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61.
62.
Journal of Dynamical and Control Systems - We classify the phase portraits in the Poincaré disc of the differential equations of the form $x^{prime } = -y + x f(x,y)$ , $dot y =x + y f(x,y)$... 相似文献
63.
Jaume Gomez-Caturla Ivan Dominguez-Candela Martha Patricia Medina-Casas Juan Ivorra-Martinez Virginia Moreno Rafael Balart Daniel Garcia-Garcia 《大分子材料与工程》2023,308(7):2200694
Diethyl l -tartrate (DET) is used as a biobased plasticizer for poly(lactide) (PLA) formulations with improved ductile properties without compromising biodegradation. Different weight percentages (wt.%) of DET in the 0–50 wt.% range are added to PLA by melt compounding and subsequently processed by injection molding. The effect of wt.% DET on mechanical, thermal, thermo-mechanical, morphology, biodegradation, and crystallinity is studied. Addition of 20 wt.% DET leads to a noticeable increase in elongation at break up to values of 567%, which is quite an interesting result considering the extreme brittleness of PLA. These results are verified by field emission scanning electron microscopy (FESEM) images, where filament-like structures are observed, indicative of an effective plasticization. Differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) show that the glass transition temperature of PLA is drastically decreased down to values of 23 °C for the sample with the highest amount of DET (50 wt.%), thus increasing its ductility and processability. Fourier-transformed infrared spectroscopy (FTIR) spectra show that there exists chemical interactions between PLA and DET. Finally, the biodegradability analysis proves that the developed blends are fully biodegradable, achieving complete disintegration after 49 days. It is observed that DET enhanced the disintegration rate of PLA. 相似文献
64.
Rebecca K. Dirkes Nathan C. Winn Thomas J. Jurrissen Dennis B. Lubahn Victoria J. Vieira-Potter Jaume Padilla Pamela S. Hinton 《International journal of molecular sciences》2021,22(4)
Estrogen receptor-α knockout (ERKO) in female, but not male, mice results in an impaired osteogenic response to exercise, but the mechanisms behind this ability in males are unknown. We explored the main and interactive effects of ERKO and exercise on cortical geometry, trabecular microarchitecture, biomechanical strength, and sclerostin expression in male mice. At 12 weeks of age, male C57BL/6J ERKO and WT animals were randomized into two groups: exercise treatment (EX) and sedentary (SED) controls, until 22 weeks of age. Cortical geometry and trabecular microarchitecture were measured via μCT; biomechanical strength was assessed via three-point bending; sclerostin expression was measured via immunohistochemistry. Two-way ANOVA was used to assess sclerostin expression and trabecular microarchitecture; two-way ANCOVA with body weight was used to assess cortical geometry and biomechanical strength. ERKO positively impacted trabecular microarchitecture, and exercise had little effect on these outcomes. ERKO significantly impaired cortical geometry, but exercise was able to partially reverse these negative alterations. EX increased cortical thickness regardless of genotype. There were no effects of genotype or exercise on sclerostin expression. In conclusion, male ERKO mice retain the ability to build bone in response to exercise, but altering sclerostin expression is not one of the mechanisms involved. 相似文献
65.
66.
Struvite precipitation as a technology to be integrated in a manure anaerobic digestion treatment plant – removal efficiency,crystal characterization and agricultural assessment 下载免费PDF全文
67.
Fuster-Garcia E Navarro C Vicente J Tortajada S García-Gómez JM Sáez C Calvar J Griffiths J Julià-Sapé M Howe FA Pujol J Peet AC Heerschap A Moreno-Torres A Martínez-Bisbal MC Martínez-Granados B Wesseling P Semmler W Capellades J Majós C Alberich-Bayarri A Capdevila A Monleón D Martí-Bonmatí L Arús C Celda B Robles M 《Magma (New York, N.Y.)》2011,24(1):35-42
Object
This study demonstrates that 3T SV-MRS data can be used with the currently available automatic brain tumour diagnostic classifiers which were trained on databases of 1.5T spectra. This will allow the existing large databases of 1.5T MRS data to be used for diagnostic classification of 3T spectra, and perhaps also the combination of 1.5T and 3T databases.Materials and methods
Brain tumour classifiers trained with 154 1.5T spectra to discriminate among high grade malignant tumours and common grade II glial tumours were evaluated with a subsequently-acquired set of 155 1.5T and 37 3T spectra. A similarity study between spectra and main brain tumour metabolite ratios for both field strengths (1.5T and 3T) was also performed.Results
Our results showed that classifiers trained with 1.5T samples had similar accuracy for both test datasets (0.87 ± 0.03 for 1.5T and 0.88 ± 0.03 for 3.0T). Moreover, non-significant differences were observed with most metabolite ratios and spectral patterns.Conclusion
These results encourage the use of existing classifiers based on 1.5T datasets for diagnosis with 3T 1H SV-MRS. The large 1.5T databases compiled throughout many years and the prediction models based on 1.5T acquisitions can therefore continue to be used with data from the new 3T instruments. 相似文献68.
Oriol A Valverde D Capellades J Cabañas ME Ribera JM Arús C 《Magma (New York, N.Y.)》2007,20(2):93-101
Object Magnetic resonance imaging (MRI) is the gold standard non-invasive technique to detect malignant disease in the bone marrow.
Proton magnetic resonance spectroscopy (MRS) can be performed as a quick adjunct to routine spinal MRI. We performed proton
MRS to patients with multiple myeloma (MM) at diagnosis and after treatment to investigate the possible correlation of MRS
data with response to therapy.
Patients and methods Twenty-one patients with newly diagnosed MM underwent combined MRI/MRS explorations of a transverse center section in the
fifth lumbar vertebral body. MRS was acquired with STEAM and 40 ms TE. Areas of unsuppressed water and lipid resonances were
used to calculate the lipid-to-water ratio (LWR).
Results No association was detected between initial LWRs and the clinical characteristics of patients. Post treatment MRS was available
in 16 patients of whom 11 (69%) presented an LWR increase, this included all complete responders (8/8, 100%, P = 0.012). A post-treatment LWR value equal to or larger than one is proposed as a non-invasive marker of complete response
to treatment.
Conclusion Only patients responding to treatment presented a significant increase in bone marrow LWR after therapy. MRS may provide
an adequate quantification of response to chemotherapy in patients with MM. 相似文献
69.
Blanca Majem Marina Rigau Jaume Reventós David T. Wong 《International journal of molecular sciences》2015,16(4):8676-8698
Saliva is a complex body fluid that comprises secretions from the major and minor salivary glands, which are extensively supplied by blood. Therefore, molecules such as proteins, DNA, RNA, etc., present in plasma could be also present in saliva. Many studies have reported that saliva body fluid can be useful for discriminating several oral diseases, but also systemic diseases including cancer. Most of these studies revealed messenger RNA (mRNA) and proteomic biomarker signatures rather than specific non-coding RNA (ncRNA) profiles. NcRNAs are emerging as new regulators of diverse biological functions, playing an important role in oncogenesis and tumor progression. Indeed, the small size of these molecules makes them very stable in different body fluids and not as susceptible as mRNAs to degradation by ribonucleases (RNases). Therefore, the development of a non-invasive salivary test, based on ncRNAs profiles, could have a significant applicability to clinical practice, not only by reducing the cost of the health system, but also by benefitting the patient. Here, we summarize the current status and clinical implications of the ncRNAs present in human saliva as a source of biological information. 相似文献
70.
Michael Lee Maria J. Lopez‐Martinez Abdoullatif Baraket Nadia Zine Jaume Esteve Jose A. Plaza Naveed Ahmed Abdelhamid Elaissari Nicole Jaffrezic‐Renault Abdelhamid Errachid 《应用聚合物科学杂志》2015,132(25)
We present a study for the development of flexible microfilters based on sealing microstructured poly(dimethylsiloxane) (PDMS) to different functionalized thermoplastic films [polyimide (PI), polyethylene naphthalate (PEN), and polyethylene terephthalate (PET)]. The microfilter was manufactured by soft‐lithography and replica molding and then combined with plasma activation and chemical treatment using 3‐(aminopropyl)triethoxysilane (APTES). To demonstrate the functionality of the PDMS microfilters, poly(lactic‐co‐glycolic acid) (PLGA) microparticles (MPS) were filtered through the microfluidic device based on the three thermoplastic films. Subsequently, the mixing capabilities of a passive PDMS micromixer was observed with the injection of polymeric MPS (fluorescent and nonfluorescent) as fluidic mixers are not generally effective at mixing particles. On mixing nonfluorescent MPS (~<10–30 µm in diameter) a mixing performance of 13.3% at 5 mm was observed. Therefore, a PDMS microfiltering device was integrated with a PDMS micromixer using a simple and cost effective home‐made polymeric connector for filtration at a size sorting of 11 µm. The results exhibit that the combination of the two microfluidic devices can be achieved with size sorting and mixing of MPS with an improved mixing performance of 62.5% at 3 mm. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42088. 相似文献