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  • Author: Wei Liu x
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Empirical results from long-horizon regression tests have been influential in the finance literature. Yet, it has come to be understood that traditional long-horizon tests may be unreliable in finite samples when regressors are persistent and when the horizon is long relative to sample size. Recent research has provided valid alternative inference procedures in long-horizon regression in the case for which the regressor follows a near-unit root autoregressive process. However, in small samples, such processes may sometimes be difficult to distinguish with confidence from other persistent data generating processes, such as those displaying long-memory or structural breaks. In this paper, we demonstrate a simple means by which existing nonparametric sign and signed rank tests may be applied to provide exact inference in long-horizon predictive tests, without requiring any modeling assumptions on the regressor. Employing this robust approach, we find evidence of stock return predictability at moderate horizons using short-term interest rates, but little evidence of either short or long-run predictability using dividend-price ratios.

Abstract

Owing to the small size, high surface-to-volume ratio, and good biocompatibility, silica nanoparticles (SiNPs) have become the normally used carrier for biomolecule immobilization. Label-based detection techniques have been used extensively for a wide range of applications in biological analysis. Organic dye, enzyme, electroactive species, and quantum dots (QDs) with unique optical and electrochemical performances have been used as probes for chemical and biological analysis. The common problem is that only a limited amount of probes can be linked to a biomolecule, which limited the extensive use of these probes in trace amounts of analyte detection. New technologies can provide efficient means to carry them with SiNPs, which possess a three-dimensional network suitable for load or encapsulating a large amount of probes. As a result, composite SiNPs can improve the detection sensitivity significantly because they carry a large amount of probes, which is beneficial for trace analysis. Also, SiNPs are nontoxic, highly water soluble, suitable for many biomolecules to conjugate, and increase the chemical and physical stability of the probes, which is very important for biological analysis. The goal of this review is to describe recent progress in the methods that SiNPs are used as a carrier of dyes, QDs, and enzyme and their application in biological analysis. Among these, SiNPs as a biolabel reagent for signal amplification in immunoassay, DNA, protein, and small molecule detection are the main topic in this review. We focus on two types of methods of carrying signal probes with SiNPs. One is to modify probes on the outer surface of the SiNPs and another is to encapsulate signal probes into the SiNPs. Particular attention is paid to update reported advances since 2009.

Abstract

Immune reconstitution inflammatory syndrome (IRIS), a common complication of AIDS, is further complicated by tuberculosis. Its clinical symptoms lack specificity but can be evaluated using diagnostic imaging. High-resolution computed tomography (HRCT) is useful in evaluating the morphology and internal microstructure of lesions associated with the syndrome, as well as the relationship of the internal microstructure with the surrounding tissues. This paper summarizes the present state and progress of imaging research on IRIS caused by AIDS and complicated by tuberculosis.

Abstract

Basic experiments have demonstrated that the effect of wound healing in moist environments is better than that in dry environments; therefore, research on moist dressing is the focus of wound healing research. 42 burn patients receiving treatment in Jiangsu Provincial People’s Hospital were selected as experimental cases. Wound surface is divided into treatment group and control group using a self-contrasted method. The treatment group received a moist dressing in the treatment of burn wounds and the control group adopted iodine gauze or Vaseline gauze coverage. Wound healing effect and the impact on the degree of pain of in the two different treatment methods were observed after treatment. The results of 42 patients were included in the analysis. The average healing time of patients’ burn wounds in treatment group is (10.9 3.3) d, and the average healing time in control group is (13.8 3.6) d, so, the difference is significant (P<0.01). Wound pain in the treatment group is significantly lower than that in the control group (P<0.01). Using moist dressing (Mepitel and Mepilex, etc.) in the treatment of burn wounds, woundhealing time can be shortened and wound pain can be reduced significantly.

Abstract

Four kinds of novel polymerizable benzophenone (BP) photoinitiators MBP, BMBP, MPBP, BMPBP containing functional maleimide groups, were used as free radical photoinitiators with N-methyldiethanolamine (MDEA) as coinitiator (H donor). Such photoredox systems were studied by means of ESR spectra. The results show that all the four photoinitiators possess the same initiation mechanism as BP/MDEA system; meanwhile, two kinds of radicals were observed as the excited triplet of the photoinitiators can abstract hydrogen from the methylene groups or the methyl groups of MDEA. The photopolymerization of three monomers with different functionality, methyl methacrylate (MMA), 1,6-hexanediol diacrylate (HDDA) and trimethylolpropane triacrylate (TMPTA), initiated by these four polymerizable photoinitiators, was studied through dilatometer and photo- DSC. The results show that different photoinitiators behave differently towards monomers: MPBP system is the most efficient for all the three monomers; BMPBP is the least efficient for MMA, and BMBP is the least efficient for HDDA and TMPTA. The efficiency of the photopolymerization is greatly affected by maleimide groups and different vinyl monomers.

Abstract

Some oscillation criteria are given for the second order linear differential equation with damping

[r(t)x′(t)]′+p(t)x′(t)+q(t)x(t) = 0, tt 0,

where p(t) and q(t) are allowed to change sign on [t 0, ∞), and r(t) > 0. These results generalize and improve some known results for the differential equations

x″(t) + q(t)x(t) = 0,

and

x″(t) + p(t)x′(t) + q(t)x(t) = 0.