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1.
Biotechnol Bioeng ; 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38923503

RESUMO

Spinal muscular atrophy (SMA) is a devastating neuromuscular disease caused by mutations in the survival motor neuron 1 (SMN1) gene. Gene editing technology repairs the conversion of the 6th base T to C in exon 7 of the paralogous SMN2 gene, compensating for the SMN protein expression and promoting the survival and function of motor neurons. However, low editing efficiency and unintended off-target effects limit the application of this technology. Here, we optimized a TaC9-adenine base editor (ABE) system by combining Cas9 nickase with the transcription activator-like effector (TALE)-adenosine deaminase fusion protein to effectively and precisely edit SMN2 without detectable Cas9 dependent off-target effects in human cell lines. We also generated human SMA-induced pluripotent stem cells (SMA-iPSCs) through the mutation of the splice acceptor or deletion of the exon 7 of SMN1. TaC9-R10 induced 45% SMN2 T6 > C conversion in the SMA-iPSCs. The SMN2 T6 > C splice-corrected SMA-iPSCs were directionally differentiated into motor neurons, exhibiting SMN protein recovery and antiapoptosis ability. Therefore, the TaC9-ABE system with dual guides from the combination of Cas9 with TALE could be a potential therapeutic strategy for SMA with high efficacy and safety.

2.
Osteoporos Int ; 34(8): 1453-1464, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37202541

RESUMO

Primary hypertrophic osteoarthropathy (PHO) is a hereditary bone disease that is grouped into PHO autosomal recessive 1 (PHOAR1) and PHO autosomal recessive 2 (PHOAR2) due to different causative genes. Data comparing bone microstructure between the two subtypes are scarce. This is the first study to find that PHOAR1 patients had inferior bone microstructure compared with PHOAR2 patients. PURPOSE: The primary goal of this study was to assess bone microarchitecture and strength in PHOAR1 and PHOAR2 patients and to compare them with age- and sex-matched healthy controls (HCs). The secondary goal was to assess the differences between PHOAR1 and PHOAR2 patients. METHODS: Twenty-seven male Chinese PHO patients (PHOAR1 = 7; PHOAR2 = 20) were recruited from Peking Union Medical College Hospital. The areal bone mineral density (aBMD) was assessed by dual-energy X-ray absorptiometry (DXA). Peripheral bone microarchitecture at the distal radius and tibia were evaluated by high-resolution peripheral quantitative computed tomography (HR-pQCT). Biochemical markers of PGE2, bone turnover, and Dickkopf-1 (DKK1) were investigated. RESULTS: Compared with HCs, PHOAR1 and PHOAR2 patients had distinctively larger bone geometry, substantially lower vBMD at the radius and tibia, and compromised cortical microstructure at the radius. For trabecular bone, PHOAR1 and PHOAR2 patients showed different changes at the tibia. PHOAR1 patients had significant deficits in the trabecular compartment, resulting in lower estimated bone strength. Conversely, PHOAR2 patients showed a higher trabecular number, narrower trabecular separation, and lower trabecular network inhomogeneity than HCs, translating into preserved or slightly high estimated bone strength. CONCLUSION: PHOAR1 patients had inferior bone microstructure and strength compared with PHOAR2 patients and HCs. Additionally, this study was the first to find differences in the bone microstructure between PHOAR1 and PHOAR2 patients.


Assuntos
Osteoartropatia Hipertrófica Primária , Humanos , Masculino , Rádio (Anatomia)/diagnóstico por imagem , Tíbia/diagnóstico por imagem , Densidade Óssea , Osso e Ossos , Absorciometria de Fóton
3.
Calcif Tissue Int ; 113(5): 483-495, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37704776

RESUMO

This study aims to investigate the influence of overweight/obesity and change in weight or body mass index (BMI) on incident fractures among Chinese postmenopausal women. According to BMI, 754 postmenopausal women were categorized into normal weight (NW), overweight (OW), and obesity (OB) groups, respectively. We used data from the baseline and the second survey for statistical analysis, including anthropometric data, clinical fractures, and morphometric vertebral fractures (MVFs) assessed by X-rays. The prevalence of previous MVFs was 32.7% and 21.8% in the OB and NW groups, respectively (p < 0.05). All incident fractures and incident MVFs accounted for 10.7 and 6.3% among all participants within five years. Overweight/obesity and increase in weight or BMI during the follow-up had no associations with all incident fractures, incident MVFs, and incident clinical non-VFs among all participants. However, after multivariate adjustment, the increased BMI at baseline was the risk factor of incident MVFs in the OW group (odds ratio, OR 2.06, 95% confidence interval, 95% CI 1.16-3.66, p = 0.014), and increase in weight (OR 0.89, 95% CI 0.79-0.99, p = 0.036) or BMI (OR 0.77, 95% CI 0.59-0.99, p = 0.045) during the follow-up were the protective factors of all incident fractures in the NW group. Overweight/obesity and change in weight or BMI do not correlate with fracture risk in postmenopausal women, but an increase in weight is the protective factor against incident fractures in normal-weight participants. Overweight postmenopausal women with a higher BMI should pay attention to the risk of MVFs.


Assuntos
Fraturas Ósseas , Fraturas da Coluna Vertebral , Feminino , Humanos , Índice de Massa Corporal , Fraturas da Coluna Vertebral/etiologia , Sobrepeso/complicações , Sobrepeso/epidemiologia , Pós-Menopausa , Pequim , Obesidade/complicações , Obesidade/epidemiologia , Fraturas Ósseas/complicações , Fatores de Risco
4.
BMC Endocr Disord ; 23(1): 226, 2023 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-37853391

RESUMO

BACKGROUND: Familial dysalbuminemic hyperthyroxinemia (FDH) is an autosomal dominant disease characterised by an abnormally increased affinity of albumin for serum thyroxine. Assay interference and differential diagnosis remain challenging for FDH. The condition is more complicated when FDH is combined with primary thyroid diseases. Co-occurrence of FDH and Graves' disease is rare. CASE PRESENTATION: We report the case of a 28-year-old woman with complex FDH and coexisting Graves' disease. Initially, the existence of FDH was not recognised. Graves' disease was relieved after treatment with antithyroid drugs and two administrations of radioactive iodine therapy. She subsequently developed primary hypothyroidism and was prescribed levothyroxine replacement. However, thyroid function failed to normalise despite frequent levothyroxine dose adjustments. Ultimately, syndromes involving the inappropriate secretion of thyroid-stimulating hormone (IST) were considered, and FDH was successfully differentiated from other causes of IST. CONCLUSIONS: A greater focus on FDH when investigating the causes of IST is critical to correctly evaluate thyroid function status and avoid inappropriate treatment, especially in complicated cases with concurrent FDH and primary thyroid diseases.


Assuntos
Doença de Graves , Hipertireoxinemia Disalbuminêmica Familiar , Neoplasias da Glândula Tireoide , Feminino , Humanos , Adulto , Hipertireoxinemia Disalbuminêmica Familiar/diagnóstico , Tiroxina/uso terapêutico , Albumina Sérica , Radioisótopos do Iodo , Doença de Graves/complicações , Doença de Graves/diagnóstico
5.
Molecules ; 28(4)2023 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-36838874

RESUMO

BACKGROUND: Cashew (Anacardium occidentale L.) is a commercially important plant. Cashew nuts are a popular food source that belong to the tree nut family. Tree nuts are one of the eight major food allergens identified by the Food and Drug Administration in the USA. Allergies to cashew nuts cause severe and systemic immune reactions. Tree nut allergies are frequently fatal and are becoming more common. AIM: We aimed to identify the key allergenic epitopes of cashew nut proteins by correlating the phage display epitope prediction results with bioinformatics analysis. DESIGN: We predicted and experimentally confirmed cashew nut allergen antigenic peptides, which we named Ana o 2 (cupin superfamily) and Ana o 3 (prolamin superfamily). The Ana o 2 and Ana o 3 epitopes were predicted using DNAstar and PyMoL (incorporated in the Swiss-model package). The predicted weak and strong epitopes were synthesized as peptides. The related phage library was built. The peptides were also tested using phage display technology. The expressed antigens were tested and confirmed using microtiter plates coated with pooled human sera from patients with cashew nut allergies or healthy controls. RESULTS: The Ana o 2 epitopes were represented by four linear peptides, with the epitopes corresponding to amino acids 108-111, 113-119, 181-186, and 218-224. Furthermore, the identified Ana o 3 epitopes corresponding to amino acids 10-24, 13-27, 39-49, 66-70, 101-106, 107-114, and 115-122 were also screened out and chosen as the key allergenic epitopes. DISCUSSION: The Ana o 3 epitopes accounted for more than 40% of the total amino acid sequence of the protein; thus, Ana o 3 is potentially more allergenic than Ana o 2. CONCLUSIONS: The bioinformatic epitope prediction produced subpar results in this study. Furthermore, the phage display method was extremely effective in identifying the allergenic epitopes of cashew nut proteins. The key allergenic epitopes were chosen, providing important information for the study of cashew nut allergens.


Assuntos
Anacardium , Hipersensibilidade a Noz , Proteínas de Nozes , Humanos , Alérgenos/química , Epitopos , Anacardium/química , Proteínas de Plantas/metabolismo , Proteínas de Nozes/análise , Imunoglobulina E , Nozes/química
6.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 45(1): 44-49, 2023 Feb.
Artigo em Zh | MEDLINE | ID: mdl-36861154

RESUMO

Objective To investigate the level of serum uric acid in patients with diabetes insipidus (DI),summarize the clinical characteristics of central diabetes insipidus (CDI) patients with hyperuricemia (HUA),and analyze the factors affecting the level of serum uric acid in the patients with CDI. Methods The clinical data of DI patients admitted to Peking Union Medical College Hospital from 2018 to 2021 were retrospectively analyzed.The patients were assigned into a child and adolescent group (≤ 18 years old) and an adult group (>18 years old) according to their ages.The demographic and biochemical data between two groups of patients with and without HUA were compared.Spearman correlation analysis and multiple linear regression analysis were performed to analyze the correlations between serum uric acid level and other factors. Results Among the 420 DI patients,411 patients had CDI (97.9%),including 189 patients with HUA (46.0%).Thirteen (6.9%) out of the 189 CDI patients with HUA presented the disappearance of thirst.The prevalence of HUA in children and adolescents was higher than that in adults (χ2=4.193,P=0.041).The level of serum uric acid in the CDI patients with HUA and disappearance of thirst was higher than those without disappearance of thirst (U=2.593,P=0.010).The multiple linear regression predicted serum creatinine (ß=0.472,95%CI=2.451-4.381,P<0.001) and body mass index (ß=0.387,95%CI=6.18-12.874,P<0.001) as the independent risk factors of serum uric acid level increment in children and adolescents,while serum creatinine (ß=0.361,95%CI=1.016-1.785,P<0.001),body mass index (ß=0.208,95%CI=2.321-6.702,P<0.001),triglyceride (ß=0.268,95%CI=12.936-28.840,P<0.001),and total cholesterol (ß=0.129,95%CI=2.708-22.250,P=0.013) were the independent risk factors in adults. Conclusions The patients with CDI were more likely to have HUA,and the prevalence of HUA in children and adolescents was higher than that in adults.Body mass index,serum creatinine,triglyceride,total cholesterol,and disappearance of thirst were the risk factors for the increased level of serum uric acid in CDI patients.


Assuntos
Diabetes Insípido , Diabetes Mellitus , Hiperuricemia , Adolescente , Adulto , Criança , Humanos , Ácido Úrico , Creatinina , Estudos Retrospectivos , Triglicerídeos , Colesterol
7.
Osteoporos Int ; 33(10): 2193-2204, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35767093

RESUMO

Gitelman syndrome (GS) is the disease model of the inactivation of thiazide-sensitive sodium chloride cotransporter (NCC), which is believed to benefit bone mass and reduce fracture risk. In this study, we found that GS patients have superior bone microarchitecture, which is associated with the disease status. Several decreased bone parameters with aging in healthy controls were reversed in GS patients to a certain extent. PURPOSE: To evaluate the impact of the inactivation of NCC on bone turnover and microarchitecture in Gitelman syndrome patients. METHODS: A cross-sectional study was conducted in 45 GS patients (25 males and 20 females). Serum procollagen type 1 N-terminal propeptide (P1NP), ß-carboxy-terminal crosslinked telopeptide of type 1 collagen (ß-CTX), and osteocalcin were measured. High-resolution peripheral quantitative computed tomography (HR-pQCT) was conducted to evaluate bone microarchitecture in GS patients and age- and sex-matched healthy controls. Areal bone mineral density (aBMD) was measured by dual-energy X-ray absorptiometry (DXA) simultaneously. RESULTS: GS patients had a relatively lower level of ß-CTX. aBMD at several skeletal sites was improved in GS patients. HR-pQCT assessment revealed that GS patients had slightly thinner but significantly more compact trabecular bone (increased trabecular number and decreased thickness), notably decreased cortical porosity, and increased volume BMD (vBMD) at both the radius and tibia compared with controls. The disease severity, represented as the relationship with the minimum level of magnesium during the course and standard base excess, was associated with bone microarchitecture parameters after adjusting for age, sex, and BMI. The decreased vBMD and Tb.BV/TV, and increased Tb.Sp and Ct.Po with aging, were reversed in GS patients to a certain extent. CONCLUSION: GS patients have superior bone microarchitecture, which suggests that the inactivation of NCC might be beneficial for avoiding osteoporosis.


Assuntos
Síndrome de Gitelman , Simportadores , Absorciometria de Fóton , Densidade Óssea/fisiologia , Colágeno Tipo I , Estudos Transversais , Feminino , Inativação Gênica , Humanos , Magnésio , Masculino , Osteocalcina , Pró-Colágeno , Rádio (Anatomia)/diagnóstico por imagem , Simportadores de Cloreto de Sódio , Tiazidas , Tíbia/diagnóstico por imagem
8.
Arch Virol ; 167(2): 415-424, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34984562

RESUMO

African swine fever (ASF) is an acute hemorrhagic disease of domestic pigs. The causative agent of ASF, ASF virus (ASFV), is a double-stranded DNA virus, the sole member in the family Asfarviridae. The non-structural protein pB602L of ASFV is a molecular chaperone of the major capsid protein p72 and plays a key role in icosahedral capsid assembly. This protein is antigenic and is a target for developing diagnostic tools for ASF. To generate monoclonal antibodies (mAbs) against pB602L, a prokaryotically expressed recombinant pB602L protein was produced, purified, and used as an antigen to immunize mice. A total of eight mouse mAbs were obtained, and their binding epitopes were screened by Western blot using an overlapping set of polypeptides from pB602L. Three linear epitopes were identified and designated epitope 1 (366ANRERYNY373), epitope 2 (415GPDAPGLSI423), and epitope 3 (498EMLNVPDD505). Based on the epitope recognized, the eight mAbs were placed into three groups: group 1 (B2A1, B2F1, and B2D10), group 2 (B2H10, B2B2, B2D8, and B2A3), and group 3 (B2E12). The mAbs B2A1, B2H10, and B2E12, each representing one of the groups, were used to detect pB602L in ASFV-infected porcine alveolar macrophages (PAMs) and pig tissues, using an indirect fluorescence assay (IFA) and immunohistochemical staining, respectively. The results showed that pB602L was detectable with all three mAbs in immunohistochemical staining, but only B2H10 was suitable for detecting the proteins in ASFV-infected PAMs by IFA. In summary, we developed eight anti-pB602L mouse mAbs recognizing three linear epitopes in the protein, which can be used as reagents for basic and applied research on ASFV.


Assuntos
Vírus da Febre Suína Africana , Febre Suína Africana , Vírus da Febre Suína Africana/genética , Animais , Anticorpos Monoclonais , Anticorpos Antivirais , Epitopos/genética , Camundongos , Suínos
9.
Proc Natl Acad Sci U S A ; 115(29): 7521-7526, 2018 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-29959208

RESUMO

Biologists and social scientists have long tried to understand why some societies have more fluid and open interpersonal relationships and how those differences influence culture. This study measures relational mobility, a socioecological variable quantifying voluntary (high relational mobility) vs. fixed (low relational mobility) interpersonal relationships. We measure relational mobility in 39 societies and test whether it predicts social behavior. People in societies with higher relational mobility report more proactive interpersonal behaviors (e.g., self-disclosure and social support) and psychological tendencies that help them build and retain relationships (e.g., general trust, intimacy, self-esteem). Finally, we explore ecological factors that could explain relational mobility differences across societies. Relational mobility was lower in societies that practiced settled, interdependent subsistence styles, such as rice farming, and in societies that had stronger ecological and historical threats.


Assuntos
Agricultura , Comportamento Social , Mobilidade Social , Feminino , Humanos , Masculino
10.
Angew Chem Int Ed Engl ; 58(28): 9625-9631, 2019 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-31102480

RESUMO

Herein, we present the realization of a class of unprecedented aromatic structures 2: metalla-aromatics with two independent and perpendicular aromatic rings spiro-fused by a transition-metal spiro atom, of which their corresponding organic analogues are impossible. Tetralithio spiro manganacycles 2 are readily synthesized from 1,4-dilithio-1,3-butadienes 1 and MnCl2 in the presence of lithium. The aromaticity of 2 is supported by experimental measurements (X-ray structural analysis, NMR) and theoretical analyses (NICS, ACID, MOs). The spiro atom Mn in 2 uses its 3dxz and 3dxy orbitals to form the two perpendicular manganacycles, which are two independent 6π aromatic systems. Theoretical analyses reveal that the Li cations play an indispensable role in governing their geometric and electronic structures and hence their aromaticity. Therefore, this work contributes not only to enrich the concept of aromaticity, but also to deepen the understanding of the fundamental chemical bonding.

11.
Cell Physiol Biochem ; 49(3): 1083-1096, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30196285

RESUMO

BACKGROUND/AIMS: Clinically, biliary obstruction is often accompanied by progressive inflammation. Dehydroandrographolide (DA) possesses anti-inflammatory properties. However, the anti-inflammatory activities of DA in cholestatic liver injury remain unclear. METHODS: Mice were administered with DA by intraperitoneal injection after bile duct ligation (BDL) on day 1. Then mice were subjected to an ileocecal vein injection of lipopolysaccharide (LPS). Liver function markers, histology, pro-inflammatory cytokine levels, NF-κB activation and fibrosis formation were evaluated in BDL mice with LPS. LPS binding to primary Kupffer cells was examined by high-content cytometers. RESULTS: DA was shown to greatly lower initially higher than normal levels of alanine aminotransferase (ALT) and total bilirubin (TBIL) in the serum and liver of BDL mice with LPS. DA exerted hepatic protective effects that were also confirmed by prolonged survival of BDL mice with LPS. Liver histopathology showed reduced inflammatory cellular infiltration, bile duct proliferation, and biliary necrosis with DA treatment. Furthermore, DA reduced the expression levels of tumor necrosis factor (TNF)-α and interleukin (IL)-6 in liver tissue and plasma and showed decreased NF-κB activation in BDL mice with LPS. DA could prevent LPS binding to primary Kupffer cells in the normal liver and BDL mice liver. DA also suppressed LPS-stimulated inflammatory responses by blocking the interaction between LPS and TLR4 in primary Kupffer cells and human LX-2 cells, thereby inhibiting NF-κB activation. CONCLUSION: DA inhibition of inflammation against liver damage following BDL with LPS may be a promising agent for the treatment of cholestatic liver injury.


Assuntos
Anti-Inflamatórios/farmacologia , Diterpenos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Alanina Transaminase/sangue , Animais , Bilirrubina/sangue , Colestase/mortalidade , Colestase/patologia , Colestase/veterinária , Humanos , Interleucina-6/sangue , Interleucina-6/metabolismo , Células de Kupffer/citologia , Células de Kupffer/efeitos dos fármacos , Células de Kupffer/metabolismo , Lipopolissacarídeos/toxicidade , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Taxa de Sobrevida , Receptor 4 Toll-Like/metabolismo , Fator de Necrose Tumoral alfa/sangue , Fator de Necrose Tumoral alfa/metabolismo
12.
J Am Chem Soc ; 139(14): 5039-5042, 2017 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-28362092

RESUMO

Since the concept of aromaticity represents one of the most fundamental principles in chemistry, the search for unprecedented and exciting aromatic systems, therefore, continues to drive research in this area. Herein we report the synthesis and characterization of spiro metalla-aromatics, in which the transition metal (Pd, Pt, or Rh) is the spiro atom, that cross-conjugates two aromatic five-membered metallacycles. These spiro metalla-aromatics tend to take square planar geometries, with the dihedral angle being influenced by the steric repulsion between the α-positioned substituents. Rationalized and classified via both experimental measurements (X-ray structural analysis, NMR spectroscopy, XPS, etc.) and theoretical analysis (DFT calculation, ISE, AICD, NICS, and CMOs), all these fundamental observations extend the concept of aromaticity and organometallic chemistry.

13.
Chemistry ; 23(4): 757-761, 2017 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-27898999

RESUMO

The selective C(sp3 )-H bond functionalization is an ideal and atom-economical method in organic synthesis. In this work, 2-aminopyrimidines are generated from a Cu-catalyzed reaction between carbodiimides and diaryliodonium salts, by cleavage of four C(sp3 )-H, one C-N, and one C=N bonds in the carbodiimides. It is the first triple C(sp3 )-H bond functionalization neighboring a C=N bond. The selective synthesis of 2-aminopyrimidines is controlled by the amount of the diaryliodonium salts. The novel mechanism involving a C-N formation/1,5-H shift/1,7-H shift/6 π-electrocyclic ring-closing/aromatization is well elucidated by the detection of important intermediates and DFT calculations.

15.
Angew Chem Int Ed Engl ; 56(50): 15886-15890, 2017 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-29110412

RESUMO

The [3+1] fragmentation reaction of rare-earth metallacyclopentadienes 1 a-c with 0.5 equivalents of P4 affords a series of rare-earth metal cyclo-P3 complexes 2 a-c and a phospholyl anion 3. 2 a-c demonstrate an unusual η3 coordination mode with one P-P bond featuring partial π-bonding character. 2 a-c are the first cyclo-P3 complexes of rare-earth metals, and also the first organo-substituted polyphosphides in the category of Group 3 and f-block elements. Rare-earth metallacyclopentadienes play a dual role in the combination of aromatization and Diels-Alder reaction. Compounds 2 a-c can coordinate to one or two [W(CO)5 ] units, yielding 4 a-c or 5 c, respectively. Furthermore, oxidation of 2 a with p-benzoquinone produces its corresponding phospholyllithium and regenerated P4 .

16.
J Am Chem Soc ; 138(1): 60-3, 2016 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-26708724

RESUMO

Metal-containing aromatic systems (metalla-aromatics) are unique and important both experimentally and theoretically. Among metalla-aromatics, six-membered metallabenzenes and metallabenzynes have attracted much attention in recent years. However, reports on their superior homologues are rare. In this work, the first series of aromatic dicupra[10]annulenes were isolated from the reaction of dilithio reagents and copper salts. Single-crystal X-ray structural analysis revealed dicupra[10]annulenes with averaged bond lengths. (7)Li NMR spectra and theoretical calculations revealed considerable aromatic character. XPS data suggested that the oxidation state of Cu atom in dicupra[10]annulenes was more likely to be Cu(I), indicating that the dilithio moieties in dicupra[10]annulenes participated as noninnocent ligands. This work demonstrates a novel approach to construct macrocyclic metalla-aromatics.

17.
Chemistry ; 22(10): 3422-3429, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26807680

RESUMO

DFT calculations have been performed on the palladium-catalyzed carboiodination reaction. The reaction involves oxidative addition, alkyne insertion, C-N bond cleavage, and reductive elimination. For the alkylpalladium iodide intermediate, LiOtBu stabilizes the intermediate in non-polar solvents, thus promoting reductive elimination and preventing ß-hydride elimination. The C-N bond cleavage process was explored and the computations show that PPh3 is not bound to the Pd center during this step. Experimentally, it was demonstrated that LiOtBu is not necessary for the oxidative addition, alkyne insertion, or C-N bond cleavage steps, lending support to the conclusions from the DFT calculations. The turnover-limiting steps were found to be C-N bond cleavage and reductive elimination, whereas oxidative addition, alkyne insertion, and formation of the indole ring provide the driving force for the reaction.

18.
Annu Rev Psychol ; 66: 631-59, 2015 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-25251481

RESUMO

We review limitations of the traditional paradigm for cultural research and propose an alternative framework, polyculturalism. Polyculturalism assumes that individuals' relationships to cultures are not categorical but rather are partial and plural; it also assumes that cultural traditions are not independent, sui generis lineages but rather are interacting systems. Individuals take influences from multiple cultures and thereby become conduits through which cultures can affect each other. Past literatures on the influence of multiple cultural identities and cultural knowledge legacies can be better understood within a polyculturalist rubric. Likewise, the concept elucidates how cultures are changed by contact with other cultures, enabling richer psychological theories of intercultural influence. Different scientific paradigms about culture imply different ideologies and policies; polyculturalism's implied policy of interculturalism provides a valuable complement to the traditional policy frames of multiculturalism and colorblindness.


Assuntos
Aculturação , Cultura , Teoria Psicológica , Identificação Social , Humanos
19.
Molecules ; 21(10)2016 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-27775665

RESUMO

In the present study, we investigated the effect of bovine colostrums on inhibition of DNA oxidative damage and low density lipoprotein (LDL) oxidation in vitro. Results showed that whey and skimmed milk exhibited not only higher inhibitory activities of oxidative damage of deoxyribose but also an inhibitory effect on the breakdown of supercoiled DNA into open circular DNA and linear DNA. The quantities of 8-OH-2'-dG formed under whey, caseins and skimmed milk treatment were 0.24, 0.24 and 1.24 µg/mL, respectively. The quantity of malondialdehyde formed through LDL oxidation induced by copprous ion was significantly decreased as colostrums protein solutions were added, in which whey and caseins led to a more significant decrease than skimmed milk. The formation of conjugated dienes could be inhibited by treatment with colostrums protein solutions. Whey exhibited the longest lag time of conjugated dienes formation among the colostrums proteins. The lag time of the whey was 2.33 times that of the control. From the results of foregoing, the bovine colostrums protein has potential value in the inhibition of DNA oxidation damage and LDL oxidation.


Assuntos
Colostro/metabolismo , Dano ao DNA , Peroxidação de Lipídeos , Lipoproteínas LDL/química , 8-Hidroxi-2'-Desoxiguanosina , Animais , Bovinos , Desoxiguanosina/análogos & derivados , Desoxiguanosina/análise , Feminino , Leite/metabolismo , Oxirredução , Gravidez , Soro do Leite/metabolismo
20.
Angew Chem Int Ed Engl ; 55(32): 9187-90, 2016 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-27304553

RESUMO

The selective construction of P-C bonds directly from P4 and nucleophiles is an ideal and step-economical approach to utilizing elemental P4 for the straightforward synthesis of organophosphorus compounds. In this work, a highly efficient one-pot reaction between P4 and 1,4-dilithio-1,3-butadienes was realized, which quantitatively affords phospholyl lithium derivatives. DFT calculations indicate that the mechanism is significantly different from that of the well-known stepwise cleavage of P-P bond in P4 activation. Instead, a cooperative nucleophilic attack of two Csp2 Li bonds on P4 , leading to simultaneous cleavage of two P-P bonds, is favorable. This mechanistic information offers a new view on the mechanism of P4 activation, as well as a reasonable explanation for the excellent yields and selectivity. This method could prove to be a useful route to P4 activation and the subsequent production of organophosphorus compounds.

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