909 research outputs found
Staged and non-staged anaerobic filters : microbial activity segregation, hydrodynamic behaviour and performance
This work describes a comparative study of staged and non-staged anaerobic flters for treating a synthetic dairy waste under similar operating conditions.
The effect of increasing the substrate concentration from 3 to 12 g COD dmˉ³ at a constant hydraulic residence time (HRT) of 2 days was evaluated with
respect to overall reactor performance, biogas production, volatile fatty acids
profiles along the height, methanogenic and acidogenic activity distribution, and
hydrodynamic behaviour. The potential maximum specific methanogenic activity
against acetate, hydrogen, propionate and butyrate and the lactose specific activity
were determined for sludge sampled from three different points in each
reactor, under two operating conditions (influent COD of 3 and 9 g COD
dmˉ³). Although all trophic groups involved in the anaerobic process were
found throughout the reactors, it was possible to identify different specific
sludges at different heights in both reactors. Performances of the two configurations
were very similar under the operating conditions tested and the plug flow
behaviour of the staged reactor was clearly reduced when the influent concentration
increased from 3 to 9 g COD dmˉ³.EU Human Capital and Mobility network Improved Application of Anaerobic
Digestion Technology - EXBCHRXCT 930262.Fundação para a Ciência e a Tecnologia – PEAM/SEL/517/95
Post-Stenotic Recirculating Flow May Cause Hemodynamic Perforator Infarction
Background and Purpose The primary mechanism underlying paramedian pontine infarction (PPI) is atheroma obliterating the perforators. Here, we encountered a patient with PPI in the post-stenotic area of basilar artery (BA) without a plaque, shown, by high-resolution magnetic resonance imaging (HR-MRI). We performed an experiment using a 3D-printed BA model and a particle image velocimetry (PIV) to explore the hemodynamic property of the post-stenotic area and the mechanism of PPI. Methods 3D-model of a BA stenosis was reconstructed with silicone compound using a 3D printer based on the source image of HR-MRI. Working fluid seeded with fluorescence particles was used and the velocity of those particles was measured horizontally and vertically. Furthermore, microtubules were inserted into the posterior aspect of the model to measure the flow rates of perforators (pre- and post-stenotic areas). The flow rates were compared between the microtubules. Results A recirculating flow was observed from the post-stenotic area in both directions forming a spiral shape. The velocity of the flow in these regions of recirculation was about one-tenth that of the flow in other regions. The location of recirculating flow well corresponded with the area with low-signal intensity at the time-of-flight magnetic resonance angiography and the location of PPI. Finally, the flow rate through the microtubule inserted into the post-stenotic area was significantly decreased comparing to others (P<0.001). Conclusions Perforator infarction may be caused by a hemodynamic mechanism altered by stenosis that induces a recirculation flow. 3D-printed modeling and PIV are helpful understanding the hemodynamics of intracranial stenosis.114Ysciescopu
Artificial Neural Network Inference (ANNI): A Study on Gene-Gene Interaction for Biomarkers in Childhood Sarcomas
Objective: To model the potential interaction between previously identified biomarkers in children sarcomas using artificial neural network inference (ANNI).
Method: To concisely demonstrate the biological interactions between correlated genes in an interaction network map, only 2 types of sarcomas in the children small round blue cell tumors (SRBCTs) dataset are discussed in this paper. A backpropagation neural network was used to model the potential interaction between genes. The prediction weights and signal directions were used to model the strengths of the interaction signals and the direction of the interaction link between genes. The ANN model was validated using Monte Carlo cross-validation to minimize the risk of over-fitting and to optimize generalization ability of the model.
Results: Strong connection links on certain genes (TNNT1 and FNDC5 in rhabdomyosarcoma (RMS); FCGRT and OLFM1 in Ewing’s sarcoma (EWS)) suggested their potency as central hubs in the interconnection of genes with different functionalities. The results showed that the RMS patients in this dataset are likely to be congenital and at low risk of cardiomyopathy development. The EWS patients are likely to be complicated by EWS-FLI fusion and deficiency in various signaling pathways, including Wnt, Fas/Rho and intracellular oxygen.
Conclusions: The ANN network inference approach and the examination of identified genes in the published literature within the context of the disease highlights the substantial influence of certain genes in sarcomas
Safety and efficacy of conversion from twice-daily tacrolimus to once-daily tacrolimus one month after transplantation: randomized controlled trial in adult renal transplantation.
PURPOSE: The purpose of this study was to compare once-daily tacrolimus with
twice-daily tacrolimus in terms of safety, efficacy, and patient satisfaction.
MATERIALS AND METHODS: This prospective, randomized, open-label, multicenter
study was conducted at three institutes. Patients in the investigational group
were converted from tacrolimus twice daily to the same dose of extended-release
tacrolimus once daily at 1 month post-transplantation, while patients in the
control group were maintained on tacrolimus twice daily. The efficacies,
safeties, and patient satisfaction for the two drugs at 6 months
post-transplantation were compared. RESULTS: Sixty patients were enrolled and
randomized to the investigational group (28 of 29 patients completed the study)
or the control group (26 of 31 patients completed the study). At 6 months
post-transplantation, composite efficacy failure rates including the incidences
of biopsy-confirmed acute rejection in the investigational and control groups
were 0% and 10.7%, respectively; patient survival was 100% in each group. No
difference in estimated glomerular filtration rate values were observed at 6
months post-transplantation (p=0.97). The safety and satisfaction profile
(immunosuppressant therapy barrier scale) of once-daily tacrolimus was comparable
with that of twice-daily tacrolimus (p=0.35). CONCLUSION: Conversion from
twice-daily tacrolimus to once-daily tacrolimus one month after transplantation
is safe and effective
Natural course of fatty liver in 36,195 South Korean adults
Nonalcoholic fatty liver disease (NAFLD) is the most common cause of liver disease, and yet the natural course remains unclear. Study population included 36,195 individuals who participated in a health-screening program and diagnosed with fatty liver by abdominal ultrasound. Participants were provided written information regarding fatty liver and advised to make lifestyle changes. Ultrasound was repeated after at least 6 months. After a mean follow up of 4.9 years (+/-3.4), 19.6% resolved their fatty liver. Individuals who resolved were more likely female (22.9% vs. 12.3%), thinner (body mass index [BMI], 25.2 +/- 2.7 vs. 26 +/- 2.7), and with lower HOMA-IR (1.4 vs. 1.7) (P .70.001). Decrease in BMI predicted resolution of fatty liver with 42% of those in the top quartile of BMI decline resolving compared with 5.7% in the lowest quartile (odds ratio [OR] (95% confidence interval [CI]) 15.65 (14.13-17.34), P < 0.001)). Baseline HOMA-IR also predicted resolution with those in the top quartile (most insulin resistant) being least likely to resolve (12%) vs. those in the lowest quartile (25%) (OR 0.36 [0.31-0.42], P < 0.001). Fatty liver disease is persistent. Individuals with higher degree of insulin resistance are also the most likely to have persistent steatosis at follow up
Cigarette smoking is an independent risk factor for post-stroke delirium
BACKGROUND: Post-stroke delirium is a common problem in the care of stroke patients, and is associated with longer hospitalization, high short-term mortality, and an increased need for long-term care. Although post-stroke delirium occurs in approximately 10 ~ 30% of patients, little is known about the risk factors for post-stroke delirium in patients who experience acute stroke.
METHODS: A total of 576 consecutive patients who experienced ischemic stroke (mean age, 65.2 years: range, 23-93 years) were screened for delirium over a 2-year period in an acute stroke care unit of a tertiary referral hospital. We screened for delirium using the Confusion Assessment Method. Once delirium was suspected, we evaluated the symptoms using the Korean Version of the Delirium Rating Scale-Revised-98. Neurological deficits were assessed using the National Institutes of Health Stroke Scale at admission and discharge, and functional ability was assessed using the Barthel Index and modified Rankin Scale at discharge and 3 months after discharge.
RESULTS: Thirty-eight (6.7%) patients with stroke developed delirium during admission to the acute stroke care unit. Patients with delirium were significantly older (70.6 vs. 64.9 years of age, P = .001) and smoked cigarettes more frequently (40% vs. 24%, P = .033) than patients without delirium. In terms of clinical features, the delirium group experienced a significantly higher rate of major hemispheric stroke (55% vs. 26%, P < .001), exhibited poorer functional performance at discharge and 3 months after discharge, and stayed in hospital significantly longer. Independent risk factors for delirium were older age, history of cigarette smoking, and major hemispheric stroke.
CONCLUSION: Abrupt cessation of cigarette smoking may be a risk factor for post-stroke delirium in ischemic stroke patients. The development of delirium after stroke is associated with worse outcome and longer hospitalization
Three cases of pancreatic pseudocysts associated with dorsal pancreatic agenesis
Agenesis of the dorsal pancreas (ADP) is an extremely rare congenital anomaly. Human pancreas is formed by ventral and dorsal endodermal buds of the foregut endoderm. The dorsal bud forms the upper part of the head, neck, body, and tail of the pancreas and the ventral bud generates most of the head and uncinate process. ADP is derived from the embryologic failure of the dorsal pancreatic bud to form the pancreatic body and tail. ADP can be related to some diseases and conditions such as pancreatitis, hypoglycemia, and rarely pancreatic tumors. The association between cystic lesions with ADP has previously been reported. Three cases of cystic lesions of the pancreas with ADP were diagnosed clinically based on the imaging features and without any past history of pancreatitis. However, the pathologic diagnosis of resected lesions confirmed pseudocysts without pathologic evidence of tumor. We report 3 cases of pancreatic pseudocysts associated with ADP
Lymph Node Ratio as a Risk Factor for Locoregional Recurrence in Breast Cancer Patients with 10 or More Axillary Nodes
PURPOSE: We analyzed the association of lymph node ratio (LNR) wth locoregional control (LRC) in breast cancer patients with >/=10 involved axillary lymph nodes who underwent multimodality treatment. METHODS: We retrospectively analyzed 234 breast cancer patients with >/=10 involved axillary lymph nodes between 2000 and 2011. All patients received adjuvant chemotherapy and radiotherapy (RT) after radical surgery. The cutoff value of LNR was obtained using receiver operating characteristic curve analysis. The majority of patients (87.2%) received chemotherapeutic regimen including taxane. RT consisted of tangential fields to the chest wall or intact breast, delivered at a median dose of 50 Gy, and a single anterior port to the supraclavicular lymph node area, delivered at a median dose of 50 Gy. For patients who underwent breast-conserving surgery, an electron boost with a total dose of 9 to 15 Gy was delivered to the tumor bed. RESULTS: Within a median follow-up period of 73.5 months (range, 11-183 months), locoregional recurrence (LRR) occurred in 30 patients (12.8%) and the 5-year LRC rate was 88.8%. After multivariate analysis, LNR >/=0.7 was the only independent factor significantly associated with LRC (hazard ratio, 2.06: 95% confidence interval, 0.99-4.29: p=0.05). CONCLUSION: An aggressive multimodal treatment approach showed favorable locoregional outcome in patients with >/=10 involved axillary lymph nodes. However, patients with a high LNR >/=0.7 still had an increased risk for LRR, even in the setting of current local treatments
Dominant mutations of the Notch ligand Jagged1 cause peripheral neuropathy
Notch signaling is a highly conserved intercellular pathway with tightly regulated and pleiotropic roles in normal tissue development and homeostasis. Dysregulated Notch signaling has also been implicated in human disease, including multiple forms of cancer, and represents an emerging therapeutic target. Successful development of such therapeutics requires a detailed understanding of potential on-target toxicities. Here, we identify autosomal dominant mutations of the canonical Notch ligand Jagged1 (or JAG1) as a cause of peripheral nerve disease in 2 unrelated families with the hereditary axonal neuropathy Charcot-Marie-Tooth disease type 2 (CMT2). Affected individuals in both families exhibited severe vocal fold paresis, a rare feature of peripheral nerve disease that can be life-threatening. Our studies of mutant protein posttranslational modification and localization indicated that the mutations (p.Ser577Arg, p.Ser650Pro) impair protein glycosylation and reduce JAG1 cell surface expression. Mice harboring heterozygous CMT2-associated mutations exhibited mild peripheral neuropathy, and homozygous expression resulted in embryonic lethality by midgestation. Together, our findings highlight a critical role for JAG1 in maintaining peripheral nerve integrity, particularly in the recurrent laryngeal nerve, and provide a basis for the evaluation of peripheral neuropathy as part of the clinical development of Notch pathway–modulating therapeutics
Selective Molecular Sieving through Porous Graphene
Membranes act as selective barriers and play an important role in processes
such as cellular compartmentalization and industrial-scale chemical and gas
purification. The ideal membrane should be as thin as possible to maximize
flux, mechanically robust to prevent fracture, and have well-defined pore sizes
to increase selectivity. Graphene is an excellent starting point for developing
size selective membranes because of its atomic thickness, high mechanical
strength, relative inertness, and impermeability to all standard gases.
However, pores that can exclude larger molecules, but allow smaller molecules
to pass through have to be introduced into the material. Here we show
UV-induced oxidative etching can create pores in micrometre-sized graphene
membranes and the resulting membranes used as molecular sieves. A pressurized
blister test and mechanical resonance is used to measure the transport of a
variety of gases (H2, CO2, Ar, N2, CH4, and SF6) through the pores. The
experimentally measured leak rates, separation factors, and Raman spectrum
agree well with models based on effusion through a small number of
angstrom-sized pores.Comment: to appear in Nature Nanotechnolog
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