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1.
Dev Dyn ; 253(7): 635-647, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38131461

RESUMO

BACKGROUND: A precise balance between the proliferation and differentiation of epidermal progenitors is required to achieve the barrier function during the development of epidermis. During the entire process of skin development, the newly formed basal layer cells divide, differentiate, and migrate outward to the surface of the skin, which is tightly regulated by a series of events related to cell cycle progression. The CRL4DTL complex (Cullin 4 RING ligase, in association with the substrate receptor DTL) has long emerged as a master regulator in various cellular processes, which mediates the degradation of key cell cycle proteins. However, the roles of DTL in regulating epidermal morphogenesis during skin development remain unclear. RESULTS: We showed that DTL deficiency in epidermal progenitor cells leads to defects in epidermal stratification and loss of hair follicles accompanied by reduced epidermal progenitor cells and disturbed cell cycle progression during skin development. Transcriptome analysis revealed that p53 pathway is activated in DTL-depleted epidermal progenitor cells. The apoptosis of epidermal cells showed in DTL deficiency mice is rescued by the absence of p53, but the proliferation and differentiation defects were p53-independent. CONCLUSION: Our findings indicate that DTL plays a vital role in epidermal malformation during skin development.


Assuntos
Diferenciação Celular , Proliferação de Células , Epiderme , Folículo Piloso , Ubiquitina-Proteína Ligases , Animais , Camundongos , Folículo Piloso/metabolismo , Folículo Piloso/citologia , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética , Epiderme/metabolismo , Células-Tronco/metabolismo , Células-Tronco/citologia , Proteína Supressora de Tumor p53/metabolismo , Proteína Supressora de Tumor p53/genética , Camundongos Knockout , Células Epidérmicas/metabolismo , Ciclo Celular/genética , Ciclo Celular/fisiologia , Pele/metabolismo , Pele/citologia
2.
Int J Mol Sci ; 25(12)2024 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-38928338

RESUMO

The flavonoids in citrus fruits are crucial physiological regulators and natural bioactive products of high pharmaceutical value. Melatonin is a pleiotropic hormone that can regulate plant morphogenesis and stress resistance and alter the accumulation of flavonoids in these processes. However, the direct effect of melatonin on citrus flavonoids remains unclear. In this study, nontargeted metabolomics and transcriptomics were utilized to reveal how exogenous melatonin affects flavonoid biosynthesis in "Bingtangcheng" citrus fruits. The melatonin treatment at 0.1 mmol L-1 significantly increased the contents of seven polymethoxylated flavones (PMFs) and up-regulated a series of flavonoid pathway genes, including 4CL (4-coumaroyl CoA ligase), FNS (flavone synthase), and FHs (flavonoid hydroxylases). Meanwhile, CHS (chalcone synthase) was down-regulated, causing a decrease in the content of most flavonoid glycosides. Pearson correlation analysis obtained 21 transcription factors co-expressed with differentially accumulated flavonoids, among which the AP2/EREBP members were the most numerous. Additionally, circadian rhythm and photosynthesis pathways were enriched in the DEG (differentially expressed gene) analysis, suggesting that melatonin might also mediate changes in the flavonoid biosynthesis pathway by affecting the fruit's circadian rhythm. These results provide valuable information for further exploration of the molecular mechanisms through which melatonin regulates citrus fruit metabolism.


Assuntos
Citrus , Flavonoides , Frutas , Regulação da Expressão Gênica de Plantas , Melatonina , Metabolômica , Citrus/metabolismo , Citrus/efeitos dos fármacos , Citrus/genética , Melatonina/farmacologia , Melatonina/metabolismo , Flavonoides/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Frutas/metabolismo , Frutas/efeitos dos fármacos , Frutas/genética , Metabolômica/métodos , Perfilação da Expressão Gênica , Transcriptoma , Metaboloma/efeitos dos fármacos , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética
3.
Biomed Chromatogr ; 37(4): e5589, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36689998

RESUMO

Li-Zhong-Xiao-Pi granules (LZXP) are effective for treating gastric precancerous lesions (GPL) in traditional Chinese medicine. However, the active compounds of LZXP and their potential therapeutic mechanism in GPL remained unclarified. The purpose of this study is to investigate the chemical composition and potential targets of LZXP. Based on the accurate masses, ion fragments, and literature data, a total of 128 compounds were identified in the LZXP sample using ultra-performance liquid chromatography and quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) in both positive and negative ion modes, and 28 of these compounds were exactly determined by comparison with authentic reference standards. Meanwhile, 11 typical components were quantified via UPLC during a 24 min period. The linearity, accuracy, stability and recovery of the method were all proven. Through the network pharmacological analysis, six chemicals (quercetin, 4'-hydroxywogonin, sinensetin, 5, 7, 8, 3', 4'-pentamethoxyflavanone, 8-gingerdione and quercetin) were identified as the active ingredients, and five LZXP targets (AKT1, CYP1B1, PTGS2, MMP9 and EGFR) were found to be the crucial molecules in the treatment of GPL. This study provides a systematic and applicable method for the rapid screening and identification of the chemical constituents from LZXP, and an effective understanding the mechanism of LZXP in the treatment of GPL.


Assuntos
Medicamentos de Ervas Chinesas , Cromatografia Líquida de Alta Pressão/métodos , Medicamentos de Ervas Chinesas/química , Quercetina , Farmacologia em Rede , Espectrometria de Massas/métodos
4.
Am J Orthod Dentofacial Orthop ; 163(4): 509-519, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37079283

RESUMO

INTRODUCTION: This retrospective clinical study investigated the clinical changes of maxillary central incisor and alveolar bone in Class II Division 2 nonextraction treatment with fixed appliances or clear aligners on the basis of cone-beam computed tomography. METHODS: Fifty-nine Chinese Han patients with similar demographic characteristics were collected from a conventional bracket group, a self-ligating bracket group, and a clear aligner group. All measurements about root resorption and alveolar bone thickness on the cone-beam computed tomography images were tested. Changes between pretreatment and posttreatment were evaluated by paired-sample t test. The variation among the 3 groups was compared by 1-way analysis of variance. RESULTS: The resistance center of the maxillary central incisor showed upward or forward movement, and the axial inclination was increased in 3 groups (P <0.0001). Root volume loss in the clear aligner group (23.68 ± 4.82 mm3) was significantly less than that in the fixed appliances group (28.24 ± 6.44 mm3 in the conventional bracket group, 28.17 ± 6.07 mm3 in the self-ligating bracket group) (P <0.05). All 3 groups showed a significant decrease in palatal alveolar bone and total bone thickness at all 3 levels at posttreatment. In contrast, labial bone thickness significantly increased except for crestal level l. Among the 3 groups, the clear aligner group had a prominent increase in labial bone thickness at the apical level (P = 0.0235). CONCLUSIONS: Clear aligner treatment for Class II Division 2 malocclusions could effectively reduce the incidence of fenestration and root resorption. Our findings will be beneficial to comprehensively understand the effectiveness of different appliances for Class II Division 2 malocclusions treatment.


Assuntos
Má Oclusão Classe II de Angle , Aparelhos Ortodônticos Removíveis , Reabsorção da Raiz , Humanos , Incisivo/diagnóstico por imagem , Estudos Retrospectivos , Má Oclusão Classe II de Angle/diagnóstico por imagem , Má Oclusão Classe II de Angle/terapia , Aparelhos Ortodônticos Fixos , Tomografia Computadorizada de Feixe Cônico , Maxila/diagnóstico por imagem
5.
Biochem Biophys Res Commun ; 614: 183-190, 2022 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-35598429

RESUMO

Maternal insults during pregnancy induces an increased risk of autism spectrum disorders (ASD) in offspring, but the neuropathological changes in this process remains not to be established. To shed light on this, the transcriptome datasets of maternal blood samples with children later diagnosed with ASD and typical development, and tissue samples of multiple brain regions from ASD patients and human neurodevelopment were conducted to identify the non-chasm differentially expressed genes (DEGs) to generate the spatio-temporal dynamic change. Combined enrichment and interaction network analysis revealed that non-chasm DEGs with similar expression trajectories in the same brain regions, were involved in neural, immune and metabolic GO functions and KEGG pathways, respectively, suggesting that did not performed exactly the same functions. Interestingly, our results found that non-chasm DEGs in frontal cortex and temporal cortex were associated with COVID-19, suggesting that as an environmental risk factor COVID-19 affects an increased risk of ASD.


Assuntos
Transtorno do Espectro Autista , COVID-19 , Transtorno do Espectro Autista/genética , Encéfalo , Criança , Feminino , Feto , Humanos , Gravidez , Transcriptoma
6.
Biomed Eng Online ; 21(1): 27, 2022 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-35449051

RESUMO

BACKGROUND: Increasing attention has been paid to the potential relationship between gut and lung. The bacterial dysbiosis in respiratory tract and intestinal tract is related to inflammatory response and the progress of lung diseases, and the pulmonary diseases could be improved by regulating the intestinal microbiome. This study aims to generate the knowledge map to identify major the research hotspots and frontier areas in the field of gut-lung axis. MATERIALS AND METHODS: Publications related to the gut-lung axis from 2011 to 2021 were identified from the Web of Science Core Collection. CiteSpace 5.7.R2 software was used to analyze the publication years, journals, countries, institutions, and authors. Reference co-citation network has been plotted, and the keywords were used to analyze the research hotspots and trends. RESULTS: A total of 3315 publications were retrieved and the number of publications per year increased over time. Our results showed that Plos One (91 articles) was the most active journal and The United States (1035 articles) published the most articles. We also observed the leading institution was the University of Michigan (48 articles) and Huffnagle Gary B, Dickson Robert P and Hansbro Philip M, who have made outstanding contributions in this field. CONCLUSION: The Inflammation, Infection and Disease were the hotspots, and the regulation of intestinal flora to improve the efficacy of immunotherapy in lung cancer was the research frontier. The research has implications for researchers engaged in gut-lung axis and its associated fields.


Assuntos
Bibliometria , Neoplasias Pulmonares , Humanos , Imunoterapia , Pulmão , Estados Unidos
7.
Tohoku J Exp Med ; 258(3): 213-218, 2022 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-36002254

RESUMO

The study aimed to evaluate the diagnostic and prognostic value of indexes detected by electrogastrography in Parkinson's disease patients. One hundred twenty early Parkinson's disease patients and 120 healthy controls were recruited, and underwent electrogastrography to detect dominant frequency (DF), instability coefficient of DF (ICDF), low frequency range (LFR), high frequency range (HFR), and normal frequency range (NFR). The receiver operating characteristic (ROC) curve was drawn for the diagnostic value analysis. The motor function was scored with the Unified Parkinson's Disease Rating Scale (UPDRS). Sniffin' Sticks test was used for the olfactory evaluation, and the TDI score consisting of odor threshold (T), odor discrimination (D) and odor identification (I) tests was calculated. The preprandial ICDF of Parkinson's disease patients was significantly higher than that of the control group, and decreased slowly during the late postprandial phase. The levels of LFR%, HFR% and NFR% in Parkinson's disease patients were higher than the control group during both the preprandial and late postprandial phase, and the changes of each index before and after meals were not obvious. Preprandial ICDF value and TDI score had the ability to distinguish Parkinson's disease patients with the AUC of 0.874 and 0.859 respectively. The ICDF detected by electrogastrography has high clinical value in the early diagnosis of Parkinson's disease, and the combination of ICDF and TDI can improve the diagnostic sensitivity and specificity of a single indicator. High ICDF levels during the preprandial phase are related to the poor prognosis of Parkinson's disease patients after treatment.


Assuntos
Transtornos do Olfato , Doença de Parkinson , Humanos , Doença de Parkinson/diagnóstico , Olfato , Odorantes , Sensibilidade e Especificidade , Progressão da Doença
8.
Curr Psychol ; 41(11): 8032-8043, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-33424207

RESUMO

Wisdom views in different cultural contexts are closely connected with the corresponding culture's worldview. Some results are found by comparing the wisdom concepts in Chinese and Western cultures: Firstly, the early wisdom concepts, both in China and the West, contain the elements of intelligence and virtue. Whereas, from the Enlightenment to the Piagetian school, the western concept of wisdom has then shifted to the role of cognition and knowledge; By contrast, the traditional Chinese wisdom concept has been treating wisdom as a virtue. Modern Chinese and western wisdom psychologists are inclined to accept the wisdom meta-theory of "integration of intelligence and virtue". Secondly, both Chinese and the Western philosophy advocate using wisdom to solve real-life problems. Western thinkers focus on practical problems in the material world, i.e. reconciling conflicts between people and the world through understanding and changing the environment. However, Chinese philosophers focus on internal spiritual problems, i.e. improving the individual realm to solve the contradictions inside oneself. Thirdly, both China and the West highlight the comprehensive application of multiple thinking modes. While comparing with the west, which is excelled in using logical and analytical thinking modes and utilizing rational cognition, China is far better at using dialectical and holistic thinking modes and applying intuitive comprehension.

9.
Nanotechnology ; 32(15): 155703, 2021 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-33378747

RESUMO

Lithium ion batteries have widely been used for electronic devices and electric vehicles. However, commercial anodes, generally graphite, have not been improved a great deal. Thus, we successfully constructed ReS2/carbon nanotube (CNT) composites by a chemical vapor deposition method, which exhibit excellent electrochemical performances when serving as anode materials for lithium ion batteries (LIBs). We confirmed that ReS2 crystals are grown on the surface of the CNTs by using scanning electron microscopy and transmission electron microscopy. As a result, the LIBs show much better long-cycle and rate performances than bare ReS2 and CNTs. The ReS2/CNTs were assembled in coin cells CR2025, presenting a stability capacity of 488 mAh g-1 at a rate of 5C. The anodes maintain a reversible capacity of 1050 mAh g-1 after nearly 60 cycles at 0.2C, which indicates that it is a promising technique to improve the performance of LIBs.

10.
Nanotechnology ; 32(50)2021 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-34551405

RESUMO

The combination of two-dimensional (2D) materials with non-2D materials (quantum dots, nanowires and bulk materials), i.e. mixed-dimensional van der Waals (md-vdW) heterostructures endow 2D materials with remarkable electronics properties. However, it remains a big challenge to synthesize md-vdW heterostructures because of the difference of crystal symmetry between 2D and non-2D materials. Meanwhile, it is difficult to initiate the nucleation due to the lack of chemical active sites on chemical inert surfaces of 2D materials. Herein, we design a general chemical vapor deposition method for synthesizing a broad class of md-vdW heterostructures with well-aligned hexagonal symmetry including MoS2/FeS, MoS2/CoS, MoS2/MnS, MoS2/ZnS, Mo(SxSe1-x)2/ZnSxSe1-x, Mo(SxSe1-x)2/CdSxSe1-x. Combining with DFT calculation, we find that the hexagonal symmetry and the centered clusters of MoS2and Mo(SxSe1-x)2nanoflakes are two crucial factors to launch the hexagonally oriented growth and nucleation of non-2D materials on 2D materials. Our discovery opens an opportunity for the versatile hetero-integration of 2D materials and allows systematic investigation of physical properties in a wide variety of md-vdW heterostructures.

11.
Oral Dis ; 27(7): 1747-1754, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33128317

RESUMO

OBJECTIVE: To explore susceptibility genes and pathways for non-syndromic cleft lip with or without cleft palate (NSCL/P). MATERIALS AND METHODS: Two genome-wide association studies (GWAS) datasets, including 858 NSCL/P cases and 1,248 controls, were integrated with expression quantitative trait loci (eQTL) dataset identified by Genotype-Tissue Expression (GTEx) project in whole-blood samples. The expression of the candidate genes in mouse orofacial development was inquired from FaceBase. Protein-protein interaction (PPI) network was visualized to identify protein functions. Go and KEGG pathway analyses were performed to explore the underlying risk pathways. RESULTS: A total of 233 eQTL single-nucleotide polymorphisms (SNPs) in 432 candidate genes were identified to be associated with the risk of NSCL/P. One hundred and eighty-three susceptible genes were expressed in mouse orofacial development according to FaceBase. PPI network analysis highlighted that these genes involved in ubiquitin-mediated proteolysis (KCTD7, ASB1, UBOX5, ANAPC4) and DNA synthesis (XRCC3, RFC3, KAT5, RHNO1) were associated with the risk of NSCL/P. GO and KEGG pathway analyses revealed that the fatty acid metabolism pathway (ACADL, HSD17B12, ACSL5, PPT1, MCAT) played an important role in the development of NSCL/P. CONCLUSIONS: Our results identified novel susceptibility genes and pathways associated with the development of NSCL/P.


Assuntos
Fenda Labial , Fissura Palatina , 17-Hidroxiesteroide Desidrogenases , Animais , Estudos de Casos e Controles , Fenda Labial/genética , Fissura Palatina/genética , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Genótipo , Camundongos , Polimorfismo de Nucleotídeo Único , Canais de Potássio , Locos de Características Quantitativas/genética , Proteínas Supressoras da Sinalização de Citocina
12.
Orthod Craniofac Res ; 23(3): 332-341, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32202038

RESUMO

OBJECTIVE: To investigate the morphological characteristics of the mandible in subjects with impacted mandibular second molars by measuring and analysing the mandible in three dimensions. SETTING AND SAMPLE POPULATION: In this retrospective study, the data of a total of 52 609 subjects who underwent cone-beam computed tomography (CBCT) for diagnosis and treatment were reviewed. According to the inclusion and exclusion criteria, 183 subjects with impacted mandibular second molars and 176 age- and sex-matched controls were included. METHODS: A retrospective case-control study was designed. The 183 subjects were divided into two groups: group 1 (G1) comprised 120 patients with unilaterally impacted mandibular second molars, and group 2 (G2) comprised 63 patients with bilaterally impacted mandibular second molars. Group 3 (G3) contained 176 age- and sex-matched controls. The mandible was reconstructed with nineteen landmarks using Mimics software. Twelve linear lengths and 3 angles were measured. RESULTS: The bilateral germination gap, mandibular body width and gonion width in G1 were significantly lower than those in G3 (P < .05), while the gnathion angle and first molar width values in G1 were significantly higher than those in G3 (P < .05). The results in G2 were similar to those in G1, but the differences between G2 and G3 were greater than those between G1 and G3. There were no significant differences in the other measurements among the groups. CONCLUSION: The mandibles of the subjects with impacted second molars were constricted in terms of the sagittal length and transverse width.


Assuntos
Dente Impactado , Estudos de Casos e Controles , Tomografia Computadorizada de Feixe Cônico , Humanos , Mandíbula , Dente Molar , Dente Serotino , Estudos Retrospectivos
13.
J Orthod ; 47(3): 257-264, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32588700

RESUMO

INTRODUCTION: This case report describes the treatment of a 21-year-old man who presented in an orthodontic office for treatment but lived in a city 100 miles away and wanted the orthognathic surgery in another state in America. The patient presented with an anterior open bite and skeletal Class III relationship. METHODS: The treatment plan included: (1) effective and careful communication of the treatment plan with the patient, orthodontist and oral and maxillofacial surgeon; (2) pre-surgical alignment and levelling of the teeth in both arches with Invisalign; (3) a long-distance communication between the orthodontist and the surgeon for surgical plan with virtual surgical planning (VSP Orthognathics; 3D Systems, www.3Dsystem.com) online; (4) maxillary advancement (LeFort I osteotomy) with mandibular set-back (bilateral sagittal split osteotomy); (5) postsurgical correction of the malocclusion with clear brackets and aligners; and (6) retention and final small tooth movement adjustments with aligners/clear retainers. RESULTS: The anterior open bite was treated, crowding was eliminated in the upper and lower anterior segment, correction of skeletal and dental Class III malocclusion was obtained, mandibular plane angle was reduced and facial profile improved. CONCLUSIONS: The results suggest that aesthetic and functional results can be achieved with long-distance communication of two specialties and with the combined use of clear aligners and clear fixed appliances.


Assuntos
Má Oclusão Classe III de Angle , Mordida Aberta , Procedimentos Cirúrgicos Ortognáticos , Adulto , Cefalometria , Humanos , Masculino , Técnicas de Movimentação Dentária , Adulto Jovem
14.
Angew Chem Int Ed Engl ; 59(39): 17225-17228, 2020 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-32558159

RESUMO

Zeolite Y, with a high SiO2 /Al2 O3 ratio (SAR), plays an important role in fluidized catalytic cracking processes. However, in situ synthesis of zeolite Y with high SARs remains a challenge because of kinetic limitations. Here, zeolite Y with an SAR of 6.35 is synthesized by a hydroxyl radical assisted route. Density-functional theory (DFT) calculations suggest that hydroxyl radicals preferentially enhanced the formation of Si-O-Si bonds, thus leading to an increased SAR. To further increase the SAR, a dealumination process was carried out using citric acid, with a subsequent second-step hydrothermal crystallization, giving an SAR of up to 7.5 while maintaining good crystallinity and high product yield. The resultant zeolite Y shows good performance in cumene cracking. Introduced here is a new strategy for synthesizing high SAR zeolite Y, which is widely used in commercial applications.

15.
Chemistry ; 25(9): 2184-2188, 2019 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-30521132

RESUMO

A new germanosilicate zeolite named SCM-15 (Sinopec Composite Material No. 15), the first zeolite containing a 3-dimensional (3D) channel system with interconnected 12-, 12-, and 10-ring channels (pore sizes: 6.1×7.2, 6.1×7.4, and 5.2×5.9 Å), has been synthesized using neutral 4-pyrrolidinopyridine as organic structure-directing agents (OSDAs). Its structure has been determined by combining single-crystal electron diffraction (SCED) and synchrotron powder X-ray diffraction (SPXD) data. The unique open framework structure of SCM-15 is related to that of FOS-5 (BEC), ITQ-7 (ISV), PKU-16 (POS), ITQ-26 (IWS), ITQ-21, Beta polymorph B, and SU-78B, since all these framework structures can be constructed from similar chains which are connected through shared 4-ring or double 4-ring (d4r) units. Based on this relation, six topologically reasonable 3D large or extra-large pore hypothetical zeolites are predicted.

16.
Sensors (Basel) ; 19(12)2019 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-31234545

RESUMO

The Chang'e-4 (CE-4) lunar rover, equipped with a visible and near-IR imaging spectrometer (VNIS) based on acousto-optic tunable filter spectroscopy, was launched to the far side of the moon on December 8, 2018. The detection band of the VNIS ranges from 0.45 to 2.4 µm. Because of the weak reflection of infrared radiation from the lunar surface, a static electronic phase-locked acquisition method is adopted in the infrared channel for signal amplification. In this paper, full-link simulations and modeling are conducted on the infrared channel information flow of the instrument. The signal characteristics of the VNIS are analyzed in depth, and the signal to noise ratio (SNR) prediction and laboratory verification are presented. On 4 January 2019, the VNIS started working successfully and acquired high-resolution spectrum data of the far side of the moon for the first time. Through analysis we have found that the SNR ratio is in line with our predictions, and the data obtained by VNIS in orbit are consistent with the information model proposed in this paper.

17.
Chemistry ; 24(2): 306-311, 2018 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-29052261

RESUMO

Synthesis of SFE-type borosilcate zeolite was successfully carried out using a commercially available low-cost organic structure directing agent (OSDA) with ultra-low OSDA and water contents within a short crystallization time. Heteroatom (Al, Ti, V, or Fe)-substituted SFE-type zeolite analogues were also directly synthesized for the first time. The obtained Al containing zeolites exhibited promising catalytic performances in the disproportionation of isopropylnaphthalene.

18.
Chemistry ; 23(66): 16829-16834, 2017 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-28967679

RESUMO

SCM-14 (Sinopec Composite Material No. 14), a new stable germanosilicate zeolite with a 12×8×8-ring channel system, was synthesized using commercially available 4-pyrrolidinopyridine as organic structure-directing agents (OSDAs) in fluoride medium. The framework structure of SCM-14 was determined using rotation electron diffraction (RED), and refined against synchrotron X-ray powder diffraction (SXPD) data for both as-made and calcined materials. The framework structure of SCM-14 is closely related to that of three known zeolites: mordenite (MOR), GUS-1 (GON), and IM-16 (UOS). SCM-14 has the same projection as that of mordenite and GUS-1 when viewed along the 12-ring channels, and possesses two more straight 8-ring channels running perpendicular to the 12-ring channels. The structure of SCM-14 can be constructed by either the same layers as that of GUS-1 or the same columns as that of IM-16. Based on their structural relationship, three topologically reasonable hypothetical zeolites were predicted.

19.
J Am Chem Soc ; 138(33): 10421-4, 2016 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-27513613

RESUMO

The NHC-stabilized silicon-carbon mixed cumulene (Me3Si)2C═Si(IPr)═Si(IPr)═C(SiMe3)2 (3, IPr = 1,3-diisopropyl-4,5-dimethyl-imidazol-2-ylidene) has been prepared by reaction of Ar(SiMe3)NK with the NHC-stabilized silene (Me3Si)2C═Si(SiMe3)Cl(IPr) (2) in toluene at low temperature via the elimination of trimethylsilyl and chloride groups from 2. X-ray crystal analysis of 3 indicated the formal C═Si═Si═C cumulene skeleton with the short Si-Si double bond distance of 2.1896(10) Å. DFT calculations disclosed its zwitterionic character. Reaction of 3 with diphenylacetylene resulted in the formation of a silatriafulvene with an exocyclic NHC-stabilized silene moiety.

20.
Dev Growth Differ ; 58(3): 270-9, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26991405

RESUMO

Mouse parthenogenetic embryonic stem cells (PgESCs) could be applied to study imprinting genes and are used in cell therapy. Our previous study found that stem cells established by aggregation of two parthenogenetic embryos at 8-cell stage (named as a2 PgESCs) had a higher efficiency than that of PgESCs, and the paternal expressed imprinting genes were observably upregulated. Therefore, we propose that increasing the number of parthenogenetic embryos in aggregation may improve the development of parthenogenetic mouse and imprinting gene expression of PgESCs. To verify this hypothesis, we aggregated four embryos together at the 4-cell stage and cultured to the blastocyst stage (named as 4aPgB). qPCR detection showed that the expression of imprinting genes Igf2, Mest, Snrpn, Igf2r, H19, Gtl2 in 4aPgB were more similar to that of fertilized blastocyst (named as fB) compared to 2aPgB (derived from two 4-cell stage parthenogenetic embryos aggregation) or PgB (single parthenogenetic blastocyst). Post-implantation development of 4aPgB extended to 11 days of gestation. The establishment efficiency of GFP-a4 PgESCs which derived from GFP-4aPgB is 62.5%. Moreover, expression of imprinting genes Igf2, Mest, Snrpn, notably downregulated and approached the level of that in fertilized embryonic stem cells (fESCs). In addition, we acquired a 13.5-day fetus totally derived from GFP-a4 PgESCs with germline contribution by 8-cell under zona pellucida (ZP) injection. In conclusion, four embryos aggregation improves parthenogenetic development, and compensates imprinting genes expression in PgESCs. It implied that a4 PgESCs could serve as a better scientific model applied in translational medicine and imprinting gene study.


Assuntos
Blastômeros/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Impressão Genômica/genética , Células-Tronco Embrionárias Murinas/metabolismo , Partenogênese/genética , Animais , Blastocisto/citologia , Blastocisto/metabolismo , Blastômeros/citologia , Agregação Celular/genética , Diferenciação Celular/genética , Desenvolvimento Embrionário/genética , Feminino , Imunofluorescência , Camundongos , Camundongos Transgênicos , Células-Tronco Embrionárias Murinas/citologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo
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