3,800 research outputs found
Clinicopathologic features and outcomes following surgery for pancreatic adenosquamous carcinoma
<p>Abstract</p> <p>Background</p> <p>Pancreatic adenosquamous carcinoma (ASC) is a rare pancreatic malignancy subtype. We investigated the clinicopathological features and outcome of pancreatic ASC patients after surgery.</p> <p>Methods</p> <p>The medical records of 12 patients with pancreatic ASC undergoing surgical treatment (1993 to 2006) were retrospectively reviewed. Survival data of patients with stage IIB pancreatic adenocarcinoma and ASC undergoing surgical resection were compared.</p> <p>Results</p> <p>Symptoms included abdominal pain (91.7%), body weight loss (83.3%), anorexia (41.7%) and jaundice (25.0%). Tumors were located at pancreatic head in 5 (41.7%) patients, tail in 5 (41.7%), and body in 4 (33.3%). Median tumor size was 6.3 cm. Surgical resection was performed on 7 patients, bypass surgery on 3, and exploratory laparotomy with biopsy on 2. No surgical mortality was identified. Seven (58.3%) and 11 (91.7%) patients died within 6 and 12 months of operation, respectively. Median survival of 12 patients was 4.41 months. Seven patients receiving surgical resection had median survival of 6.51 months. Patients with stage IIB pancreatic ASC had shorter median survival compared to those with adenocarcinoma.</p> <p>Conclusion</p> <p>Aggressive surgical management does not appear effective in treating pancreatic ASC patients. Strategies involving non-surgical treatment such as chemotherapy, radiotherapy or target agents should be tested.</p
Brain Microvascular Injury and White Matter Disease Provoked by Diabetes-Associated Hyperamylinemia
OBJECTIVE: The brain blood vessels of patients with type 2 diabetes and dementia have deposition of amylin, an amyloidogenic hormone cosecreted with insulin. It is not known whether vascular amylin deposition is a consequence or a trigger of vascular injury. We tested the hypothesis that the vascular amylin deposits cause endothelial dysfunction and microvascular injury and are modulated by amylin transport in the brain via plasma apolipoproteins.
METHODS: Rats overexpressing amyloidogenic (human) amylin in the pancreas (HIP rats) and amylin knockout (AKO) rats intravenously infused with aggregated amylin were used for in vivo phenotyping. We also carried out biochemical analyses of human brain tissues and studied the effects of the aggregated amylin on endothelial cells ex vivo.
RESULTS: Amylin deposition in brain blood vessels is associated with vessel wall disruption and abnormal surrounding neuropil in patients with type 2 diabetes and dementia, in HIP rats, and in AKO rats infused with aggregated amylin. HIP rats have brain microhemorrhages, white matter injury, and neurologic deficits. Vascular amylin deposition provokes loss of endothelial cell coverage and tight junctions. Intravenous infusion in AKO rats of human amylin, or combined human amylin and apolipoprotein E4, showed that amylin binds to plasma apolipoproteins. The intravenous infusion of apolipoprotein E4 exacerbated the brain accumulation of aggregated amylin and vascular pathology in HIP rats.
INTERPRETATION: These data identify vascular amylin deposition as a trigger of brain endothelial dysfunction that is modulated by plasma apolipoproteins and represents a potential therapeutic target in diabetes-associated dementia and stroke. Ann Neurol 2017;82:208-222
Recommended from our members
High-Quality Draft Genome Sequence of Desulfovibrio carbinoliphilus FW-101-2B, an Organic Acid-Oxidizing Sulfate-Reducing Bacterium Isolated from Uranium(VI)-Contaminated Groundwater.
Desulfovibrio carbinoliphilus subsp. oakridgensis FW-101-2B is an anaerobic, organic acid/alcohol-oxidizing, sulfate-reducing δ-proteobacterium. FW-101-2B was isolated from contaminated groundwater at The Field Research Center at Oak Ridge National Lab after in situ stimulation for heavy metal-reducing conditions. The genome will help elucidate the metabolic potential of sulfate-reducing bacteria during uranium reduction
Strain Anisotropy Driven Spontaneous Formation of Nanoscrolls from Two-Dimensional Janus Layers
Two-dimensional Janus transition metal dichalcogenides (TMDs) have attracted
attention due to their emergent properties arising from broken mirror symmetry
and self-driven polarisation fields. While it has been proposed that their vdW
superlattices hold the key to achieving superior properties in piezoelectricity
and photovoltiacs, available synthesis has ultimately limited their
realisation. Here, we report the first packed vdW nanoscrolls made from Janus
TMDs through a simple one-drop solution technique. Our results, including
ab-initio simulations, show that the Bohr radius difference between the top
sulphur and the bottom selenium atoms within Janus M_Se^S (M=Mo, W) results in
a permanent compressive surface strain that acts as a nanoscroll formation
catalyst after small liquid interaction. Unlike classical 2D layers, the
surface strain in Janus TMDs can be engineered from compressive to tensile by
placing larger Bohr radius atoms on top (M_S^Se) to yield inverted C scrolls.
Detailed microscopy studies offer the first insights into their morphology and
readily formed Moir\'e lattices. In contrast, spectroscopy and FETs studies
establish their excitonic and device properties and highlight significant
differences compared to 2D flat Janus TMDs. These results introduce the first
polar Janus TMD nanoscrolls and introduce inherent strain-driven scrolling
dynamics as a catalyst to create superlattices
Preparation and Application of Starch/Polyvinyl Alcohol/Citric Acid Ternary Blend Antimicrobial Functional Food Packaging Films
Ternary blend films were prepared with different ratios of starch/polyvinyl alcohol (PVA)/citric acid. The films were characterized by field emission scanning electron microscopy (FE-SEM), thermogravimetric analysis, as well as Fourier transform infrared (FTIR) analysis. The influence of different ratios of starch/polyvinyl alcohol (PVA)/citric acid and different drying times on the performance properties, transparency, tensile strength (TS), water vapor permeability (WVP), water solubility (WS), color difference (ΔE), and antimicrobial activity of the ternary blends films were investigated. The starch/polyvinyl alcohol/citric acid (S/P/C1:1:0, S/P/C3:1:0.08, and S/P/C3:3:0.08) films were all highly transparent. The S/P/C3:3:0.08 had a 54.31 times water-holding capacity of its own weight and its mechanical tensile strength was 46.45 MPa. In addition, its surface had good uniformity and compactness. The S/P/C3:1:0.08 and S/P/C3:3:0.08 showed strong antimicrobial activity to Listeria monocytogenes and Escherichia coli, which were the food-borne pathogenic bacteria used. The freshness test results of fresh figs showed that all of the blends prevented the formation of condensed water on the surface of the film, and the S/P/C3:1:0.08 and S/P/C3:3:0.08 prevented the deterioration of figs during storage. The films can be used as an active food packaging system due to their strong antibacterial effect
Hyperbaric oxygen therapy improves colorectal anastomotic healing
Purpose: Hyperbaric oxygen treatment (HBOT) has been found to improve the healing of poorly oxygenated tissues. This study aimed to investigate the influence of HBOT on the healing in ischemic colorectal anastomosis. Methods: Forty Wistar rats were randomly divided into a treatment group that received HBOT for 10 consecutive days (7 days before and 3 days after surgery), or in a control group, which did not receive the therapy. Colectomy with an ischemic anastomosis was performed in all rats. In each group, the rats were followed for 3 or 7 days after surgery to determine the influence of HBOT on anastomotic healing. Results: Five rats from each group died during follow-up. No anastomotic dehiscence was seen in the HBOT group, compared to 37.5 % and 28.6 % dehiscence in the control group on postoperative day (POD) 3 and 7, respectively. The HBOT group had a significantly higher bursting pressure (130.9 ± 17.0 mmHg) than the control group (88.4 ± 46.7 mmHg; p = 0.03) on POD 3. On POD 3 and POD 7, the adhesion severity was significantly higher in the control groups than in the HBOT groups (p < 0.005). Kidney function (creatinine level) of the HBOT group was significantly better than of the control group on POD 7 (p = 0.001). Interestingly, a significantly higher number of CD206+ cells (marker for type 2 macrophages) was observed in the HBOT group at the anastomotic area on POD 3. Conclusion: Hyperbaric oxygen enhanced the healing of ischemic anastomoses in rats and improved the postoperative kidney function
In-plane magnetic domains and N\'eel-like domain walls in thin flakes of the room temperature CrTe van der Waals ferromagnet
The recent discovery of magnetic van der Waals materials has triggered a
wealth of investigations in materials science, and now offers genuinely new
prospects for both fundamental and applied research. Although the catalogue of
van der Waals ferromagnets is rapidly expanding, most of them have a Curie
temperature below 300 K, a notable disadvantage for potential applications.
Combining element-selective x-ray magnetic imaging and magnetic force
microscopy, we resolve at room temperature the magnetic domains and domains
walls in micron-sized flakes of the CrTe van der Waals ferromagnet.
Flux-closure magnetic patterns suggesting in-plane six-fold symmetry are
observed. Upon annealing the material above its Curie point (315 K), the
magnetic domains disappear. By cooling back down the sample, a different
magnetic domain distribution is obtained, indicating material stability and
lack of magnetic memory upon thermal cycling. The domain walls presumably have
N\'eel texture, are preferentially oriented along directions separated by 120
degrees, and have a width of several tens of nanometers. Besides microscopic
mapping of magnetic domains and domain walls, the coercivity of the material is
found to be of a few mT only, showing that the CrTe compound is
magnetically soft. The coercivity is found to increase as the volume of the
material decreases
Complex 3D microfluidic architectures formed by mechanically guided compressive buckling.
Microfluidic technologies have wide-ranging applications in chemical analysis systems, drug delivery platforms, and artificial vascular networks. This latter area is particularly relevant to 3D cell cultures, engineered tissues, and artificial organs, where volumetric capabilities in fluid distribution are essential. Existing schemes for fabricating 3D microfluidic structures are constrained in realizing desired layout designs, producing physiologically relevant microvascular structures, and/or integrating active electronic/optoelectronic/microelectromechanical components for sensing and actuation. This paper presents a guided assembly approach that bypasses these limitations to yield complex 3D microvascular structures from 2D precursors that exploit the full sophistication of 2D fabrication methods. The capabilities extend to feature sizes <5 ÎĽm, in extended arrays and with various embedded sensors and actuators, across wide ranges of overall dimensions, in a parallel, high-throughput process. Examples include 3D microvascular networks with sophisticated layouts, deterministically designed and constructed to expand the geometries and operating features of artificial vascular networks
Deep-Learning-Enabled Fast Optical Identification and Characterization of Two-Dimensional Materials
Advanced microscopy and/or spectroscopy tools play indispensable role in
nanoscience and nanotechnology research, as it provides rich information about
the growth mechanism, chemical compositions, crystallography, and other
important physical and chemical properties. However, the interpretation of
imaging data heavily relies on the "intuition" of experienced researchers. As a
result, many of the deep graphical features obtained through these tools are
often unused because of difficulties in processing the data and finding the
correlations. Such challenges can be well addressed by deep learning. In this
work, we use the optical characterization of two-dimensional (2D) materials as
a case study, and demonstrate a neural-network-based algorithm for the material
and thickness identification of exfoliated 2D materials with high prediction
accuracy and real-time processing capability. Further analysis shows that the
trained network can extract deep graphical features such as contrast, color,
edges, shapes, segment sizes and their distributions, based on which we develop
an ensemble approach topredict the most relevant physical properties of 2D
materials. Finally, a transfer learning technique is applied to adapt the
pretrained network to other applications such as identifying layer numbers of a
new 2D material, or materials produced by a different synthetic approach. Our
artificial-intelligence-based material characterization approach is a powerful
tool that would speed up the preparation, initial characterization of 2D
materials and other nanomaterials and potentially accelerate new material
discoveries
Spontaneous honeybee behaviour is altered by persistent organic pollutants
The effect of environmental pollutants on honeybee behaviour has focused mainly on currently used pesticides. However, honeybees are also exposed to persistent organic pollutants (POPs). The aim of this laboratory based study was to determine if exposure to sublethal field-relevant concentrations of POPs altered the spontaneous behaviour of foraging-age worker honeybees. Honeybees (Apis mellifera) were orally exposed to either a sublethal concentration of the polychlorinated biphenyl (PCB) mixture Aroclor 1254 (100 ng/ml), the organochlorine insecticide lindane (2.91 ng/ml) or vehicle (0.01% DMSO, 0.00015% ethanol in 1M sucrose) for 1–4 days. The frequency of single event behaviours and the time engaged in one of four behavioural states (walking, flying, upside down and stationary) were monitored for 15 min after 1, 2, 3 and 4 days exposure. Exposure to Aroclor 1254 but not lindane increased the frequency and time engaged in honeybee motor activity behaviours in comparison to vehicle. The Aroclor 1254—induced hyperactivity was evident after 1 day of exposure and persisted with repeated daily exposure. In contrast, 1 day of exposure to lindane elicited abdominal spasms and increased the frequency of grooming behaviours in comparison to vehicle exposure. After 4 days of exposure, abdominal spasms and increased grooming behaviours were also evident in honeybees exposed to Aroclor 1254. These data demonstrate that POPs can induce distinct behavioural patterns, indicating different toxicokinetic and toxicodynamic properties. The changes in spontaneous behaviour, particularly the PCB-induced chronic hyperactivity and the associated energy demands, may have implications for colony health
- …