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1.
Biomater Sci ; 2020 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-32350485

RESUMO

Elimination of infection and enhancement of osteogenesis by orthopaedic implants are two critical factors in the treatment of complex bone infections. A prolonged and expensive procedure requiring two surgical steps and a 6-8-week period of joint immobilisation is utilised as a primary treatment for revision arthroplasty of an infected prosthesis, greatly affecting long-term patient care for the ageing population. Here, we evaluated the effects of vancomycin-loaded in micro-arc oxidised (MAO) three-dimensional (3D) printed porous Ti6Al4V scaffolds on osteogenesis. This system showed a high loading capacity and sustained vancomycin release kinetics, as demonstrated using high-performance liquid chromatography. In vivo, 0.1 mL of 108 colony forming units (CFU) methicillin-resistant Staphylococcus aureus was injected into the tibias of rabbits to induce severe osteomyelitis. Physical, haematological, radiographic, microbiological, and histopathological analyses were performed to evaluate the effects of treatment. Rabbits with vancomycin-loaded in MAO scaffolds showed the inhibition of bone infection and enhancement of osteogenesis, resulting in better outcomes than in the other groups. Overall, these findings demonstrated the potential of this 3D printed porous Ti6Al4V, with good osteogenesis and sustained vancomycin release properties, for application in the treatment of complex bone infections.

2.
Artigo em Inglês | MEDLINE | ID: mdl-32372203

RESUMO

Human tissue plasminogen activator was the first recombinant therapy protein that successfully produced in Chinese hamster ovary cells in 1986 and approved for clinical use. Since then, more and more therapeutic proteins are being manufactured in mammalian cells, and the technologies for recombinant protein production in this expression system have developed rapidly, with the optimization of both upstream and downstream processes. One of the most promising strategies is expression vector cassette optimization based on the expression vector cassette. In this review paper, these approaches and developments are summarized, and the future strategy on the utilizing of expression cassettes for the production of recombinant therapeutic proteins in mammalian cells is discussed.

4.
Phys Chem Chem Phys ; 2020 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-32296801

RESUMO

Understanding the interactions between O2 and small metal clusters is of great importance in exploring heterogeneous catalysis particularly involving an oxidation reaction. We herein present the dissociative chemisorption of O2 on Agn and Agn-1Ir clusters (n = 3-26) by using density functional theory calculations. Combining a particle swarm optimization algorithm and a minima hopping method, we have optimized and obtained stable geometric structures of Agn and Agn-1Ir clusters without and with O2 adsorption. Some important physical parameters, including bond length, adsorption energy, dissociation barriers and bader charge, have been systematically calculated for appraising the stability and reactivity of Agn and Agn-1Ir clusters. It is found that the dopant Ir atom can largely enhance the stability and promote the O2 dissociation, especially on small Agn-1Ir clusters (n = 3-10). It is mainly attributed to the dopant Ir atom being completely exposed outside the Ag atoms. For O2 adsorption and dissociation on large Agn-1Ir clusters (n = 11-26), the dissociation barriers are much higher due to the dopant Ir emerging into the core of Agn-1Ir clusters, which is very similar to those on large Agn (n = 11-26). Microkinetic simulation results provide direct evidence for high reaction temperature and pressure effects on improving O2 dissociation on Agn and Agn-1Ir clusters especially for small clusters (n < 10). It is found that the Ag5Ir cluster is the most suitable nanocluster for promoting O2 dissociation at the given reaction temperatures and pressures. Our theoretical work is helpful for the rational design of doped silver nanocluster catalysts in future experiments.

5.
BMC Neurol ; 20(1): 125, 2020 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-32268889

RESUMO

BACKGROUND: Neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative condition characterized by the loss of neurons and the presence of eosinophilic nuclear inclusions in the central and peripheral nervous system, skin and visceral organs. In this paper, we present a case of NIID with recurrent encephalitic attacks that remained stable and nonprogressive for seven years; no such case has previously been reported. CASE PRESENTATION: A 63-year-old female was hospitalized due to light-headedness, vomiting, unstable gait and cognitive impairment. Seven years prior, she had experienced an episode of light-headedness, central facial paralysis, unstable gait, aphasia, nausea, vomiting and loss of consciousness. She regained consciousness within 12 h, and her other symptoms were completely resolved within one week. During the present hospitalization, a brain magnetic resonance imaging (MRI) examination detected high signal intensity on diffusion-weighted imaging (DWI) of the bilateral frontal grey matter-white matter junction. We reviewed the patient's previous MRI results and found that she had also had high signal intensity on DWI of the bilateral frontal grey matter-white matter junction seven years prior. In the intervening seven years, the high signal intensity in the frontal lobes had spread along the grey matter-white matter junction, but the deep white matter remained unaffected. Skin biopsy was performed, and intranuclear inclusions were found in adipocytes, fibroblasts and sweat gland cells. GGC repeat expansions in the NOTCH2NLC (Notch 2 N-terminal like C) gene confirmed the diagnosis of NIID. She received supportive treatment such as nutrition support therapy and vitamin B and C supplementation, as well as symptomatic treatment during hospitalization. The patient's symptoms were completely relieved within one week. CONCLUSION: This is a detailed report of a case of NIID with multiple reversible encephalitic attacks, diagnosed by clinical symptoms, intranuclear inclusions, characteristic DWI signals, and genetic tests.

6.
J Photochem Photobiol B ; 207: 111869, 2020 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-32278270

RESUMO

An animal laboratory in a teaching hospital is a possible cause of cross infection. We aimed to assess the infection control in our animal laboratory and evaluate the disinfectant effects of a portable pulsed xenon ultraviolet (PX-UV) machine. Samples were taken from the surface of research tables, other high touch places, such as doorknobs, weighing scales, and handles of trolleys, and from air in the barrier system pre- and post-manual cleaning and post-PX-UV disinfection. The bacteria types were identified. We found that routine manual cleaning significantly reduced bacterial colony form unit (CFU)/cm2 (P = .02), and the median of CFU/cm2 reduced from 0.5 pre-cleaning to zero post-cleaning. PX-UV disinfection also significantly reduced residual bacterial counts (P = .002), with the highest counts 10 pre-PX-UV disinfection and 1 afterwards. Without manual cleaning, PX-UV disinfected surfaces significantly (P < .001), median count 6 pre-PX-UV disinfection and zero afterwards. PX-UV significantly reduced bacterial colony counts in the air with the median count falling from 6 to zero (P < .001). Some of the 21 species of pathogens we identified in the current study are pathogenic, resistant to antibiotics, and able to cause nosocomial infections and zoonosis. PX-UV reduced counts of most of the pathogens. PX-UV is an effective agent against these pathogens.

7.
J Ethnopharmacol ; 257: 112892, 2020 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-32320727

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Licorice is an ancient food and medicinal plant. Liquiritigenin and liquiritin, two kinds of major flavonoes in licorice, are effective substances used as antioxidant, anti-inflammatory and tumor-suppressive in food, cosmetics or medicines. However, their in vivo metabolites have not been fully explored. AIM OF STUDY: To clarify the metabolism of liquiritigenin and liquiritin in mice. MATERIALS AND METHODS: In this study, we developed a liquid chromatography coupled with quadrupole/time-of-flight mass spectrometry method to determine the metabolites in mice plasma, bile, urine and feces after oral administration of liquiritigenin or liquiritin. The structures of those metabolites were tentatively identified according to their fragment pathway, accurate mass, characteristic product ion, metabolism law and reference standard matching. RESULTS: A total of 26 and 24 metabolites of liquiritigenin or liquiritin were respectively identified. The products related with apigenin, luteolin or quercetin were the major metabolites of liquiritigenin or liquiritin in mice. Seven main metabolic pathways including (de)hydrogenation, (de)hydroxylation, (de)glycosylation, (de)methoxylation, acetylation, glucuronidation and sulfation were summarized to tentatively explain their biotransformation. CONCLUSION: This study not only can provide the evidence for in vivo metabolites and pharmacokinetic mechanism of liquiritigenin and liquiritin, but also may lay the foundation for further development and utilization of liquiritigenin, liquiritin and then licorice.

9.
Eur Spine J ; 29(5): 1092-1097, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32157387

RESUMO

OBJECTIVE: To explore the characteristics of vertebral CT Hounsfield units (HU) in elderly patients with acute vertebral fragility fractures. METHODS: A total of 299 patients aged ≥ 65 years with acute vertebral fragility fractures were retrospectively reviewed, and 77 patients of them were age- and sex-matched with 77 control patients without any fractures. The vertebral HU value of L1(L1-HU) was measured, and T12 and L2 were used as alternatives for L1 in the case of L1 fracture. RESULTS: There were 460 thoracic and lumbar vertebral fractures in the 299 elderly patients, including 349 acute vertebral fragility fractures and 111 chronic fractures. The average L1-HU value was 66.0 ± 30.6 HU and showed significant difference among patients having different numbers of vertebral fractures (one fracture: 73.3 ± 27.0 HU, two fractures: 58.7 ± 32.5 HU, three or more fractures: 40.7 ± 28.8 HU; P < 0.001). As for the 1:1 age- and sex-matched patients, the L1-HU of the 77 patients with fractures was lower than that of the control patients (70.6 ± 23.4 HU vs. 101.5 ± 36.2 HU, P < 0.001). The area under the receiver operating characteristic curve of using L1-HU to differentiate patients with fractures from controls was 0.77(95% CI 0.70-0.85, P < 0.001). The cutoff value had high specificity of 90% or high sensitivity of 90% to identify patients with fractures of 60 HU and 100 HU, respectively. CONCLUSIONS: The elderly patients with acute vertebral fragility fractures have much lower HU values than those without fractures. Moreover, the lower the vertebral HU value is, the more likely the patients have more than one vertebral fracture. These slides can be retrieved under Electronic Supplementary Material.

10.
J Dig Dis ; 21(4): 205-214, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32223013

RESUMO

OBJECTIVE: To investigate histopathologic changes of muscularis mucosae (MM) and submucosa in the gastric cardia. METHODS: We performed a histopathology study of 50 distal esophagectomies with proximal gastrectomies for esophageal squamous cell carcinoma as the study (non-cancerous cardiac) group and 60 gastrectomies for early gastric cardiac carcinoma as the cancer group. The gastroesophageal junction was defined as the distal end of squamous epithelium, multilayered epithelium, or deep esophageal glands or ducts. Gastric cardia (n = 110) was defined as the presence of cardiac and cardio-oxyntic mucosae distal to the gastroesophageal junction. RESULTS: The average thickness of MM and submucosa in the cardia was 1.04 and 1.41 mm, respectively, which was significantly thicker than that in distal stomach (n = 34) (0.22 and 0.99 mm) or distal esophagus (n = 92) (0.60 and 1.15 mm). In the cardia, thickened MM displayed frayed muscle fibers (93.3%) with a significantly higher prevalence of entrapped glands, cysts, and lymphoid follicles than in the distal stomach or distal esophagus. In the submucosa fatty changes, cysts, and abnormal arteries were significantly more common in the cardia than in the distal stomach or distal esophagus. Compared with the study group, the cardia in the cancer group showed significantly thicker MM (average 1.31 vs 0.72 mm) and submucosa (average 1.61 vs 1.16 mm), more frequent frayed MM (93.3% vs 60.0%), prolapse-like changes (50.0% vs 2.0%), and cysts (26.7% vs 4.0%). CONCLUSION: MM and submucosa of the cardia were significantly thickened, especially in early gastric cardiac carcinomas.

12.
Neurobiol Aging ; 89: 142.e1-142.e7, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32081467

RESUMO

Recently, the (GGC)n repeat expansion in the NOTCH2NLC gene has been identified to be associated with neuronal intranuclear inclusion disease (NIID). Given the clinical overlap of dementia-dominant NIID with neurodegenerative dementia, we therefore hypothesized that the NOTCH2NLC repeat expansion might also contribute to these diseases. In the present study, repeat primed polymerase chain reaction (RP-PCR) and GC-rich PCR were conducted to detect the repeats of NOTCH2NLC in a cohort of 1004 patients with neurodegenerative dementias from mainland China. As a result, 4 sporadic patients were found to carry the NOTCH2NLC repeats expansion, totally accounting for 0.4% of all dementia individuals, and the accurate repeated sizes were 110, 133,120 and 76 respectively. Of 4 mutation carriers, three and one were clinically diagnosed Alzheimer's disease (AD) and frontotemporal dementia (FTD) respectively. In addition, 3 out of them revealed leukoencephalopathy in T2-Flair imaging. This study revealed that although rare, the NOTCH2NLC repeat expansions may be associated with AD or FTD-like phenotype as well as leukoencephalopathy.

13.
FEBS Open Bio ; 10(4): 627-636, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32105410

RESUMO

Osteosarcoma, one of the most common malignant bone tumors, is characterized by a high rate of metastasis, and the survival rate of patients with metastatic osteosarcoma is poor. Previous studies have reported that miRNAs often regulate the occurrence and development of various tumors. In this work, we identified miRNA-542-5p as a critical miRNA in osteosarcoma by overlapping three Gene Expression Omnibus datasets, and then evaluated miRNA-542-5p expression profiles using Gene Expression Omnibus and Sarcoma-microRNA Expression Database. We used MISIM to investigate miRNAs correlated with miR-542 and identified potential target genes of miRNA-542-5p using miRWalk. Functional and pathway enrichment analyses were performed using The Database for Annotation, Visualization and Integrated Discovery. Protein-protein interaction was performed using Search Tool for the Retrieval of Interacting Genes and Cytoscape. We report that the relative level of miRNA-542-5p was significantly higher in osteosarcoma than in healthy bone. Expressions of hsa-miR-330 and hsa-miR-1202 were found to be strongly correlated with that of miR-542-5p. Furthermore, we identified a total of 514 down-regulated genes as possible targets of miR-542-5p. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis demonstrated that the putative target genes of miR-542-5p were most enriched in the cell-cycle process. The differentially expressed genes CDCA5, PARP12 and HSPD1 were found to be hub genes in protein-protein interaction networks. Finally, transfection of the osteosarcoma cell line U2OS with miR-542-5p mimics or inhibitor revealed that miR-542-5p can promote cell proliferation. In conclusion, our results suggest that miR-542-5p may promote osteosarcoma proliferation; thus, this miRNA may have potential as a biomarker for diagnosis and prognosis.

14.
Head Neck ; 2020 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-32011052

RESUMO

BACKGROUND: We investigated treatment results, the effects of different treatment modality, and pretreatment Epstein-Barr virus (EBV) viral load for stage III nasopharyngeal carcinoma (NPC) patients. METHODS: The initial definitive treatment for 356 stage III NPC patients consisted of concurrent chemoradiotherapy (CCRT) or induction chemotherapy plus radiotherapy (IndCT-RT). The pretreatment EBV DNA level separated patients into a high (n = 106) or low (n = 250) viral load (≥ or < 1000 copies/mL) subgroup. Outcome measures include relapse rates and various survivals. RESULTS: The 5-year rates of overall survival (OS), progression-free survival (PFS), distant metastasis failure-free survival (DMFFS), and locoregional failure-free survival (LRFFS) were 88.6%, 83.0%, 90.5%, and 90.5%, respectively. Patient characteristics and pretreatment viral load between IndCT-RT and CCRT were no significant differences except for a higher percentage of N2 disease in the IndCT-RT subgroup. Both treatment modality resulted in similar relapse rates (P = .56), OS (P = .20), PFS (P = .53), DMFFS (P = .89), and LRFFS (P = .35). However, patients with a high viral load experienced a higher relapse rate (33.0% vs 12.4%, P < .001) and worse OS (5-year rate, 79.0% vs 92.8%, P < .001), PFS (73.7% vs 88.4%, P < .001), DMFFS (80.2% vs 95.0%, P < .001), and LRFFS (85.6% vs 92.6%, P = .005) than those with a low viral load. CONCLUSION: Long-term treatment results for stage III NPC patients are rather good. IndCT-RT can achieve the same treatment outcome as CCRT. Risk grouping by pretreatment viral load identified a subgroup (30%) of patients associated with a significantly higher relapse rates and worse survivals. These high-risk patients need to strengthen treatment intensity in future trials.

15.
Phytochemistry ; 171: 112226, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31923721

RESUMO

Apricot (Prunus armeniaca L.) is an important fruit crop that is widely planted throughout the world. But drought affects both yield and quality of apricot. In order to study the effects of long-term drought on the molecular and physiological mechanisms of apricot, we used transcriptome sequencing and measured physiological indices. First, 322 million high-quality clean reads were obtained, and 74,892 unigenes were generated for the transcriptome. Among the assembled unigenes, 18,671 simple sequence repeats (SSRs) and 5581 differentially expressed genes (DEGs) were identified. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of the DEGs revealed that starch and sucrose metabolism, plant-pathogen interaction and plant hormone signal transduction pathways are enriched. Additionally, we used quantitative real-time PCR (qRT-PCR) to confirm the RNA-seq results with 11 drought-related DEGs. Second, through the physiological analysis of apricot leaves under constant drought stress, and the results show the internal microstructure of apricot leaves changed to withstand drought stress. At the same time, plants exposed to long-term drought stress showed higher degree of membrane damage, which reduced photosynthesis in the damaged leaves. Our findings enrich the genome resources for apricot and refine our understanding of the molecular and physiological mechanisms of drought response in this fruit crop, providing insights into drought adaptation of the apricot.


Assuntos
Secas , Regulação da Expressão Gênica de Plantas/genética , Compostos Fitoquímicos/genética , Prunus armeniaca/genética , Estresse Fisiológico/genética , Transcriptoma
16.
Injury ; 51(3): 683-687, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31987607

RESUMO

INTRODUCTION: To introduce a classification for medial wall fragments in pertrochanteric femur fractures and investigate potential preoperative predictors of implant failure following fixation. MATERIAL AND METHODS: Medical records of 324 adult patients receiving routine operative treatment using intramedullary devices for pertrochanteric femur fractures with medial wall fragments between August 2008 and May 2018 were retrospectively analyzed. Potential predictors including age, gender, body mass index, comorbidities, AO/OTA classification of fractures were noted. The medial wall fractures were categorized into three types: 1) Type I: avulsion of the lesser trochanter; fracture line does not exceed the base of the lesser trochanter; 2) Type II: fragment involving the posterior cortex near the base of the lesser trochanter; fracture line does not reach the midline of the posterior wall; 3) Type III: fragment involving the large posterior cortex; fracture line reaches or exceeds the midline of the posterior wall. RESULTS: The 8 (2.5%) implant failures comprised 1 in 186 Type I fractures, 1 in 76 Type II fractures and 6 in 62 Type III fractures. The failure rates of each fracture type were 0.5% in Type I, 1.3% in Type II and significantly increased to 9.7% in Type III (odds ratio [OR], 19.821; 95% confidence interval [CI], 2.337-168.135; p=0.001). CONCLUSIONS: Type III fractures had a significantly increased failure rate. It is important for orthopedists to identify Type III fractures presurgically, reduction of the medial wall fragment and fixation should be considered during surgery using intramedullary nails.

17.
Sci Total Environ ; 709: 136210, 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-31905552

RESUMO

Understanding the temporal dynamics and influencing factors of ecosystem respiration (Reco) in semi-arid shrublands is critical for predicting how their carbon balance may respond to climate change. Using the eddy-covariance technique, we quantified the net ecosystem CO2 exchange (NEE) in a semi-arid shrubland of northern China from July 2011 to December 2016, and partitioned NEE into Reco and gross primary productivity (GPP). Annual Reco varied from 300 g C m-2 yr-1 in 2014 to 426 g C m-2 yr-1 in 2012, and GPP ranged from 277 g C m-2 yr-1 in 2014 to 503 g C m-2 yr-1 in 2012. The relationship between half-hourly nighttime Reco and air temperature (Ta) was well-described by the Lloyd & Taylor model. Indicators of the seasonal temperature sensitivity (E0 and Q10) of Reco increased with both the annual integral and seasonal amplitude of GPP. However, when averaged into 1 °C Ta bins, nighttime Reco increased with Ta up to an optimal temperature of ~20 °C, above which it decreased with increasing Ta. Periods of low soil moisture in spring and summer markedly depressed Reco, contributing to its seasonal and interannual variations. In addition, low soil moisture had little effect on nighttime Reco when Ta was below 15 °C, but substantially reduced nighttime Reco when Ta was above 15 °C. Ecosystem respiration increased linearly with GPP at both seasonal and interannual scales, with the slope being 0.50 and 0.55, respectively. Our results have important implications for predicting Reco under climate change, considering continuous warming and increases in the frequency and intensity of extreme events (e.g., heat waves, droughts). Moreover, our results suggest that process-based carbon models should adequately represent the effects of substrate supply (e.g., by GPP) on Reco and its temperature sensitivity.

18.
Orthop Surg ; 12(1): 224-232, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31958886

RESUMO

OBJECTIVE: To assess the therapeutic effect of a novel tension band using 3.0 mm cannulated screw combined with a titanium cable and specific shims comparatively with patellotibial tubercle cerclage in comminuted fractures of the inferior pole of the patella. METHODS: The retrospective study from March 2012 to July 2017 was conducted in Peking University Third Hospital and comprised 63 patients with comminuted fractures of the inferior pole of the patella: 41 treated with new tension band using 3.0 mm cannulated screw combined with a titanium cable and specific shims (new tension band group) and 22 with patellotibial tubercle cerclage (tubercle cerclage group). Gender, age, AO/OTA fracture type, injury mechanism, inter-fragmentary gap, and follow-up time of patients were recorded. Two groups were compared regarding: operation time, blood loss, partial weight-bearing time, fracture-healed time, Bostman score and knee mobility at 12-month follow-up, and postoperative complications. Continuous and categorical parameters were analyzed by Mann-Whitney U test and the chi-squared test, respectively. Fisher's exact test was used for small data subsets. RESULTS: Between the two groups, no statistically significant difference was found in mean age, gender, AO/OTA fracture type, injury mechanism, mean inter-fragmentary gap, or mean follow-up time (P > 0.05). The mean operation time of new tension band group was significantly longer than that of tubercle cerclage group (76.4 min vs 64.2 min, P = 0.006), while there was no significant difference in blood loss. After surgery, new tension band group had a significantly earlier mean partial weight-bearing time (5.2 weeks vs 7.4 weeks, P < 0.001) and fracture-healed time (9.6 weeks vs 11.6 weeks, P < 0.001). At 12-month follow-up, patients of new tension band group had a significantly higher mean Bostman score (28.5 vs 25.8, P < 0.001) and knee mobility (126.7 vs 117.3, P < 0.001). Ten complications related with internal fixation were found in tubercle cerclage group including two cases of loose internal fixation, two cases of cerclage breakage, and six cases of low patella position who undertook secondary operation. No complications were found in new tension band group (0 in 41 vs 10 in 22, P < 0.001). CONCLUSION: Patients with comminuted fractures of the inferior pole of the patella treated with a novel tension band experienced a longer operation time, but earlier partial-weight-bearing and fracture-healed time, better clinical outcomes at 12-month follow-up, and less complications. It should be considered an alternative therapy for the treatment of distal pole patellar fractures.

19.
Anatol J Cardiol ; 23(1): 35-40, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31911569

RESUMO

OBJECTIVE: The present study aims to investigate the effect of losartan, an selective angiotensin II type 1 receptor (AT1R) blocker, on both the increase of IKs current and shortening of action potential duration (APD) induced by stretch of atrial myocytes, and to uncover the mechanism underlying the treatment of fibrillation (AF) by AT1R blockers. METHODS: Hyposmotic solution (Hypo-S) was applied in the guinea pig atrial myocytes to simulate cell stretch, then patch-clamp technique was applied to record the IKs and APD in atrial myocytes. RESULTS: Hypo-S increased the IKs by 105.6%, while Hypo-S+1-20 µM of losartan only increased the IKs by 70.3-75.5% (p<0.05 vs. Hypo-S). Meanwhile, Hypo-S shortened APD90 by 20.2%, while Hypo-S+1-20 µM of losartan shortened APD90 by 13.03-14.56% (p<0.05 vs. Hypo-S). CONCLUSION: The above data indicate that the effect of losartan on the electrophysiological changes induced by stretch of atrial myocytes is associated with blocking of AT1 receptor, and is beneficial for the treatment of AF that is often accompanied by the expansion of atrial myocytes and the increase of effective refractory period.

20.
Proc Natl Acad Sci U S A ; 117(5): 2282-2287, 2020 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-31964812

RESUMO

Biomimetic superhydrophobic surfaces display many excellent underwater functionalities, which attribute to the slippery air mattress trapped in the structures on the surface. However, the air mattress is easy to collapse due to various disturbances, leading to the fully wetted Wenzel state, while the water filling the microstructures is difficult to be repelled to completely recover the air mattress even on superhydrophobic surfaces like lotus leaves. Beyond superhydrophobicity, here we find that the floating fern, Salvinia molesta, has the superrepellent capability to efficiently replace the water in the microstructures with air and robustly recover the continuous air mattress. The hierarchical structures on the leaf surface are demonstrated to be crucial to the recovery. The interconnected wedge-shaped grooves between epidermal cells are key to the spontaneous spreading of air over the entire leaf governed by a gas wicking effect to form a thin air film, which provides a base for the later growth of the air mattress in thickness synchronously along the hairy structures. Inspired by nature, biomimetic artificial Salvinia surfaces are fabricated using 3D printing technology, which successfully achieves a complete recovery of a continuous air mattress to exactly imitate the superrepellent capability of Salvinia leaves. This finding will benefit the design principles of water-repellent materials and expand their underwater applications, especially in extreme environments.

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