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1.
The present investigation examined whether daily smokers with posttraumatic stress disorder (PTSD), as compared to daily smokers with either anxiety psychopathology or no current Axis I psychopathology, have decreased success in the early phases of a self-guided smoking quit attempt. Participants were 140 daily smokers (81 women; M (age) = 29.5; SD = 11.9; range = 18-65 years); approximately one-third of the sample met criteria for current PTSD (n = 47), one-third met criteria for other current anxiety disorders (without PTSD; n = 33), and one-third did not meet criteria for any current Axis I disorder (n = 60). Consistent with prediction, membership in the PTSD group, compared to membership in the other anxiety disorders group and the group with no current Axis I psychopathology, was associated with increased risk of lapse during the first week following quit day. Additionally, daily smokers with PTSD and other anxiety disorders were at significantly increased risk of relapse during the first week post-cessation compared to persons without Axis I psychopathology. However, the PTSD group and the other anxiety disorders group did not differ from one another in terms of relapse. Results suggest that PTSD is associated with increased risk of smoking lapse and relapse compared to smokers with no current Axis I psychiatric problems, and increased risk of early smoking lapse but not relapse, as compared to those with other anxiety disorders. Findings provide novel evidence that PTSD, and perhaps anxiety disorders more generally, may be important factors in reducing the odds of successful unaided quit attempts in the early phases of cessation.  相似文献   
2.
The feasibility of using a visible/near‐infrared hyperspectral imaging system with a wavelength range between 400 and 1000 nm to detect and differentiate different levels of aflatoxin B1 (AFB1) artificially titrated on maize kernel surface was examined. To reduce the color effects of maize kernels, image analysis was limited to a subset of original spectra (600 to 1000 nm). Residual staining from the AFB1 on the kernels surface was selected as regions of interest for analysis. Principal components analysis (PCA) was applied to reduce the dimensionality of hyperspectral image data, and then a stepwise factorial discriminant analysis (FDA) was performed on latent PCA variables. The results indicated that discriminant factors F2 can be used to separate control samples from all of the other groups of kernels with AFB1 inoculated, whereas the discriminant factors F1 can be used to identify maize kernels with levels of AFB1 as low as 10 ppb. An overall classification accuracy of 98% was achieved. Finally, the peaks of β coefficients of the discrimination factors F1 and F2 were analyzed and several key wavelengths identified for differentiating maize kernels with and without AFB1, as well as those with differing levels of AFB1 inoculation. Results indicated that Vis/NIR hyperspectral imaging technology combined with the PCA–FDA was a practical method to detect and differentiate different levels of AFB1 artificially inoculated on the maize kernels surface. However, indicated the potential to detect and differentiate naturally occurring toxins in maize kernel.  相似文献   
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4.
The presence of Campylobacter in foods of animal origin is the leading cause of bacterially induced human gastroenteritis. Isolation and detection of Campylobacter in foods via direct plating involves lengthy laboratory procedures including enrichments and microaerobic incubations, which take several days to a week. The incubation time for growing Campylobacter colonies in agar media usually takes 24–48 h. Oftentimes the problem is the difficulty of visually differentiating Campylobacter colonies from non-Campylobacter contaminants that frequently grow together with Campylobacter on many existing agars. In this study, a new screening technique using non-destructive and non-contact hyperspectral imaging was developed to detect Campylobacter colonies in Petri dishes. A reflectance spectral library of Campylobacter and non-Campylobacter contaminants was constructed for characterization of absorption features in wavelengths from 400 to 900 nm and for developing classification methods. Blood agar and Campy-Cefex agar were used as culture media. The study found that blood agar was the better culture medium than Campy-Cefex agar in terms of Campylobacter detection accuracy. Classification algorithms including single-band thresholding, band-ratio thresholding and spectral feature fitting were developed for detection of Campylobacter colonies as early as 24 h of incubation time. A band ratio algorithm using two bands at 426 and 458 nm chosen from continuum-removed spectra of the blood agar bacterial cultures achieved 97–99% of detection accuracy. This research has profound implications for early detection of Campylobacter colonies with high accuracy. Also, the developed hyperspectral reflectance imaging protocol is applicable to other pathogen detection studies.  相似文献   
5.
Messenger RNA (mRNA) is emerging as an attractive biopolymer for therapy and vaccination. To become suitable for vaccination, mRNA is usually converted to a biomaterial, using cationic peptides, polymers or lipids. An alternative form of converting mRNA into a material is demonstrated that uses branched oligoribonucleotide hybrids with the ability to hybridize with one or more regions of the mRNA sequence. Two such hybrids with hexamer arms and adamantane tetraol as branching element were prepared by solution-phase synthesis. When a rabies mRNA was treated with the branched hybrids at 1 M NaCl concentration, biomaterials formed that contained both of the nucleic acids. These results show that branched oligoribonucleotides are an alternative to the often toxic reagents commonly used to formulate mRNA for medical applications.  相似文献   
6.
This study represents an effort to better understand the latent structure of anxiety sensitivity (AS), as indexed by the 16-item Anxiety Sensitivity Index (ASI; S. Reiss, R. A. Peterson, M. Gursky, & R. J. McNally, 1986), by using taxometric and factor-analytic approaches in an integrative manner. Taxometric analyses indicated that AS has a taxonic latent class structure (i.e., a dichotomous latent class structure) in a large sample of North American adults (N = 2,515). As predicted, confirmatory factor analyses indicated that a multidimensional 3-factor model of AS provided a good fit for the AS complement class (normative or low-risk form) but not the AS taxon class (high-risk form). Exploratory factor analytic results suggested that the AS taxon may demonstrate a unique, unidimensional factor solution, though there are alternative indications that it may be characterized by a 2-factor solution. Findings suggest that the latent structural nature of AS can be conceptualized as a taxonic latent class structure composed of 2 types or forms of AS, each of these forms characterized by its own unique latent continuity and dimensional structure. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   
7.
In this paper, a MEMS-based electronically steerable antenna array (ESA) fabricated using printed circuit processing techniques is reported. A Kapton polyimide film is used as the structural layer for fabricating MEMS varactors. The MEMS varactors have been used in the bistable mode to design loaded- line-type MEMS phase shifters. These MEMS phase shifters have been monolithically integrated with the ESA on a Duroid substrate using printed circuit processing techniques. For proof-of-concept demonstration of the proposed MEMS-based ESA, a 3-bit MEMS phase shifter has been monolithically integrated with a two- element double-folded slot-antenna array on a Duroid substrate. An X-band ESA prototype with a beam steering angle of 20deg at 9.1 GHz is presented.  相似文献   
8.
Posttraumatic stress disorder (PTSD) is associated with high rates of smoking and fear of bodily perturbation. The current study examined the role of nicotine withdrawal in the association between PTSD and responding to bodily arousal among 52 participants (27 women; Mage = 30.50 years). Compared to participants without current axis I psychopathology, persons with current PTSD responded to a 3-min voluntary hyperventilation procedure with greater increases in anxiety and more intense cognitive and physical panic symptoms, despite no group differences in physiological arousal. Nicotine withdrawal demonstrated significant mediational effects in the relations between diagnostic group and panic symptoms elicited by the hyperventilation procedure. Findings suggest nicotine withdrawal is an important factor to consider in terms of better understanding the nature of fear responding to bodily sensations among persons with PTSD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
9.
Replies to the article by Mineka and Zinbarg (see record 2006-00920-002), which illustrated how a contemporary learning theory informs the etiology and maintenance of anxiety disorders. In our view, the challenge facing contemporary learning theory is to explain how and why potentiated fear conditioning is problematic and capable of yielding an anxiety disorder. Neither potentiated fear and fear learning itself, nor individual differences that potentiate both, explain how an anxiety disorder develops. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
10.
Samples from five chicken meat products, obtained at retail stores, were evaluated for the presence of Bacillus cereus. The products tested were as follows: breaded, fully cooked, frozen nuggets (NUGGETS); breaded, fully cooked, frozen tenders (TENDERS); fully cooked, frozen, white-meat fajita-style strips (STRIPS); raw, refrigerated, boneless, skinless, marinated breast fillets (FILLETS); and raw, refrigerated, cut-up, tray-pack bone-in parts (PARTS), either split breasts or thighs. Four packages of each item were obtained on three different days (n = 60). Frozen and refrigerated products were held overnight in their respective environments as appropriate; then packages were opened aseptically, and a total of 25 g of tissue was excised from multiple pieces within a package. The 25-g samples were enriched in 225 ml of Trypticase soy-polymixin broth for 18 to 24 h at 30 degrees C and then plated on mannitol-egg yolk-polymixin agar and incubated for 18 to 24 h at 30 degrees C. Colonies characteristic of B. cereus were chosen and replated for isolation on mannitol-egg yolk-polymixin agar. Suspect colonies were confirmed as Bacillus spp. by Gram stain, hemolysis on blood agar, and a biochemical test strip. Isolates were further confirmed as B. cereus using Bacteriological Analytical Manual procedures, including tests for motility, rhizoid growth, hemolysis, and protein toxin crystal production. B. cereus was detected in 27 of 60 total samples. By product, the prevalence levels were as follows: NUGGETS, 11 of 12 positive; TENDERS, 8 of 12 positive; STRIPS, 6 of 12 positive; FILLETS, 0 of 12 positive; and PARTS, 2 of 12 positive. Isolates were tested by PCR for presence of the toxin-encoding genes bceT, nheABC, hblACD, and cytK. Results indicate that B. cereus organisms were present on four of the five retail poultry products tested in this study, with the highest rates reported for the three fully cooked items, especially the two breaded products. All strains isolated contained the gene(s) for at least one of the toxins, although none of the strains contained the cytK gene.  相似文献   
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