope our efforts summarized in this Account will encourage chemists worldwide to devise innovative strategies toward solving the challenging issues that remain in this field, thus promoting its development to a higher level.


Asunto(s)
Alcaloides , Indoles , Alquenos , Anhídridos , Indoles/química , Ligandos , Oxindoles , Estereoisomerismo , Estirenos
9.
Transgenic Res ; 32(1-2): 135-141, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36547785

RESUMEN

The Dmp1-Cre mouse, expressing Cre from an 8-kb DNA fragment of the mouse Dmp1 gene, is a common tool to study gene functions in osteocytes. Here we report that the deletion of Tsc1 (TSC complex subunit 1) by 8 kb Dmp1-Cre causes rectal prolapse in mice. Histological examination shows the presence of colon polyps in Tsc1-deficient mice in association with significantly larger colon and narrower lumen, which recapitulates the common polyps pathology in Tuberous Sclerosis, an autosomal dominant disorder caused by mutations in either TSC1 or TSC2. The intestine in Tsc1-deficient mice is also enlarged with the presence of taller villi. Using the Ai14 reporter mice that express a red fluorescence protein upon Cre recombination, we show that 8 kb Dmp1-Cre activity is evident in portion of the mesenchyme of the colon and small intestine. Lastly, our data show that Tsc1 deletion by Dmp1-Cre leads to an increased proliferation in the mesenchyme of colon, which at least partly contributes to the polyps pathology seen in this mouse model and is likely a contributing factor of the polyps in Tuberous Sclerosis.


Asunto(s)
Esclerosis Tuberosa , Proteínas Supresoras de Tumor , Ratones , Animales , Proteínas Supresoras de Tumor/genética , Proteínas Supresoras de Tumor/metabolismo , Proteína 1 del Complejo de la Esclerosis Tuberosa/genética , Proteína 1 del Complejo de la Esclerosis Tuberosa/metabolismo , Esclerosis Tuberosa/genética , Esclerosis Tuberosa/patología , Integrasas/genética , Proteínas de la Matriz Extracelular
10.
Ann Hematol ; 2023 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-37548690

RESUMEN

N6-methyladenosine (m6A) RNA modification has recently emerged as an essential regulator of normal and malignant hematopoiesis. As a reversible epigenetic modification found in messenger RNAs and non-coding RNAs, m6A affects the fate of the modified RNA molecules. It is essential in most vital bioprocesses, contributing to cancer development. Here, we review the up-to-date knowledge of the pathological functions and underlying molecular mechanism of m6A modifications in normal hematopoiesis, leukemia pathogenesis, and drug response/resistance. At last, we discuss the critical role of m6A in immune response, the therapeutic potential of targeting m6A regulators, and the possible combination therapy for AML.

11.
Environ Dev Sustain ; 25(7): 7075-7099, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-35493768

RESUMEN

The COVID-19 prevention and control measures are taken by China's government, especially traffic restrictions and production suspension, had spillover effects on air quality improvement. These effects differed among cities, but these differences have not been adequately studied. To provide more knowledge, we studied the air quality index (AQI) and five air pollutants (PM2.5, PM10, SO2, NO2, and O3) before and after the COVID-19 outbreak in Shanghai, Wuhan, and Tangshan. The pollution data from two types of monitoring stations (traffic and non-traffic stations) were separately compared and evaluated. We used monitoring data from the traffic stations to study the emission reduction caused by traffic restrictions. Based on monitoring data from the non-traffic stations, we established a difference-in-difference model to study the emission reduction caused by production suspension. The COVID-19 control measures reduced AQI and the concentrations of all pollutants except O3 (which increased greatly), but the magnitude of the changes differed among the three cities. The control measures improved air quality most in Wuhan, followed by Shanghai and then Tangshan. We investigated the reasons for these differences and found that differences in the characteristics of these three types of cities could explain these differences in spillover effects. Understanding these differences could provide some guidance and support for formulating differentiated air pollution control measures in different cities. For example, whole-process emission reduction technology should be adopted in cities with the concentrated distribution of continuous process enterprises, whereas vehicles that use cleaner energy and public transport should be vigorously promoted in cities with high traffic development level.

12.
J Am Chem Soc ; 144(47): 21502-21511, 2022 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-36332199

RESUMEN

Electrochemical CO2 conversion is a promising way for sustainable chemical fuel production, yet the conversion efficiency is strongly limited by the sluggish kinetics and complex reaction pathways. Here we report the ultrathin conjugated metalloporphyrin covalent organic framework epitaxially grown on graphene as a two-dimensional van der Waals heterostructure to catalyze CO2 reduction. Operando X-ray absorption and density functional theory calculations reveal the strong interlayer coupling leads to electron-deficient metal centers and speeds up electrocatalysis. The Co(III)-N4 centers exhibit a CO Faradaic efficiency of 97% at a partial current density of 8.2 mA cm-2 in an H-cell, along with a stable running over 30 h. The selectivity of CO approached 99% with a partial current density of 191 mA cm-2 in a liquid flow cell, and the turnover frequency achieved 50 400 h-1 at -1.15 V vs RHE, outperforming most reported organometallic frameworks. This work highlights the key role of strong electronic coupling between van der Waals layers for accelerating the dynamics of CO2 conversion.

13.
Nanotechnology ; 33(47)2022 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-35981489

RESUMEN

Triboelectric nanogenerators (TENG) are generally utilized on the grounds that they can catch low-recurrence mechanical energy from various types of movement and convert it into electricity. It has been proved that the adulteration of conductive particles in the triboelectric layer can improve its output performance, but metal nanomaterials have different properties at different scales. In this paper, the triboelectric layer of TENG is a composite film made of silver nanoparticles (AgNPs) with different particle sizes (20 nm, 50 nm, 200 nm and 500 nm) that were dispersed and mixed with two-component liquid silica gel step by step. The open circuit voltage (Voc) and short circuit current (Isc) of the 20 nm component of the AgNPs-dispersed/two-component liquid silica gel TENG(At-TENG) are 102.8 V and 4.42µA, which are higher than the result execution of the other components. Smaller size nanoparticles have more number of nanoparticles when the mass fraction is the same. AgNPs form micro-capacitance structures in the insulating polymer layer and enhance the dielectric properties of the composite films through an interfacial polarization mechanism. At-TENG can light up 53 commercial LEDs and power calculators or wristband electronic watches, proving its utility as a self-powered power source. An extensive experiment proves the advantage of small size using comparison and theoretical analysis and provides suggestions for the selection of TENG dopants.

14.
Int J Mol Sci ; 23(2)2022 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-35054795

RESUMEN

Polyetheretherketone (PEEK) is a potential substitute for conventional metallic biomedical implants owing to its superior mechanical and chemical properties, as well as biocompatibility. However, its inherent bio-inertness and poor osseointegration limit its use in clinical applications. Herein, thin titanium films were deposited on the PEEK substrate by plasma sputtering, and porous nanonetwork structures were incorporated on the PEEK surface by alkali treatment (PEEK-TNS). Changes in the physical and chemical characteristics of the PEEK surface were analyzed to establish the interactions with cell behaviors. The osteoimmunomodulatory properties were evaluated using macrophage cells and osteoblast lineage cells. The functionalized nanostructured surface of PEEK-TNS effectively promoted initial cell adhesion and proliferation, suppressed inflammatory responses, and induced macrophages to anti-inflammatory M2 polarization. Compared with PEEK, PEEK-TNS provided a more beneficial osteoimmune environment, including increased levels of osteogenic, angiogenic, and fibrogenic gene expression, and balanced osteoclast activities. Furthermore, the crosstalk between macrophages and osteoblast cells showed that PEEK-TNS could provide favorable osteoimmunodulatory environment for bone regeneration. PEEK-TNS exhibited high osteogenic activity, as indicated by alkaline phosphatase activity, osteogenic factor production, and the osteogenesis/osteoclastogenesis-related gene expression of osteoblasts. The study establishes that the fabrication of titanate nanonetwork structures on PEEK surfaces could extract an adequate immune response and favorable osteogenesis for functional bone regeneration. Furthermore, it indicates the potential of PEEK-TNS in implant applications.


Asunto(s)
Benzofenonas/farmacología , Factores Inmunológicos/farmacología , Nanopartículas/química , Osteogénesis , Polímeros/farmacología , Titanio/farmacología , Fosfatasa Alcalina/metabolismo , Animales , Calcificación Fisiológica/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/genética , Proliferación Celular/efectos de los fármacos , Proliferación Celular/genética , Forma de la Célula/efectos de los fármacos , Forma de la Célula/genética , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/genética , Matriz Extracelular/efectos de los fármacos , Matriz Extracelular/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Inmunidad/efectos de los fármacos , Inflamación/patología , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Macrófagos/patología , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/efectos de los fármacos , Células Madre Mesenquimatosas/metabolismo , Ratones , Osteogénesis/efectos de los fármacos , Osteogénesis/genética , Células RAW 264.7 , Propiedades de Superficie
15.
Genesis ; 59(5-6): e23419, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33851764

RESUMEN

BMP signaling plays pleiotropic roles in various tissues during embryogenesis and after birth. We have previously generated a constitutively activated Acvr1(ca-Acvr1) transgenic mouse line (line L35) through pronuclei injection to investigate impacts of enhanced BMP signaling in a tissue specific manner. However, line L35 shows a restricted expression pattern of the transgene. Here, we generated another ca-Acvr1 transgenic line, line A11, using embryonic stem (ES) transgenesis. The generated line A11 shows distinctive phenotypes from line L35, along with very limited expression levels of the transgene. When the transgene is activated in the neural crest cells in a Cre-dependent manner, line A11 exhibits cleft palate and shorter jaws, while line L35 develops ectopic cartilages and highly hypomorphic facial structures. When activated in limb buds, line A11 develops organized but smaller limb skeletal structures, while line L35 forms disorganized limbs with little mineralization. Additionally, no heterotopic ossification (HO) is identified in line A11 when bred with NFATc1-Cre mice even after induction of tissue injury, which is an established protocol for HO for line L35. Therefore, the newly generated conditional ca-Acvr1 mouse line A11 provides an additional resource to dissect highly context dependent functions of BMP signaling in development and disease.


Asunto(s)
Receptores de Activinas Tipo I/genética , Proteínas Morfogenéticas Óseas/metabolismo , Marcación de Gen/métodos , Pleiotropía Genética , Transgenes , Receptores de Activinas Tipo I/metabolismo , Animales , Cartílago/metabolismo , Condrogénesis , Esbozos de los Miembros/embriología , Esbozos de los Miembros/metabolismo , Ratones , Ratones Endogámicos C57BL , Transducción de Señal , Activación Transcripcional
16.
Genesis ; 59(10): e23450, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34487426

RESUMEN

Podoplanin, PDPN, is a mucin-type transmembrane glycoprotein widely expressed in many tissues, including lung, kidney, lymph nodes, and mineralized tissues. Its function is critical for lymphatic formation, differentiation of type I alveolar epithelial lung cells, and for bone response to biomechanical loading. It has previously been shown that Pdpn null mice die at birth due to respiratory failure emphasizing the importance of Pdpn in alveolar lung development. During the course of generation of Pdpn mutant mice, we found that most Pdpn null mice in the 129S6 and C57BL6/J mixed genetic background die at the perinatal stage, similar to previously published studies with Pdpn null mice, while all Pdpn null mice bred with Swiss outbred mice survived. Surviving mutant mice in the 129S6 and C57BL6/J mixed genetic background showed alterations in the osteocyte lacunocanalicular network, especially reduced osteocyte canaliculi in the tibial cortex with increased tibial trabecular bone. However, adult Pdpn null mice in the Swiss outbred background showed no overt differences in their osteocyte lacunocnalicular network, bone density, and no overt differences when challenged with exercise. Together, these data suggest that genetic variations present in the Swiss outbred mice compensate for the loss of function of PDPN in lung, kidney, and bone.


Asunto(s)
Células Epiteliales Alveolares/metabolismo , Diferenciación Celular/genética , Linfangiogénesis/genética , Glicoproteínas de Membrana/genética , Animales , Calcificación Fisiológica/genética , Hueso Esponjoso/crecimiento & desarrollo , Hueso Esponjoso/metabolismo , Regulación del Desarrollo de la Expresión Génica/genética , Riñón/crecimiento & desarrollo , Pulmón/crecimiento & desarrollo , Pulmón/metabolismo , Ganglios Linfáticos/crecimiento & desarrollo , Ratones , Osteocitos/metabolismo , Tibia/crecimiento & desarrollo , Tibia/metabolismo
17.
J Am Chem Soc ; 143(32): 12836-12846, 2021 08 18.
Artículo en Inglés | MEDLINE | ID: mdl-34351745

RESUMEN

Transition-metal-catalyzed reductive coupling reactions have emerged as powerful protocols to construct C-C bonds. However, the development of enantioselective C(sp3)-C(sp3) reductive coupling remains challenging. Herein, we report a highly regio-, diastereo-, and enantioselective reductive homocoupling of allylic acetates through cooperative palladium and photoredox catalysis using diisopropylethylamine or Hantzsch ester as a homogeneous organic reductant. This straightforward protocol enables the stereoselective construction of C(sp3)-C(sp3) bonds under mild reaction conditions. A series of C2-symmetrical chiral 1,5-dienes were easily prepared with excellent enantioselectivities (up to >99% ee), diastereoselectivities (up to >95:5 dr), and regioselectivities (up to >95:5 rr). The resultant chiral 1,5-dienes can be directly used as chiral ligands in asymmetric synthesis, and they can be also transformed into other valuable chiral ligands.

18.
Opt Lett ; 45(12): 3344-3347, 2020 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-32538979

RESUMEN

A method for optimizing a computer-generated hologram (CGH) for high-stability laser processing is proposed. The CGH is optimized during laser processing; therefore, unpredicted dynamic changes in the laser processing system, in addition to its static imperfections, are automatically compensated for by exploiting the rewritable capability of the spatial light modulator. Consequently, the short-term and long-term stability are improved, which will contribute to the realization of high-speed, high-precision laser processing. A CGH that generated 36 parallel beams was continuously optimized, and the maximum uniformity reached 0.98, which is higher than reported in previous research. To the best of our knowledge, this is the first demonstration of gradual improvement of parallel laser processing with in-process optimization of the CGH. Furthermore, it was also demonstrated that the performance of the laser processing system against unexpected disturbances was improved.

19.
Phys Rev Lett ; 125(2): 021801, 2020 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-32701315

RESUMEN

We propose a new nonthermal mechanism of dark matter production based on vacuum misalignment. A global X-charge asymmetry is generated at high temperatures, under which both the will-be Higgs boson and the dark matter are charged. At lower energies, the vacuum changes alignment and breaks the U(1)_{X}, leading to the emergence of the Higgs bosonand of a fraction of charge asymmetry stored in the stable dark matter relic. This mechanism can be present in a wide variety of models based on vacuum misalignment, and we demonstrate it in a composite Higgs template model, where all the necessary ingredients are naturally present. A light pseudo-scalar η is always predicted, with interesting implications for cosmology, future supernova observations and exotic Z→γη decays.

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