Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 759
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Artigo em Inglês | MEDLINE | ID: mdl-31951101

RESUMO

BACKGROUND: Empty nose syndrome (ENS) remains a controversial disease primarily associated with inferior turbinate tissue loss. Cotton placement into the inferior meatus often alleviates ENS symptoms within minutes, but the physiologic explanation for this phenomenon is unknown. Computational fluid dynamics (CFD) was employed to evaluate the mechanisms of altered nasal airflow conferred by cotton testing. METHODS: Six ENS patients (12 sides) with pre-existing sinus computed tomography (CT) imaging were enrolled after marked symptomatic improvement (decrease in score on the Empty Nose Syndrome 6-Item Questionnaire [ENS6Q] of >7 points) with office-based cotton testing. The fashioned cotton plug was labeled in situ with iohexol contrast spray, and sinus CT was immediately obtained to detect cotton contouring in the inferior meatus. CT imaging from pre- and post-cotton placement was analyzed using comparative CFD techniques. RESULTS: After cotton placement, significant symptomatic improvement and reduced ENS6Q scores (16.8 ± 4.1 to 3.1 ± 2.4; p < 0.001) were recorded. Using CFD, cotton placement produced an expected 21% increase in upper airway resistance (p < 0.05). However, a significant shift in the nasal airflow distribution was also detected, with a transition of airflow vectors away from a middle meatus jetstream (-41%; p < 0.002). CONCLUSION: Objective CFD assessment confirmed that the cotton test not only increases nasal resistance, but also restores airflow distribution to the inferior meatus in symptomatic ENS patients. These results highlight the potential efficacy of cotton test in ENS patients and further bolster the utility of this tool in identifying appropriate candidates for the inferior meatus augmentation procedure.

2.
Artigo em Inglês | MEDLINE | ID: mdl-31964827

RESUMO

The three-dimensional (3D) crystal structures of the GAF3 domain of cyanobacteriochrome Slr1393 (Synechocystis PCC6803) carrying a phycocyanobilin chromophore could be solved in both 15-Z dark-adapted state, Pr, λmax = 649 nm, and 15-E photoproduct, Pg, λmax = 536 nm (resolution, 1.6 and 1.86 Å, respectively). The structural data allowed identifying the large spectral shift of the Pr-to-Pg conversion as resulting from an out-of-plane rotation of the chromophore's peripheral rings and an outward movement of a short helix formed from a formerly unstructured loop. In addition, a third structure (2.1-Å resolution) starting from the photoproduct crystals allowed identification of elements that regulate the absorption maxima. In this peculiar form, generated during X-ray exposition, protein and chromophore conformation still resemble the photoproduct state, except for the D-ring already in 15-Z configuration and tilted out of plane akin the dark state. Due to its formation from the photoproduct, it might be considered an early conformational change initiating the parental state-recovering photocycle. The high quality and the distinct features of the three forms allowed for applying quantum-chemical calculations in the framework of multiscale modeling to rationalize the absorption maxima changes. A systematic analysis of the PCB chromophore in the presence and absence of the protein environment showed that the direct electrostatic effect is negligible on the spectral tuning. However, the protein forces the outer pyrrole rings of the chromophore to deviate from coplanarity, which is identified as the dominating factor for the color regulation.

3.
Small ; : e1907172, 2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31967725

RESUMO

Structural symmetry is a simple way to quantify the anisotropic properties of materials toward unique device applications including anisotropic transportation and polarization-sensitive photodetection. The enhancement of anisotropy can be achieved by artificial symmetry-reduction design. A core-shell SbI3 /Sb2 O3 nanowire, a heterostructure bonded by van der Waals forces, is introduced as an example of enhancing the performance of polarization-sensitive photodetectors via symmetry reduction. The structural, vibrational, and optical anisotropies of such core-shell nanostructures are systematically investigated. It is found that the anisotropic absorbance of a core-shell nanowire is obviously higher than that of two single compounds from both theoretical and experimental investigations. Anisotropic photocurrents of the polarization-sensitive photodetectors based on these core-shell SbI3 /Sb2 O3 van der Waals nanowires are measured ranging from ultraviolet (UV) to visible light (360-532 nm). Compared with other van der Waals 1D materials, low anisotropy ratio (Imax /Imin ) is measured based on SbI3 but a device based on this core-shell nanowire possesses a relatively high anisotropy ratio of ≈3.14 under 450 nm polarized light. This work shows that the low-symmetrical core-shell van der Waals heterostructure has large potential to be applied in wide range polarization-sensitive photodetectors.

4.
Acta Pharmacol Sin ; 2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31969689

RESUMO

Vonoprazan is characterized as having a long-lasting antisecretory effect on gastric acid. In this study we developed a physiologically based pharmacokinetic (PBPK)-pharmacodynamic (PD) model linking to stomach to simultaneously predict vonoprazan pharmacokinetics and its antisecretory effects following administration to rats, dogs, and humans based on in vitro parameters. The vonoprazan disposition in the stomach was illustrated using a limited-membrane model. In vitro metabolic and transport parameters were derived from hepatic microsomes and Caco-2 cells, respectively. We found the most predicted plasma concentrations and pharmacokinetic parameters of vonoprazan in rats, dogs and humans were within twofold errors of the observed data. Free vonoprazan concentrations (fu × C2) in the stomach were simulated and linked to the antisecretory effects of the drug (I) (increases in pH or acid output) using the fomula dI/dt = k × fu × C2 × (Imax - I) - kd × I. The vonoprazan dissociation rate constant kd (0.00246 min-1) and inhibition index KI (35 nM) for H+/K+-ATPase were obtained from literatures. The vonoprazan-H+/K+-ATPase binding rate constant k was 0.07028 min-1· µM-1 using ratio of kd to KI. The predicted antisecretory effects were consistent with the observations following intravenous administration to rats (0.7 and 1.0 mg/kg), oral administration to dogs (0.3 and 1.0 mg/kg) and oral single dose or multidose to humans (20, 30, and 40 mg). Simulations showed that vonoprazan concentrations in stomach were 1000-fold higher than those in the plasma at 24 h following administration to human. Vonoprazan pharmacokinetics and its antisecretory effects may be predicted from in vitro data using the PBPK-PD model of the stomach. These findings may highlight 24-h antisecretory effects of vonoprazan in humans following single-dose or the sustained inhibition throughout each 24-h dosing interval during multidose administration.

5.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi ; 34(1): 41-45, 2020 Jan 15.
Artigo em Chinês | MEDLINE | ID: mdl-31939233

RESUMO

Objective: To summarize the technique and effectiveness of double metatarsal osteotomy for treating severe hallux valgus with increased distal metatarsal articular angle (DMAA). Methods: Between June 2014 and December 2017, 64 patients (94 feet) of severe hallux valgus with an increased DMAA were treated with the double metatarsal osteotomy (distal metatarsal Reverdin osteotomy+proximal metatarsal open wedge osteotomy) combined with Akin osteotomy and soft tissue surgery to correct the deformity. There were 10 males (15 feet) and 54 females (79 feet) with an average age of 44.5 years (range, 26-66 years), including 34 of unilateral foot and 30 of bilateral feet. The Maryland metatarsophalangeal joint score of the American Orthopaedic Foot and Ankle Society (AOFAS) was 54.3±7.4 and the visual analogue scale (VAS) score was 6.0±2.0. The pre- and post-operative AOFAS score, VAS score, DMAA, hallux valgus angle (HVA), first-second intermetatarsal angle (1-2IMA), and the first metatarsal length (FML) were recorded and compared. Results: All incisions healed by first intention. All patients were followed up 12-15 months, with an average of 13.2 months. The complications occurred in 4 feet, including 1 foot of hallux stiffness, 1 foot of numbness at the edge of the wound, 1 foot of metastatic metatarsalgia, and 1 foot of metatarsal bone necrosis. At 1 year after operation, the Maryland metatarsal joint score of AOFAS was 89.2±7.4, showing significant difference compared with preoperative score ( t=18.427, P=0.000); and the effectiveness was rated as excellent in 78 feet, good in 12 feet, poor in 3 feet, and bad in 1 foot, with an excellent and good rate of 95.7%. The VAS score was 1.5±2.0, showing significant difference compared with the preoperative score ( t=10.238, P=0.000). The X-ray films showed that the osteotomies achieved bony healing at 3 months after operation. There were significant differences ( P<0.05) in HVA, 1-2IMA, and DMAA between preoperation and 6 months and 1 year after operation; but no significant difference was found in FML between preoperation and 1 year after operation ( t=0.136, P=0.863). Conclusion: For the patients with severe hallux valgus with increased DMAA, the double metatarsal osteotomy can significantly relieve the clinical symptoms and improve the imaging parameters with less postoperative complications.

6.
Int J Mol Sci ; 21(2)2020 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-31940963

RESUMO

Chitosan is a product of the deacetylation of chitin, which is widely found in nature. Chitosan is insoluble in water and most organic solvents, which seriously limits both its application scope and applicable fields. However, chitosan contains active functional groups that are liable to chemical reactions; thus, chitosan derivatives can be obtained through the chemical modification of chitosan. The modification of chitosan has been an important aspect of chitosan research, showing a better solubility, pH-sensitive targeting, an increased number of delivery systems, etc. This review summarizes the modification of chitosan by acylation, carboxylation, alkylation, and quaternization in order to improve the water solubility, pH sensitivity, and the targeting of chitosan derivatives. The applications of chitosan derivatives in the antibacterial, sustained slowly release, targeting, and delivery system fields are also described. Chitosan derivatives will have a large impact and show potential in biomedicine for the development of drugs in future.

7.
Genome Biol Evol ; 12(1): 3725-3737, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31917411

RESUMO

Sympatric speciation remains a central focus of evolutionary biology. Although some evidence shows speciation occurring in this way, little is known about the gene expression evolution and the characteristics of population genetics as species diverge. Two closely related Gymnocypris fish (Gymnocypris chui and Gymnocypris scleracanthus), which come from a small glacier lake in the Tibetan Plateau, Lake Langcuo, exist a possible incipient sympatric adaptive ecological speciation. We generated large amounts of RNA-Seq data from multiple individuals and tissues from each of the two species and compared gene expression patterns and genetic polymorphisms between them. Ordination analysis separated samples by organ rather than by species. The degree of expression difference between organs within and between species was different. Phylogenetic analyses indicated that the two closely related taxa formed a monophyletic complex. Population structure analysis displayed two distinctly divergent clusters of G. chui and G. scleracanthus populations. By contrast, G. scleracanthus population genetic diversity is higher than that of G. chui. Considerable sites of the two populations were differentiated with a coefficient of FST = 0.25-0.50, implying that a small proportion of loci nevertheless exhibited deep divergence in two comparisons. Concomitantly, putatively selected genes during speciation revealed functional categories are enriched in bone morphogenesis, cell growth, neurogenetics, enzyme activity, and binding activity in G. chui population. In contrast, nutrition and localization were highlighted in G. scleracanthus. Collectively, morphological traits and dietary preference combine with genetic variation and expression variation, probably contributed to the incipient speciation of two sympatric populations.

8.
J Pharm Pharmacol ; 72(1): 68-75, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31721211

RESUMO

OBJECTIVES: MicroRNAs are abundant in eukaryotic cells and play key roles in cancers. Circular RNAs (CircRNAs) served as the competing endogenous RNAs (ceRNAs) in mediating multiple cell processes. This study aims to define the role of CircRNA CircZNF609/miR-134-5p in glioma as well as the underlying regulating mechanism. METHODS: Relative expression of miR-134-5p, CircZNF609 and BTG-2 mRNA was determined by quantitative real-time PCR. Cell proliferation was analysed by CCK-8 assay. Cell migration was assessed by cell wound scratch assay. The direct regulatory of miR-134-5p on BTG-2 and CircZNF609 was verified by luciferase report gene assay. KEY FINDINGS: MiR-134-5p was significantly upregulated in glioma cells. The overexpression of miR-134-5p inhibited cell proliferation and migration of glioma cell U251 and U87. Reversely, knock-down of miR-134-5p enhanced cell proliferation and migration. Both BTG-2 and CircZNF609 are the direct targets of miR-134-5p, and their expression could be negatively regulated by miR-134-5p. CircZNF609 was significantly upregulated in U251 and U87 cells and acted as an oncogene to promote cell proliferation and cell migration of glioma cell U251 and U87. CONCLUSIONS: These data proved that CircZNF609 served as a competing RNA to bind miR-134-5p that promoted BTG-2 expression leading to reduced proliferation and migration of glioma cell.

9.
Front Cell Neurosci ; 13: 511, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31798418

RESUMO

The amygdala is an important center of fear learning and memory and plays a critical role in regulating stress disorders. Previous studies have shown that changes in the amygdala caused by stress are an important cause of mental disorders including anxiety, but the specific mechanism remains unclear. Therefore, the purpose of this study was to investigate whether mental disorders induced by stress are related to γ-aminobutyric acid (GABA)ergic neuron damage in the basolateral amygdala (BLA) and whether endoplasmic reticulum stress (ERS) is involved in the injury process. Rat models of different durations of stress were established by restraint and forced ice-water swimming. Behavioral tests and high-performance liquid chromatography (HPLC) were used to detect anxiety in rats and changes in neurotransmitter levels in the BLA. Morphological approaches and microscopy-based multicolor tissue cytometry (MMTC) were used to detect the damage-induced changes in GABAergic neurons in the BLA. Immunofluorescence double labeling was used to detect the expression of ERS-related proteins before and after the inhibition of protein kinase R-like endoplasmic reticulum kinase (PERK) pathway. Stress resulted in damage to GABAergic neurons in the BLA, decreased GABA and increased glutamic acid (GLU) levels, perturbation of the excitation/inhibition (E/I) ratio in the BLA, and obvious anxiety disorders in rats. Moreover, ERS-mediated GABAergic neuron injury was an important cause of neurotransmitter level changes in the BLA. These results suggested that ERS-mediated GABAergic neuron injury in the BLA may be an important cause of stress-induced mental disorders.

10.
Plant J ; 2019 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-31820831

RESUMO

Phycobilisomes are large light-harvesting complexes attached on the stromal side of thylakoids of cyanobacteria and red algae. They can be remodeled or degraded in response to changing light and nutritional status. Both the core and the peripheral rods of the phycobilisome contain biliproteins. During biliprotein biosynthesis, open-chain tetrapyrrole chromophores are attached covalently to the apoproteins by dedicated lyases. Another set of non-bleaching proteins has been implicated in phycobilisome degradation, among them NblA and NblB. We report in vitro experiments with lyases, biliproteins and NblA/B implying more involved functions than currently discussed: lyases can also detach the chromophores and NblA and NblB can modulate lyase-catalyzed binding and detachment of chromophores in a complex fashion. We show: 1) NblA and NblB can interfere with chromophorylation as well as chromophore-detachment of phycobiliprotein, they are generally inhibitors but in some cases enhance the reaction. 2) NblA and NblB promote dissociation of whole phycobilisomes, cores and, in particular, allophycocyanin trimers. 3) While NblA and NblB do not interact with each other, both interact with lyases, apo- and holo-biliproteins. 4) They promote synergistically the lyase-catalyzed chromophorylation of the ß-subunit of the major rod component, CPC. 5) They modulate lyase-catalyzed and lyase-independent chromophore transfers among biliproteins, with the core protein, ApcF, the rod protein, CpcA, and sensory biliproteins (phytochromes, cyanobacteriochromes) acting as potential traps. The results indicate that NblA/B can cooperate with the lyases in remodeling the phycobilisomes, for balancing the metabolic requirements of acclimating their light-harvesting capacity without straining the overall metabolic economy of the cell.

11.
World Neurosurg ; 2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-31785439

RESUMO

INTRODUCTION: The suboccipital midline approach is common dealing with posterior fossa tumors but facing a high risk of postoperative complications, such as pseudomeningocele, cerebrospinal fluid (CSF) leak and meningitis. Neurosurgeons used various kinds of method to lower its rate. METHODS: A retrospective, single-center review of patients diagnosed with posterior fossa tumor underwent a suboccipital midline approach. Compare the rate of pseudomeningocele, CSF leak and meningitis between two groups (artificial dura-mater or cervical fascia autograft). We get the cervical fascia autograft from the superficial layer of deep cervical fascia just above the trapezius. RESULTS: Our retrospective review involved 123 patients matching the inclusion criteria between January 2009 and April 2019. The complication rate of pseudomeningocele, CSF leak and meningitis were 8.9%, 4.9% and 17.9% respectively. Presence of pseudomeningocele or CSF leak for group "artificial" were 11 of 75 (14.67%), for group "autograft" 3 of 48 (6.25%). The rate of meningitis for group "artificial" (24.0%, 18 of 75) was significantly higher(P=0.027) than the one for group "autograft" (8.33%, 4 of 48). Multivariate regression analysis suggested that the age was negatively correlated with postoperative pseudomeningocele or CSF leak (P=0.006), with meningitis (P<0.001). Using cervical fascia autograft decreased the rate of meningitis (P=0.021), while showed no statistically significant clinical impact on pseudomeningocele or CSF leak. CONCLUSIONS: Applying the cervical fascia autograft to reconstruct the dura during posterior fossa surgery is a simple and effective method to reduce the rate of meningitis as compared with artificial dura mater.

12.
Vaccine ; 2019 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-31813649

RESUMO

Vaccination is the most cost-effective and sustainable way to prevent and eliminate infectious diseases. Compared with traditional vaccines, novel vaccines have better stability, longer duration and require less antigen usage. In addition, novel vaccines have better immune effects and significantly less toxic side effects. However, both novel vaccines and traditional vaccines require carrier molecules or adjuvants to produce an optimal immune response. There is an increasing demand for vaccine adjuvants and delivery systems that can induce stronger immune response whilst reducing production cost and the dose of vaccine. In recent years, nanotechnology has played an important role in the development of novel vaccine adjuvants and nano-delivery systems. Biodegradable materials have also received a lot of attention in medical science because they have excellent biocompatibility, biodegradability and low toxicity, which can protect antigens from degradation, increase antigen stability and provide slow release; resulting in enhanced immunogenicity. Therefore, biodegradable nanoparticles have attracted much attention in the formulation of vaccines. In this review, we outline some key features of biodegradable nanomaterials in the developing safer and more effective vaccines. The properties, structural characteristics, advantages and disadvantage of the biodegradable nanomaterials will be systematically reviewed. Additionally, applications, research progress and future prospects of biodegradable nanomaterials are discussed. This review will be help in future research work directed at developing biodegradable vaccine adjuvants or delivery carriers.

13.
G3 (Bethesda) ; 2019 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-31818874

RESUMO

Aspergillus flavus is a fungus that produces aflatoxin B1, one of the most carcinogenic secondary metabolites. Understanding the regulation mechanism of aflatoxin biosynthesis in this fungus requires precise methods for genomic integration of mutant alleles. To avoid the disadvantage of DNA integration into the genome by non-homologous or ectopic recombination, we developed a novel strategy for site-specific integration of foreign DNA by using a carboxin-resistant sdh2R allele (His 249 Leu). Our results demonstrated that the transformants were generated with a high efficiency (>96 %) of correct integration into the sdh2-locus of the genome of A. flavus NRRL 3357. The advantage of this method is that introduction of the eGFP expression cassette into the sdh2-locus had little effect on fungal growth and virulence while also being rapid and efficient. This system will be a valuable tool for genetic manipulation in A. flavus To the best of our knowledge, this is the first report on the efficient site-specific integration at the sdh2-locus in the genome of Aspergillus.

14.
Chem Sci ; 10(38): 8792-8798, 2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31803451

RESUMO

Stereoselective ß-C(sp2)-H alkylation of enamides with redox-active N-hydroxyphthalimide esters via a photoredox-catalyzed decarboxylative cross-coupling reaction is demonstrated. This methodology features operational simplicity, broad substrate scopes, and excellent stereoselectivities and functional group tolerance, affording a diverse array of geometrically defined and synthetically valuable enamides bearing primary, secondary or tertiary alkyl groups in satisfactory yields.

16.
Huan Jing Ke Xue ; 40(10): 4569-4577, 2019 Oct 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854825

RESUMO

Low C/N domestic sewage was treated in a SBR. With an operating temperature of (25±0.5)℃, NO2--N accumulation rates reached 96.79%, 98.80%, and 98.78% after 69, 63, and 58 cycles, respectively. In each case, alternating modes of hypoxia/aerobic (four times), aerobic/anoxic (five times), and aerobic/anoxic (four times) were applied, respectively, with an alternating time of 30 min. At the same temperature, when the aerobic/anoxic time ratios were 30 min:30 min, 40 min:20 min, and 30 min:60 min, and the single-cycle alternating times were 5, 3, and 5, respectively, stable NO2--N accumulation rates reached 98.81%, 97.71%, and 94.64% after 63, 73, and 78 cycles, respectively. The activity of AOB was 96.30, 99.27, and 102.26, respectively. Simultaneous nitrification and denitrification occurred under the three aerobic/anoxic time ratios. The total amounts of nitrogen removed by synchronous nitrification and denitrification were 29.89, 28.77, and 29.78 mg·L-1. When temperatures were adjusted to 18, 25, and 30℃, and when the aerobic/anoxic time ratio was 30 min:30 min, the NO2--N accumulation rates were 99.58%, 99.21%, and 95.93% after 90, 64, and 61 cycles, respectively. The activity of the sludge (f) peaked when after 64, 40, and 48 cycles, while the sludge-settling performance was good.

17.
Sci Rep ; 9(1): 19370, 2019 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-31852965

RESUMO

Sepsis is a life-threatening disease caused by infection. Inflammation is a key pathogenic process in sepsis. Paeonol, an active ingredient in moutan cortex (a Chinese herb), has many pharmacological activities, such as anti-inflammatory and antitumour actions. Previous studies have indicated that paeonol inhibits the expression of HMGB1 and the transcriptional activity of NF-κB. However, its underlying mechanism is still unknown. In this study, microarray assay and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) results confirmed that paeonol could significantly up-regulate the expression of miR-339-5p in RAW264.7 cells stimulated by LPS. Dual-luciferase assays indicated that miR-339-5p interacted with the 3' untranslated region (3'-UTR) of HMGB1. Western blot, immunofluorescence and enzyme-linked immunosorbent assay (ELISA) analyses indicated that miR-339-5p mimic and siHMGB1 both negatively regulated the expression and secretion of inflammatory cytokines (e.g., HMGB1, IL-1ß and TNF-α) in LPS-induced RAW264.7 cells. Studies have confirmed that IKK-ß is targeted by miR-339-5p, and we further found that paeonol could inhibit IKK-ß expression. Positive mutual feedback between HMGB1 and IKK-ß was observed when we silenced HMGB1 or IKK-ß. These results indicated that paeonol could attenuate the inflammation mediated by HMGB1 and IKK-ß by upregulating miR-339-5p expression. In addition, we constructed CLP model mice by cecal ligation and puncture. Paeonol was used to intervene to investigate its anti-inflammatory effect in vivo. The results showed that paeonol could improve the survival rate of sepsis mice and protect the kidney of sepsis mice.

18.
Front Oncol ; 9: 1058, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31681594

RESUMO

Acute myeloid leukemia (AML) requires refined risk stratification tools to drive decisions concerning effective therapeutic strategies. Here, genome-wide screening was carried out for identifying miRNA molecules capable of predicting treatment outcome in AML patients based on the TCGA dataset. We identified miR-340 as a prognostic factor for selecting treatment between chemotherapy and allogeneic transplantation (allo-HSCT). In multivariable analyses, low miR-340 expression independently predicted reduced OS (HR = 2.07, P = 0.004) and EFS (HR = 1.909, P = 0.01) independent of other well-known prognostic factors. Meanwhile, allo-HSCT overcome deleterious outcomes related to low miR-340. Cases administered allo-HSCT showed markedly improved OS (HR = 0.316, P < 0.0001) and EFS (HR = 0.391, P = 0.002) in comparison with those receiving chemotherapy in the low miR-340 group. Gene expression assessment revealed that elevated miR-340 amounts were negatively correlated with HOXA/HOXB cluster levels, as well as the amounts of the HOX cofactor MEIS1. Strikingly, in silico analysis pointing to HOXA10, HOXB2, and MEIS1 as miR-340 targets. The miR-340 expression may help identify cases requiring strategies for selecting the optimal therapeutic option between chemotherapy and allo-HCST. AML cases showing low miR-340 levels should be strongly considered for early allo-HSCT treatment.

19.
Artigo em Inglês | MEDLINE | ID: mdl-31714237

RESUMO

In this article, a neural network (NN)-based robust adaptive fault-tolerant control (FTC) algorithm is proposed for a class of multi-input multi-output (MIMO) strict-feedback nonlinear systems with input quantization and actuation faults as well as asymmetric yet time-varying output constraints. By introducing a key nonlinear decomposition for quantized input, the developed control scheme does not require the detailed information of quantization parameters. By imposing a reasonable condition on the gain matrix under actuation faults, together with the inherent approximation capability of NN, the difficulty of FTC design caused by anomaly actuation can be handled gracefully, and the normally used yet rigorous assumption on control gain matrix in most existing results is significantly relaxed. Furthermore, a brand new barrier function is constructed to handle the asymmetric yet time-varying output constraints such that the analysis and design are extremely simplified compared with the traditional barrier Lyapunov function (BLF)-based methods. NNs are used to approximate the unknown nonlinear continuous functions. The stability of the closed-loop system is analyzed by using the Lyapunov method and is verified through a simulation example.

20.
Laryngoscope ; 2019 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-31714627

RESUMO

OBJECTIVES/HYPOTHESIS: Patients are frequently advised to sneeze with an open mouth and avoid nose-blowing following an endoscopic endonasal approache (EEA) to the skull base, despite a lack of quantitative evidence. This study applies computational fluid dynamics (CFD) to quantify sinus pressures along the skull base during sneezing. STUDY DESIGN: Case-control series. METHODS: Computed tomography or magnetic resonance imaging scans of four post-EEA patients and four healthy controls were collected and analyzed utilizing CFD techniques. A pressure drop of 6,000 Pa was applied to the nasopharynx based on values in the literature to simulate expiratory nasal airflow during sneezing. Peak pressures along the skull base in frontal, ethmoid, and sphenoid sinuses were collected. RESULTS: Significant increases in skull base peak pressure was observed during sneezing, with significant individual variations from 2,185 to 5,685 Pa. Interestingly, healthy controls had significantly higher pressures compared to post-EEA patients (5179.37 ± 198.42 Pa vs. patients 3,347.82 ± 1,472.20 Pa, P < .05), which could be related to higher anterior nasal resistance in unoperated healthy controls (0.44 ± 0.22 vs. 0.31 ± 0.16 Pa/mL/sec for patients, P = .38). The sinus pressure buildup may be due to airway resistance functioning as a valve preventing air from being released quickly. Supporting this theory, there was a strong correlation (r = 0.82) between peak skull base pressure and the ratio of anterior resistance to total resistance. Within-subject variation in pressures between different skull base regions was much lower (average = ~5%). CONCLUSIONS: This study provided the first quantitative analysis of air pressure along the skull base during sneezing in post-EEA patients through CFD, suggesting that pressure buildup may depend on individual anatomy. LEVEL OF EVIDENCE: 3b Laryngoscope, 2019.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA