Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 25
Filter
Add more filters










Publication year range
1.
Nat Commun ; 15(1): 4744, 2024 Jun 04.
Article in English | MEDLINE | ID: mdl-38834549

ABSTRACT

Developing mild photocatalytic bromination strategies using sustainable bromo source has been attracting intense interests, but there is still much room for improvement. Full utilization of redox centers of photocatalysts for efficient generation of Br+ species is the key. Herein we report heterogenous organophotocatalytic HBr oxidation coupled with oxygen reduction to furnish Br2 and H2O2 for effective bromination of arenes over Al2O3 supported perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA). Mechanism studies suggest that O-vacancy in Al2O3 can provide Lewis-acid-type anchoring sites for O2, enabling unexpected dual-electron transfer from anchored photoexcited PTCDA to chemically bound O2 to produce H2O2. The in-situ generated H2O2 and Br2 over redox centers work together to generate HBrO for bromination of arenes. This work provides new insights that heterogenization of organophotocatalysts can not only help to improve their stability and recyclability, but also endow them with the ability to trigger unusual reaction mode via cooperative catalysis with supports.

2.
Org Lett ; 26(26): 5415-5419, 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38917369

ABSTRACT

Spirocyclic compounds are abundant in biologically active products. However, the divergent synthesis of spirocyclic compounds using low-cost and abundant available starting materials remains a challenge. Herein, we report an effective method for producing spirocyclic motifs using a cyclic ß-carbonyl ester or amide and ethylene via thianthrenation. This strategy highlights the exciting possibility of utilizing abundant ethylene as a C-2 synthon and allows regulating the core structure of the spirocyclic compound by simply altering the base type.

4.
BMC Musculoskelet Disord ; 25(1): 230, 2024 Mar 23.
Article in English | MEDLINE | ID: mdl-38521939

ABSTRACT

BACKGROUND: To clarify the value of gait analysis and its consistency with traditional scoring scales for the evaluation of knee joint function after total knee arthroplasty (TKA). METHODS: This study included 25 patients with knee osteoarthritis (KOA) who underwent bilateral TKA, and 25 conditionally matched healthy individuals, categorised into the experimental and control groups, respectively. Patients in the experimental group underwent gait analysis and Western Ontario and McMaster University Osteoarthritis Index (WOMAC) evaluation before and 1 year after TKA. Weight-bearing balance and walking stability were assessed using discrete trends of relevant gait indicators. Pearson's correlation analysis was performed on the gait and WOMAC score data of the experimental group before and after TKA. RESULTS: One year after TKA, patients' gait indices (except gait cycle) were significantly better than before surgery, but significantly worse than that of the control group (P < 0.01). The shape of patients' plantar pressure curves did not return to normal. Additionally, the discrete trend of related gait indicators reflecting weight-bearing balance and walking stability were smaller than before TKA, but still greater than that of the control group. The WOMAC scores of patients 1 year after TKA were significantly lower than those before TKA (P < 0.001), and the efficacy index was > 80%. The WOMAC scores and gait analysis results were significantly correlated before TKA (P < 0.05). CONCLUSIONS: Gait analysis should be used in conjunction with scoring scales to assess joint functions.


Subject(s)
Arthroplasty, Replacement, Knee , Osteoarthritis, Knee , Humans , Arthroplasty, Replacement, Knee/methods , Knee Joint/surgery , Ontario , Universities , Treatment Outcome , Osteoarthritis, Knee/diagnosis , Osteoarthritis, Knee/surgery , Gait
5.
J Pain Res ; 15: 4017-4027, 2022.
Article in English | MEDLINE | ID: mdl-36569982

ABSTRACT

Objective: Knee osteoarthritis (KOA) is a painful chronic disorder. Evidence has shown that a history of chronic pain plays an important role in shaping empathy. Empathy, a valuable indicator of social functioning that refers to an individual's ability to share the experiences of others, however, has been overlooked in KOA patients. This study aimed to investigate empathy and its association with clinical pain in KOA patients. Methods: KOA patients (n=47) and healthy controls (HCs, n=44) completed two empathy-for-pain tasks: a pain judgment task in which participants judged whether a person in an image felt pain or not, and a pain rating task in which they estimated pain intensity for themselves and others. The Interpersonal Reactivity Index was used to measure participants' trait empathy, and clinical severity and psychological factors were assessed using relevant instruments. Results: Compared to HCs, KOA patients showed higher accuracy when judging pain and non-pain images and reported overall higher pain intensity when rating for themselves and others. KOA patients also showed greater personal distress than HCs in terms of their self-reported empathy. Moreover, pain catastrophizing particularly mediated the relationship between pain severity and pain ratings for others, and depression, anxiety, and pain catastrophizing all mediated the association between pain severity and empathy-induced personal distress. Conclusion: These findings suggest that patients with KOA have increased empathy, demonstrated by elevated sensitivity to pain-related scenes and intense emotional responses.

6.
Front Pharmacol ; 13: 849102, 2022.
Article in English | MEDLINE | ID: mdl-36133821

ABSTRACT

Post-traumatic osteoarthritis is a special type of osteoarthritis and a common disease, with few effective treatments available. α2-Macroglobulin (α2M) is important to chondral protection in post-traumatic osteoarthritis. However, its injection into xenogeneic joint cavities involves safety hazards, limiting clinical applications. Exploring serum α2M-enriching strategies and the therapeutic effect and mechanism of α2M-rich serum (α2MRS) autologous joint injection to treat post-traumatic osteoarthritis has significant value. In the present study, a unique filtration process was used to obtain α2MRS from human and mini pig serum. We evaluated the potential of α2MRS in protecting against post-surgery cartilage degeneration. We identify the potential of α2MRS in reducing the expression of inflammatory cytokines and factors that hasten cartilage degeneration in post-operative conditions leading to post-traumatic osteoarthritis. The potential of α2MRS was analyzed in interleukin-1ß induced human chondrocytes and mini pig models. In the chondrocyte model, α2MRS significantly promoted human chondrocyte proliferation and reduced apoptosis and chondrocyte catabolic cytokine gene transcription and secretion. The anterior cruciate ligament autograft reconstruction model of mini pigs was randomized into groups, operated on, and injected with α2MRS or saline. The results showed that α2MRS injection significantly suppressed the levels of inflammatory factors, improved gait, and showed significantly lower cartilage degeneration than the groups that did not receive α2MRS injections. This study highlights the chondroprotective effects of α2MRS, elucidated its potential applications against cartilage degeneration, and could provide a basis for the clinical translation of α2MRS.

7.
Math Biosci Eng ; 19(11): 11367-11379, 2022 08 09.
Article in English | MEDLINE | ID: mdl-36124594

ABSTRACT

In the era of cloud computing, the technique of access control is vital to protect the confidentiality and integrity of cloud data. From the perspective of servers, they should only allow authenticated clients to gain the access of data. Specifically, the server will share a communication channel with the client by generating a common session key. It is thus regarded as a symmetric key for encrypting data in the current channel. An access control mechanism using attribute-based encryptions is most flexible, since the decryption privilege can be granted to the ones who have sufficient attributes. In the paper, the authors propose a secure access control consisting of the attributed-based mutual authentication and the attribute-based encryption. The most appealing property of our system is that the attribute keys associated with each user is periodically updatable. Moreover, we will also show that our system fulfills the security of fuzzy selective-ID assuming the hardness of Decisional Modified Bilinear Diffie-Hellman (DMBDH) problem.


Subject(s)
Algorithms , Computer Security , Cloud Computing , Confidentiality , Humans
8.
Int Immunopharmacol ; 99: 107905, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34242997

ABSTRACT

OBJECTIVE: To determine whether idealized anterior cruciate ligament reconstruction (IACL-R) restores normal gait features, and whether inflammatory factors are involved in the pathogenesisof post-traumatic osteoarthritis (PTOA). METHODS: Fourteen mature female minipigs were allocated to a sham group (n = 7) or an IACL-R group (n = 7). Load asymmetry during gait was recorded using a pressure-sensing walkway measurement system to evaluate the gait features of the right knee joint before and after surgery. Inflammatory factors (including interleukin [IL]-1α, IL-1ß, IL-2, IL-6, IL-8, IL-18, tumor necrosis factor-α, and granulocyte-macrophage colony-stimulating factor) in synovial fluid were measured using Luminex assays before and after surgery. Cartilage integrity and the subchondral bone plate of the right knee were evaluated using histology and imaging at 3 months postoperatively. RESULTS: Swing time and stance time returned to their preoperative values on day 31, while maximum force, contact area, peak force ,and impulse returned to their preoperative values on day 45 after the surgery in the IACL-R group (P = 0.073, 0.053, 0.107, 0.052, 0.152, and 0.059, respectively).Thus, IACL-R restored normal gait. Compared with their preoperative concentrations, all tested inflammatory factors showed significantly increased concentrations in the synovial fluid in the IACL-R group, especially at 3, 7, and 15 days postoperatively. X-ray, computed tomography, magnetic resonance imaging, and histological data showed severe cartilage damage in the IACL-R model. CONCLUSION: IACL-R restored normal gait features but caused significant cartilage damage, indicating that significantly elevated inflammatory factors maybe crucial for the pathogenesis of PTOA.


Subject(s)
Anterior Cruciate Ligament Reconstruction , Osteoarthritis, Knee/therapy , Animals , Cartilage, Articular/diagnostic imaging , Cartilage, Articular/pathology , Cytokines/immunology , Disease Models, Animal , Female , Gait Analysis , Knee Joint/diagnostic imaging , Knee Joint/pathology , Osteoarthritis, Knee/diagnostic imaging , Osteoarthritis, Knee/immunology , Osteoarthritis, Knee/physiopathology , Swine , Swine, Miniature , Synovial Fluid/immunology
9.
Clin Res Hepatol Gastroenterol ; 45(2): 101312, 2021 Mar.
Article in English | MEDLINE | ID: mdl-33592427

ABSTRACT

BACKGROUND: The morbidity of nonalcoholic fatty liver disease (NAFLD) has increased consistently in recent years. Exenatide could reverse liver fibrosis and lower the occurrence of fatty liver. The aim of the study was to identify and characterize mRNA and miRNA expression to elucidate the mechanism of exenatide in the gerbil model. METHODS: Gerbils were fed a high-fat diet for 8 weeks to induce a fibrosis model; then, the gerbil models were treated with exenatide for 4 weeks. The total RNA extracted from the liver tissue samples was used to prepare the library and sequence on a HiSeq 2000. Bioinformatic methods were employed to analyze the sequence data to identify the mRNAs and miRNAs and to acquire the miRNA-mRNA regulatory network. RESULTS: By RNA-seq, 2344 differentially expressed genes (DEGs) and 72 miRNAs were found in the model group. Compared with the model group, 591 DEGs and 19 miRNAs were found in the quercetin group, whereas 876 DEGs and 18 miRNAs were found in the treatment group. The miRNA-mRNA regulatory network was constructed in a gerbil model. Immunohistochemistry and RNA sequencing confirmed that the therapeutic effect of exenatide may be derived from extrahepatic signal transduction. The key differential genes are CYP3A, CYP4A11, ACAA1, ACSM, PHX1, MAO, FMO, UGT, ACOX2, ABAT, PIK3C and PLCG1. The key miRNAs are miR-15a, miR-27b, miR-532-3P, miR-627, miR-3596, miR-142-3P, Let-7e-5p, miR-214-5, miR-101-3p, miR-378d. New miRNAs, such as novel_127, novel_143, novel_15, novel_204 are associated with liver fibrosis, while novel_127, novel_15, and novel_54 are associated with reverse treated with exenatide. CONCLUSIONS: Our research represents the first description of mRNA/miRNA profiles in a gerbil model of fatty liver fibrosis treated with exenatide, which may provide insights into the pathogenesis or treatment of the metabolic syndrome.


Subject(s)
MicroRNAs , Non-alcoholic Fatty Liver Disease , Animals , Exenatide , Gene Expression Profiling , Gene Regulatory Networks , Gerbillinae , Humans , Liver Cirrhosis/chemically induced , Liver Cirrhosis/drug therapy , Liver Cirrhosis/genetics , MicroRNAs/genetics , Non-alcoholic Fatty Liver Disease/drug therapy , Non-alcoholic Fatty Liver Disease/genetics , RNA, Messenger
10.
ACS Appl Mater Interfaces ; 12(21): 23867-23873, 2020 May 27.
Article in English | MEDLINE | ID: mdl-32368905

ABSTRACT

Lithium-sulfur (Li-S) batteries have attracted considerable attention in the energy storage field due to their high theoretical energy density and low price. However, the dissolution of polysulfides and the "shuttle effect" lead to serious capacity degradation, which greatly hinders the industrial application of Li-S batteries. Herein, we propose a bifunctional quinone-type salt to anchor polysulfides and suppress their dissolution for use in high-performance Li-S batteries. We find that the tetrahydroxy-1,4-benzoquinone disodium salt dimer (TBS-dimer) does not dissolve in organic electrolytes and can be generated at 400 °C. The abundant reactive keto groups and double bonds result in the TBS-dimers having numerous "hot spots" for capturing sulfur (TBS/S-400) in the three-dimensional space of the molecule. The insolubility and abundant active sites of the organic salt remarkably suppress the dissolution of lithium polysulfides. As a result, the TBS/S-400 composite delivers a capacity decay rate of only 0.023% per cycle over 600 cycles at 2 C. The use of organic salts to effectively suppress the dissolution of lithium polysulfides opens a new avenue for the practical applications of high-performance Li-S batteries.

11.
Angew Chem Int Ed Engl ; 57(34): 10848-10853, 2018 Aug 20.
Article in English | MEDLINE | ID: mdl-29749675

ABSTRACT

The development of graphene oxide (GO)-based materials for C-C cross-coupling represents a significant advance in carbocatalysis. Although GO has been used widely in various catalytic reactions, the scope of reactions reported is quite narrow, and the relationships between the type of functional groups present and the specific activity of the GO are not well understood. Herein, we explore CH-CH-type cross-coupling of xanthenes with arenes using GO as real carbocatalysts, and not as stoichiometric reactants. Mechanistic studies involving molecular analogues, as well as trapped intermediates, were carried out to probe the active sites, which were traced to quinone-type functionalities as well as the zigzag edges in GO materials. GO-catalyzed cross-dehydrogenative coupling is operationally simple, shows reusability over multiple cycles, can be conducted in air, and exhibits good functional group tolerance.

12.
Medicine (Baltimore) ; 97(6): e9840, 2018 Feb.
Article in English | MEDLINE | ID: mdl-29419691

ABSTRACT

RATIONALE: Intrauterine contraceptive devices (IUDs) are recommended as a means of contraception. Translocation of IUD is a rare and serious complication. Colonic inflammatory mass caused by translocated IUD initially misdiagnosed as a colonic polyp is extremely rare and has not been reported yet. PATIENT CONCERNS: This report presents a case of sigmoid colon translocation of intrauterine device on a 37-year-old female patient. Colonoscopy was performed due to her complain of repeated blood in stools and subsequently the patient was misdiagnosed as a sigmoid colon polyp. Nonetheless, the "polyp" was not able to be removed endoscopically. DIAGNOSES: Sigmoid colon translocation of an intrauterine device. INTERVENTIONS: To further clarify the diagnosis, computed tomography (CT) scan was performed and the "polyp" was confirmed to be caused by a translocated IUD. OUTCOMES: The translocated IUD was removed easily by surgery, and the patient recovered soon after the operation. LESSONS: The present case indicates that an annual gynaecologic examination is necessary to determine the position of the IUD, and a CT examination may help confirm an ectopic IUD.


Subject(s)
Colitis , Colon, Sigmoid , Colonic Polyps/diagnosis , Colonoscopy/methods , Diagnostic Errors , Intrauterine Device Migration/adverse effects , Adult , Colitis/diagnosis , Colitis/etiology , Colitis/surgery , Colon, Sigmoid/pathology , Colon, Sigmoid/surgery , Device Removal/methods , Diagnosis, Differential , Female , Humans , Intrauterine Devices/adverse effects , Tomography, X-Ray Computed/methods , Treatment Outcome
13.
J Org Chem ; 81(13): 5337-44, 2016 07 01.
Article in English | MEDLINE | ID: mdl-27281555

ABSTRACT

A highly efficient and facile cobalt-catalyzed C-H activation and peroxidation of 2-oxindoles was reported, which provides a new pathway for the synthesis of biologically active 3-peroxy-2-oxindoles from readily available starting materials in excellent chemical yields. The resulting products could be further transformed into various substituted 3-peroxyoxindoles in good to excellent yields. The developed method has been successfully applied to the synthesis of the natural product (±)-N-[2-(3-hydroxy-2-oxo-2,3-dihydro-1H-indol-3-yl)ethyl]acetamide.

14.
Org Lett ; 18(6): 1382-5, 2016 Mar 18.
Article in English | MEDLINE | ID: mdl-26950164

ABSTRACT

A novel FeCl3-mediated reaction of 3-benzyl-2-oxindoles with styrene derivatives was developed. The reaction provided spirocyclohexene oxindoles in good yields and excellent diastereoselectivities via a tandem radical addition/cyclization process.


Subject(s)
Chlorides/chemistry , Cyclohexenes/chemical synthesis , Ferric Compounds/chemistry , Indoles/chemical synthesis , Spiro Compounds/chemical synthesis , Styrenes/chemistry , Catalysis , Cyclization , Cyclohexenes/chemistry , Indoles/chemistry , Molecular Structure , Oxindoles , Spiro Compounds/chemistry , Stereoisomerism
15.
Org Biomol Chem ; 14(7): 2210-7, 2016 Feb 21.
Article in English | MEDLINE | ID: mdl-26740014

ABSTRACT

A metal-free cascade reaction of aryl alkynoates with five different types of radical precursors (R-H) through an yne-addition/1,4-aryl migration/decarboxylation process was reported, which allowed facile and convenient access to functionalized vinyl products with "R" and protons located at the identical carbon of the formed double bond.

16.
Mediators Inflamm ; 2016: 5715719, 2016.
Article in English | MEDLINE | ID: mdl-28053372

ABSTRACT

Oral squamous cell carcinoma (OSCC) is an aggressive, invasive malignancy of epithelial origin. The progression from premalignant lesions-oral leukoplakia (OLK) and oral lichen planus (OLP)-to OSCC involves complex inflammatory processes that have not been elucidated. We investigated the roles of inflammatory mediators and infiltrating immunocytes in the pathogenic progression of OLK and OLP to OSCC. The occurrence of regulatory T-cells (Tregs) and tumor-associated macrophages (TAMs) and the expression of anti-inflammatory cytokines and proinflammatory cytokines were investigated in OLK, OLP, and OSCC tissues. Immunohistochemical staining of CD4, FOXP3, CD68, TGF-ß1, IL-10, IL-4, IFN-γ, and MCP-1 showed that the occurrence of Tregs and TAMs increased in parallel with disease progression in OLK and OSCC. IL-10 gradually increased during the early stages of OLK and in OSCC. Infiltrating IL-4+ macrophages were seen with increasing frequency in OLK tissue during the progression of oral dysplasia. Fewer TGF-ß1+ macrophages were seen in OSCC than in OLK and OLP. The expression of IFN-γ decreased gradually with the OLK development and had the lowest expression in OSCC. MCP-1 expression did not change significantly during the development of OSCC. The results suggested that the immunosuppression induced by chronic inflammation promotes tumorigenesis in OSCC, rather than initiating it.


Subject(s)
Carcinoma, Squamous Cell/pathology , Immune Tolerance , Inflammation/pathology , Mouth Neoplasms/pathology , Administration, Oral , Adult , Aged , Chemokine CCL2/metabolism , Chronic Disease , Cytokines/metabolism , Disease Progression , Female , Humans , Interleukin-4/metabolism , Leukoplakia, Oral/pathology , Lichen Planus, Oral/pathology , Macrophages/metabolism , Male , Middle Aged , T-Lymphocytes, Regulatory/metabolism , Transforming Growth Factor beta1/metabolism
17.
J Asian Nat Prod Res ; 17(12): 1196-203, 2015.
Article in English | MEDLINE | ID: mdl-26666298

ABSTRACT

1,4-Naphthoquinone (1) and a new coumarin (3) were isolated from Ajania salicifolia, together with two known compounds (2, 4). The structures and stereochemistry of new compounds were elucidated using spectroscopic methods. Two compounds exhibited potent ABTS cation radical scavenging activities with IC50 values ranging 7.97-8.44 µM. Two quinones (1, 2) exhibited moderate cytotoxic activity against the human cancer cell lines (Hela, HepG2, and K562) with IC50 values of 11.24-35.15 µM in vitro. This is the first report of naphthoquinone in the genus Ajania.


Subject(s)
Antineoplastic Agents, Phytogenic/isolation & purification , Antineoplastic Agents, Phytogenic/pharmacology , Antioxidants/isolation & purification , Antioxidants/pharmacology , Asteraceae/chemistry , Coumarins/isolation & purification , Coumarins/pharmacology , Free Radical Scavengers/isolation & purification , Free Radical Scavengers/pharmacology , Naphthoquinones/isolation & purification , Naphthoquinones/pharmacology , Quinones/isolation & purification , Quinones/pharmacology , Antineoplastic Agents, Phytogenic/chemistry , Antioxidants/chemistry , Cell Survival/drug effects , Coumarins/chemistry , Drug Screening Assays, Antitumor , Free Radical Scavengers/chemistry , HeLa Cells , Hep G2 Cells , Humans , Inhibitory Concentration 50 , Molecular Structure , Naphthoquinones/chemistry , Quinones/chemistry
18.
Fitoterapia ; 106: 175-83, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26344425

ABSTRACT

Five new nor-ursane type triterpenoids, gelse-norursane A-E, together with twenty known compounds, were isolated from the whole plant of Gelsemium elegans. The structures of new compounds were established as (2R,3R,7R,17S,19R)-2,3,7,19-tetrahydroxy-6-oxo-24-norurs-4(23),12-dien-28-oic acid (1), (2R,3R,7R,17S)-2,3,7-trihydroxy-6-oxo-24-norurs-4(23), 12-dien-28-oic acid (2), (2R,3R,7R,17S)-2,3,4-trihydroxy-23-norurs-20(30),12-dien-28-oic acid (3), (2R,3R,30R)-2,3-dihydroxy-24-norurs-4(23),12-dien-30-oic acid (4), and (2R,3R,30R)-2, 3-dihydroxy-24-norurs-4,12-dien-30-oic acid (5), using spectroscopic analysis, including HRESIMS, 1D and 2D NMR. The absolute configurations of 1 and 4 were established through comparison of experimental and calculated ECD spectra. The gelse-norursane A-E are isolated as the 24-nor-ursane type triterpenoids from the family Loganiaceae for the first time. The cytotoxicities of the selected compounds against a panel of four human cancer HL60, Hela, Hep-G2, and Smmc 7221 cell lines were evaluated using the MTT assay in vitro.


Subject(s)
Gelsemium/chemistry , Triterpenes/chemistry , Cell Line, Tumor , Humans , Molecular Structure , Plant Extracts/chemistry , Triterpenes/isolation & purification
19.
Chemistry ; 21(47): 16744-8, 2015 Nov 16.
Article in English | MEDLINE | ID: mdl-26374085

ABSTRACT

An efficient Fe(III)-catalyzed cross-dehydrogenative arylation (CDA) of 3-substituted oxindoles with activated arenes under an air atmosphere was developed to provide 3,3'-disubstituted oxindoles in good yields.

20.
Org Lett ; 17(15): 3702-5, 2015 Aug 07.
Article in English | MEDLINE | ID: mdl-26214240

ABSTRACT

A direct intermolecular olefination of sp(3) C-H bond between 2-oxindoles and simple alkenes via a Cross-Dehydrogenative Coupling (CDC) strategy has been developed. In the absence of additional base, moderate to excellent yields have been obtained by using a catalytic amount of iodine with atmospheric oxygen as the reoxidant. Based on the observation of a radical capture experiment, the transformation is proposed to proceed via a radical process.

SELECTION OF CITATIONS
SEARCH DETAIL
...