Fabrication and Assembly of Patchy Particles with Uniform Patches

Patchy colloidal particles have been widely studied as the self-assembly building blocks to illustrate their potential for forming complex structures. The parameters affecting the final assembly structures include (i) patch size, shape, and number per particle, (ii) their relative positions, and (iii) the surface properties of the patch material. Recent computational studies have highlighted the impact of patch shape on assembly structure; however, there are only a limited number of methods that can provide control over patch shape and size. In this thesis, a template is introduced to the Glancing Angle Vapor Deposition method (GLAD) to create surface anisotropy on colloidal particles with uniform and controlled patch size and shape. Further, a mathematical model is derived that instructs the patchy particle fabrication process and also assists in the quantitative description of patch area. The template-assisted GLAD method is used to fabricate patchy particles, i.e., colloidal particles with a predefined patch on their surface. The patch size is controlled by varying the incident angle and rotation angle when particle size and template dimension are fixed. Due to the shadowing effect of the template and adjacent particles, a large variety of patch shapes can be achieved, including but not limited to symmetric semi-spherical caps and asymmetric crescent moon and triangular-shaped patches. A second vapor deposition enables the addition of another patch, which partly overlaps with the first patch. The mathematical model provides instruction on selecting adequate parameters to achieve a specific patch shape. In addition, it can also be used to calculate the patch size. In the model, the patch shape is defined in a three-dimensional space thereby enabling the description of various patch shapes obtained from the different fabrication parameters. Last but not least, the model also predicts patch position and calculates the size of the overlapping region of two patches. Overall, the template-assisted GLAD method is illustrated to be a powerful tool for the control of patch size, shape and uniformity, while providing the opportunity for scalability and reduced occurrence of defects. Such patchy particles with a specific patch shape and/or multiple patches made of different materials have great potential to provide more intricate assembly structures and potential applications

Pregabalin alleviates postherpetic neuralgia by downregulating spinal TRPV1 channel protein

Purpose: To determine the mechanism involved in pregabalin-induced alleviation of postherpetic neuralgia in a rat model.Methods: Ninety-sixty healthy Sprague-Dawley (SD) rats were assigned to sham, model andpregabalin groups (32 rats per group). A model of postherpetic neuralgia (PN) was established. The expressions of IL-1β and TNF-α in spinal cord tissue were determined 7 days after administration of treatments. The proportions of fluorescence areas in astrocytes in the dorsal horn, prefrontal lobe and hippocampus, and level of spinal cord TRPV1 channel protein in each group were evaluated.Results: Relative to model rats, IL-1β and TNF-α in spinal cord of pregabalin rats were significantly reduced (p < 0.05). The areas of fluorescence in astrocytes in dorsal horn of spinal cord, prefrontal lobe and hippocampus of model group were significantly increased, relative to sham, but were decreased in rats in pregabalin group (p < 0.05).Conclusion: Pregabalin significantly alleviates postherpetic neuralgia via mechanisms which may be related to the inflammatory response of spinal dorsal horn and downregulation of TRPV1 channel protein expression. This finding may be useful in developing new drugs for alleviating postherpetic neuralgia

Classification of Power Quality Disturbances Using Resnet with Channel Attention Mechanism

The detection and classification of power quality disturbances (PQDs) carries significant importance for power systems. In response to this imperative, numerous intelligent diagnostic methods have been developed. However, existing identification methods usually concentrate on single-type signals or on complex signals with two types, rendering them susceptible to noisy labels and environmental effects. This study proposes a novel method for the classification of PQDs, termed ST-GSResNet, which utilizes the S-Transform and an improved residual neural network (ResNet) with a channel attention mechanism. The ST-GSResNet approach initially uses the S-Transform to transform a time-series signal into a 2D time-frequency image for feature enhancement. Then, an improved ResNet model is introduced, which employs grouped convolution instead of the traditional convolution operation. This improvement aims to facilitate learning with a block-diagonal structured sparsity on the channel dimension, the highly-correlated filters are learned in a more structured way in the networks with filter groups. By reducing the number of parameters in the network in this significant manner, the model becomes less prone to overfitting. Furthermore, the SE module concentrates on primary components, which enhances the model\u27s robustness in recognition and immunity to noise. Experimental results demonstrate that, compared to existing deep learning models, our approach has advantages in computational efficiency and classification accuracy

Solitary pancreatic tuberculous abscess mimicking pancreatic cystadenocarcinoma: a case report

BACKGROUND: The incidence of pancreatic tuberculosis is extremely rare, and it frequently misdiagnosed as pancreatic neoplasms. The nonsurgical diagnosis of this entity continues to be a challenge. CASE PRESENTATION: A 33 year old male with six-month history of intermittent right epigastric vague pain and weight lost had found a solitary pancreatic cystic mass and diagnosed as pancreatic cystadenocarcinoma. The chest X-ray film and physical examination revealed no abnormalities. Abdominal ultrasound (US) examination showed an irregular hypoechoic lesion of 6.6 cm × 4.4 cm in the head of pancreas, and color Doppler flow imaging did not demonstrate blood stream in the mass. The attempts to obtain pathological evidence of the lesion by US-guided percutaneous fine needle aspiration failed, an exploratory laparotomy and incisional biopsy revealed a caseous abscess of the head of pancreas without typical changes of tuberculous granuloma, but acid-fast stain was positive. CONCLUSIONS: Pancreatic tuberculosis should be considered in the differential diagnosis of focal pancreatic lesions, especially for young people in developing countries

Mast Cell Degranulation and Fibroblast Activation in the Morphine-induced Spinal Mass: Role of Mas-related G Protein-coupled Receptor Signaling.

BackgroundAs the meningeally derived, fibroblast-rich, mass-produced by intrathecal morphine infusion is not produced by all opiates, but reduced by mast cell stabilizers, the authors hypothesized a role for meningeal mast cell/fibroblast activation. Using the guinea pig, the authors asked: (1) Are intrathecal morphine masses blocked by opiate antagonism?; (2) Do opioid agonists not producing mast cell degranulation or fibroblast activation produce masses?; and (3) Do masses covary with Mas-related G protein-coupled receptor signaling thought to mediate mast cell degranulation?MethodsIn adult male guinea pigs (N = 66), lumbar intrathecal catheters connected to osmotic minipumps (14 days; 0.5 µl/h) were placed to deliver saline or equianalgesic concentrations of morphine sulfate (33 nmol/h), 2',6'-dimethyl tyrosine-(Tyr-D-Arg-Phe-Lys-NH2) (abbreviated as DMT-DALDA; 10 pmol/h; μ agonist) or PZM21 (27 nmol/h; biased μ agonist). A second pump delivered subcutaneous naltrexone (25 µg/h) in some animals. After 14 to 16 days, animals were anesthetized and perfusion-fixed. Drug effects on degranulation of human cultured mast cells, mouse embryonic fibroblast activation/migration/collagen formation, and Mas-related G protein-coupled receptor activation (PRESTO-Tango assays) were determined.ResultsIntrathecal infusion of morphine, DMT-DALDA or PZM21, but not saline, comparably increased thermal thresholds for 7 days. Spinal masses proximal to catheter tip, composed of fibroblast/collagen type I (median: interquartile range, 0 to 4 scale), were produced by morphine (2.3: 2.0 to 3.5) and morphine plus naltrexone (2.5: 1.4 to 3.1), but not vehicle (1.2: 1.1 to 1.5), DMT-DALDA (1.0: 0.6 to 1.3), or PZM21 (0.5: 0.4 to 0.8). Morphine in a naloxone-insensitive fashion, but not PZM21 or DMT-DALDA, resulted in mast cell degranulation and fibroblast proliferation/collagen formation. Morphine-induced fibroblast proliferation, as mast cell degranulation, is blocked by cromolyn. Mas-related G protein-coupled receptor activation was produced by morphine and TAN67 (∂-opioid agonist), but not by PZM21, TRV130 (mu biased ligand), or DMT-DALDA.ConclusionsOpiates that activate Mas-related G protein-coupled receptor will degranulate mast cells, activate fibroblasts, and result in intrathecal mass formation. Results suggest a mechanistically rational path forward to safer intrathecal opioid therapeutics

Study on Flow and Heat Transfer Characteristics of a New-Proposed Alternating Elliptical U-Channel in the Midchord Region of Gas Turbine Blade

Abstract This paper proposed an alternating elliptical U-bend cooling channel, which can be applied in the midchord region of gas turbine blade and manufactured by precision casting, based on the optimal flow field structure deduced from the field synergy principle, and investigated the flow and heat transfer characteristics in this alternating elliptical U-bend cooling channel thoroughly. Numerical simulations were performed by using three-dimensional steady solver of Reynolds-averaged Navier–Stokes equations with the standard k–ε turbulence model. The influence of alternating of cross section on heat transfer and pressure drop of the channel was studied by comparing with the smooth elliptical U-bend channel. On this basis, the effect of aspect ratio (length ratio of the major axis to the minor axis) and alternating angle were further investigated. The results showed that, in the first pass of the alternating elliptical U-bend channel, for different Re, four or eight longitudinal vortices were generated. In the second pass, the alternating elliptical channel restrained the flow separation to a certain extent and a double-vortex structure was formed. The averaged Nusselt number of the alternating elliptical U-bend channel was significantly higher than that of the smooth channel, but the pressure loss only increased slightly. With the increase of aspect ratio, the thermal performance of the channel increased, and when the alternating angle is between 40 deg and 90 deg, the thermal performance nearly kept constant and also the best.</jats:p

Solitary pancreatic tuberculous abscess mimicking pancreatic cystadenocarcinoma: a case report

Abstract Background The incidence of pancreatic tuberculosis is extremely rare, and it frequently misdiagnosed as pancreatic neoplasms. The nonsurgical diagnosis of this entity continues to be a challenge. Case presentation A 33 year old male with six-month history of intermittent right epigastric vague pain and weight lost had found a solitary pancreatic cystic mass and diagnosed as pancreatic cystadenocarcinoma. The chest X-ray film and physical examination revealed no abnormalities. Abdominal ultrasound (US) examination showed an irregular hypoechoic lesion of 6.6 cm × 4.4 cm in the head of pancreas, and color Doppler flow imaging did not demonstrate blood stream in the mass. The attempts to obtain pathological evidence of the lesion by US-guided percutaneous fine needle aspiration failed, an exploratory laparotomy and incisional biopsy revealed a caseous abscess of the head of pancreas without typical changes of tuberculous granuloma, but acid-fast stain was positive. Conclusions Pancreatic tuberculosis should be considered in the differential diagnosis of focal pancreatic lesions, especially for young people in developing countries.</p