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1.
AME Case Rep ; 8: 49, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38711901

RESUMEN

Background: Fibrosing mediastinitis (FM) secondary to atypical sarcoidosis (atypical presentation of sarcoidosis) is rarely reported at home and abroad. Its clinical manifestations represent a lack of specificity, and the initial diagnosis is frequently difficult. In particular, this case has multiple pulmonary nodules with mediastinal lymph node enlargement and bilateral pleural effusion, and pulmonary fibrosis still exists after treatment, which is inconsistent with any clinical stage of pulmonary sarcoidosis, further increasing the diagnostic difficulty. We retrospectively analyzed the clinical data of a case of FM secondary to atypical sarcoidosis diagnosed by endobronchial ultrasound-guided cautery-assisted transbronchial mediastinal cryobiopsy (EBUS-CA-TBMCB) in Chongqing University Fuling Hospital, to improve clinicians' attention to FM and understand that EBUS-CA-TBMCB remains an effective way of etiological diagnosis. Case Description: A 70-year-old man was hospitalized with cough and dyspnea for two months. After admission, through chest computed tomography (CT), ultrasound guided bilateral lung biopsy, left parietal pleural biopsy, and EBUS-CA-TBMCB, the final diagnosis was atypical sarcoidosis secondary FM. After taking glucocorticoid orally, the patient's condition improved significantly, and was discharged from the hospital. We continued following up outside the hospital, and the patient's condition was further improved. Conclusions: The diagnosis of FM is mainly based on typical imaging manifestations. When the contrast-enhanced chest CT finds localized or diffuse soft tissue density shadows around the mediastinum and pulmonary hilum with an irregular shape, with or without calcification, particular attention should be paid to exclude FM. EBUS-CA-TBMCB, as an improved minimally invasive method, can obtain enough tissue samples for pathological diagnosis, which may be the effective biopsy method for the etiology of FM to avoid missed diagnosis and misdiagnosis in the future.

2.
J Org Chem ; 88(22): 15696-15707, 2023 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-37906125

RESUMEN

Cyanoacrylates have a wide range of biological activities and are extensively applied in production and daily life. Classic synthetic routes to cyanoacrylates have many limitations. Herein, we demonstrate an elemental sulfur-promoted method for the synthesis of ß,ß-diaryl cyanoacrylates by a tandem 1,6-Michael addition/oxidation/elimination process from p-QMs and cyanoacetates under optimal conditions. The effective protocol has good substrate scopes and yields, and the ratio of inseparable E/Z isomers of cyanoacrylates is also determined by 1HNMR.

3.
Transl Vis Sci Technol ; 12(4): 7, 2023 04 03.
Artículo en Inglés | MEDLINE | ID: mdl-37022710

RESUMEN

Purpose: The incidence of orbital blowout fractures (OBFs) is gradually increasing due to traffic accidents, sports injuries, and ocular trauma. Orbital computed tomography (CT) is crucial for accurate clinical diagnosis. In this study, we built an artificial intelligence (AI) system based on two available deep learning networks (DenseNet-169 and UNet) for fracture identification, fracture side distinguishment, and fracture area segmentation. Methods: We established a database of orbital CT images and manually annotated the fracture areas. DenseNet-169 was trained and evaluated on the identification of CT images with OBFs. We also trained and evaluated DenseNet-169 and UNet for fracture side distinguishment and fracture area segmentation. We used cross-validation to evaluate the performance of the AI algorithm after training. Results: For fracture identification, DenseNet-169 achieved an area under the receiver operating characteristic curve (AUC) of 0.9920 ± 0.0021, with an accuracy, sensitivity, and specificity of 0.9693 ± 0.0028, 0.9717 ± 0.0143, and 0.9596 ± 0.0330, respectively. DenseNet-169 realized the distinguishment of the fracture side with accuracy, sensitivity, specificity, and AUC of 0.9859 ± 0.0059, 0.9743 ± 0.0101, 0.9980 ± 0.0041, and 0.9923 ± 0.0008, respectively. The intersection over union (IoU) and Dice coefficient of UNet for fracture area segmentation were 0.8180 ± 0.0093 and 0.8849 ± 0.0090, respectively, showing a high agreement with manual segmentation. Conclusions: The trained AI system could realize the automatic identification and segmentation of OBFs, which might be a new tool for smart diagnoses and improved efficiencies of three-dimensional (3D) printing-assisted surgical repair of OBFs. Translational Relevance: Our AI system, based on two available deep learning network models, could help in precise diagnoses and accurate surgical repairs.


Asunto(s)
Algoritmos , Inteligencia Artificial , Tomografía Computarizada por Rayos X/métodos
4.
Cell Mol Neurobiol ; 43(3): 1037-1048, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35792991

RESUMEN

Retinitis pigmentosa (RP) is a group of genetic disorders resulting in inherited blindness due to the degeneration of rod and cone photoreceptors. The various mechanisms underlying rod degeneration primarily rely on genetic mutations, leading to night blindness initially. Cones gradually degenerate after rods are almost eliminated, resulting in varying degrees of visual disability and blindness. The mechanism of cone degeneration remains unclear. An understanding of the mechanisms underlying cone degeneration in RP, a highly heterogeneous disease, is essential to develop novel treatments of RP. Herein, we review recent advancements in the five hypotheses of cone degeneration, including oxidative stress, trophic factors, metabolic stress, light damage, and inflammation activation. We also discuss the connection among these theories to provide a better understanding of secondary cone degeneration in RP. Five current mechanisms of cone degenerations in RP Interactions among different pathways are involved in RP.


Asunto(s)
Células Fotorreceptoras Retinianas Conos , Retinitis Pigmentosa , Humanos , Células Fotorreceptoras Retinianas Conos/metabolismo , Células Fotorreceptoras Retinianas Bastones/metabolismo , Retinitis Pigmentosa/genética , Retinitis Pigmentosa/metabolismo , Retinitis Pigmentosa/terapia , Ceguera/metabolismo , Estrés Oxidativo
5.
Front Cell Dev Biol ; 10: 1069248, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36467418

RESUMEN

Orbital and eyelid disorders affect normal visual functions and facial appearance, and precise oculoplastic and reconstructive surgeries are crucial. Artificial intelligence (AI) network models exhibit a remarkable ability to analyze large sets of medical images to locate lesions. Currently, AI-based technology can automatically diagnose and grade orbital and eyelid diseases, such as thyroid-associated ophthalmopathy (TAO), as well as measure eyelid morphological parameters based on external ocular photographs to assist surgical strategies. The various types of imaging data for orbital and eyelid diseases provide a large amount of training data for network models, which might be the next breakthrough in AI-related research. This paper retrospectively summarizes different imaging data aspects addressed in AI-related research on orbital and eyelid diseases, and discusses the advantages and limitations of this research field.

6.
Biomolecules ; 12(12)2022 12 03.
Artículo en Inglés | MEDLINE | ID: mdl-36551239

RESUMEN

Photobiomodulation (PBM) refers to the beneficial effect produced from low-energy light irradiation on target cells or tissues. Increasing evidence in the literature suggests that PBM plays a positive role in the treatment of retinal diseases. However, there is great variation in the light sources and illumination parameters used in different studies, resulting in significantly different conclusions regarding PBM's therapeutic effects. In addition, the mechanism by which PBM improves retinal function has not been fully elucidated. In this study, we conducted a narrative review of the published literature on PBM for treating retinal diseases and summarized the key illumination parameters used in PBM. Furthermore, we explored the potential molecular mechanisms of PBM at the retinal cellular level with the goal of providing evidence for the improved utilization of PBM in the treatment of retinal diseases.


Asunto(s)
Terapia por Luz de Baja Intensidad , Enfermedades de la Retina , Humanos , Terapia por Luz de Baja Intensidad/métodos , Retina , Enfermedades de la Retina/radioterapia , Neuronas
7.
World J Clin Cases ; 10(30): 11101-11110, 2022 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-36338208

RESUMEN

BACKGROUND: Klebsiella pneumoniae (K. pneumoniae) is a clinically common Gram-negative bacillus that can cause community- and hospital-acquired infections and lead to pneumonia, liver abscesses, bloodstream infections, and other infectious diseases; however, severe pneumonia caused by hypervirulent K. pneumoniae (hvKp) complicated by acute intra-abdominal multiple arterial thrombosis and bacterial embolism is rarely seen in the clinical setting and has not been reported in the literature. CASE SUMMARY: A 51-year-old man was hospitalized with fever and dyspnea. Persistent mild pain in the middle and upper abdomen began at dawn on the 3rd day following admission and developed into persistent severe pain in the left upper abdomen 8 h later. Based on chest computed tomography (CT), bronchoscopy, bronchoalveolar lavage fluid metagenomic next-generation sequencing, abdominal aortic CT angiography (CTA), and culture of the superior mesenteric artery embolus, adult community-acquired severe hvKp pneumonia complicated by acute intra-abdominal multiple arterial thrombosis and bacterial embolism was diagnosed. Notably, he recovered and was discharged from the hospital after receiving effective meropenem anti-infection, endovascular contact thrombolytic, and systemic anticoagulant therapies and undergoing percutaneous thrombus aspiration. Ten days later, the patient returned to the hospital for abdominal CTA examination, which indicated blocked initial common pathway of the celiac trunk and superior mesenteric artery, and local stenosis. Therefore, celiac trunk artery stenting was performed in Chongqing Hospital, and postoperative recovery was good. CONCLUSION: We report a case of hvKp severe pneumonia complicated by acute intra-abdominal multiple arterial thrombosis and bacterial embolism and suggest that clinicians should consider the possibility of a Gram-negative bacillus infection and conduct effective pathogen detection in a timely fashion when managing patients with severe community-acquired pneumonia before obtaining bacteriologic and drug sensitivity results. At the same time, when patients have severe pulmonary infection complicated by severe abdominal pain, an acute mesenteric artery embolism should be considered to avoid delays in treatment.

8.
Ann Palliat Med ; 11(9): 2939-2951, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-36217623

RESUMEN

BACKGROUND: The incidence of multidrug-resistant Gram-negative bacteria (MDR-GNB) pneumonia has increased in the last decade. If antibiotics are given only through intravenous, the antibiotic concentrations in lung tissue will be insufficient. Recently, nebulized antibiotics have shown effectiveness as an adjunctive therapy with intravenous antibiotics for resistant strains. Therefore, the goal of this study was to assess the efficacy and safety of adjunctive nebulized colistin sulfate in combination with intravenous antibiotics in patients with MDR-GNB pneumonia. METHODS: A total of 203 patients who were infected with MDR-GNB pneumonia were selected. Based on whether patients received nebulized colistin sulfate, patients were divided into 2 groups: the NCIA group (nebulized colistin sulfate in combination with intravenous antibiotics) and the IA group (intravenous antibiotics without nebulized colistin sulfate). After propensity score matching (PSM) analysis, we compared the efficacy in terms of favorable clinical outcomes, the bacteria detection rate, days of hospital stay, days of intensive care unit (ICU) stay, days of mechanical ventilation (MV), antipyretic time, days of antibiotic therapy, and 28-day all-cause mortality. Safety was also compared between groups. RESULTS: A total of 116 patients met the criteria for evaluation, with 46 patients in the NCIA group and 70 patients in the IA group. After PSM, 31 patients were selected from each group. There were significant differences in favorable clinical outcomes on days 7 (67.7% vs. 32.3%, P=0.005) and 14 (71% vs. 41.9%, P=0.045) and the bacteria detection rate on days 7, 14, and the last day. There were also significant differences in days of hospital stay (17 vs. 23 days, P=0.01), antipyretic time (0.5 vs. 7.5 days, P=0.037), and days of antibiotic therapy (14 vs. 23 days, P=0.002). However, there were no significant differences in days of ICU stay, days of MV, and 28-day all-cause mortality. For nephrotoxicity, the NCIA group did not increase the risk of acute kidney injury (16.1% vs. 9.7%, P=0.707), only one patient (3.2%) in the NCIA group developed airway hyperresponsiveness (P=1.000). CONCLUSIONS: For MDR-GNB pneumonia, nebulized colistin sulfate as an adjuvant supportive treatment for intravenous antibiotics maybe can improve clinical efficacy and has high safety.


Asunto(s)
Antipiréticos , Neumonía Asociada al Ventilador , Antibacterianos/uso terapéutico , Antipiréticos/uso terapéutico , Estudios de Cohortes , Colistina/uso terapéutico , Bacterias Gramnegativas , Humanos , Neumonía Asociada al Ventilador/etiología , Neumonía Asociada al Ventilador/microbiología , Estudios Retrospectivos , Resultado del Tratamiento
9.
J Colloid Interface Sci ; 628(Pt A): 22-30, 2022 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-35908428

RESUMEN

The development of highly-catalytic counter electrode (CE) materials is vital to the construction of quantum dot-sensitized solar cells (QDSCs) but is still challenging. Here, a novel self-assembly double-faced decorated carbon nanosheets with MOF-derived CuxS nanospheres (DF-CuxS/C NSs) were prepared as high-performance hybrid CEs for improving the catalytic activity towards polysulfide electrolytes and enhancing the performance of QDSCs. It is shown that the MOF-derived CuxS nanospheres disperse well on the surface of the carbon NSs in the obtained DF-CuxS/C NSs hybrids. Electrochemical characterization demonstrated that the DF-CuxS/C NSs with moderate mass ratio exhibited enhanced electrocatalytic activity towards the reduction of the polysulfide redox couple (Sn2-/S2-) and decreased charge transfer resistance at the interface of the CE/electrolyte. Benefitting from the merits of this novel hybrid CE, the power conversion efficiency (PCE) of the CdSeTe QDs-based QDSCs is increased to 9.39%, which is higher than the pristine carrageenan (CA)-derived CEs (5.84%) and Cu-BTC-derived CEs (7.74%). With the further optimization of the substrate, the highest PCE of 11.36% was achieved based on the Ti mesh substrate supported hybrid CE.


Asunto(s)
Puntos Cuánticos , Carbono/química , Carragenina , Electrodos , Electrólitos , Puntos Cuánticos/química , Sulfuros
10.
Oxid Med Cell Longev ; 2022: 8482149, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35498134

RESUMEN

Natural visible light is an electromagnetic wave composed of a spectrum of monochromatic wavelengths, each with a characteristic color. Photons are the basic units of light, and their wavelength correlates to the energy of light; short-wavelength photons carry high energy. The retina is a fragile neuronal tissue that senses light and generates visual signals conducted to the brain. However, excessive and intensive light exposure will cause retinal light damage. Within the visible spectrum, short-wavelength light, such as blue light, carries higher energy, and thus the retinal injury, is more significant when exposed to these wavelengths. The damage mechanism triggered by different short-wavelength light varies due to photons carrying different energy and being absorbed by different photosensitive molecules in the retinal neurons. However, photooxidation might be a common molecular step to initiate cell death. Herein, we summarize the historical understanding of light, the key molecular steps related to retinal light injury, and the death pathways of photoreceptors to further decipher the molecular mechanism of retinal light injury and explore potential neuroprotective strategies.


Asunto(s)
Enfermedades de la Retina , Humanos , Retina/metabolismo , Enfermedades de la Retina/metabolismo
11.
Carbohydr Polym ; 269: 118277, 2021 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-34294309

RESUMEN

Citronellol (CI)-loaded, chitosan (CS)-enclosed dendritic mesoporous organosilica nanoparticles (CI@D-MONs@CS) are successfully fabricated. The synthesized CI@D-MONs@CS present spherical shape with the particle size of 424±24 nm in diameter and dendritic mesopores. CI loading ratio of CI@D-MONs@CS is about 12.42% from TGA analysis. CI release from CI@D-MONs@CS exhibits pH-redox dual responsiveness. More interesting, the axillary deodorant effect is investigated with Staphylococcus haemolyticus in an artificial sweat model. The results show that CI@D-MONs@CS present an excellent bacteria-killing effect and the smell of artificial sweat is greatly improved, avoiding the formation of undesirable odorant compounds from the bacteria. The obtained CI@D-MONs@CS is a potential carrier of natural fragrance or actives with dual responsive release. The application of CI@D-MONs@CS is a new and effective strategy to the axillary odor problem.

12.
Oxid Med Cell Longev ; 2020: 2896036, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32831993

RESUMEN

Age-related macular degeneration (AMD) is a leading cause of severe visual loss and irreversible blindness in the elderly population worldwide. Retinal pigment epithelial (RPE) cells are the major site of pathological alterations in AMD. They are responsible for the phagocytosis of shed photoreceptor outer segments (POSs) and clearance of cellular waste under physiological conditions. Age-related, cumulative oxidative stimuli contribute to the pathogenesis of AMD. Excessive oxidative stress induces RPE cell degeneration and incomplete digestion of POSs, leading to the continuous accumulation of cellular waste (such as lipofuscin). Autophagy is a major system of degradation of damaged or unnecessary proteins. However, degenerative RPE cells in AMD patients cannot perform autophagy sufficiently to resist oxidative damage. Increasing evidence supports the idea that enhancing the autophagic process can properly alleviate oxidative injury in AMD and protect RPE and photoreceptor cells from degeneration and death, although overactivated autophagy may lead to cell death at early stages of retinal degenerative diseases. The crosstalk among the NFE2L2, PGC-1, p62, AMPK, and PI3K/Akt/mTOR pathways may play a crucial role in improving disturbed autophagy and mitigating the progression of AMD. In this review, we discuss how autophagy prevents oxidative damage in AMD, summarize potential neuroprotective strategies for therapeutic interventions, and provide an overview of these neuroprotective mechanisms.


Asunto(s)
Autofagia/genética , Degeneración Macular/genética , Estrés Oxidativo/genética , Anciano , Animales , Humanos , Ratones
13.
Pathol Res Pract ; 214(11): 1892-1897, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30270103

RESUMEN

BACKGROUND: Papillary thyroid carcinoma (PTC) is often associated with cervical lymph node metastasis (LNM), which may cause poor prognosis. Both fine-needle aspiration cytology (FNAC) and thyroglobulin measurement with fine-needle aspiration (Tg-FNA) have high diagnostic efficacy, but the diagnostic values and relationships among BRAFv600e mutation (BRAFMUT) testing, FNAC and FNA-Tg are unclear. METHODS: We enrolled 145 patients with confirmed PTC and lymph nodes (LNs) that were suspected to be metastatic based on ultrasound findings, who were treated from May 2017 to April 2018, and underwent FNAC, Tg-FNA and BRAFMUT tests. Diagnostic efficacy was calculated by diagnostic and chi-square tests. RESULTS: Diagnostic values were FNAC-sensitivity: 67%, specificity: 100%, PPV: 100%, NPV: 66%, accuracy: 80%; and FNA-Tg (at a cut-off of 2.23 ng/mL)-sensitivity: 97.3%, specificity: 87.8%, PPV: 87.8%, NPV: 97.3%, accuracy: 92.3%. In the BRAFMUT+ group, sensitivities and specificities were FNAC: 68.6% and 100%, Tg-FNA: 94.4% and 85.7%; compared with FNAC: 75% and 90.9%, Tg-FNA: 80% and 100% in the BRAFMUT- group. CONCLUSION: The combination of Tg-FNA + FNAC is useful in diagnosing metastatic PTC. BRAF mutational status does not affect the diagnostic performance of FNAC or Tg-FNA.


Asunto(s)
Biopsia con Aguja Fina/métodos , Metástasis Linfática/diagnóstico , Tiroglobulina/análisis , Cáncer Papilar Tiroideo/diagnóstico , Adulto , Área Bajo la Curva , Citodiagnóstico/métodos , Análisis Mutacional de ADN , Femenino , Humanos , Metástasis Linfática/genética , Masculino , Persona de Mediana Edad , Mutación , Proteínas Proto-Oncogénicas B-raf/genética , Curva ROC , Sensibilidad y Especificidad , Cáncer Papilar Tiroideo/genética
14.
Dalton Trans ; 47(6): 1764-1767, 2018 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-29337320

RESUMEN

Enantiopure ligands, namely (R,R)- and (S,S)-2,2'-(1,4-phenylene) bis(4,5-dihydrothiazole-4-carboxylic acid) (H2LRR, and H2LSS) were synthesized, and homochiral metallocyclic rings {Ni6LRR6(H2O)12} (1RR) and {Ni6LSS6(H2O)12} (1SS) were obtained and their structures were determined. The complexes exhibit excellent activity for the photocatalytic degradation of organic dyes.

15.
Int J Mol Med ; 40(2): 454-464, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28627620

RESUMEN

Human serum amyloid P (hSAP), a member of the pentraxin family, inhibits the activation of fibrocytes in culture and inhibits experimental renal, lung, skin and cardiac fibrosis. As hepatic inflammation is one of the causes of liver fibrosis, in the present study, we investigated the hepatoprotective effects of hSAP against carbon tetrachloride (CCl4)-induced liver injury. Our data indicated that hSAP attenuated hepatic histopathological abnormalities and significantly decreased inflammatory cell infiltration and pro-inflammatory factor expression. Moreover, CCl4-induced apoptosis in the mouse liver was inhibited by hSAP, as measured by terminal-deoxynucleotidyl transferase mediated nick-end labeling (TUNEL) assay and cleaved caspase-3 expression. hSAP significantly restored the expression of B cell lymphoma/leukemia (Bcl)-2 and suppressed the expression of Bcl-2-associated X protein (Bax) in vivo. The number of hepatocytes in early apoptosis stained with Annexin V was significantly reduced by 28-30% in the hSAP treatment group compared with the CCl4 group, and the expression of Bcl-2 was increased, whereas the expression of Bax and cleaved caspase-3 were significantly inhibited in the hSAP pre-treatment group compared with the CCl4 group. hSAP administration also inhibited the migration and activation of hepatic stellate cells (HSCs) in CCl4-injured liver and suppressed the activation of isolated primary HSCs induced by transforming growth factor (TGF)-ß1 in vitro. Collectively, these findings suggest that hSAP exerts a protective effect againts CCl4-induced hepatic injury by suppressing the inflammatory response and hepatocyte apoptosis, potentially by inhibiting HSC activation.


Asunto(s)
Tetracloruro de Carbono , Enfermedad Hepática Inducida por Sustancias y Drogas/patología , Enfermedad Hepática Inducida por Sustancias y Drogas/prevención & control , Hígado/efectos de los fármacos , Hígado/patología , Sustancias Protectoras/uso terapéutico , Componente Amiloide P Sérico/uso terapéutico , Animales , Antiinflamatorios/uso terapéutico , Apoptosis/efectos de los fármacos , Línea Celular , Células Cultivadas , Enfermedad Hepática Inducida por Sustancias y Drogas/inmunología , Citocinas/análisis , Citocinas/inmunología , Humanos , Inflamación/inmunología , Inflamación/patología , Inflamación/prevención & control , Hígado/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL
16.
Chem Commun (Camb) ; 52(81): 12036-12039, 2016 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-27711397

RESUMEN

Herein, we report the intriguing structure, optical absorption and electrochemical properties of the transition-sized Au92(TBBT)44 (Au92 for short, TBBT = 4-tert-butylbenzenethiolate) nanoparticle. An interesting observation is the 4H phase array of Au92 nanoparticles in the unit cells of single crystals.

17.
J Am Chem Soc ; 138(33): 10425-8, 2016 08 24.
Artículo en Inglés | MEDLINE | ID: mdl-27490914

RESUMEN

The 18-electron shell closure structure of Au nanoclusters protected by thiol ligands has not been reported until now. Herein, we synthesize a novel nanocluster bearing the same gold atom number but a different thiolate number as another structurally resolved nanocluster Au44(TBBT)28 (TBBTH = 4-tert-butylbenzenelthiol). The new cluster was determined to be Au44(2,4-DMBT)26 (2,4-DMBTH = 2,4-dimethylbenzenethiol) using multiple techniques, including mass spectrometry and single crystal X-ray crystallography (SCXC). Au44(2,4-DMBT)26 represents the first 18-electron closed-shell gold nanocluster. SCXC reveals that the atomic structure of Au44(2,4-DMBT)26 is completely different from that of Au44(TBBT)28 but is similar to the structure of Au38Q. The arrangement of staples (bridging thiolates) and part of the Au29 kernel atom induces the chirality of Au44(2,4-DMBT)26. The finding that a small portion of the gold kernel exhibits chirality is interesting because it has not been previously reported to the best of our knowledge. Although Au44(2,4-DMBT)26 bears an 18-electron shell closure structure, it is less thermostable than Au44(TBBT)28, indicating that multiple factors contribute to the thermostability of gold nanoclusters. Surprisingly, the small difference in Au/thiolate molar ratio between Au44(2,4-DMBT)26 and Au44(TBBT)28 leads to a dramatic distinction in Au 4f X-ray photoelectron spectroscopy, where it is found that the charge state of Au in Au44(2,4-DMBT)26 is remarkably more positive than that in Au44(TBBT)28 and even slightly more positive than the charge states of gold in Au-(2,4-DMBT) or Au-TBBT complexes.

18.
Chemistry ; 22(40): 14162-5, 2016 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-27434063

RESUMEN

The use of 1,3-dicyclohexylimidazol-2-ylidene (ICy) as ligand has enabled the preparation of the high-spin tetrahedral iron(I)- and iron(0)-N2 complexes, namely [(ICy)3 Fe(N2 )][BPh4 ] (1) and [(ICy)3 Fe(N2 )] (2), the electronic structures of which have been established by various spectroscopic characterization and DFT calculations. The frequency of the N-N stretching resonance of the iron(0)-N2 complex is the lowest among the reported terminal N2 complexes of iron, signifying the beneficial roles of strongly σ-donating ligands in combination with the high-spin low-valent iron center in promoting N2 -activation. The iron(0)-N2 complex can convert reversibly to the low-spin iron(II)-N2 hydride complex [(ICy)2 (ICy')Fe(N2 )(H)] (4).

19.
Dalton Trans ; 44(17): 7770-3, 2015 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-25857286

RESUMEN

A new porous metal-organic framework (MOF) {[Cu4(OH)2(tci)2(bpy)2]·11H2O} (1) based on a tetranuclear copper cluster with intracluster antiferromagnetic interactions was synthesized. Quartz crystal microbalance (QCM) sensor studies reveal sensitive and selective sensing for small molecules.

20.
Pharm Biol ; 53(1): 117-24, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25255928

RESUMEN

UNLABELLED: Abstract Context: Most of the present studies on the antitumor efficiency of Cymbopogon citratus (DC.) Stapf (Gramineae) are limited to its low-mass compounds, and little information about the antitumor activity of polysaccharides from this plant is available. OBJECTIVES: This study focused on the potential antitumor and immunomodulatory activities of polysaccharides (CCPS) from C. citratus. MATERIALS AND METHODS: CCPS was isolated using the water extraction-ethanol precipitation method. The sarcoma 180 (S180) cells-inoculated mice were intraperitoneally administrated with CCPS (30-200 mg/kg/d) for seven consecutive days. The effects of CCPS on tumor growth, thymus and spleen weights, splenocyte proliferation, and cytokine secretion in the tumor-bearing mice were measured. The cytotoxicity of CCPS (50-800 µg/mL) towards S180 cells was also studied. RESULTS: CCPS significantly inhibited the growth of the transplanted S180 tumors, with the inhibition rates ranging from 14.8 to 37.8%. Simultaneously, CCPS dose-dependently improved the immunity of the tumor-bearing mice. With the highest dose of 200 mg/kg/d, the thymus and spleen indices were increased by 21.9 and 91.9%, respectively; ConA- and LSP-induced splenocyte proliferations were increased by 32.7 and 35.3%, respectively. The secretions of interleukin 2 (IL-2), interleukin 6 (IL-6), interleukin 2 (IL-12), and tumor necrosis factor-α (TNF-α) were increased by 103.2, 40.2, 23.6, and 26.3%, respectively. Nevertheless, almost no toxicity of CCPS towards S180 cells was observed, with the maximal inhibition rate less than 15% at the CCPS concentration of 800 µg/mL. CONCLUSION: CCPS exhibited antitumor activity in vivo, and this activity might be achieved by immunoenhancement rather than direct cytotoxicity.


Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Cymbopogon/química , Factores Inmunológicos/farmacología , Polisacáridos/farmacología , Animales , Antineoplásicos Fitogénicos/aislamiento & purificación , Antineoplásicos Fitogénicos/uso terapéutico , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Factores Inmunológicos/aislamiento & purificación , Factores Inmunológicos/uso terapéutico , Masculino , Ratones Endogámicos , Trasplante de Neoplasias , Tamaño de los Órganos/efectos de los fármacos , Componentes Aéreos de las Plantas/química , Polisacáridos/aislamiento & purificación , Polisacáridos/uso terapéutico , Sarcoma 180/tratamiento farmacológico , Sarcoma 180/inmunología , Sarcoma 180/patología , Bazo/efectos de los fármacos , Bazo/inmunología , Bazo/patología , Timo/efectos de los fármacos , Timo/inmunología , Timo/patología
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