136 research outputs found
High strength mullite-bond SiC porous ceramics fabricated by digital light processing
Fabricating SiC ceramics via the digital light processing (DLP) technology is of great challenge due to strong light absorption and high refractive index of deep-colored SiC powders, which highly differ from those of resin, and thus significantly affect the curing performance of the photosensitive SiC slurry. In this paper, a thin silicon oxide (SiO2) layer was in-situ formed on the surface of SiC powders by pre-oxidation treatment. This method was proven to effectively improve the curing ability of SiC slurry. The SiC photosensitive slurry was fabricated with solid content of 55 vol% and viscosity of 7.77 Pa s (shear rate of 30 s-1). The curing thickness was 50 μm with exposure time of only 5 s. Then, a well-designed sintering additive was added to completely convert low-strength SiO2 into mullite reinforcement during sintering. Complexshaped mullite-bond SiC ceramics were successfully fabricated. The flexural strength of SiC ceramics sintered at 1550 °C in air reached 97.6 MPa with porosity of 39.2 vol%, as high as those prepared by spark plasma sintering (SPS) techniques.</p
Glycemic variability evaluated by HbA1c rather than fasting plasma glucose is associated with adverse cardiovascular events
BackgroundAlthough studies have shown that glycemic variability is positively associated with an increased risk of cardiovascular disease, few studies have compared hemoglobin A1c (HbA1c) and fasting plasma glucose (FPG) variability with adverse cardiovascular events in patients with type 2 diabetes mellitus (T2DM).MethodsThis was a post hoc analysis of the Action to Control Cardiovascular Risk in Diabetes (ACCORD) study. Cox proportional hazards models were used to explore the relationship between HbA1c or FPG variability and the incidence of major adverse cardiovascular events (MACEs).ResultsIn total, 9,547 patients with T2DM were enrolled in this study. During the median 4.6 ± 1.5 years follow-up period, 907 patients developed MACEs. The risk of MACEs increased in the HbA1c variability group in each higher quartile of HbA1c variability (P < 0.01). Compared with those in the first quartile of HbA1c variability, patients in the fourth quartile had a hazard ratio of 1.37 (Model 2, 95% confidence interval: 1.13–1.67) for MACEs. Higher FPG variability was not associated with a higher risk of MACEs in patients with T2DM (P for trend=0.28). A U-shaped relationship was observed between HbA1c and FPG variability, and MACEs. Glucose control therapy modified the relationship between HbA1c and MACEs; participants with higher HbA1c variability receiving intensive glucose control were more likely to develop MACEs (P for interaction <0.01).ConclusionIn adults with T2DM, the relationship between glycemic variability evaluated using HbA1c and FPG was U-shaped, and an increase in HbA1c variability rather than FPG variability was significantly associated with MACEs. The relationship between HbA1c variability and MACEs was affected by the glucose control strategy, and a higher HbA1c variability was more strongly associated with MACEs in patients receiving an intensive glucose control strategy
Evaluation of genipin-crosslinked chitosan hydrogels as a potential carrier for silver sulfadiazine nanocrystals
In the present study genipin crosslinked chitosan (CHI) hydrogels, which had been
constructed and reported in our previous studies (Lei Gao, et al. Colloids Surf. B
Biointerfaces. 2014, 117: 398), were further evaluated for their advantage as a carrier
for silver sulfadiazine (AgSD) nanocrystal systems. Firstly, AgSD nanocrystals with a
mean particle size of 289 nm were prepared by wet milling method and encapsulated
into genipin crosslinked CHI hydrogels. AgSD nanocrystals displayed a uniform
distribution and very good physical stability in the hydrogel network.
Swelling-dependent release pattern was found for AgSD nanocrystals from hydrogels
and the release profile could be well fitted with Peppas equation. When AgSD
nanocrystals were encapsulated in hydrogels their fibroblast cytotoxicity decreased
markedly, and their antibacterial effects against Staphylococcus aureus, Escherichia
coli and Pseudomonas aeruginosa were still comparable to unencapsulated AgSD
nanocrystals. In vivo evaluation in excision and burn cutaneous wound models in
mice showed that AgSD nanocrystal hydrogels markedly decreased the expression of
inflammatory cytokine IL-6, but increased the levels of growth factors VEGF-A and
TGF-β1. Histopathologically, the wounds treated by hydrogels containing AgSD
nanocrystals showed the best healing state compared with commercial AgSD cream,
hydrogels containing AgSD bulk powders and blank hydrogels. The wounds treated
by AgSD nanocrystal hydrogels were dominated by marked fibroblast proliferation,
new blood vessels and thick regenerated epithelial layer. Sirius Red staining assay
indicated that AgSD nanocrystal hydrogels resulted in more collagen deposition
characterized by a large proportion of type I fibers. Our study suggested that
genipin-crosslinked CHI hydrogel was a potential carrier for local antibacterial
nanomedicines
Dachengqi Decoction Attenuates Inflammatory Response via Inhibiting HMGB1 Mediated NF-κB and P38 MAPK Signaling Pathways in Severe Acute Pancreatitis
Reduced NOV expression correlates with disease progression in colorectal cancer and is associated with survival, invasion and chemoresistance of cancer cells
Aberrant expression of nephroblastoma overexpressed (NOV) has been evident
in certain malignancies. In the current study, we aim to investigate the role played by
NOV in colorectal cancer (CRC). NOV expression was determined in a cohort of 359 CRC
tissues and 174 normal colorectal tissues. Its impact on CRC cells was investigated
using in vitro NOV knockdown and overexpression models. NOV transcripts were
reduced in the CRC tumours compared with the paired adjacent normal colorectal
tissues (p < 0.01) and was associated with distant metastases. NOV knockdown
resulted in increased cell proliferation and invasion of RKO cells, whilst an opposite
effect was seen in the HT115 NOV over expressing cells. A positive association
between Caspase-3/-8 and NOV was seen in NOV knockdown and overexpression
cell lines which contributed to the survival of serum deprived CRC cells. Further
investigation showed that NOV regulated proliferation, survival and invasion through
the JNK pathway. NOV knockdown in RKO cells reduced the responsiveness to
5-Fluorouracil treatment, whilst overexpression in HT115 cells exhibited a contrasting
effect. Taken together, NOV is reduced in CRC tumours and this is associated with
disease progression. NOV inhibits the proliferation and invasion of CRC cells in vitro.
Inhibition of proliferation is mediated by a regulation of Caspase-3/-8, via the JNK
pathway, which has potential for predicting and preventing chemoresistance
Aspergillus Myosin-V Supports Polarized Growth in the Absence of Microtubule-Based Transport
In the filamentous fungus Aspergillus nidulans, both microtubules and actin filaments are important for polarized growth at the hyphal tip. Less clear is how different microtubule-based and actin-based motors work together to support this growth. Here we examined the role of myosin-V (MYOV) in hyphal growth. MYOV-depleted cells form elongated hyphae, but the rate of hyphal elongation is significantly reduced. In addition, although wild type cells without microtubules still undergo polarized growth, microtubule disassembly abolishes polarized growth in MYOV-depleted cells. Thus, MYOV is essential for polarized growth in the absence of microtubules. Moreover, while a triple kinesin null mutant lacking kinesin-1 (KINA) and two kinesin-3s (UNCA and UNCB) undergoes hyphal elongation and forms a colony, depleting MYOV in this triple mutant results in lethality due to a severe defect in polarized growth. These results argue that MYOV, through its ability to transport secretory cargo, can support a significant amount of polarized hyphal tip growth in the absence of any microtubule-based transport. Finally, our genetic analyses also indicate that KINA (kinesin-1) rather than UNCA (kinesin-3) is the major kinesin motor that supports polarized growth in the absence of MYOV
Evaluation of genipin-crosslinked chitosan hydrogels as a potential carrier for silver sulfadiazine nanocrystals
This paper was accepted for publication in the journal Colloids and Surfaces B: Biointerfaces and the definitive published version is available at http://dx.doi.org/10.1016/j.colsurfb.2016.06.016In the present study genipin crosslinked chitosan (CHI) hydrogels, which had been
constructed and reported in our previous studies (Lei Gao, et al. Colloids Surf. B
Biointerfaces. 2014, 117: 398), were further evaluated for their advantage as a carrier
for silver sulfadiazine (AgSD) nanocrystal systems. Firstly, AgSD nanocrystals with a
mean particle size of 289 nm were prepared by wet milling method and encapsulated
into genipin crosslinked CHI hydrogels. AgSD nanocrystals displayed a uniform
distribution and very good physical stability in the hydrogel network.
Swelling-dependent release pattern was found for AgSD nanocrystals from hydrogels
and the release profile could be well fitted with Peppas equation. When AgSD
nanocrystals were encapsulated in hydrogels their fibroblast cytotoxicity decreased
markedly, and their antibacterial effects against Staphylococcus aureus, Escherichia
coli and Pseudomonas aeruginosa were still comparable to unencapsulated AgSD
nanocrystals. In vivo evaluation in excision and burn cutaneous wound models in
mice showed that AgSD nanocrystal hydrogels markedly decreased the expression of
inflammatory cytokine IL-6, but increased the levels of growth factors VEGF-A and
TGF-β1. Histopathologically, the wounds treated by hydrogels containing AgSD
nanocrystals showed the best healing state compared with commercial AgSD cream,
hydrogels containing AgSD bulk powders and blank hydrogels. The wounds treated
by AgSD nanocrystal hydrogels were dominated by marked fibroblast proliferation,
new blood vessels and thick regenerated epithelial layer. Sirius Red staining assay
indicated that AgSD nanocrystal hydrogels resulted in more collagen deposition
characterized by a large proportion of type I fibers. Our study suggested that
genipin-crosslinked CHI hydrogel was a potential carrier for local antibacterial
nanomedicines
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Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study
Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat
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Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study
The original version of this article unfortunately contained a mistake
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