Search

Microneedles (MNs) have emerged as an innovative, virtually painless technique for intradermal drug delivery. However, the complex and costly fabrication process has limited their widespread accessibility, especially for individuals requiring frequent drug administration. This study introduces a groundbreaking and cost-effective method for producing MNs utilizing fused deposition modeling (FDM) 3D printing technology to enhance transdermal drug delivery. The proposed fabrication process involves the elongation of molten polylactic acid (PLA) filaments to create meticulously designed conoid and neiloid MNs with smooth surfaces. This study underscores the critical role of printing parameters, particularly extrusion length and printing speed, in determining the shape of the MNs. Notably, the conoid-shaped MNs exhibit exceptional skin-penetrating capabilities. In order to evaluate their effectiveness, the MNs were tested on a polydimethylsiloxane (PDMS) skin model for skin penetration. The results highlight the high potential of 3D-printed MNs for transdermal drug administration. This novel approach capitalizes on the benefits of 3D printing technology to fabricate MNs that hold the promise of transforming painless drug administration for a variety of medical applications. [ABSTRACT FROM AUTHOR]

Copyright of Rare Metals is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The development of tumors is a complex pathological process involving multiple factors, multiple steps, and multiple genes. Their prevention and treatment have always been a difficult problem at present. A large number of studies have proved that the tumor microenvironment plays an important role in the progression of tumors. The tumor microenvironment is the place where tumor cells depend for survival, and it plays an important role in regulating the growth, proliferation, apoptosis, migration, and invasion of tumor cells. P2X purinergic receptors, which depend on the ATP ion channel, can be activated by ATP in the tumor microenvironment, and by mediating tumor cells and related cells (such as immune cells) in the tumor microenvironment. They play an important regulatory role on the effects of the skeleton, membrane fluidity, and intracellular molecular metabolism of tumor cells. Therefore, here, we outlined the biological characteristics of P2X purinergic receptors, described the effect of tumor microenvironment on tumor progression, and discussed the effect of ATP on tumor. Moreover, we explored the role of P2X purinergic receptors in the development of tumors and anti-tumor therapy. These data indicate that P2X purinergic receptors may be used as another potential pharmacological target for tumor prevention and treatment. [ABSTRACT FROM AUTHOR]

Objectives: Meta-analysis was used to determine the association between rs3751143 polymorphism of P2RX7 gene and the risk of chronic lymphocytic leukemia (CLL). Methods: Search for published articles about the association between the rs3751143 and CLL in PubMed, MEDINE, Web of Science, and Embase databases, with a calculated odds ratio of (OR) and 95% confidence interval (95%CI). Results: A total of 1184 cases and 1725 controls in 8 studies were pooled together for evaluation of the overall association between rs3751143 and risk of CLL. Allele model (A vs C, p = 0.16, OR = 0.85, 95%CI = 0.71–1.17), homozygous model (AA vs CC, p = 0.07; OR = 0.78, 95%CI = 0.84–1.08), and heterozygous model (AC vs CC, p = 0.76; OR = 0.85; 95%CI = 0.68–0.79) did not show decreased risk of developing CLL. Similarly, dominant model (AA + AC vs. CC: p = 0.58; OR = 1.10, 95%CI = 0.69–1.75), and recessive model (AA vs AC + CC, p = 0.21, OR = 1.18, 95%CI = 0.70–1.99) failed to show decreased risk of developing CLL. However, in familial, heterozygous model (AC vs. CC: p = 0.0006, OR = 0.64, 95%CI = 0.67–1.50) and recessive model (AA vs. AC + CC: p = 0.0017; OR = 1.02, 95%CI = 0.73–2.35) indicated the association between the inheritance of rs3751143 and the risk of developing CLL. In the overall survival prognosis, no significant association between rs3751143 and CLL was detected with relatively high heterogeneity. Conclusions: Our pooled data indicates that there is a correlation between the inheritance of rs3751143 and the risk of CLL in familial. [ABSTRACT FROM AUTHOR]

Functionalized silica gel organic-inorganic hybrid materials based on covalently grafted lanthanide coordinations onto organosilicone have been the subject of intense study due to their superior physicochemical properties. However, it cannot be assumed that all the primary guest molecules can be directly covalent-grafted onto the host that prevents H2O molecules from coordinating with the central ion; the introduction of a medium could be useful in this regard. In the present work, a medium β-cyclodextrin (β-CD) was employed, and by sol-gel and molecular assembly processes, immobilization of a europium-β-CD inclusion on silica and the preparation of a novel fluorescent polymeric hybrid material β-CD-TESPIC-TTA-Eu were achieved. This research shows that β-CD can prevent the H2O molecules from coordinating with the central ion Eu3+ (inclusion). The novel hybrid material has an amorphous and homogeneous network surface and exhibits excellent film-forming properties, bright-red light emission that is dominated by the 5D0 → 7F2 transition of Eu3+, and a lifetime of 0.44 ms. [ABSTRACT FROM AUTHOR]

In motion estimation, illumination change is always a troublesome obstacle, which often causes severely performance reduction of optical flow computation. The essential reason is that most of estimation methods fail to formalize a unified definition in color or gradient domain for diverse environmental changes. In this paper, we propose a new solution based on deep convolutional networks to solve the key issue. Our idea is to train deep convolutional networks to represent the complex motion features under illumination change, and further predict the final optical flow fields. To this end, we construct a training dataset of multi-exposure image pairs by performing a series of non-linear adjustments in the traditional datasets of optical flow estimation. Our multi-exposure flow networks (MEFNet) model consists of three main components: low-level feature network, fusion feature network, and motion estimation network. The former two components belong to the contracting part of our model in order to extract and represent the multi-exposure motion features; the third component is the expanding part of our model in order to learn and predict the high-quality optical flow. Compared with many state-of-the-art methods, our motion estimation method can eliminate the obstacle of illumination change and yield optical flow results with competitive accuracy and time efficiency. Moreover, the good performance of our model is also demonstrated in some multi-exposure video applications, like HDR (high dynamic range) composition and flicker removal. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Zhejiang University: Science B is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objectives: To summarize the computed tomography (CT) and magnetic resonance imaging (MRI) findings of rare primitive neuroectodermal tumors (PNETs) in the maxillofacial region. Methods: The clinical data, and CT and MRI findings of seven patients with pathologically proven PNETs in the maxillofacial region were retrospectively reviewed. The patients comprised five males and two females with a mean age of 16.4 years. The tumor location, size, margin, CT attenuation or signal intensity, contrast enhancement characteristics, and involvement of adjacent tissues were assessed. Results: There were a total of seven tumors. Four lesions were located in the masticator space. The lesions were seen as ill-defined ( n = 6) or well-defined ( n = 1) aggressive masses with a mean size of 5.6 cm. Bone destruction was found in six patients. The density or signal enhancement patterns of the lesions were heterogeneous, with necrosis seen in all seven tumors. Calcification and regional enlarged lymph nodes were not seen in any patients. Conclusions: A large, ill-defined, and aggressive mass in the maxillofacial region of a young patient, associated with heterogeneous density or signal intensity but lack of calcification and regional lymphadenopathy, may suggest a diagnosis of PNET. [ABSTRACT FROM AUTHOR]

High-quality c-axis oriented 7 mol% Al and 1.5 mol% Er co-doped ZnO films (ZEAO) were prepared on the quartz glass substrates by using sol-gel method. The influence of the annealing temperature on the crystal orientation, microstructure and optical properties of the ZEAO thin films were studied by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and UV-vis transmittance spectrophotometer, respectively. XRD results revealed that all the samples were polycrystalline with hexagonal structure and exhibited (002) preferential orientation. With increasing the annealing temperature, the grain size and orientation extent increased. The optical studies showed each ZEAO film had a relatively high transmittance above 85 %. The transmittance as high as 95 % was obtained at the annealing temperature of 800 °C, and the corresponding average grain size was about 50 nm. The cathodoluminescence (CL) spectra of these films were also used to characterize the luminescence properties. Strong UV emission centered at 380 nm was observed in the CL spectra taken for the pure ZnO. For the ZEAO sample, the blue-green emission is related to the 4 f shell transition in the Er ions of ZnO matrices, corresponding to a transition from the excited states (F). [ABSTRACT FROM AUTHOR]

Colonoscopy is the most sensitive and specific means for detection of colon cancers and polyps. To make colonoscopy more effective several problems must be overcome including: pain associated with the procedure, the risk of perforation, and incomplete intubation colonoscopy. Technically, these problems are the result of loop formation during colonoscopy. Although, several solutions such as modifying the stiffness of the colonoscope, using an overtube and developing image-guided instruments have been introduced to resolve the looping problem, the results of these systems are not completely satisfactory. A new paradigm to overcome loop formation is proposed that is doctor-assistive colonoscopy. In this approach, the endoscopists performance is enhanced by providing using a kinetic model that provides information such as the shape of the scope, direction of the colon and forces exerted within certain sections. It is expected that with the help of this model, the endoscopist would be able to adjust the manipulation to avoid loop formation. In the present studies, the kinetic model is developed and validated using an ex vivo colonoscopy test-bed with a comprehensive kinematic and kinetic data collection. The model utilizes an established colon model based on animal tissue with position tracking sensors, contact force sensors for the intraluminal portion of the scope and a Colonoscopy Force Monitor for the external insertion tube. [ABSTRACT FROM AUTHOR]

This paper proposes a general design methodology for conceptual design of microchannel systems by applying axiomatic design theory (ADT). As an example, this paper takes a microchannel system that is used to produce uniform microspheres based on the phase separation principle. There are two general design goals for this system: controllability of the size of microspheres and uniformity or narrow size distribution of microspheres. It is found that the conventional approach to this example system will result in a so-called 'coupled design,' which is considered a poor design, according to ADT. This paper demonstrates how to change the coupled design for the example system to a better design called 'decoupled design' (according to ADT). The proposed methodology can be applied to all the microchannel systems based on the phase separation principle and, as a matter of fact, can be used to generate many decoupled designs. The effectiveness of such a decoupled design is demonstrated through simulation. [ABSTRACT FROM AUTHOR]

The roles of the interactions between nervous, endocrine, and immune systems have been well established in human health and diseases. At present, little is known about the cellular bases for neural-endocrine-immune networks in the gastrointestinal mucosa. In the current study, duodenum, jejunum, ileum, cecum, colon, and rectum autopsies from 15 rhesus macaques and endoscopic duodenal biopsies from 12 rhesus macaques were collected, and the spatial relationships between the endocrine cells and immune cells in the intestinal mucosa were examined by transmission electron microscopy. Eight types of enteroendocrine cells similar to human enterochromaffin cells (EC), D1, G, I, K, L, N, and S cells were found to lie within a one-cell-size distance from immunocytes, in particular the eosinophils in the epithelia or lamina propria. Close apposition of large areas of plasma membranes between many types of enteroendocrine cells and immunocytes, especially between EC, K, S cells and eosinophils, were observed in the epithelia for the first time. These data indicate that complex interactions occur between diverse types of enteroendocrine cells and various immune cells through paracrine mechanisms or via mechanisms dependent on cell-to-cell contact; such interactions might play key roles in maintaining the gut mucosal barrier integrity of rhesus macaques. [ABSTRACT FROM AUTHOR]

In this paper, a distributed compressive spectrum sensing scheme in wideband cognitive radio networks is investigated. An analog-to-information converters (AIC) RF front-end sampling structure is proposed which use parallel low rate analog to digital conversions (ADCs) and fewer storage units for wideband spectrum signal sampling. The proposed scheme uses multiple low rate congitive radios (CRs) collecting compressed samples through AICs distritbutedly and recover the signal spectrum jointly. A general joint sparsity model is defined in this scenario, along with a universal recovery algorithm based on simultaneous orthogonal matching pursuit (S-OMP). Numerical simulations show this algorithm outperforms current existing algorithms under this model and works competently under other existing models. [ABSTRACT FROM AUTHOR]

NaO-BaO-SrO-NbO-BO-SiO glass-ceramics were prepared by melt-casting followed by controlled crystallization. X-ray diffraction results show that BaSrNbO with tungsten bronze structure formed as the dielectric phases from the glass matrix at 800°C. However, a secondary phase NaSrBaNbO occurs when crystallization temperature exceeds 850°C. The glass-ceramics exhibit excellent stability in permittivity values from room temperature to 200°C and low dielectric losses below 0.05. Electrical testing demonstrates that the breakdown strength increases with crystallization temperature. The P-E characteristics at room temperature do not show any clear ferroelectric behavior. The glass-ceramic material heated at 800°C/3 h + 950°C/3 h shows a breakdown strength of 1400 kV/cm and its energy storage density can reach up to 4.0 J/cm, which may be a strong candidate for high energy density storage capacitors for portable or pulsed power applications. [ABSTRACT FROM AUTHOR]

The multi-principal high-entropy alloys (HEAs) are promising new alloys. However, it is a challenge to screen out the suitable composition from the diverse combinations. Referring to the prototype AuCu with AB-L1 structure, where it becomes a face-centered cubic (fcc) structure if element A and B are the same element, the site occupying tendencies of the elements and thermodynamic functions are predicted by using the sublattice model supported with first-principles total energy calculations. By considering the Gibbs energy of formation and the configurational entropy, the fcc HEAs in available literatures are examined, and the results of the quinary system with equal-atomic composition CoFeMnNi M and the hexbasic system with equal-atomic composition CoFeMnNiSm M are reported, respectively, where the element M is selected from the rest of the periodical table. When M=Cr, Zn, Ru, Rh, Pd, Re, Os, Ir, or Pt in the quinary systems CoFeMnNi M and when M=Ru, Pd, or Pt in the hexbasic systems CoFeMnNiSm M, respectively, the alloys are recommended to be potential fcc HEAs. The new approach opens a new way to mine the rich ores of HEAs. [ABSTRACT FROM AUTHOR]

This paper deals with optimal training design and placement over multiple orthogonal frequency division multiplexing (OFDM) symbols for the least squares (LS) channel estimation in multiple-input multipleoutput (MIMO) OFDM systems. First, the optimal pilot sequences over multiple OFDM symbols are derived by co-cyclic Jacket matrices based on the minimum mean square error (MSE) of the LS channel estimation. Then, an enhanced channel estimation method using sliding window is proposed to improve further the performance for the optimal pilot sequences in fast-varying channels. Simulation results show that the enhanced method can efficiently improve the performances for the optimal pilot sequences over two and four OFDM symbols, especially in fast-varying channels. [ABSTRACT FROM AUTHOR]

We propose an adaptive fractional window increasing algorithm (AFW) to improve the performance of the fractional window increment (FeW) in (Nahm et al., 2005). AFW fully utilizes the bandwidth when the network is idle, and limits the operating window when the network is congested. We evaluate AFW and compare the total throughput of AFW with that of FeW in different scenarios over chain, grid, random topologies and with hybrid traffics. Extensive simulation through ns2 shows that AFW obtains 5% higher throughput than FeW, whose throughput is significantly higher than that of TCP-Newreno, with limited modifications. [ABSTRACT FROM AUTHOR]

Least mean square (LMS) decision feedback equalizer (DFE) is preferred as an effective solution to coping with inter-symbol interference (ISI) for ATSC digital television (DTV) receivers. In DTV transmission environment, echo delay often covers several hundreds symbols, which leads to very large-scale equalizer. One consequence of the large-scale equalizer is the very slow convergence, which combined with error propagation, inherent drawback of DFE, seriously deteriorates the performance of the receivers, especially in severe channels. More working modes and corresponding robust control mechanism were given to help the equalizer converge to the stable state smoothly. Simulation results show that the improved equalizer can perform better, especially in the severe channels. [ABSTRACT FROM AUTHOR]

OBJECTIVES: Since the introduction of endoscopic retrograde cholangiopancreatology (ERCP) in clinical use, pancreatitis has become a common complication of ERCP. Octreotide is an inhibitor of pancreatic enzyme secretions. Several studies have evaluated the effect of octreotide on the incidence of clinical pancreatitis after ERCP, but with different results. The aim was to determine the efficacy of prophylactic administration of octreotide for the prevention of post-ERCP pancreatitis (PEP) and hyperamylasemia. METHODS: In this study, patients with scheduled ERCP were randomized to receive either octreotide (0.3 mg) via intramuscular injection or a placebo. The study was conducted in 12 digestive endoscopic units in China. Patients were randomized into two groups: an octreotide group (N = 414) and a control group (N = 418). In the octreotide group, octreotide (0.3 mg) was dissolved in 500 mL of 0.9% saline solution and administered by continuous intravenous infusion, beginning 1 h before endoscopic examination and continued for 6 h thereafter; 0.1 mg of octreotide was injected subcutaneously at 6 and 12 h after the intravenous injection was stopped. The control group was given a placebo intravenously. The end point was the development of acute pancreatitis. RESULTS: The overall incidence of acute pancreatitis was 3.85%; this included 2.42% (10/414) in the octreotide group and 5.26% (22/418) in the control group ( P= 0.046). The overall incidence of hyperamylasemia was 14.9%; 12.32% (51/414) in the octreotide group and 17.46% (73/418) in the control group ( P= 0.041). No side effects were found. CONCLUSION: The results indicate that octreotide can prevent PEP and hyperamylasemia. [ABSTRACT FROM AUTHOR]

For video streaming over lossy channels, intra refresh can mitigate the error-propagation effect caused by packet losses. Besides some intra-mode macroblocks (MBs) generated by the “Lagrangian rate-distortion” or “Sum of absolute difference” mode decision, the encoder or transcoder possibly needs to increase some “forced” intra-mode MBs for robust video streaming. Based on the error-propagation analysis in a group of pictures (GOP), we propose an unequal Forced-Intra-Refresh (FIR) scheme to improve packet loss resilience of video streaming. According to a GOP-level error-propagation model, the proposed unequal FIR scheme can optimally increase the unequal number of forced intra-mode MBs for different frames in a GOP. Simulation results showed that the proposed scheme can effectively enhance the robustness of video streaming under different channel conditions, and achieve about 0.1∼0.9 dB gains over the average FIR scheme in H.264/AVC tools. [ABSTRACT FROM AUTHOR]

In this paper, a fast mode decision algorithm for inter macroblocks in H.264/AVC is proposed. The algorithm is able to classify all modes by both gradient operator and comparison of space-time correlation. Because only part of modes is used to compare with each other the computational complexity can be reduced greatly. The simulation results show that it takes about 75% of encoding time for other algorithm with similar visual quality. [ABSTRACT FROM AUTHOR]

Block-matching motion estimation plays an important role in video coding. The simple and efficient fast block-matching algorithm using Variable Shape Search (VSS) proposed in this paper is based on diamond search and hexagon search. The initial big diamond search is designed to fit the directional centre-biased characteristics of the real-world video sequence, and the directional hexagon search is designed to identify a small region where the best motion vector is expected to locate. Finally, the small diamond search is used to select the best motion vector in the located small region. Experimental results showed that the proposed VSS algorithm can significantly reduce the computational complexity, and provide competitive computational speedup with similar distortion performance as compared with the popular Diamond-based Search (DS) algorithm in the MPEG-4 Simple Profile. [ABSTRACT FROM AUTHOR]

In this paper, a class of biholomorphic mappings called complete quasiconvex mappings is introduced and studied in bounded convex Reinhardt domains of ℂ n. Through a detailed analysis of the analytic characterization for this class of mappings, it is shown that this class of mappings contains the convex mappings and is also a subset of the class of starlike mappings. In the special case of the polydisc, a decomposition theorem is established for the complete quasiconvex mappings, which in turn is used to derive an improved sufficient condition for the convex mappings. [ABSTRACT FROM AUTHOR]

A new absorbing boundary condition (ABC) for frequency-dependent finite-difference time-domain algorithm for the arbitrary dispersive media is presented. The concepts of the digital systems are introduced to the (FD)2TD method. On the basis of digital filter designing and vector algebra, the absorbing boundary condition under arbitrary angle of incidence are derived. The transient electromagnetic problems in two-dimensions and three-dimensions are calculated and the validity of the ABC is verified. [ABSTRACT FROM AUTHOR]

A new frequency dependent finite difference time domain (FD-FDTD) method using digital signal processing (DSP) is proposed. The dispersive media is characterized as an infinite-impulse response (IIR) filter, directly leading to FDTD equations. The representation of a dispersive medium is therefore converted to a problem of digital IIR design. It is shown that the numerical results are consistent with analytic solution. [ABSTRACT FROM AUTHOR]

The article focuses on a study conducted to analyze molecular characteristics of the SLA-1 gene from Chinese Hebao pigs. The SLA-1 gene from the Hebao pig was cloned and was then the molecular characteristics of the gene were analyzed. The results of the study showed that the Hebao pig is resistant to infectious diseases including classical swine fever (CSF) and suggests that key binding sites for antigen processing for SLA-1-HB might determine susceptibility to the infection.

Polydimethylsiloxane (PDMS) has become one of the most widely used materials in the fabrication of microfluidic systems bonded onto glass substrates, especially for cell biology applications. However, PDMS is often unsuitable for building microfluidic systems onto polystyrene (PS) which is the preferred substrate in most cell-culture protocols. In particular, PS is required for culturing many stem cell and primary cell types. Here, we propose a novel approach to building PDMS-PS microfluidic cell-culture systems, specifically realizing a strong and reversible bonding of PDMS on PS without using chemical agents which can have negative effects on cell viability. Our strategy to strengthen the bonding of PDMS to PS surfaces is to increase the surface free energy (SFE) by adjusting the mixing ratio of PDMS base to curing agent and by treating the surfaces of PDMS and PS with O2 plasma and annealing. Our results show that using this method for PDMS-PS bonding, we are able to produce reliable reversible and leakage-free PDMS-PS microfluidic cell-culture systems. [ABSTRACT FROM AUTHOR]