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We study nonconvex homogeneous quadratically constrained quadratic optimization with m(∈ {1, 2}) constraints, denoted by (QQm). (QQ2) contains (QQ1), the trust region subproblem (TRS) and its generalization (GTRS), and the ellipsoid regularized total least squares problem as special cases. It is known that there is a necessary and sufficient optimality condition for the global minimizer of (QQ2). In this paper, we first show that any local minimizer of (QQ1) is globally optimal. Unlike its special case (TRS) with at most one local nonglobal minimizer, (QQ2) may have infinitely many local nonglobal minimizers. At any local nonglobal minimizer of (QQ2), both the linear independence constraint qualification and the strict complementary slackness condition hold, and the Hessian of the Lagrangian has exactly one negative eigenvalue. As the main contribution, we prove that the standard second-order sufficient optimality condition for any strict local nonglobal minimizer of (QQ2) remains necessary. It turns out that finding all local nonglobal minimizers of (GTRS) or proving the nonexistence can be done in polynomial time. More applications and the impossibility of extending our main result are discussed. [ABSTRACT FROM AUTHOR]

[Objectives] This study was conducted te understand the process of soil nitrogen mineralization in Eucalyptus plantations, and te identify the characteso istics oS soii nitrogen mineralization with different litter inputs. [Methods] With the soil of the Eucalyptus plantation in Fusui County, Guangxi as the research object, the soit nitrooen mineralization of the Eucalyptus plantation under different litter ireatmeny (removing littee, adding litter and retaining litter) was studied by PVC tube closed-top in-situ incubation. [Resuls] 1 After 1 year of litter yeatment, the inoraanio nitrooen (NHQ-N + NO3 -N) in the soii ot different treat ment ranked as adding littee (20.15 mg/kg) > retaining littee (16.02 mg/kg) > removing littee (11.60 mg)/kg), and the dferences reached a sienificant levei (P < 0. 05). # Mter 30 d of in-situ incubation, there were sienificant dferences in soil nitrate nitrooen content before and after incubation in the three treatment (removing littee, adding littee, and retaining litter) before and after incubation (P<0.05), but no significant dferences were observed in soii ammonium nitrogen content (P >0. 05). Soii nitrate nitrogen contents increased from 1.47, 2. 01 and 1.72 mg/kg before incubation te 3.66, 6. 73 and 5. 02 mg/kg, respectively, and soil ammonium nitrogen content increased from 11.60,20.15 and 16. 02 mg/kg before incubation to 13. 65, 21.54 and 17.18 mg/kg, respectively. The net nitrogen mineralization quantities of the three treatments were 4.24, 6. 11 and 4.46 mg/kg, respectively, and the net nitrogen mineralization rates from larae te small were adding litter[0.180 mg/(kg * d) # > retaining litter[0.141 mg/(kg * d) # > removing litter[0.125 mg/(kg * d)$. Therefore, both removal and addition of inter affected the soil nitrogen input and nitrogen mineralization rate of the Eucalyptus plantation, thereby affecting soil nitrogen avnlabyity and the abnity of soii te mintain plant-ovailable nitrogen. [Conclusions] Thiz study provides a theoretici basis for nutrient management in Eucalyptus plantations, especially nitrogen nueetenemanagemene. [ABSTRACT FROM AUTHOR]

A modified parallel electrode method (MPEM) by placing a positively charged ring between the needle and the parallel electrode collector was presented to fabricate highly aligned electrospun nanofibers. The experimental and theoretical analyses were carried out to study mechanical mechanism of the MPEM. As a result the ring could be used to optimize and control the nanofiber alignment, and an optimal ring voltage was determined. In addition, the effectiveness of the MPEM was demonstrated by measuring the diameter distribution and the degree of nanofiber alignment. And the results showed the MPEM could decrease the nanofiber diameter, enhance the diameter distribution, and improve the nanofiber alignment two times more than the parallel electrode method (PEM). [ABSTRACT FROM AUTHOR]

Histological observation of dual-stained colon sections is usually performed by visual observation under a light microscope, or by viewing on a computer screen with the assistance of image processing software in both research and clinical settings. These traditional methods are usually not sufficient to reliably differentiate spatially overlapping chromogens generated by different dyes. Hyperspectral microscopic imaging technology offers a solution for these constraints as the hyperspectral microscopic images contain information that allows differentiation between spatially co-located chromogens with similar but different spectra. In this paper, a hyperspectral microscopic imaging (HMI) system is used to identify methyl green and nitrotetrazolium blue chloride in dual-stained colon sections. Hyperspectral microscopic images are captured and the normalized score algorithm is proposed to identify the stains and generate the co-expression results. Experimental results show that the proposed normalized score algorithm can generate more accurate co-localization results than the spectral angle mapper algorithm. The hyperspectral microscopic imaging technology can enhance the visualization of dual-stained colon sections, improve the contrast and legibility of each stain using their spectral signatures, which is helpful for pathologist performing histological analyses. [ABSTRACT FROM AUTHOR]

Crumb rubber obtained from scrap tires has been incorporated with asphalt binder to improve the performance of asphalt mixtures in the past decades. However, rubber asphalt mixtures demand higher production temperatures than conventional asphalt binders due to the higher viscosity of asphalt rubber binder. The objective of this paper is to evaluate the rheological properties of crumb rubber modified asphalt by adding trans-polyoctenamer rubber (TOR) additives and investigate the modification mechanism between TOR and crumb rubber modified asphalt. In this study, CRMA was prepared by mixing Karamay 70 penetration grade base asphalt at 15%, 20% and 25% crumb rubber proportions by weight of asphalt. TOR, a typical reactive modifier, was added to CRMA at two percentages of 0% and 4.5%, respectively. Several conventional laboratory rheological tests were carried out to evaluate the performance of CRMA with and without TOR additive at different temperatures. Furthermore, in order to investigate the interaction mechanism of TOR and CRMA, a series of advanced tools, including the scanning electron microscopy (SEM) test, differential scanning calorimeter (DSC) test, Fourier transform infrared spectroscopy (FTIR) test were conducted. From the experimental results obtained, it may be concluded that CRMA with adding TOR not only improves the engineering properties of the rubber modified asphalt, but also improves the performance of asphalt rubber. From the microscopic tests, it is concluded that there is a complex chemical reaction between TOR and CRMA, which changes the rheological properties of CRAM and contributes to the storage stability of asphalt binder. [ABSTRACT FROM AUTHOR]

Based on an accelerated asphalt-aging test in the laboratory, the authors evaluated the physical and chemical properties of asphalt at different aging times and temperatures for this paper. They evaluated the properties of the asphalt binder, such as saturates, aromatics, resins, asphaltenes, penetration, softening point, and molecular distribution of the asphalt, by using experimental results from the accelerated asphalt-aging tests. They employed gel permeation chromatography (GPC), Fourier transforms infrared spectroscopy, asphalt constituents fraction analysis, and rheological test techniques to analyze the effects of asphalt from different crude oil sources on antiaging performance. They used asphalt-aging tests to determine the relevant kinetic parameters needed in the aging kinetics equation. They found that the asphalt-aging reaction perfectly fits to the first order kinetics equation, and during the asphalt-aging process, the asphalt had a higher activation energy and a lower reaction rate coefficient. Moreover, the molecular weight (Mw) of asphalt increased, whereas the dispersity decreased. The asphalt-aging process was divided into two stages: one stage is from aliphatic sulfide to sulfoxide and the other stage was from benzylic carbon to carbonyl. The aging resistance of asphalt was influenced by the asphalt fraction, wax content, and molecular weight. [ABSTRACT FROM AUTHOR]

In this work, a signal amplification supersandwich strategy was developed for highly selective and sensitive detection of cancer cells using aptamer-DNA concatamer-quantum dots (QDs) probes. First of all, electrode materials denoted as MWCNTs@PDA@AuNPs were fabricated by multiwall carbon nanotubes (MWCNTs), gold nanoparticles (AuNPs), and polydopamine (PDA) using a layer-by-layer technique. Then, the prepared bases as matrices were applied to bind concanavalin A (Con A), resulting in high stability, bioactivity, and capability for cell capture. Meanwhile, aptamer-DNA concatamer-QDs were designed via DNA hybridization followed by covalent assembling, which incorporated the specific recognition of the aptamer with the signal amplification of the DNA concatamer and QDs. With aptamer-DNA concatamer-QDs as recognizing probes, the model cancer cells (CCRF-CEM cells) were detected using a MWCNTs@PDA@AuNPs modified electrode with trapped Con A by means of fluorescence and electrochemical methods. The proposed supersandwich cytosensor showed high sensitivity with the detection limit of 50 cells mL-1. More importantly, it could distinguish cancer cells from normal cells, which indicated the promising applications of our method in clinical diagnosis and treatment of cancers. [ABSTRACT FROM AUTHOR]

Background: Wireless capsule endoscopes for diagnosis and treatment in the gastrointestinal tract face the common problem of active actuation. To tackle this difficulty, a non-invasive intestinal bio-robot system with active actuation based on nerve stimulation was developed. Methods: This intestinal inspection system utilized a natural organism--the mud eel--to serve as the locomotion mechanism, and it was controlled by a LabVIEW-programmed pulse generator. The exterior control unit was able to actively drive and remotely control the navigation and site-specific anchoring of the organism. Results: Through in vitro stimulation experiments, a method of controlling the organism's forward motion was obtained: when the organism was stimulated at the tail, it moved forward at a relatively fast speed and with high repeatability. The stimulator parameters were as follows: amplitude 1.85 µA, frequency 2 Hz, pulse duration 500 µs. Conclusions: Since this is a preliminary study, considerable work remains to be done. However, the results could provide a solid theoretical basis for further research toward producing a practical intestinal bio-robot for the diagnosis and treatment of the gastrointestinal tract. [ABSTRACT FROM AUTHOR]

Electrogenerated chemiluminescence (ECL) emission was observed from the water-soluble, bovine serum albumin (BSA)-stabiized Au nanoclusters for the first time. The possible ECL mechanism was discussed according to the presented results and ascribed to the effective electron transfer from the conduction-band of excited indium tin oxide (ITO) to Au nanoclusters (NCs). A simple label-free method for the detection of dopamine has been developed based on the Au NCs ECL in aqueous media. The Au NCs could be an effective candidate for new types of ECL biosensors in the future due to their fascinating features, such as good water solubility, low toxicity, ease of labeling, and excellent stability. [ABSTRACT FROM AUTHOR]

Abstract: Remote controlled capsule (RCC) has been extensively used in the field of site-specific drug delivery. It is a potent tool to study the regional drug absorption of the gastrointestinal (GI) tract that provides pharmaceutical scientists with significant pharmacokinetics data for oral drug formulation development. In present investigations, a patented novel RCC has been devised based on micro-electronic mechanical system (MEMS) technology. Micro-thrusters were for the first time exploited as drug release actuators of RCCs. As the micro-thruster is ignited by a radio frequency (RF) signal, the thrust force generated by the propellants pushes the piston forward and leads to a rapid and complete expulsion of therapeutic agents from the capsule. The micro-thruster merely consumes 120mW for ignition and the duration time of drug release is decreased to less than 1s. The feasibility of the novel RCC was evaluated through animal experiments in beagles using aminophylline as the model drug. The novel RCC developed is a promising alternative for site-specific drug delivery in human GI tract. [Copyright &y& Elsevier]

Highly fluorescent and water-soluble gold nanoclusters (AuNCs) with near-infrared-emission and Au@AgNCs with yellow-emission were successfully prepared viaa rapid sonochemical approach, and the as-prepared AuNCs could be applied in the determination of Cu2+with a wider detection range and lower detection limit. [ABSTRACT FROM AUTHOR]

As the core component of a precision power operation system for Neurosurgery, medical micro-motors need to have characteristics of high reliability, high speed, high precision, low temperature rise and capability of repeated autoclave sterilization. Therefore, high requirements of design and manufacture are put forward. In view of the above, a super-high speed micro motor with a micro flow channel auxiliary cooling system was proposed in this paper. We used Ansoft to analyze the magnetic field distribution of the motor and operating performances at rated speed, and calculate the motor loss and motor temperature distribution. The results showed that the motor speed could reach 89000 Rpm in stable operation and the output power was 60 W. The temperature rise of the rotor and stator core was very low, when the temperature of the liquid coolant in cooling system was 20°C, which could efficiently prolong load working hours. This research provided a new idea for the design of a super-high speed micro-motor utilized in neurosurgical power operation system. [ABSTRACT FROM AUTHOR]

The discovery of new therapeutic drugs with the efficacious and safe ability to prevent epidermal hyperplasia is extremely urgent for psoriasis. Cryptotanshinone (CTS), an active component isolated from the root of Salvia miltiorrhiza Bunge, has been reported to have antibacterial and antitumor effects. However, its effects on psoriasis have not been reported. Here, we investigated the therapeutic effects of CTS on imiquimod (IMQ)-induced psoriatic-like skin model and explored the underlying mechanisms. Our results revealed that CTS effectively alleviates IMQ- induced epidermal hyperplasia. In vitro studies also indicated that CTS potently inhibits the growth of keratinocytes. We further found that STAT3, a transcription factor for the cell growth, is the key mediator of CTS on the proliferation of keratinocytes. Taken together, our findings indicated that the curative effects of CTS on psoriasis are accomplished mainly through modulating STAT3, which providing evidences to develop CTS as a potential therapeutic agent for patients with psoriasis. [ABSTRACT FROM AUTHOR]

Since the beginning of grape cultivation in the 1980 s in Wuhan City,the grape industry has shown a steady growth trend. Through the survey of the local grape industry,it found out the regional distribution,scale and benefits of the grape,as well as the variety structure and cultivation management mode. It analyzed main problems in the grape production,including low degree of organization,concentrated maturity,low rate of good fruit,small cultivation scale,and low labor-saving and high-efficiency cultivation technologies. On the basis of the development status,it came up with pertinent recommendations,including optimizing the variety structure,implementing standardized management,strengthening construction of sightseeing parks,promoting integration of primary and tertiary industries,and developing the gardening experience,to promote healthy and sustainable development of the grape industry. [ABSTRACT FROM AUTHOR]

Interferon regulatory factor 1 (IRF1), as an important transcription factor, is abundantly induced upon virus infections and participates in host antiviral immune responses. However, the roles of porcine IRF1 (poIRF1) in host antiviral defense remain poorly understood. In this study, we determined that poIRF1 was upregulated upon infection with viruses and distributed in nucleus in porcine PK-15 cells. Subsequently, we tested the antiviral activities of poIRF1 against several swine viruses in cells. Overexpression of poIRF1 can efficiently suppress the replication of viruses, and knockdown of poIRF1 promotes moderately viral replication. Interestingly, overexpression of poIRF1 enhances dsRNA-induced IFN-β and IFN-stimulated response element (ISRE) promoter activation, whereas knockdown of poIRF1 cannot significantly affect the activation of IFN-β promoter induced by RNA viruses. This study suggests that poIRF1 plays a significant role in cellular antiviral response against swine viruses, but might be dispensable for IFN-β induction triggered by RNA viruses in PK-15 cells. Given these results, poIRF1 plays potential roles in cellular antiviral responses against swine viruses. [ABSTRACT FROM AUTHOR]

Fly Ere is an elite variety of North American Begonia (Malus micromalus), which is characterized with dark red flowers, red young leaves, red peel, red bark, large flower amount, long flowering period and long fruit bearing period. It is propagated mainly through grafting, and is suitable for popularization and application in the landscape of the Yangtze River basin and north of the Yangtze River. [ABSTRACT FROM AUTHOR]

A resample-based spatial variant apodization (SVA) algorithm for sidelobe reduction was studied for synthetic aperture radar (SAR) and inverse SAR (ISAR) imagery with a noninteger Nyquist sampling rate. The weighting function of every sample in the image domain was calculated with the sample and two adjacent noninteger samples. The noninteger samples were obtained by interpolation in the image domain using sinc function. With the proper selection of two noninteger samples, the monotonic property of the weighting function on each side of the sampling point was preserved. The unequivocal determination of sidelobe suppression was achieved for noninteger Nyquist sampled (NINS) SAR and ISAR imagery. In addition, the lower and upper boundaries of the weighting function under the cosine-on-pedestal condition were extended for further sidelobe suppression and main lobe sharpening. The algorithm was implemented and applied to NINS imagery that is simulated. The algorithm was then assessed for acquired SAR and ISAR images. Improved results have been qualitatively and quantitatively achieved in sidelobe suppression and main lobe sharping in comparison with an existing algorithm. [ABSTRACT FROM PUBLISHER]

Spectral imaging is a technology that integrates conventional imaging and spectroscopy to get both spatial and spectral information from an object. Although this technology was originally developed for remote sensing, it has been extended to the biomedical engineering field as a powerful analytical tool for biological and biomedical research. This review introduces the basics of spectral imaging, imaging methods, current equipment, and recent advances in biomedical applications. The performance and analytical capabilities of spectral imaging systems for biological and biomedical imaging are discussed. In particular, the current achievements and limitations of this technology in biomedical engineering are presented. The benefits and development trends of biomedical spectral imaging are highlighted to provide the reader with an insight into the current technological advances and its potential for biomedical research. [ABSTRACT FROM AUTHOR]

White blood cells (WBC) are comparatively significant components in the human blood system, and they have a pathological relationship with some blood-related diseases. To analyze the disease information accurately, the most essential work is to segment WBCs. We propose a new method for pathological WBC segmentation based on a hyperspectral imaging system. This imaging system is used to capture WBC images, which is characterized by acquiring 1-D spectral information and 2-D spatial information for each pixel. A spectral information divergence algorithm is presented to segment pathological WBCs into four parts. In order to evaluate the performance of the new approach, K-means and spectral angle mapper-based segmental methods are tested in contrast on six groups of blood smears. Experimental results show that the presented method can segment pathological WBCs more accurately, regardless of their irregular shapes, sizes, and gray-values. [ABSTRACT FROM AUTHOR]

A carbon nanotube (CNTs)/lanthanum hydroxide(La(OH)3)nanocomposite was firstly synthesized, and characterized in terms of structure and morphology through X-ray diffraction analysis and transmission electron microscopy. The electrochemical behavior and potential electrochemical applications of the nanocomposite modified electrode were also studied. Cyclic voltammetry was used to probe the characterization of the modified electrode. The modified electrode was used for the determination of adenine and guanine, and the, accelerated electron transfer mechanism was investigated. The result demonstrated that the CNTs/La(OH)3 modified electrode provides an effective method for the determination of adenine and guanine with detection limits 0.22 and 0.26 µM, respectively. [ABSTRACT FROM AUTHOR]

In this paper, ZnO nanorods–Ag nanoparticles hybrids were first synthesized via a facile, rapid, and in situ plasma sputtering method without using any silver precursor. The obtained materials were then characterized by scanning electron microscopy, high-resolution transmission electron microscopy, energy-dispersive x-ray spectroscopy, and cyclic voltammetry. Based on the electrochemical catalytic properties of the obtained nanohybrids, a non-enzymatic hydrogen peroxide biosensor was constructed by immobilizing the obtained ZnO nanorods–Ag nanoparticles hybrids on the surface of a glassy carbon electrode. Under optimal conditions, the resulting biosensor displayed a good response for H2O2 with a linear range of 0.2 to 12.8 mM, and a detection limit of 7.8 μM at a signal-to-noise ratio of 3. In addition, it exhibited excellent anti-interference ability and fast response. The current work provides a feasible platform to fabricate a variety of non-enzymatic biosensors. [ABSTRACT FROM AUTHOR]