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Helicobacter pylori, a human pathogen with a high global prevalence, is the causative pathogen for multiple gastrointestinal diseases, especially chronic gastritis, peptic ulcers, gastric mucosa-associated lymphoid tissue lymphoma, and gastric malignancies. Antibiotic therapies remain the mainstay for H. pylori eradication; however, this strategy is hampered by the emergence and spread of H. pylori antibiotic resistance. Exploring the mechanistic basis of this resistance is becoming one of the major research questions in contemporary biomedical research, as such knowledge could be exploited to devise novel rational avenues for counteracting the existing resistance and devising strategies to avoid the development of a novel anti-H. pylori medication. Encouragingly, important progress in this field has been made recently. Here, we attempt to review the current state and progress with respect to the molecular mechanism of antibiotic resistance for H. pylori. A picture is emerging in which mutations of various genes in H. pylori, resulting in decreased membrane permeability, altered oxidation-reduction potential, and a more efficient efflux pump system. The increased knowledge on these mechanisms produces hope that antibiotic resistance in H. pylori can ultimately be countered.
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Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Farmacorresistencia Bacteriana , Infecciones por Helicobacter/tratamiento farmacológico , Infecciones por Helicobacter/microbiología , Helicobacter pylori/efectos de los fármacos , Genes Bacterianos , Infecciones por Helicobacter/genética , Humanos , MutaciónRESUMEN
BACKGROUND: In 2010, undifferentiated early-stage gastric cancers (EGCs; ≤1 cm and confined to the mucosa) were included in the expanded criteria for endoscopic submucosal dissection (ESD), as established by the Japanese Gastric Cancer Association. OBJECTIVE: To evaluate the safety and efficacy of the newly expanded criteria of ESD for EGCs. METHODS: PubMed, Embase, and the Cochrane Library were searched for relevant studies published between January 1, 2010 and July 10, 2014. These studies were collected by 2 authors and then analyzed with RevMan 5.0. RESULTS: Six studies including 6,687 patients were identified. Compared to the standard group (SG), the expanded group (EG) had higher bleeding (OR 1.66; 95% CI 1.02-2.68), perforation (OR 2.03; 95% CI 1.25-3.31), positive lateral margin rates (OR 16.88; 95% CI 3.83-74.5) and lower en bloc resection rate (OR 0.48; 95% CI 0.34-0.70). The local recurrence (OR 2.46; 95% CI 0.31-19.23) and total survival rates (OR 0.92; 95% CI 0.76-1.12) between the 2 groups were not statistically different. CONCLUSIONS: Considering the similar rates of local recurrence and total survival between the SG and EG, the use of ESD for the management of EGCs that meet the expanded criteria could be considered a safe and effective treatment method.
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Disección/normas , Detección Precoz del Cáncer/normas , Endoscopía Gastrointestinal/normas , Neoplasias Gástricas/cirugía , Anciano , Femenino , Mucosa Gástrica/cirugía , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Neoplasias Gástricas/patología , Resultado del TratamientoRESUMEN
OBJECTIVE: To study the role of nuclear factor (NF)-kappaB pathway with p38MAPK in Curcuma wenyujin diterpenoid compound C (CDCC) fighting against inflammation and inducing gastric cancer cell apoptosis by stimulating gastric cell SGC7901 with tumor necrosis factor-alpha (TNF-alpha). METHODS: Human umbilical vein endothelial cells (HUVECs) and human gastric cancer SGC-7901 cells were in vitro acted by CDCC in different concentrations at different time points. Their growth inhibition ratios were measured by MTT assay. The apoptosis rate of gastric cancer cells was detected by Annexin V-FITC/PI double staining. Nuclear translocation of p65 was detected by cell immunofluorescence. Expression levels of p38MAPK/P-p38MAPK, p65/P-p65, and Caspase 3/P-Caspase 3 were measured by Western blot. RESULTS: CDCC had significant inhibitory effect on the proliferation of SGC-7901. It also could effectively induce the apoptosis of gastric cancer cell SGC-7901. It also could reduce nuclear translocation of p65 in gastric cancer cell SGC-7901. Results of Western blot indicated that expression levels of p38MAPK and p65 were reduced and the expression level of Caspase-3 was elevated along with increased concentrations of CDCC (P<0.05). CONCLUSION: Apoptosis executive protein Caspase 3 activated by regulating p65 via p38MAPK might be one of possible mechanisms for CDCC fighting against inflammation and gastric cancer.
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Medicamentos Herbarios Chinos/uso terapéutico , Neoplasias Gástricas/tratamiento farmacológico , Apoptosis , Caspasa 3 , Línea Celular Tumoral , Curcuma , Diterpenos , Humanos , FN-kappa B , Factor de Necrosis Tumoral alfaRESUMEN
OBJECTIVE: To study the mechanism of reversal effect of Curcuma Wenyujin n-Butyl alcohol extract (CWNAE) on multiple drugs resistance (MDR) of SGC7901/VCR cells. METHODS: SGC7901/VCR cells were co-culured with different concentrations CWNAE (80, 40, and 20 µg/mL) and Verapamil (VP, 10 µg/mL) for 24 h, and then acted with Adriamycin (ADM) for 1, 2, and 4 h, respec- tively. SGC7901/VCR cells with no intervention were taken as the vehicle control group. SGC7901/VCR cells treated with ADM alone were taken as the control group. The effect of CWNAE on intracellular ADM concentration was detected by flow cytometry (FCM). Cells were treated as mentioned before without any intervention of ADM. SGC7901/VCR with no ADM intervention were taken as the control group. The effect of CWNAE on the expression of P-glycoprotein (P-gp), lung resistance protein (LRP), and glu- cosylceramide synthase (GCS) was studied by Western blot. The effect of CWNAE on the location and expression quantity of P-gp was further illustrated by immunohistochemistry (IHC). RESULTS: Compared with the ADM group, the expression ratio obviously increased in the W80, W40, W20, and VP10 groups with statistical difference (all P < 0.05). The comparative expression quantity of P-gp, GCS, and LRP in SGC7901/VCR cells was obviously higher than that of non-MDR with statistical difference (all P < 0.05). The expression quantity of P-gp and GCS could be obviously down-regulated by 80 and 40 µg/mL CWN- AE, and 10 µg/mL VP, with no effect on the expression of LRP. Results of IHC proved that P-gp was mainly expressed on the cytomembrane or in the plasma, and it was also expressed on the nuclear membrane. P-gp in different locations could all be down-regulated by CWNAE. CONCLUSIONS: CWNAE could reverse the MDR of SGC7901/VCR cell line probably by inhibiting the expression of P-gp and GCS. CWNAE had no effect on LRP that also highly expressed on SGC7901/VCR. So we supposed that CWNAE could become a potential drug to reverse MDR of highly expressed P-gp and GCS.
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Curcuma , Resistencia a Múltiples Medicamentos/efectos de los fármacos , Resistencia a Antineoplásicos/efectos de los fármacos , Medicamentos Herbarios Chinos/farmacología , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP , Línea Celular Tumoral , Doxorrubicina , Medicamentos Herbarios Chinos/uso terapéutico , Humanos , Neoplasias GástricasRESUMEN
Flame-retardant epoxy resins with tough, transparent, ultraviolet shielding, and low dielectric properties have fascinating prospects in electronic and electrical applications, but it is still challenging at present. In this work, a bio-based macromolecule was synthesized from vanillin (a lignin derivative), phenyl dichlorophosphate, 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO), and poly(propylene glycol) bis(2-aminopropyl ether). The bio-based macromolecule, namely, MFR, was designed and added to the epoxy resin (EP). The cured EP containing 15 wt% MFR (i.e., EP/MFR15) exhibits excellent flame retardancy with an Underwriter Laboratory 94 (UL-94) V-0 rating and a limiting oxygen index (LOI) of 29.2 %. Furthermore, the peak heat release rate (PHRR) and total heat release rate (THR) are drastically reduced by 59.5 % and 40.7 %, respectively. Meanwhile, EP/MFR15 shows 20.3 % and 43.8 % improvements in tensile strength and toughness, respectively. Moreover, MFR simultaneously endows EP with accessional ultraviolet shielding performance and low dielectric constant without sacrificing transparency. This work provides a promising strategy for fabricating a bio-based macromolecular flame retardant and preparing a high-performance EP composite with versatile properties.
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Benzaldehídos , Resinas Epoxi , Retardadores de Llama , Rayos Ultravioleta , Benzaldehídos/química , Resinas Epoxi/química , Resistencia a la Tracción , Sustancias Macromoleculares/químicaRESUMEN
OBJECTIVE: To evaluate the diagnostic accuracy and safety of using magnetically guided capsule endoscopy with a detachable string (ds-MCE) for detecting and grading oesophagogastric varices in adults with cirrhosis. DESIGN: Prospective multicentre diagnostic accuracy study. SETTING: 14 medical centres in China. PARTICIPANTS: 607 adults (>18 years) with cirrhosis recruited between 7 January 2021 and 25 August 2022. Participants underwent ds-MCE (index test), followed by oesophagogastroduodenoscopy (OGD, reference test) within 48 hours. The participants were divided into development and validation cohorts in a ratio of 2:1. MAIN OUTCOME MEASURES: The primary outcomes were the sensitivity and specificity of ds-MCE in detecting oesophagogastric varices compared with OGD. Secondary outcomes included the sensitivity and specificity of ds-MCE for detecting high risk oesophageal varices and the diagnostic accuracy of ds-MCE for detecting high risk oesophagogastric varices, oesophageal varices, and gastric varices. RESULTS: ds-MCE and OGD examinations were completed in 582 (95.9%) of the 607 participants. Using OGD as the reference standard, ds-MCE had a sensitivity of 97.5% (95% confidence interval 95.5% to 98.7%) and specificity of 97.8% (94.4% to 99.1%) for detecting oesophagogastric varices (both P<0.001 compared with a prespecified 85% threshold). When using the optimal 18% threshold for luminal circumference of the oesophagus derived from the development cohort (n=393), the sensitivity and specificity of ds-MCE for detecting high risk oesophageal varices in the validation cohort (n=189) were 95.8% (89.7% to 98.4%) and 94.7% (88.2% to 97.7%), respectively. The diagnostic accuracy of ds-MCE for detecting high risk oesophagogastric varices, oesophageal varices, and gastric varices was 96.3% (92.6% to 98.2%), 96.9% (95.2% to 98.0%), and 96.7% (95.0% to 97.9%), respectively. Two serious adverse events occurred with OGD but none with ds-MCE. CONCLUSION: The findings of this study suggest that ds-MCE is a highly accurate and safe diagnostic tool for detecting and grading oesophagogastric varices and is a promising alternative to OGD for screening and surveillance of oesophagogastric varices in patients with cirrhosis. TRIAL REGISTRATION: ClinicalTrials.gov NCT03748563.
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Endoscopía Capsular , Várices Esofágicas y Gástricas , Várices , Adulto , Humanos , Várices Esofágicas y Gástricas/diagnóstico , Várices Esofágicas y Gástricas/etiología , Cirrosis Hepática/complicaciones , Estudios ProspectivosRESUMEN
Polyunsaturated fatty acids (PUFAs) have tumoricidal action, though the exact mechanism of their action is not clear. The results of the present study showed that of all the fatty acids tested, linoleic acid (LA) and α-linolenic acid (ALA) were the most effective in suppressing the growth of normal gastric cells (GES1) at 180 and 200 µM, while gastric carcinoma cells (MGC and SGC) were inhibited at 200 µM. Arachidonic acid (AA) suppressed the growth of GES1, MGC and SGC cells and lower concentrations (120 and 160 µM) of AA were more effective against gastric carcinoma (MGC and SGC) cells compared to normal gastric cells (GES1). Paradoxically, both eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids though are more unsaturated than AA, were less effective compared with LA, ALA and AA in suppressing the growth of both normal and cancer cells. At the concentration used, methotrexate showed much less growth suppressive action compared to all the fatty acids tested. PUFAs-treated cells showed accumulation of lipid droplets. A close association was noted between apoptosis and lipid peroxides formed compared to the ability of normal and tumor cells to generate ROS (reactive oxygen species) and induce SOD (superoxide dismutase activity) in response to fatty acids tested and methotrexate. Both normal and tumor cells generated lipoxin A4 (LXA4) in response to supplementation of fatty acids and methotrexate though no significant correlation was noted between their ability to induce apoptosis and LXA4 formed. These results suggest that PUFAs induced apoptosis of normal gastric and gastric carcinoma cells could, partly, be attributed to lipid peroxidation process.
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Ácidos Grasos Insaturados/farmacología , Neoplasias Gástricas/tratamiento farmacológico , Apoptosis/efectos de los fármacos , Línea Celular/efectos de los fármacos , Línea Celular Tumoral/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Ácidos Grasos/metabolismo , Humanos , Ácido Linoleico/farmacología , Gotas Lipídicas/efectos de los fármacos , Gotas Lipídicas/metabolismo , Lipoxinas/metabolismo , Estrés Oxidativo/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patología , Superóxido Dismutasa/metabolismo , Ácido alfa-Linolénico/farmacologíaRESUMEN
In order to fully investigate the anti-aging value of the plants polysaccharides, the fermentation method was applied to modify the Polygonatum kingianum polysaccharides (PKPS), and the ultra-filtration was used to further segment the hydrolyzed polysaccharides. It was found that the fermentation induced an increase in the in vitro anti-aging-related activities of PKPS including antioxidant, hypoglycemic and hypolipidemic activity, and cellular aging-delaying ability. In particular, the low Mw fraction PS2-4 (10-50 kDa) separated from the fermented polysaccharide exhibited superior anti-aging activity on experimental animals. PS2-4 extended the Caenorhabditis elegans lifespan by 20.70 %, with an increased effect of 10.09 % compared to the original polysaccharide; it was also more effective than the original one in improving movement ability and reducing lipofuscin accumulation of worms. This fraction was screened as the optimal anti-aging active polysaccharide. After fermentation, the main molecular weight distribution of PKPS changed from 50-650 kDa to 2-100 kDa, and the chemical composition and monosaccharide composition also changed; the initial rough and porous microtopography turned into smooth state. These alterations in physicochemical characteristics suggest that fermentation exerted an influence on the structure of PKPS, which contributed to the enhanced anti-aging activity, indicating that fermentation was promising in the structural modification of polysaccharides.
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Polygonatum , Animales , Polygonatum/química , Fermentación , Polisacáridos/farmacología , Polisacáridos/química , Antioxidantes/farmacología , Antioxidantes/química , EnvejecimientoRESUMEN
It has been always attractive to design a sustainable bio-derived adsorbent based on industrial waste lignin for removing organic dyes from water. However, existing adsorbent strategies often lead to the difficulties in adsorbent separation and recycling. Herein, we report a novel magnetically recyclable bio-adsorbent of Mg(OH)2/Fe3O4/PEI functionalized enzymatic lignin (EL) composite (EL-PEI@Fe3O4-Mg) for removing Congo red (CR) by Mannish reaction and hydrolysis-precipitation. The Mg(OH)2 and PEI functionalized EL on the surface act as active sites for the removal of CR, while the Fe3O4 allows for the easy separation under the help of a magnet. As-obtained EL-PEI@Fe3O4-Mg forms flower-like spheres and has a relatively lager surface area of 24.8 m2 g-1 which is 6 times that of EL. The EL-PEI@Fe3O4-Mg exhibits a relatively high CR adsorption capacity of 74.7 mg g-1 which is 15 times that of EL when initial concentration is around 100 mg L-1. And it can be easily separated from water by applying an external magnetic field. Moreover, EL-PEI@Fe3O4-Mg shows an excellent anti-interference capability according to the results of pH values and salt ions influences. Importantly, EL-PEI@Fe3O4-Mg possesses a good reusability and a removal efficiency of 92 % for CR remains after five consecutive cycles. It is illustrated that electrostatic attraction, π-π interaction and hydrogen binding are primary mechanisms for the removal of CR onto EL-PEI@Fe3O4-Mg. This work provides a novel sustainable strategy for the development of highly efficient, easy separable, recyclability bio-derived adsorbents for removing organic dyes, boosting the efficient utilization of industrial waste lignin.
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Rojo Congo , Contaminantes Químicos del Agua , Rojo Congo/química , Lignina , Residuos Industriales , Contaminantes Químicos del Agua/química , Agua/química , Colorantes , Adsorción , Concentración de Iones de Hidrógeno , CinéticaRESUMEN
The aim of the present study was to explore the value of detecting antibiotic-resistant genes in Helicobacter pylori (H. pylori) and the association between genotype and antibiotic resistance. Two gastric mucosa samples from each H. pylori-positive patient were collected. Each patient's H. pylori sample was cultured in vitro, and the agar plate dilution method was conducted. In addition, all patient samples were analyzed for the detection of antibiotic resistance-related mutant genes and VacA gene genotypes. The association between VacA genotypes and antibiotic resistance was also determined and the value of mutant gene detection in predicting H. pylori resistance to antibiotics was evaluated. In total, 133 H. pylori-positive patients were enrolled. A total of 22 strains of H. pylori failed to grow in in vitro culture and 25 strains were negative in a H. pylori gene test. Among 108 strains detected by PCR, a total of 39 VacA s1m1 strains, 69 VacA s1m2 strains and no VacA s2 strain were identified. There was no significant association between VacA genotypes and antibiotic resistance. The mutation rates of G616A in the rdxA gene, T87A, G91A, A91G and G91T in the gyrA gene and A2143G and A2142G in the 23S rRNA gene were 32.1, 32.3, 22.6, 12.9, 6.5, 81.8 and 0.0%, respectively. Among these mutant sites, the mutation coincidence rates were as follows, according to the agar plate dilution method: rdxA G616A (81.8%), gyrA G91T (66.7%), gyrA G91A (54.5%), 23 S rRNA A2143G (49.1%), gyrA T87A (45.5%), gyrA A91G (33.3%), penicillin-binding protein 1 (PBP1) C556G (0.0%), PBP1 A562T (0.0%), PBP1 A562G (0.0%) and 16 S rRNA 926-927 (AT-GT) (0.0%). VacA m subtypes were not associated with H. pylori antibiotic resistance. In conclusion, the present findings suggested that the detection of related mutant genes had a clinical application value in predicting the antibiotic resistance of H. pylori, particularly resistance to clarithromycin and levofloxacin.
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Lignin, as a natural polymer material, has the advantages of green safety, renewable, and pollution-free. It has a wide application prospect in the field of thermosetting. However, it has been attractive but a huge challenge to design high performance and high added-value lignin-based epoxy resin. Herein, lignin-based epoxy (LEP) was synthesized from moso bamboo-derived lignin, and then lignin-based epoxy/titanium dioxide (LEP/TiO2) hybrid nanoparticle was synthesized via liquid deposition method for modifying lignin-based epoxy resin to prepare multifunctional bio-based epoxy. The results show that the LEP/TiO2 hybrid nanoparticle exhibits a stable topological surface shape and good dispersion and uniformity. By adding 10 wt% LEP/TiO2 hybrid nanoparticles, the multifunctional bio-based epoxy exhibits good mechanical strength and toughness, and the tensile strength and fracture toughness reach 36 MPa and 1.26 MPa·m1/2, respectively. In addition, the thermal stability, UV absorption and antibacterial properties of the multifunctional bio-based epoxy are further improved. This study provides a facile and efficient method for the preparation of high-performance multifunctional bio-based epoxy composite and a novel solution for the utilization of lignin.
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Resinas Epoxi , Nanopartículas , Antibacterianos/farmacología , Lignina , TitanioRESUMEN
A P-/N-containing bamboo-activated carbon (BACm) was successfully synthesized by steam activation of bamboo charcoal and chemical grafting to as-prepared activated carbon using the reaction of phosphoric acid and urea. Characterizations of BACm presented a synergistic grafting of P and N elements to the BAC surface. The BACm was further loaded in a polylactic acid (PLA) matrix to prepare BACm/PLA composites. Mechanical strength study showed tensile strength dropped from 75.19 MPa to 61.30 MPa, and tensile modulus from 602.49 MPa to 375.56 MPa, suggesting a rigidity reduction and deformation resistance enhancement owing to the roughened surface of BACm that interlocked with the polymer. The thermogravimetric analysis showed that the carbon residue rate of BACm dramatically fell to 49.25 wt.% in contrast to 88.28% for the control BAC, and cone calorimeter measurements confirmed the enhancement of flame retardancy of the composites with BACm loading, and the carbon residue rate increased progressively with BACm loading in the composites, notably up to 8.60 wt.% for the BAC/PLA9 composite, which outweighed the theoretical residue rate by more than 50%. The elemental analysis also confirmed rich P/N levels of the dense carbon residue layer that could perform synergistically and effectively in fire suppression. The BACm tended to stimulate the earlier decomposition of the composites and formed a continuous residual carbon layer which functioned as an effective barrier hindering the mass and heat transfer between the combustion zone and the underlying matrix. Moreover, 9 wt.% of BACm loading could attain a V-0 rating (UL94) for the composite with an improved limiting oxygen index up to 31.7%. The biomass-based modified activated carbon in this work could be considered as an alternative flame retardant in polymer applications.
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Solid epoxy resin is highly desired in adhesives, electronic materials and coatings due to the attractive characteristics of solvent-free, highly efficient utilization and convenient storage and transportation. However, the challenges remain in fabricating high-toughness solid epoxy resin through a facile and efficient way. Here, a high-performance environment-friendly solid epoxy resin was fabricated by employing maleic anhydride grafted ethylene-vinyl acetate copolymer (EVA-g-MAH) as the flexibilizer via one-step banburying method. The results showed that the modified epoxy resin maintained a high glass transition temperature (T g) and thermal stability, while its impact strength, tensile toughness and flexural toughness were significantly increased compared with the neat epoxy resin. The impact strength, tensile toughness and flexural toughness of R-EM10 are improved 138%, 195% and 149%, respectively. The EVA-g-MAH was introduced in the epoxy matrix as a separate phase to increase toughness via transfer stress and dissipated energy. The attractive properties of this facile fabrication process and the high-toughness, as well as the environment-friendly performance make this solid epoxy highly promising for large-scale industrial application.
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Recycling hazardous gas of H2S is one of the most important strategies to promote sustainable development. Herein, a novel method regarding purifying H2S is proposed by using yellow phosphorus and phosphate rock slurry as absorbent. The H2SO4, formed in situ by H2S conversion, can be devoted to decompose phosphate rock, and the spent absorption slurry was applied as raw material for the production of phosphorus chemical products. According to the characterization analysis, it was found that H2S was first oxidized to SO2 via O2 as well as O3 induced by P4. Subsequently, the generated SO2 dissolved rapidly in water to form H2SO4, and then reacted with the main component of phosphate rock, CaMg(CO3)2. Most notably, the active substances, such as, O3, SO4â¢- and OHâ¢, produced in the reaction process, can oxidize H2S and HS- to these sulfur products. In addition, trace amounts of Fe3+ and Mn2+ that were dissolved from phosphate rock displayed a promotional effect on the formation of active substances. Consequently, as high as 85% of H2S removal efficiency can be obtained even under acidic condition and low temperature. The proposed H2S purification method offers a promising option for sulfur recovery and H2S pollution control.
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RATIONALE: A Dieulafoy lesion is a rare cause of gastrointestinal (GI) bleeding, especially in the jejunum, and the presence of calcifications on CT might be suspicious of the diagnosis. PATIENT CONCERNS: We describe a 72-year-old woman with anemia and melena. Hemoglobin was 6.0âg/dL, and the stools were positive for occult blood (4+). Blood pressure was 116/54âmm Hg. Physical examination showed pale face and pitting edema in both lower limbs. Abdominal computerized tomography showed calcification in the small intestine of the left lower abdomen. Capsule endoscopy showed a blood clot. DIAGNOSES: Dieulafoy lesion. INTERVENTIONS: Single balloon endoscopy was performed via the oral approach and showed a blood clot on the suspected submucosal tumor of jejunum. A hemostatic clip was placed at the base of the lesion to allow the surgeon to locate it during the operation. Laparoscopy was performed, and the lesion was resected. OUTCOMES: The postoperative pathology showed a Dieulafoy lesion. The lower extremity edema subsided. GI bleeding did not recur over 1âyear of follow-up, and hemoglobin was 12.2âg/dL. A Dieulafoy lesion is a rare cause of GI bleeding, and it is even rarer in the jejunum. LESSONS: A Dieulafoy lesion does not have special imaging features, but the presence of calcifications in the small intestine on computerized tomography might be suspicious of the diagnosis. When endoscopic treatment is difficult, surgical treatment could be considered.
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Anemia/etiología , Arteriolas/anomalías , Yeyuno/irrigación sanguínea , Melena/etiología , Calcificación Vascular/diagnóstico , Anciano , Anemia/diagnóstico , Anemia/cirugía , Endoscopía Capsular , Femenino , Humanos , Mucosa Intestinal/irrigación sanguínea , Mucosa Intestinal/diagnóstico por imagen , Mucosa Intestinal/cirugía , Yeyuno/diagnóstico por imagen , Yeyuno/cirugía , Laparoscopía , Melena/diagnóstico , Melena/cirugía , Tomografía Computarizada por Rayos X , Resultado del Tratamiento , Calcificación Vascular/complicaciones , Calcificación Vascular/cirugíaRESUMEN
The emission of SO2 and the disposal of waste phosphate mine tailings are generally regarded as two major environmental issues in phosphorus chemical activities. In this paper, an environmentally friendly and efficient route for removing SO2 from phosphorus chemical processes by using waste phosphate mine tailings as adsorbent was proposed. It was indicated that the desulfurization performance of the waste phosphate mine tailings was better than that of its raw ore. The characterization analysis illustrated that higher content of CaMg(CO3)2 was shown on the waste phosphate mine tailings, which played a dominant role in determining the better desulfurization activity. In contrast, the accumulation of PO43- and H+ ions resulted from the dissolution of Ca5(PO4)3F on the raw ore caused negative effect on SO2 removal. In the typical desulfurization system, the produced sulfuric acid from desulfurization process was used to decompose phosphate mine tailings, and these spent tailings can be subsequently applied as raw materials for the production of phosphorus products. As a result, the present approach can achieve the dual goal of reducing the cost of desulfurization process and recycling the waste tailings, which is of great environmental and economic significance.
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OBJECTIVE: To investigate the effects and possible mechanisms of action of Curcuma wenyujin Y. H. Chen et C. Ling n-Butyl alcohol extract (CWNAE) on repression of human gastric cancer (GC) AGS cell invasion induced by co-culturing with Helicobacter pylori (HP). METHODS: AGS cells were cultured with HP of positive or negative cytotoxin-associated gene A (CagA) and vacuolating cytotoxin gene A (VacA) expression (CagA+/- or VacA+/-) and divided into 5 group. Group A was cultured without HP as a control, Group B with HPCagA+VacA+, Group C with HPCagA-VacA-, Group D with HPCagA+VacA+ and CWNAE, and Group E with HPCagA-VacA- and CWNAE. Methylthiazolyldiphenyl-tetrazolium bromide (MTT) and tumor invasion assays, examinations of morphology and ultramicroscopic structures, quantitative real-time polymerase chain reaction and Western blots were performed to measure the effects and uncover the mechanisms behind these effects of HPCagA+VacA+ and CWNAE on the epithelial-mesenchymal transition (EMT) of AGS cells. RESULTS: The 10% inhibitory concentration of CWNAE against AGS cells after a 48 h incubation was 19.73±1.30 µg/mL. More AGS cells were elongated after co-culturing with HPCagA+VacA+ than after culturing with HPCagA-VacA-. In tumor invasion assays, HPCagA+VacA+ significantly enhanced the invasiveness of AGS cells compared to the other experimental groups (all P value <0.05), and this effect was inhibited by CWNAE. Treatment with CWNAE normalized tight junctions and reduced the number of pseudopodia of AGS cells co-cultured with HPCagA+VacA+. HPCagA+VacA+ up-regulated zincfinger ebox binding homeobox 1 (ZEB1) in AGS cells after co-culturing for 24 h. Expression of caudal type homeobox transcription factor (CDX-2) and claudin-2 was significantly increased by HPCagA+VacA+ (P<0.05), but not by HPCagA-VacA-. CONCLUSION: HPCagA+VacA+ promoted the invasiveness of AGS cells through up-regulation of ZEB1 transcription and claudin-2 and CDX-2 expression. CWNAE inhibited these effects of HPCagA+VacA+ on AGS cells by down-regulating ZEB1 transcription, and CDX-2 and claudin-2 expression.
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Factor de Transcripción CDX2/metabolismo , Claudina-2/metabolismo , Curcuma/química , Helicobacter pylori/efectos de los fármacos , Extractos Vegetales/farmacología , Neoplasias Gástricas/microbiología , Línea Celular Tumoral , Helicobacter pylori/metabolismo , Humanos , Neoplasias Gástricas/tratamiento farmacológicoRESUMEN
Expanding the application range of flame-retardant polymer biocomposites remains a huge challenge for a sustainable society. Despite largely enhanced flame retardancy, until now the resultant poly(lactic acid) (PLA) composites still suffer reduced tensile strength and impact toughness due to improper material design strategies. We, herein, demonstrate the design of a green flame retardant additive (ammonium polyphosphate (APP)@cellulose nanofiber (CNF)) via using the cellulose nanofibers (CNFs) as the green multifunctional additives hybridized with ammonium polyphosphate (APP). The results show that PLA composite with 5 wt % loading of APP@CNF can pass the UL-94 V-0 rating, besides a high limited oxygen index of 27.5%, indicative of a significantly enhanced flame retardancy. Moreover, the 5 wt % of APP@CNF enables the impact strength (σi) of the PVA matrix to significantly improve from 7.63 to 11.8 kJ/m2 (increase by 54%), in addition to a high tensile strength of 50.3 MPa for the resultant flame-retardant PLA composite. The enhanced flame retardancy and mechanical strength performances are attributed to the improved dispersion of APP@CNF and its smaller phase size within the PLA matrix along with their synergistic effect between APP and CNF. This work opens up a facile innovative methodology for the design of high-performance ecofriendly flame retardants and their advanced polymeric composites.
RESUMEN
The combination of high strength, great toughness, and high heat resistance for polymeric materials is a vital factor for their practical applications. Unfortunately, until now it has remained a major challenge to achieve this performance portfolio because the mechanisms of strength and toughness are mutually exclusive. In the natural world, spider silk features the combination of high strength, great toughness, and excellent thermal stability, which are governed by the nanoconfinement of hydrogen-bonded ß-sheets. Here, we report a facile bioinspired methodology for fabricating advanced polymer composite films with a high tensile strength of 152.8 MPa, a high stiffness of 4.35 GPa, and a tensile toughness of 30.3 MJ/m3 in addition to high thermal stability (69 °C higher than that of the polymer matrix) only by adding 2.0 wt % of artificial ß-sheets. The mechanical and thermostable performance portfolio is superior to that of its counterparts developed to date because of the nanoconfinement and hydrogen-bond cross-linking effects of artificial ß-sheets. Our study offers a facile biomimetic strategy for the design of integrated mechanically robust and thermostable polymer materials, which hold promise for many applications in electrical devices and tissue engineering fields.
Asunto(s)
Nanoestructuras/química , Polímeros/química , Temperatura , Ensayo de Materiales , Tamaño de la Partícula , Propiedades de Superficie , Ingeniería de TejidosRESUMEN
Chromophoric dissolved organic matter (CDOM) represents the fraction of the dissolved organic pool which absorbs light in the visible as well as UV ranges. It could affect the color of the waters. It is necessary to study it during in research on ecosystem, remote sensing of the water color and the cycle of carbon in waters. CDOM can fluoresce when excited, so fluorescence spectrum has been used to study its origin, distribution, and change. In the present article the fluorescence spectrophotometer was used to study the relation between the fluorescence intensity, spectrum area and the concentration of CDOM. When the concentration of CDOM is low (less than 75 mg x L(-1)), there is a better linear relationship (r2 > 0.98) between the fluorescence intensity, the spectrum area and the concentration of CDOM. Meanwhile good linear relations were found between the fluorescence intensity and spectrum area, which showed the same changeable trend of the fluorescence intensity and spectrum area with the concentration change of CDOM. A method was established to quantify the concentration of CDOM in water from different source using the linear relationship between the spectrum area and the concentration. It suits the complicated constituent analysis of CDOM and could really and accurately show the concentration of CDOM in natural water.