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The aim of this study is to propose a new diagnostic model based on "segmentation + classification" to improve the routine screening of Thyroid nodule ultrasonography by utilizing the key domain knowledge of medical diagnostic tasks. A Multi-scale segmentation network based on a pyramidal pooling structure of multi-parallel void spaces is proposed. First, in the segmentation network, the exact information of the underlying feature space is obtained by an Attention Gate. Second, the inflated convolutional part of Atrous Spatial Pyramid Pooling (ASPP) is cascaded for multiple downsampling. Finally, a three-branch classification network combined with expert knowledge is designed, drawing on doctors' clinical diagnosis experience, to extract features from the original image of the nodule, the regional image of the nodule, and the edge image of the nodule, respectively, and to improve the classification accuracy of the model by utilizing the Coordinate attention (CA) mechanism and cross-level feature fusion. The Multi-scale segmentation network achieves 94.27%, 93.90% and 88.85% of mean precision (mPA), Dice value (Dice) and mean joint intersection (MIoU), respectively, and the accuracy, specificity and sensitivity of the classification network reaches 86.07%, 81.34% and 90.19%, respectively. Comparison tests show that this method outperforms the U-Net, AGU-Net and DeepLab V3+ classical models as well as the nnU-Net, Swin UNetr and MedFormer models that have emerged in recent years. This algorithm, as an auxiliary diagnostic tool, can help physicians more accurately assess the benign or malignant nature of Thyroid nodules. It can provide objective quantitative indicators, reduce the bias of subjective judgment, and improve the consistency and accuracy of diagnosis. Codes and models are available at https://github.com/enheliang/Thyroid-Segmentation-Network.git

Accurate identification of single nucleotide variants (SNVs) in key driver genes holds a significant value for disease diagnosis and treatment. Fluorescent probes exhibit tremendous potential in specific, high-resolution, and rapid detection of SNVs. However, additional steps are required in most post-PCR assays to convert double-stranded DNA (dsDNA) products into single-stranded DNA (ssDNA), enabling them to possess hybridization activity to trigger subsequent reactions. This process not only prolongs the complexity of the experiment but also introduces the risk of losing target information. In this study, we proposed two strategies for enriching active double-stranded DNA, involving PCR based on obstructive groups and cleavable units. Building upon this, we explored the impact of modified units on the strand displacement reaction (SDR) and assessed their discriminatory efficacy for mutations. The results showed that detection of low variant allele frequencies (VAF) as low as 0.1% can be achieved. The proposed strategy allowed orthogonal identification of 45 clinical colorectal cancer tissue samples with 100% specificity, and the results were generally consistent with sequencing results. Compared to existing methods for enriching active targets, our approach offers a more diverse set of enrichment strategies, characterized by the advantage of being simple and fast and preserving original information to the maximum extent. The objective of this study is to offer an effective solution for the swift and facile acquisition of active double-stranded DNA. We anticipate that our work will facilitate the practical applications of SDR based on dsDNA.

Objective: To observe the therapeutic effect of mild moxibustion on irritable bowel syndrome (IBS) visceral hyperalgesia model rats and its regulatory effect on P2X3 receptors in the spinal cord, anterior cingutate cortex (ACC) and thalamic ventral posterolateral nucleus (VPL). Methods: Thirty 8-day-old newborn rats were randomly divided into a normal group (n=6) and a modeling group (n=24) according to the completely random number table method. Rats in the normal group were bred routinely, and those in the modeling group were subjected to preparing IBS chronic visceral hyperalgesia model using colorectal distention (CRD) in stimulation method. Rats successfully modelled were re-divided into a model group, a mild moxibustion group, a P2X3 receptor antagonist group, and a normal saline group according to the completely random number table method with 6 rats in each group. Rats in each group received corresponding interventions from the 37-day old, once a day for 7 consecutive days. Immunohistochemistry and Western blot assays were used to detect P2X3 protein expressions in the spinal cord, ACC and VPL of rats. Results: Under different intensities of CRD stimulation, the abdominal withdrawal reflex (AWR) scores of the model group were significantly increased versus the normal group (all P<0.05); the AWR scores of the mild moxibustion group and the P2X3 receptor antagonist group were significantly reduced versus the model group (all P<0.01). The P2X3 protein expressions in rat spinal cord, ACC and VPL tissues of the model group were significantly increased versus the normal group (all P<0.01); the P2X3 protein expressions in rat spinal cord, ACC and VPL tissues of the mild moxibustion group and the P2X3 receptor antagonist group were significantly reduced versus the model group (all P<0.01). Conclusion: Mild moxibustion can inhibit the P2X3 receptor expressions in the spinal cord, ACC, and VPL tissues of IBS visceral hyperalgesia model rats, which may be the mechanism of mild moxibustion in relieving the central sensitization of rats with IBS visceral hyperalgesia.

In recent years, formation control of multi-agent has been a significant research subject in the field of cooperative control. However, previous works have mainly concentrated on formation control for simple point-mass model and linear model. In contrast, this paper presents a novel cooperative algorithm for multiple air vehicles formation control, which aims to devise a control strategy based on guidance route to achieve precisely coordinated formation control for a group of fixed-wing aircraft in a complex task environment. The proposed method introduces the leader-follower structure for effective organization of the multi-agent coordination. Moreover, the Partial Integrated Formation and Control (PIFC) is adopted to design the control law for Guidance-Route based Formation Control (GRFC). Additionally, the proposed approach designs two guidance-route generation strategies for two special situations to demonstrate the effectiveness of GRFC in complex task environments. Theoretical analysis reveals that the proposed control protocol for guidance command can ensure the overall stability and tracking accuracy of the system. Numerical simulations are performed to illustrate the theoretical results, and verify that the proposed approach can achieve coordinated formation control precisely in a complex task environment.

Based on the Paris model of fatigue crack growth theory, the fatigue crack growth behaviour of Center Crack Tension (CCT) specimens of laser melting deposited 12CrNi2 alloy steel is studied by extended finite element method (XFEM). The crack growth rules and fatigue life are analyzed by experiment and finite element simulation. The experimental results are in good agreement with the finite element results, which verifies the accuracy of XFEM method to simulate the fatigue crack growth behaviour of laser melting deposited 12CrNi2 alloy steel components. Based on this, the effects of initial crack direction and load amplitude on fatigue crack growth behaviour are discussed. The results indicate that even if the initial crack direction is different, the crack will finally propagate in a direction perpendicular to the load. With the increase of the load amplitude, the fatigue life of the specimen with initial crack decreases exponentially.

A practical method for identification of defects that occur occasionally during the production of biaxial oriented polypropylene (BOPP) films is developed. The size and morphology of the defects in the BOPP film were observed with optical microscopy, and micro Fourier transform infrared (Micro-FTIR) and Raman spectroscopies were employed to identify the chemical composition of the defects. Significant amounts of ethylene and propylene units were found in the defects, and characteristic vibrational bands for crystalline PP were observed by both IR and Raman. However, one defect exhibited IR characteristics for ordered PE whereas the other showed amorphous PE structure. These results indicate that the defects are composed of either ethylene-propylene block copolymers with long sequences of both propylene and ethylene that can form ordered structures, or ethylene-propylene segmented copolymers with long propylene sequences that can crystallize and shorter ethylene sequences that are amorphous. Possible sources of these foreign materials and corresponding mitigation measures were discussed.

New agents with particular specificity toward targeted bacteria and superefficacy in antibacterial activity are urgently needed in facing the crisis of worldwide antibiotic resistance. Herein, a novel strategy by equipping bacteriophage (PAP) with photodynamic inactivation (PDI)-active AIEgens (luminogens with aggregation-induced emission property) was presented to generate a type of AIE–PAP bioconjugate with superior capability for both targeted imaging and synergistic killing of certain species of bacteria. The targeting ability inherited from the bacteriophage enabled the bioconjugates to specifically recognize the host bacteria with preserved infection activity of phage itself. Meanwhile, the AIE characteristic empowered them a monitoring functionality, and the real-time tracking of their interactions with targets was therefore realized via convenient fluorescence imaging. More importantly, the PDI-active AIEgens could serve as powerful in situ photosensitizers producing high-efficiency reactive oxygen species (ROS) under white light irradiation. As a result, selective targeting and synergistic killing of both antibiotic-sensitive and multi-drug-resistant (MDR) bacteria were successfully achieved in in vitro and in vivo antibacterial tests with excellent biocompatibility. This novel AIE–phage integrated strategy would diversify the existing pool of antibacterial agents and inspire the development of promising drug candidates in the future.

Multiplex PCR encounters difficulties in primer designing with all the primer pairs working at the same annealing temperature. In this study, we have developed a double-strand primer-mediated multiple strand displacement reaction for the detection of SARS-COV-2 ORF, N and E genes (as examples). The double primer is composed of a 5′-modified fluorophore strand, which does not impact polymerase extension and a 3′-modified quencher strand, which cannot impact elongation. At the annealing temperature, the fluorophore strand combined with the template, extended and resulted in fluorescence signal release. Results showed that the double-strand primer relatively exhibits a wide annealing temperature range and good compatibility between three pairs of primers and probes. These merits allow the simple and multiplex real-time fluorescence quantification of nucleic acids. The detection limit was 400 copies/mL, and the detection time was approximately 2 h. In addition to its extreme specificity and simplicity, this method has a wide range of applications such as multiple PCR and SNP detection.

To investigate the antagonistic cell injury effect and molecular mechanism of scutellarin (SCU) in hypoxia reoxygenation (HR) treated human cardiac microvascular endothelial cells (HCMECs).

To observe the regulatory effects of herbal cake-partitioned moxibustion on Crohn's disease (CD) rat’s colon inflammatory cytokine interleukin-17 (IL-17), IL-23 and their mRNAs, and to investigate the action mechanism of moxibustion in treating CD. Forty SPF grade Sprague-Dauley (SD) male rats were randomly divided into a normal group, a model group, an herbal cake-partitioned moxibustion group and a Western medicine group, with 10 rats in each group. Except the normal group, rats in the other three groups were used to make CD model by giving an enema in colon with Trinitro-benzene-sulfonic acid (TNBS). When the models were successful made, rats in the model group had no therapeutic intervention; rats in the herbal cake-partitioned moxibustion group were subjected to herbal cake-partitioned moxibustion treatment at bilateral Tianshu (ST 25) plus Qihai (CV 6); and rats in the Western medicine group were given oral Mesalazine. After treatment, the histopathological changes and inflammatory cytokines IL-17, IL-23 and their mRNAs expressions were observed in descending colon by hematoxylin-eosin (HE) staining, immunohistochemistry (IHC) and real-time polymerase chain reaction (RT-PCR) methods. Colon tissues of TNBS enema rat models showed cracks-like ulcers accompanied by mucous layer inflammation, granulomas, and inflammatory cytokines IL-17, IL-23 and their mRNAs expressions were all higher than those in the normal group (P<0.01); after intervention, colon tissue cracks-like ulcers and inflammation degree reduced, inflammatory cytokines IL-17, IL-23 and their mRNAs expressions were all significantly decreased (P<0.01) in the herbal cake-partitioned moxibustion group and the Western medicine group. Herbal cake-partitioned moxibustion may improve colon tissue ulcers and relieve intestinal inflammation by down-regulation of IL-17, IL-23 and their mRNAs expressions in CD model rats’ colonic mucosa. 观察隔药灸对克罗恩病(Crohn's Disease, CD)大鼠结肠炎症因子白介素-17 (interleukin-17, IL-17)、白介素-23 (interleukin-23, IL-23)及其mRNA 的调节作用, 探讨灸法治疗CD 的效应机制。 将40 只SPF 级SD 雄性大鼠随机分为正常组、模型组、隔药灸组和西药组, 每组10 只。除正常组以外, 其余3 组大鼠采用三硝基苯磺酸溶液灌肠制备CD 模型, 模型制备成功后, 模型组不进行任何治疗干预, 隔药灸组取双侧天枢、气海穴进行隔药饼灸治疗,西药组予以美沙拉嗪灌胃治疗。治疗结束后, 采用苏木素-伊红(hematoxylin-eosin, HE)病理染色, 免疫组织化学(immunohistochemistry, IHC)和实时聚合酶链反应(real-time polymerase chain reaction, RT-PCR)方法观察各组大鼠结肠降部组织病理学变化及炎症因子IL-17、IL-23 及其mRNA 的表达情况。 TNBS 灌肠模型大鼠结肠组织出现裂隙状溃疡伴随黏膜层炎症、肉芽肿, 炎症因子IL-17、IL-23及其mRNA的表达均高于正常组(P<0.01); 隔药灸组、西药组大鼠经干预后, 结肠组织裂隙状溃疡及炎症程度减轻, 炎症因子IL-17、IL-23 及其mRNA 表达均显著降低(P<0.01)。 隔药灸可能通过下调CD 模型大鼠结肠黏膜IL-17、IL-23 及其mRNA 的表达来发挥改善结肠组织溃疡, 缓解肠道炎症的治疗作用。

Methyl or methoxy introduction compounds like 7oor 7fprovided higher anti-ischemic stroke activity than lead compound 1, while methylene introduction compounds like 7b, 7eand 7rshowed loss of activity.

In some tunnels of railway lines located in water-rich region, due to the long-term water leakage and erosion, the foundation of railway lines showed large uneven settlement deformation, so the above concrete roadbed slabs also experienced uneven settlement accordingly. The smoothness of railway tracks diminished, and the speed of passing trains had to be limited to ensure safety. To restore the smoothness of the tracks, a dedicated polymer injection technology for quick uplift rehabilitation of uneven settlement concrete roadbed slabs was studied on site just within the specified daily skylight time (about 3 hours every day) of the railway lines. A hydrophobic polymer with low-viscosity, quick-setting and high-strength properties was used for injecting, filling and uplifting the concrete slabs in water-rich foundations. The high-precision electronic levels were adopted to monitor rising height of the tracks in real time. After rehabilitation, the filling quality of polymer injection under roadbed slabs was examined using Φ50 mm core samples and the strength of hardened polymer was verified by compressive strength test. Results indicated that the polymer could uplift the concrete roadbed slabs effectively and restore the smoothness of railway tracks accurately even in the water-rich environment. The research can provide some valuable references for quick rehabilitation of uneven settlement concrete roadbed slabs in water-rich tunnels.

DNA strand displacement plays an essential role in the field of dynamic DNA nanotechnology. However, flexible regulation of strand displacement remains a significant challenge. Most previous regulatory tools focused on controllable activation of toehold and thus limited the design flexibility. Here, we introduce a regulatory tool termed cooperative branch migration (CBM), through which DNA strand displacement can be controlled by regulating the complementarity of branch migration domains. CBM shows perfect compatibility with the majority of existing regulatory tools, and when combined with forked toehold, it permits continuous fine-tuning of the strand displacement rate spanning 5 orders of magnitude. CBM manifests multifunctional regulation ability, including rate fine-tuning, continuous dynamic regulation, reaction resetting, and selective activation. To exemplify the powerful function, we also constructed a nested if-function signal processing system on the basis of cascading CBM reactions. We believe that the proposed regulatory strategy would effectively enrich the DNA strand displacement toolbox and ultimately promote the construction of DNA machines of higher complexity in nucleic acid research and biomedical applications.

Based on the rigorous coupled wave theory, the narrowband reflect spectral imaging characteristics on two-dimensional photonic crystal are analyzed, and two-dimensional photonic crystal sensor probe biological structure and photonic crystal biosensor system are constructed. The simulation proved that, when the adsorption medium at the surface of two-dimensional photonic crystal are different, the white light narrowband reflection resonance mode peak wavelength would drift, and the drift quantity of the peak wavelength and the refractive index of the adsorptive medium is in a linear relationship. Colored the space imaging spectra of photonic crystal, the changes of the adsorbate refractive index in different area of the photonic crystal surface can be observed , the adsorbate concentration changes can also be got. This conclusion can be applied to biochemical substances, pharmaceutical, biological molecules and environmental pollution detection.

Plasma spraying process was carried out to prepare NiCoCrAlY bonding coating and Al2O3-13%TiO2 ceramic coating on AZ91D magnesium alloy by orthogonal experiments. The microstructural characteristics and properties of coating were investigated by SEM，tests of tensile, electrochemical method and weight loss. The results reveal that spraying power is the most important processing parameter to affect the bonding strength of the coating. The corrosion resistance of magnesium alloy is remarkably improved by plasma-sprayed NiCoCrAlY/(Al2O3-13%TiO2) coatings, especially when the coatings were sealed with epoxy resin.

The microstructure and properties of plasma sprayed Al2O3-13wt%TiO2 (AT13) coating on AZ91D magnesium substrate were investigated. The results indicated that the AT13 coatings consisted of γ-Al2O3, α-Al2O3 and Al2TiO5, presented a lamellar structure with pores and microcracks. The microhardness increased from the substrate to the coating, significantly conformed to Normal and Weibull distributions. The friction coefficient of AT13 coating increases with the increase of time, load and rotation speed under lower working condition (10N, 20N;100r/min,150r/min), but abnormal phenomenon appeared under high load and rotational speed.

Three new nortriterpenoids, schigrandilactones A−C (1−3), along with eight known compounds, were isolated from an organic solvent extract of Schisandra grandiflora. Compounds 1and 2feature a spirocyclic moiety in their structures, and compound 3was characterized with a new oxygenated pattern. The relative configurations of 1and 3were determined through single-crystal X-ray experiments. In addition, compounds 1and 2displayed cytotoxic activity against two human cancer cell lines, and compound 3showed anti-HIV-1 inhibition in infected C8166 cells.

Xerophilusin A (1), xerophilusin B (2), longikaurin B (3), and xerophilusin F (4) from Isodon xerophylusinhibit LPS-induced NO production in RAW 264.7 macrophages, with IC50values of 0.60, 0.23, 0.44, and 0.67 μM, respectively, and they all inhibited mRNA production in these same cells. They decreased the luciferase activity in RAW 264.7 cells transiently transfected with the NF-κB-dependent luciferase reporter, with IC50values of 1.8, 0.7, 1.2, and 1.6 μM, respectively. Compounds 1−3reduced NF-κB activation, with compound 4showing no effect, but p65 translocation from the cytoplasm to the nucleus and the LPS-induced degradation of IκB were inhibited by all four test compounds. These findings indicate that ent-kauranes are potential anti-inflammatory agents, with a specific mechanism in which both the inhibition of NF-κB translocation and the consequent decrease of pro-inflammatory mediators are implicated.

In this paper, we are presenting a design method and its results for a space optical system with high resolution and wide field of view. This optical system can be used both in infrared and visible configurations. The designing of this system is based on an on-axis three-mirror anastigmatic (TMA) system. Here the on-axis concept allows wide field of view (FOV) enabling a diversity of designs available for the Multi-Object Spectrometer instruments optimized for low scattered and low emissive light. The available FOVs are upto 1º in both spectrum ranges, whereas the available aperture range is F/15 - F/10. The final optical system is a three-mirror telescope with two on-axis and one off-axis segment and its resolution is 0.3m or even lower. The distinguished feature of this design is that it maintains diffraction-limited image at wide wavelengths. The technological developments in the field of computer generated shaping of large-sized optical surface details with diffraction-limited imagery have opened new avenues towards the designing techniques. Such techniques permit us to expand these technological opportunities to fabricate the aspherical off-axis mirrors for a complex configuration.

Bioassay-directed fractionation of the leaves of the medicinal plant Isodon xerophilusled to the isolation of a series of potential antitumor molecules. Thirteen new (1−13) and 23 (14−36) known diterpenoids were isolated and identified, representing ent-kauranoids of several structural types. The structures of 1−13were determined by means of spectroscopic studies. The absolute configurations of the new compounds were clarified by CD spectroscopic studies or were postulated on biogenetic grounds. All compounds obtained were evaluated for their cytotoxic activity against the K562, MKN45, and HepG2 cell lines. Compounds 1, 2, 11, 16−19, 23, 26−28, 30, and 32demonstrated significant cytotoxic activity for one or more cell lines.

A phytochemical study of secondary metabolites produced by Schisandra chinensishas led to the isolation of six novel highly oxygenated nortriterpenoids, wuweizidilactones A–F (1–6). Compounds 3–6possess an unprecedented 3,4‐seco‐18(13→14)‐abeo‐artane skeleton. Interestingly, structures 3–6have a β‐oriented methyl group at the C‐14 position. This structural feature corroborates the biogenetic pathway proposed for the formation of 18‐norschiartane‐type compounds 1and 2. The structures of these novel metabolites were established on the basis of their detailed spectroscopic analysis. The structure of 1was also confirmed by single‐crystal X‐ray diffraction analysis. For the first time, the absolute configuration of these nortriterpenoids was determined by using a modified Mosher method.

Poly(vinyl chloride)/layered double hydroxides (PVC/LDHs) composite resins were prepared by in situ suspension polymerization of vinyl chloride monomer in the presence of LDHs intercalated with dodecyl sulfate anions (LDH‐DS), and were further processed to obtain PVC/LDH‐DS nanocomposites. It was found that the mean particle size of PVC composite resins decreased as LDH‐DS was added in the polymerization system. The 5 and 10% weight loss temperatures of PVC resins significantly increased with the increase of LDH‐DS weight fraction in the composite resins. The transmission electron microscopy images showed that LDH‐DS particles were partially intercalated and partially exfoliated, and well distributed in the PVC nanocomposites. The storage modulus below the glass transition region and the glass temperature of the PVC/LDH‐DS nanocomposites are greater than that of the pristine PVC. The mechanical properties of PVC/LDH‐DS nanocomposites indicate that LDH‐DS nanoparticles stiffen and toughen PVC. The tensile strength, Young's modulus, and Charpy notched impact strength of the PVC/LDH‐DS nanocomposites are greater than those of the pristine PVC and PVC/LDH‐DS composites prepared by the melt blending. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1471–1477, 2006

The effect of the grade, the content, and the particle diameter on the thermal conductivity of high‐density polyethylene (HDPE) filled with graphite were studied. The results show an increase of thermal conductivity of the HDPE/graphite composite with increase of graphite content. The thermal conductivity of the HDPE filled with the expanded graphite was larger than that of the HDPE filled with the colloid graphite system. At the same volume content (7%), the thermal conductivity of the former was twice that of the latter one. The particle diameter of the graphite also affected the thermal conductivity of HDPE composites. With increase of the particle diameter of the colloid graphite, the thermal conductivity of the HDPE/graphite increased. However, when the particle diameter of colloid graphite was larger than 15 μm, the increase of thermal conductivity of HDPE/graphite changed by inches. Some models proposed to predict thermal conductivity of a composite in a two‐phase system could not be applied to HDPE filled graphite powder composites, such as Maxwell‐Eucken, Cheng and Vachon, Zieblend, Lewis and Nielsen, Agari and Uno equations. But, according to the increase of thermal conductivity of HDPE composites filled with the colloid graphite, we find that Ziebland equation is suitable except of some constant. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3806–3810, 2006

Effect of acrylonitrile water solubility on the suspension polymerization of acrylonitile and styrene was investigated. It was found that the copolymer composition produced in the suspension polymerization of acrylonitrile and styrene was significantly different from that in the bulk polymerization at the same monomer feed ratio, since acrylonitrile is partially soluble in water. To predict accurately and then control the copolymer composition in the suspension polymerization, a model to calculate the copolymer composition was proposed based on considering the phase partition of actylonitrile between monomer and aqueous phases. The results calculated by the model are in agreement with the experimental data. The real reactivity ratios in monomer phase used in the model are the same as that in the bulk polymerization, but the apparent reactivity ratios used in the classical theory for the suspension polymerization vary significantly with water/oil ratio. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4270–4274, 2006

The effect of N,N,N′N′-tetraalkyl terephthalamide (TATA) on the crystallization of polypropylene (PP) was studied by means of differential scanning calorimetry, wide angle X-ray diffraction and polarized optical microscopy. It was found that the addition of TATA effectively induced the formation of β-crystalline form of PP. With the increase of TATA content both the total crystallinity degree (x) and crystallinity degree for β-crystalline form (xβ) of PP increased significantly, while the crystallinity degree for α-crystalline form (xα) decreased. Polarized optical micrographs indicated that the addition of TATA led to a substantial decrease in the size of spherulites of PP and the boundaries of spherulites were hardly distinguished. TATA could significantly improve the impact strength, flexural strength and modulus of PP, while the tensile strength of PP did not change greatly with TATA content.

Two new ent-kaurane-derived diterpene derivatives, phyllostacins A (1) and B (2), were isolated from the aerial parts of Isodon phyllostachys, together with two known compounds, irroratin A (3) and serrin B (4). Both 1 and 2 were found to be present as diastereoisomers. In the case of 1, the corresponding diastereoisomeric diacetates 5 and 6 were prepared and separated. The structures of the new compounds were elucidated by extensive 1D- and 2D-NMR spectroscopic methods, in combination with MS experiments. In (D5)pyridine solution, the two epimers of 1 are present in equal amounts, but in CDCl3 or CD3OD, the (S)-epimer predominates in the mixture of hemiacetals.

Hybrid nonacapsules are synthesized by miniemulsion (co)polymerization of styrene and 3-trimethoxysilylpropylmethacrylate silane (MPS) in one step. Hydrocarbon droplets are encapsulated by organic−inorganic hybrid material, which is formed by simultaneous free radical polymerization reaction and hydrolysis−condensation reaction of organosilane in MPS. The morphology and the microstructure are characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), solid-state NMR, and infrared (IR) spectroscopy. The capsule morphology is achieved by polymerization inducing phase separation within minidroplets dispersed in aqueous phase. The feasibility of the final morphology is analyzed by thermodynamic and kinetic factors first. Particle nucleation processes with different formulation are followed by DLS, and it has a great influence on the latex morphology. Monomer/hydrocarbon ratio in the droplets and MPS fraction in the capsules are also of great important to the morphology due to their influence on phase separation behavior and mechanic properties of capsules, respectively. Finally, the loading and releasing processes of this capsule are monitored by ultraviolet−visible (UV) measurement.

A series of superabsorbent polymers were synthesized by an inverse suspension polymerization, with potassium persulfate as the initiator, Span60 as the dispersant, and N,N′‐methylene bisacrylamide (BIS) and divinylbenzene (DVB) as multiple crosslinkers. The synthesis conditions, including the amount of dispersant, concentration of crosslinkers, oil‐to‐water phase ratio (O/W) of the polymerization system, total monomer concentration, and acrylamide (AM) content were studied. The results indicated that there were optima for the following properties: BIS crosslinker concentration (0.075 wt %), O/W (3 : 1), total monomer concentration (37.5 wt %), and AM content (5 wt %). In addition, the particle size had a significant influence on the absorption speed, and the absorption speed increased with decreasing particle size. In comparison with the conventional sample crosslinked only by BIS, the superabsorbent with the same particle size but crosslinked by multiple crosslinkers had the higher absorption rate because of surface crosslinking. It also showed that the salt resistance and antihydrolyzing property of the superabsorbent crosslinked by multiple crosslinkers (BIS and DVB) were enhanced, which was also attributed to surface crosslinking by DVB. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1594–1600, 2006

Poly(butyl acrylate)/poly(methyl methacrylate) (PBA/PMMA) core–shell particles embedded with nanometer‐sized silica particles were prepared by emulsion polymerization of butyl acrylate (BA) in the presence of silica particles preabsorbed with 2,2′‐azobis(2‐amidinopropane)dihydrochloride (AIBA) initiator and subsequent MMA emulsion polymerization in the presence of PBA/silica composite particles. The morphologies of the resulting PBA/silica and PBA/silica/PMMA composite particles were characterized, which showed that AIBA could be absorbed effectively onto silica particles when the pH of the dispersion medium was greater than the isoelectric potential point of silica. The critical amount of AIBA added to have stable dispersion of silica particles increased as the pH of the dispersion medium increased. PBA/silica composite particles prepared by in situ emulsion polymerization using silica preabsorbed with AIBA showed higher silica absorption efficiency than did the PBA/silica composite particles prepared by direct mixing of PBA latex and silica dispersion or by emulsion polymerization in which AIBA was added after the mixing of BA and silica. The PBA/silica composite particles exhibited a raspberrylike morphology, with silica particles “adhered” to the surfaces of the PBA particles, whereas the PBA/silica/PMMA composite latex particles exhibited a sandwich morphology, with silica particles mainly at the interface between the PBA core and the PMMA shell. Subsequently, the PBA/silica/PMMA composite latex obtained had a narrow particle size distribution and good dispersion stability. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99: 3425–3432, 2006

Determining how cells regulate their transcriptional response to extracellular signals is key to the understanding of complex eukaryotic systems. This study was initiated with the goals of furthering the study of mammalian transcriptional regulation and analyzing the relative benefits of related computational methodologies. One dataset available for such an analysis involved gene expression profiling of the early growth factor response to platelet derived growth factor (PDGF) in a human glioblastoma cell line; this study differentiated genes whose expression was regulated by signaling through the phosphoinositide-3-kinase (PI3K) versus the extracellular-signal regulated kinase (ERK) pathways. We have compared the inferred transcription factors from this previous study with additional predictions of regulatory transcription factors using two alternative promoter sequence analysis techniques. This comparative analysis, in which the algorithms predict overlapping, although not identical, sets of factors, argues for meticulous benchmarking of promoter sequence analysis methods to determine the positive and negative attributes that contribute to their varying results. Finally, we inferred transcriptional regulatory networks deriving from various signaling pathways using the CARRIE program suite. These networks not only included previously described transcriptional features of the response to growth signals, but also predicted new regulatory features for the propagation and modulation of the growth signal.

ABSTRACTA laboratory-based surveillance network of 11 clinical virological laboratories for influenza viruses was established in Taiwan under the coordination of the Center for Disease Control and Prevention (CDC), Taiwan. From October 2000 to March 2004, 3,244 influenza viruses were isolated, including 1,969 influenza A and 1,275 influenza B viruses. The influenza infections usually occurred frequently in winter in the northern hemisphere. However, the influenza seasonality in Taiwan was not clear during the four seasons under investigation. For example, the influenza A viruses peaked during the winters of 2001, 2002, and 2003. However, some isolated peaks were also found in the summer and fall (June to November) of 2001 and 2002. An unusual peak of influenza B also occurred in the summer of 2002 (June to August). Phylogenetic analysis shows that influenza A isolates from the same year were often grouped together. However, influenza B isolates from the year 2002 clustered into different groups, and the data indicate that both B/Victoria/2/87-like and B/Yamagata/16/88-like lineages of influenza B viruses were cocirculating. Sequence comparison of epidemic strains versus vaccine strains shows that many vaccine-like Taiwanese strains were circulating at least 2 years before the vaccine strains were introduced. No clear seasonality of influenza reports in Taiwan occurred in contrast to other more continental regions.

A new emulsion polymerization process, in which water acted as the dispersed phase and a mixture of methyl methacrylate (MMA) and cyclohexane acted as the continuous phase, was applied to the preparation of a poly(methyl methacrylate) (PMMA) resin. The primary (latex) particles were formed in the early stage of polymerization and coagulated as the polymerization conversion increased. Scanning electron micrographs showed that the final PMMA particles were porous and composed of loosely aggregated primary particles. The porosity characterized by cold di(2‐ethylhexyl) phthalate absorption increased as the water/oil and cyclohexane/MMA mass ratios increased. The PMMA primary particles were smaller than the primary particles in the PMMA resin prepared by suspension polymerization in the presence of cyclohexane. Because of the phase composition of the reaction system, the solubility of PMMA in a mixture of cyclohexane and MMA, and the particle morphology of PMMA, a particle formation mechanism, including the formation, growth, and coagulation of primary particles in dispersed water droplets, was proposed. The primary particles formed mainly through a homogeneous nucleation mechanism and increased in size as MMA diffused from the oil phase to the water phase to the primary particles. The coagulation of the primary particles occurred because of the lower colloidal stability and the space limitations of the primary particles. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1905–1911, 2004

The bulk free‐radical polymerization of styrene in the presence of a new cyclic trifunctional initiator, 3,6,9‐triethyl‐3,6,9‐trimethyl‐1,4,7‐triperoxonane, was studied. Full‐conversion‐range experiments were carried out to assess the effects of the temperature and initiator concentration on the polymerization kinetics, molecular weight, and polydispersity. Gel permeation chromatography was used to measure the molecular weight and the molecular weight distribution of polystyrene. When this multifunctional initiator was used for styrene polymerization at higher temperatures, it was possible to produce polymers with higher molecular weights and narrower molecular weight polydispersity at a higher rate. This showed that the molecular weight and polydispersity were influenced by the initiator concentration and the polymerization temperature in an unusual manner. Moreover, polystyrene, obtained with trifunctional peroxide, had O&bond;O bonds in the molecular chains and was investigated with differential scanning calorimetry and gel permeation chromatography. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1035–1042, 2004

Acrylic-based superabsorbent polymers with partial-neutralized acrylic acid were synthesized by inverse suspension polymerization. The effects of reaction parameters, including the concentration of crosslinking agent and initiator, the neutralization degree of monomer, the monomer concentration, and phase ratio of a system, on the water absorption have been investigated. Furthermore, to improve the properties of salt-resistance and antielectrolyte for the polymer, acrylamide monomer containing nonionic and hydrophilic groups was introduced into the system, which can suppress the salt effect and homoion effect. The water absorption Q^5/3 is proportional to the reciprocal of ionic strength, 1/S, which follows Flory's elasticity gel theory. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 619–624, 2004

In the present article, the kinetic model for vinylidene chloride polymerization obtained in the previous article was analyzed and simplified. A series of kinetic experiments was carried out in stainless-steel batch reactors to evaluate the model. The kinetic parameters were estimated by using these experimental data. The theoretical model prediction was compared with the experimental data. The result shows that the present model is in good agreement with experimental data over nearly the entire conversion range. © 2003 Wiley Periodicals, Inc. J Apply Polym Sci 91: 2582-2587, 2004

The similarities and differences between the heterogeneous polymerization of vinylidene chloride (VDC) and vinyl chloride (VC) were compared and analyzed. The effect of the poly(vinylidene chloride)(PVDC) crystal morphology on the kinetics of VDC polymerization was discussed. Based on the assumption that polymerization occurs in the monomer phase and on the edges of the PVDC lamellar crystals, a mechanism of VDC polymerization is proposed and then a kinetic model for VDC bulk/suspension polymerization is developed according to the elementary reactions. The model can be used to predict polymerization rate and conversion. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2576-2581, 2004

Effects of individual and composed poly(vinyl alcohol) (PVA) suspending agents on the particle morphology of poly(vinyl chloride) (PVC) resins were investigated and discussed in the view of PVA absorption at the oil/water interface and interfacial behavior. It was shown that the percentage and surface coverage of PVA at the oil/water interface decreased with the increase of the degree of hydrolysis (DH) of PVA in the DH range of 70–98 mol %, while the interfacial tension of VC/PVA aqueous solution increased linearly with the increase of DH of PVA. PVC resin with more regular particle shape, increased agglomeration and fusion of primary particles, lower porosity and higher bulk density, was prepared by using PVA with a higher DH as a suspending agent. This was caused by the occurrence of drop coalescence at the very early stage of VC polymerization, the increase of particle shrinkage, and the lower colloidal protection to primary particles. It was also shown that the interfacial tension of VC/water in the presence of composed PVA suspending agents varied linearly with the weight composition of the composed PVA suspending agents. The particle properties of PVC resin prepared by using the composed PVC suspending agents were usually situated in between the properties of PVC resins prepared by using the corresponding individual PVA suspending agent. The particle morphology and properties of PVC resin could be controlled by the suitable choice of the composed PVA suspending agents. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3848–3855, 2003

The concept of physical crosslinking was introduced into the research field of oil-absorption resins, which were traditionally synthesized only by chemical crosslinking. Specifically, the partially physical crosslinking acrylic series for high-oil-absorption resins were prepared in the suspension process, and the swelling behavior of the samples was observed and recorded online. This demonstrated that a kind of relaxing three-dimensional network was indeed formed by the introduction of polybutadiene (PB). The effects of monomer feed ratios, crosslinking agent concentration and type, particle size, and temperature on the oil absorbency and oil-absorption speed were investigated. The results indicated that there were an optimum monomer feed ratio and an optimum amount of ethylene glycol dimethacrylate or PB. In addition, the particle size and temperature had a serious influence on the oil-absorption speed in comparison with the monomer feed ratio and the crosslinking agent concentration and type. The results also showed that particle size affected oil absorbency to a great degree and that the effect of temperature on oil absorbency was complex. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3945–3950, 2003

Polybutadiene (PB) is used to fill an oil absorption resin as a physical crosslinker to construct a kind of 3-dimensional network with a high degree crosslinking and low crosslink density. A series of acrylic resin particles with various compositions are prepared by suspension polymerization, using benzoyl peroxide (BPO) as an initiator and ethylene glycol dimethacrylate (EGDMA) as a chemical crosslinker. The effects of the polymerization temperature, initiator concentration, monomer feed ratio, and chemical and physical crosslinker concentrations on the oil absorbency and gel fraction (degree of crosslinking) are studied. The recipe and operation conditions are optimized as follows: a mass ratio of 3:1 for styrene (St)/dodecyl methacrylate or St/butyl acrylate, 0.5 wt % BPO, and 80°C for 7–8 h. The effect of the physical crosslinker (PB) concentration is complex. The oil absorbency increases with increasing PB at lower EGDMA concentrations. However, under this same condition, particles cannot be formed if the PB concentration is higher than a certain value. By contrast, there is an optimum PB concentration when the EGDMA concentration is higher. The oil absorption speed is also investigated. The presence of PB can speed up absorption. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3309–3314, 2003

The water solubility of acrylonitrile (AN) and its effects on vinylidene chloride/acrylonitrile/styrene (VDC/AN/St) suspension copolymerization were investigated in this study. It shows that the VDC/St ratio and the presence of suspending agent have no obvious influences on AN phase partition between the monomer and aqueous phases, whereas the water solubility of AN increases as temperature increases. Polymerization in the aqueous phase occurs extensively with azobis(isobutyronitrile) (AIBN) as initiator, whereas with lauryl peroxide (LPO) as initiator, polymerization in the aqueous phase is negligible. Theoretical analysis and experimental results indicate that transport of the monomer molecule is possible during polymerization. Both VDC and AN transfer from the monomer phase to the aqueous phase when AIBN is used as initiator. AN transfers from the aqueous phase to the monomer phase for the polymerization system initiated by LPO. Sodium nitrite (NaNO2), but not sodium sulfide (Na2S), can be used to effectively inhibit polymerization in water and exerts less influence on the polymerization in the monomer phase. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1431–1438, 2001

The micro- and stereostructures and sequence distribution of methyl methacrylate (MMA)/N-phenylmaleimide (PMI) and styrene (St)–PMI copolymers were studied in detail with NMR spectroscopy. The MMA–PMI copolymer was in a random sequence distribution and the St–PMI copolymer was alternating in structure. Some micro- and stereoinformation of the MMA–PMI copolymers could be obtained from ¹H-NMR spectra. The average number sequence length obtained from the copolymer triad by ¹³C-NMR spectra was in agreement with that calculated from the reactivity ratios measured by an elemental analyzer. From the triad fraction of the copolymer measured by ¹³C-NMR, the copolymer chain of MMA–PMI was proved to be a one-order Markov chain. More suitable propagation reactions were proposed from the deviation of sequence distribution of the St–PMI copolymer. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2581–2587, 2000

Vinyl chloride–diallyl phthalate (VC–DAP) suspension copolymerization was carried out in a 5-L autoclave and 200-mL stainless steel vessel at 45°C. The apparent reactivity ratios of VC–DAP suspension copolymerization system were calculated as rVC = 0.77 and rDAP = 0.37. It shows that VC–DAP copolymer contains no gel when the feed concentration of DAP (f⁰2) is lower than a critical concentration (fcr, inside the range of 0.466–0.493 mmol/mol VC at 80–85% conversion), the polymerization degree (DP) of copolymer increases with the increase of f⁰2 and conversion. VC–DAP copolymer is composed of gel and sol fractions when f⁰2 is larger than fcr. The DP of sol fraction decreases as f⁰2 increases, but the gel content and the crosslinking density of gel increase. The gel content also increases as conversion increases. The results also show that the index of polydispersity of molecular weight of sol changes with f⁰2, a maximum value appears when f⁰2 is close to fcr. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 156–162, 2000

Chemical crosslinked poly(vinyl chloride) (C-PVC) was synthesized by vinyl chloride suspension polymerization in the presence of diallyl phthalate (DAP) and plasticized to prepare poly(vinyl chloride) (PVC) thermoplastic elastomer (TPE) materials. The chemical crosslinking and physical crosslinking structure in chemical crosslinked PVC-TPE were investigated. It showed that the gel fraction and the crosslinking density of gel increased as the feed concentration of DAP increased. C-PVC prepared by VC/DAP copolymerization was lightly crosslinked as compared with irradiation crosslinked PVC. Physical entanglements would greatly influence the crosslinking density of gel when the gel fraction was high. Chemical crosslinking had little influence on the recrystallization behavior of PVC. A structure model of chemical crosslinked PVC-TPE was proposed, in which chemical networks acted with physical networks cooperatively. It also showed that chemical crosslinking and physical crosslinking influenced the processability and mechanical properties of chemical crosslinked PVC-TPE cooperatively. Although the processability of PVC-TPE deteriorated with chemical crosslinking, the dimension stability and elasticity of PVC-TPE were improved as the permanent chemical networks were introduced. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 868–874, 2000

The copolymerization rate of vinyl chloride(VC)/N-phenylmaleimide (PMI) was investigated. The cross termination constant ϕ was measured to be 8.3 by using nonlinear least square fitting. The value showed that the cross termination was significant. A model of the copolymerization rate of VC/PMI was obtained. Using the calculated modeling parameters, the effects of temperature and initiator concentration on the copolymerization rate were predicted. The predicted values were in good agreement with the experimental data. Acrylonitrile, a third monomer, was selected to reduce the range of copolymer composition of this system, but it further lowered the copolymerization rate. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2649–2656, 1999