Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Nano Lett ; 2024 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-38511842

RESUMEN

Methane oxidation using molecular oxygen remains a grand challenge in which the obstacle is not only the activation of methane but also the reaction with oxygen, considering the mismatch of the ground spin states. Herein, we report TiO2-supported Pt nanocrystals (Pt/TiO2) with surface Pt-Ti alloyed layers that directly convert methane into oxygenates by using O2 as the oxidant with the assistance of CO. The oxygenate yield reached 749.8 mmol gPt-1 in a H2O aqueous solution over 0.1% Pt/TiO2 under 31 bar of mixed gas (20:5:6 CH4:CO:O2) at 150 °C for 3 h, while the CH3OH selectivity was 62.3%. On the basis of the control experiments and spectroscopic results, we identified the surface Pt-Ti alloy as the active sites. Moreover, CO promoted the dissociation of O2 on the surface of Pt-Ti alloyed layers and the subsequent activation of CH4 to form oxygenated products.

2.
Nano Lett ; 24(3): 852-858, 2024 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-38051031

RESUMEN

Currently, the hydroformylation of short olefins is operated almost exclusively by using Rh catalysts. Considering the high cost and scarcity of rhodium resources, it is important to develop non-noble metal catalysts toward hydroformylation. Herein, we report an efficient cobalt-based catalyst rich in interfacial sites between metallic and oxidized cobalt species for the hydroformylation of short olefin, propene, under a moderate syngas pressure. The catalyst exhibited a high specific activity of 252 mol molCo-1 h-1 in toluene under 2 bar of propene and 40 bar of CO/H2 mixed gas (CO/H2 = 1:1) at 160 °C. According to mechanistic studies, the interface of metallic and oxidized cobalt species promoted the adsorption of CO and propene. Moreover, the interfacial sites lowered the energy barrier for CO* hydrogenation and C-C coupling compared with metallic cobalt.

3.
Mar Drugs ; 21(2)2023 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-36827169

RESUMEN

Fucoidans, discovered in 1913, are fucose-rich sulfated polysaccharides extracted mainly from brown seaweed. These versatile and nontoxic marine-origin heteropolysaccharides have a wide range of favorable biological activities, including antitumor, immunomodulatory, antiviral, antithrombotic, anticoagulant, antithrombotic, antioxidant, and lipid-lowering activities. In the early 1980s, fucoidans were first recognized for their role in supporting the immune response and later, in the 1990s, their effects on immune potentiation began to emerge. In recent years, the understanding of the immunomodulatory effects of fucoidan has expanded significantly. The ability of fucoidan(s) to activate CTL-mediated cytotoxicity against cancer cells, strong antitumor property, and robust safety profile make fucoidans desirable for effective cancer immunotherapy. This review focusses on current progress and understanding of the immunopotentiation activity of various fucoidans, emphasizing their relevance to cancer immunotherapy. Here, we will discuss the action of fucoidans in different immune cells and review how fucoidans can be used as adjuvants in conjunction with immunotherapeutic products to improve cancer treatment and clinical outcome. Some key rationales for the possible combination of fucoidans with immunotherapy will be discussed. An update is provided on human clinical studies and available registered cancer clinical trials using fucoidans while highlighting future prospects and challenges.


Asunto(s)
Neoplasias , Algas Marinas , Humanos , Fibrinolíticos , Anticoagulantes/farmacología , Polisacáridos/farmacología , Inmunoterapia
4.
Cancer Invest ; 40(4): 337-347, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35100066

RESUMEN

We detected PD-L1 and intra-tumoral CD8+ T lymphocytes (CD8+ TIL) in 19 patients with esophageal carcinosarcoma (ECS). The median follow-up period of these patients was 43 months, and the three- and five-year survival rates were 78.9 and 63.2%, respectively. No statistically significant correlation was observed between PD-L1 and CD8+ TIL in sarcomatous components(SC) (r = -0.262, p = 0.279) and epithelial carcinomatous (EC) (r = 0.055, p = 0.824). This study examined the immunological markers in ECS for the first time. PD-L1 is highly expressed in the SC and is associated with a poorer prognosis.


Asunto(s)
Carcinosarcoma , Neoplasias Esofágicas , Antígeno B7-H1/metabolismo , Linfocitos T CD8-positivos , Carcinosarcoma/metabolismo , Neoplasias Esofágicas/metabolismo , Humanos , Linfocitos Infiltrantes de Tumor/metabolismo , Pronóstico
5.
Soft Robot ; 7(3): 396-407, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-31905330

RESUMEN

Soft hands based only on an actuator system using a motor, air compressor, or smart material show obvious shortcomings due to the characteristics of each actuator. In this article, to overcome the weaknesses of each actuator system, a novel soft hand with a hybrid actuator system is presented to improve the grasping capacity and complete complex tasks, as the individual actuators can complement each other. First, the structure and actuation system of the soft hand are presented. DC motors are used to output sufficient torque to bend the soft fingers. Shape memory alloy wires are used to rotate the fingertips. The electromagnets embedded in the soft fingers are actuated to bond the fingers to improve the load capability without changing the fingers' stiffness. Then, four different grasping methods are tested to manipulate objects: (1) the soft hand actuated only by motors is tested in terms of its ability to grasp objects of different shapes; (2) the soft robot can grasp the inside of the objects using rotated fingertips; (3) grasping involving the fingers tightly bonded by an electromagnetic force is tested; and (4) small objects are also secured and prevented from falling from the fingers by a gap-filling grasping method. In conclusion, the soft hand actuated by the hybrid system should be a viable alternative to soft manipulators that can compensate for the weaknesses of each actuator and improve the grasping capacity relative to that of individual actuators.


Asunto(s)
Imanes , Aleaciones con Memoria de Forma , Dedos , Mano , Fuerza de la Mano
6.
Biomed Pharmacother ; 121: 109625, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31733578

RESUMEN

Unprecedented efficacy of chimeric antigen receptor (CAR) T cell therapy in the treatment of hematologic malignancies brings new hope for patients with many cancer types including solid tumors. However, the challenges for CAR-T cell therapy in eradicating solid tumors are immense. To overcome these seemingly intractable hurdles, more "powerful" CAR-T cells with enhanced antitumor efficacy are required. Emerging data support that the anti-tumor activity of CAR-T cells can be enhanced significantly without evident toxicity through simultaneous PD-1 disruption by genome editing. This review focuses on the current progress of PD-1 gene disrupted CAR-T cells in cancer therapy. Here we discuss key rationales for this new combination strategy and summarize the available pre-clinical studies. An update is provided on human clinical studies and available registered cancer clinical trials using CAR-T cells with PD-1 disruption. Future prospects and challenges are also discussed.


Asunto(s)
Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Inmunoterapia Adoptiva , Neoplasias/terapia , Ensayos Clínicos como Asunto , Edición Génica , Humanos
8.
Antiviral Res ; 137: 67-75, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27864074

RESUMEN

The Enterovirus A71 (EV-A71) subgenogroup C4 is prevalent in China. EV-A71 causes hand, foot and mouth disease (HFMD) in children and may lead to severe neurological diseases. The development of antiviral and protective vaccines against EV-A71 is significantly hindered by the lack of suitable animal models to recapitulate human neurological symptoms. In this study, GZ-CII, a highly virulent EV-A71 subgenogroup C4 strain, was isolated from hospitalized children with HFMD. Intraperitoneal infections of GZ-CII resulted in progressive neurological disease in mice as old as 14 days. Administration of an inactivated EV-A71 vaccine or an anti-EV-A71 immune serum protected the mice against the GZ-CII infection. This demonstrated that a mouse model with EV-A71 GZ-CII could be used to evaluate potential vaccine candidates and therapeutics for subgenogroup C4. Comparing the genome sequence of GZ-CII with that of the avirulent EV-A71 subgenogroup C4 strain revealed unique mutations in GZ-CII. When mutation VP2-K149I was introduced into the nonpathogenic EV-A71 subgenogroup C4 strain, the variant similar to GZ-CII significantly increased viral replication and virulence in mice. These results indicated that the VP2-K149I mutation played an important role in enhancing the virulence of the EV-A71 subgenogroup C4 strain in mice, and that mice infected with the GZ-CII strain are a promising model for evaluating vaccines and therapeutics against the EV-A71 subgenogroup C4.


Asunto(s)
Modelos Animales de Enfermedad , Enterovirus Humano A/clasificación , Enterovirus Humano A/patogenicidad , Infecciones por Enterovirus/virología , Enfermedad de Boca, Mano y Pie/virología , Ratones , Factores de Edad , Animales , Niño , China , Enterovirus Humano A/genética , Enterovirus Humano A/aislamiento & purificación , Infecciones por Enterovirus/inmunología , Infecciones por Enterovirus/prevención & control , Infecciones por Enterovirus/terapia , Enfermedad de Boca, Mano y Pie/inmunología , Enfermedad de Boca, Mano y Pie/prevención & control , Enfermedad de Boca, Mano y Pie/terapia , Humanos , Inmunización Pasiva , Mutación , Vacunas de Productos Inactivados/administración & dosificación , Vacunas de Productos Inactivados/inmunología , Vacunas Virales/administración & dosificación , Vacunas Virales/inmunología , Virulencia , Replicación Viral
9.
Medicine (Baltimore) ; 94(1): e361, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25569654

RESUMEN

In this study, we tried to find a safe as well as fast effective treatment for sedation and analgesia for intrathecal injection in childhood leukemia patients, relieving treatment difficulties and pain, increasing the success rate of single intrathecal injection.The patients were divided into the experimental group (fentanyl combined with etomidate) and the control group (lidocaine only) randomly. The experimental group was given fentanyl 1 to 2 µg/kg intravenously first, then etomidate 0.1 to 0.3 mg/kg intravenously after the pipe washed. The patients younger than 1.5 years or who did not achieve satisfied sedative and analgesic situation received an additional time of etomidate (0.1-0.3 mg/kg). The patients were given oxygen at the rate of 4-5 L/min during the whole operation, and the finger pulse oximeter was used simultaneously to detect the changes in heart rate (HR) and blood oxygen saturation (SpO2). The doctors who performed the procedures assessed the quality of sedation and analgesia.In the experimental group, the patients' HR increased slightly after given fentanyl combined with etomidate. The patients' SpO2 was stable. Most patients achieved a good sedative and analgesic state within 1 to 2 minutes, and no case of respiration depression or cardiac arrhythmias occurred during the whole operation. The wake-up time was 55.42 ±â€Š20.62 min. In the control group, the patients were not very cooperative during the intrathecal injection, which made the procedures very difficult.During intrathecal injection, pain obviously reduced and the success rate of single lumbar puncture increased. It is safe and effective to apply fentanyl combined with etomidate for sedation and analgesia.


Asunto(s)
Anestésicos Intravenosos/uso terapéutico , Etomidato/uso terapéutico , Fentanilo/uso terapéutico , Inyecciones Espinales/efectos adversos , Dolor/prevención & control , Niño , Femenino , Humanos , Leucemia/tratamiento farmacológico , Masculino , Dolor/etiología
10.
Zhen Ci Yan Jiu ; 38(2): 158-62, 2013 Apr.
Artículo en Chino | MEDLINE | ID: mdl-23819221

RESUMEN

OBJECTIVE: To observe the arousal effect of electroacupuncture (EA) stimulation of Baihui (GV 20), Shuigou (GV 26), etc. on severe craniocerebral injury patients. METHODS: A total of 90 cases of severe craniocerebral injury were randomly allocated to routine medication, naloxone and EA groups, with 30 cases in each group. For patients of the routine medication group, mild hypothermia therapy, medicines for dehydration, hormonal therapy, vascular dilation, cerebral nutrition supporting, anti-inflammation, etc. were given. For patients of the naloxone group, intravenous drip of naloxone 0.4 mg/kg in the first 3 days, 0.2 mg/kg for 7 days and 0. 1 mg/kg afterwards. For patients of the EA group, EA (1 Hz/50 Hz) was given for 30 min once daily. All the treatments were conducted once a day for 14 days. The Glasgow Coma Scale (GCS) and Glasgow Outcome Scale (GOS) were used for assessing the therapeutic effect. RESULTS: In comparison with pre-treatment in each one of the routine medication, naloxone and EA groups, GCS scores were all obviously increased in the 3 groups following the treatment, and one month's follow-up (P<0. 05). The GCS scores of both naloxone and EA groups were significantly higher than those of the routine medication group (P<0.05). No significant difference was found between the naloxone group and EA group in GCS scores (P>0. 05). According to the GOS, one month's follow-up showed that of the three 30 cases in the routine medication, naloxone and EA groups, 6, 12 and 14 were improved, 8, 10 and 10 moderate handicap, 8, 3 and 2 severe handicap, 5, 3 and 2 vegetative state, and 3, 2 and 2 dead, with the arousal rates being 46. 66% , 73. 33% and 80. 00%, respectively. The therapeutic effects of both naloxone and EA groups were significantly superior to those of the routine medication group (P<0.05). CONCLUSION: EA intervention at early stage can promote the recovery of neurological function, accelerate the consciousness from coma and improve the outcomes of patients with severe traumatic brain injury.


Asunto(s)
Lesiones Encefálicas/terapia , Coma/terapia , Estado de Conciencia , Electroacupuntura , Adolescente , Adulto , Lesiones Encefálicas/psicología , Coma/psicología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
11.
Acta Crystallogr Sect E Struct Rep Online ; 65(Pt 3): o649, 2009 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-21582297

RESUMEN

In the mol-ecule of the title compound, C(15)H(15)NO(4)S, the two six-membered rings are almost parallel to each other [dihedral angle = 1.87 (9)°] and perpendicular to the mean plane through the five-membered ring [dihedral angles of 89.98 (10) and 89.04 (10)°]. The crystal structure is stabilized by inter-molecular C-H⋯O hydrogen-bonding inter-actions.

12.
Guang Pu Xue Yu Guang Pu Fen Xi ; 27(5): 966-8, 2007 May.
Artículo en Chino | MEDLINE | ID: mdl-17655115

RESUMEN

Three kinds of derivatives, 16alpha, 17alpha-epoxy-6-methylene-pregn-4-ene-3,20-dione(EMPD I), 16alpha, 17alpha-epoxy-6-methyl-pregn-4,6-diene-3,20-dione (EMPD II) and 16alpha, 17alpha-epoxy-6-methyl-pregn-4-ene-3, 20-dione(EMPD III) were synthesized and their FTIR, UV and 1H NMR spectra were described. EMPD II is a novel compound. In the UV spectra, the maximum absorptions peaks of EMPD I, EMPD II and EMPD III are at 259, 287 and 239 nm respectively. Their IR spectra are also obviously different. For EMPD I, there are two absorption peaks, which are respectively at 3084 cm(-1) originated from ==CH2 and 3 030 cm(-1) from C==CH--. For EMPD II and III, there is only one absorption peak at 3054 cm(-1). From 1710-1660 cm(-1), only one absorption peak appears for EMPD III, but two appear for EMPD I and EMPD II. In 1H NMR spectrum, the peaks at 4.92 (s, 1H), 5.06 (s, 1H) and 5.88 (s, 1H) were observed for EMPD I; the peaks at 1.83 (s, 3H), 5.87 (s, 1H) and 5.85 (s, 1H) for EMPD II; while the peaks at 1.06-1.07 (d, 3H), 5.78 ppm (s, 1H, 1 ppm=l nicrog x mL(-1)), for EMPD III.


Asunto(s)
Compuestos Epoxi/análisis , Compuestos Epoxi/síntesis química , Espectroscopía de Resonancia Magnética/métodos , Pregnenos/análisis , Pregnenos/síntesis química , Espectrofotometría/métodos , Espectroscopía Infrarroja por Transformada de Fourier/métodos
13.
Yi Chuan ; 25(3): 307-10, 2003 May.
Artículo en Chino | MEDLINE | ID: mdl-15639876

RESUMEN

Some selected available sequences of reporter genes,resistant genes, promoters and terminators are amplified by PCR for the probes of transgenic crop detection gene chip. These probes are arrayed at definite density and printed on the surface of amino-slides by bioRobot MicroGrid II. Results showed that gene chip worked quickly and correctly, when transgenic rice, pawpaw,maize and soybean were applied.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...