The dynamic behavior of a GaAs photoconductive switch was studied with an electro-optic imaging system during the first 2 ns after optical illumination. The switch behavior changed as a function of ...the spatial distribution of the optical illumination. Symmetric and asymmetric illumination schemes were investigated experimentally with our electro-optic imaging system. The electric fields were significantly enhanced in the regions of low photo-carrier density. Approximately 1 ns after illumination the simple longitudinal variation of the electric field gave way to nonuniform transverse structure. The experimental results were modeled by treating the switch as an integral part of a transmission line consisting of discrete elements. The experimental results matched the predictions of the transmission-line model in terms of the electric-field enhancements and efficiency.< >
Background Gigantomastia is the overdevelopment of the female mammary gland, and it causes great physiological and psychological burdens to patients. A better understanding of the molecular ...mechanisms involved in gigantomastia is needed to develop less invasive and more effective medical treatments. MicroRNA （miRNA） is a class of small noncoding RNAs that play an important regulatory role at the post-transcriptional level. These miRNAs are known to be involved in many diseases, including breast cancer; however, the relationship between miRNA and gigantomastia is largely unknown. Methods Whole genome-wide expression of miRNA and mRNA in gigantomastia was detected using microarray and functional annotation was performed based on the altered expression of miRNAs and mRNAs. Results We found many miRNAs and mRNAs to be significantly differentially expressed in gigantomastia compared with normal breast tissues. Functional annotation analysis indicated that APK, Wnt, and Neurotrophin signaling pathways may participate in gigantomastia. Conclusion This study addresses the need for better diagnosis and treatment of gigantomastia by providing new insight into the molecular mechanisms underlying this disease.
Learning to program is difficult for many first year undergraduate students. Instructional strategies of traditional programming courses tend to focus on syntactic issues and assigning practice ...exercises using the presentation-examples-practice formula and by showing the verbal and visual explanation of a teacher during the â??step by step
Our previous studies described that the human cricopharyngeus (CP) is composed of two neuromuscular compartments (NMCs), horizontal and oblique. The present study was designed to explore the ...differences in muscle fiber-type distribution between the NMCs within the human CP and to examine the oxidative capacity of the muscle fibers. Seven adult human CP muscles obtained from autopsies were stained for myofibrillar ATPase, reduced nicotinamide adenine dinucleotide tetrazolium reductase (NADH-TR), and succinic dehydrogenase (SDH) to analyze enzyme-histochemical fiber-type characteristics. Notable findings obtained from this study are as follows: (1) Different NMCs within the human CP contained different percentages of muscle fiber types. The horizontal CP (CPh) contained more slow-twitch fibers than the oblique CP (CPo). (2) Each of the NMCs was dividable histochemically into two layers or subcompartments: a slow fiber-type inner layer and a relatively fast fiber outer layer. (3) As a whole, type I fibers had higher levels of NADH-TR and SDH than type II fibers. However, in both type I and II muscle fiber types, different patterns of oxidative enzyme activity were seen. Histochemically defined fiber layers of the CP are not seen in other mammals, suggesting that CP function is more specialized in humans.
Late diagnoses of foreign body aspiration were defined as occurring beyond 3 days between the aspiration of the foreign body, or onset of symptoms, and correct diagnosis. We reviewed a total of 210 ...children with late diagnosis of foreign body aspiration. The causes creating late diagnosis of foreign body aspiration in children were as follows: (1) parental negligence (106/210, 50%); (2) misdiagnosis by the fellow professionals and pediatricians (39/210, 19%); (3) the normal chest roentgenographic findings (29/210, 14%); (4) lack of typical symptoms and signs (26/210, 12%); (5) mismanagement (8/210, 4%); and (6) a negative bronchoscopic finding (2/210, 1%). The most common complications encountered were obstructive emphysema (77/186, 41%), mediastinal shift (63/186, 34%), pneumonia (43/186, 24%), and atelectasis (33/186, 18%) in 186 patients who underwent a chest roentgenographic examination. The incidence of major complications was 64% (48/75) in the children who were diagnosed within 4 to 7 days; however, the complication rate was 70% (39/56) in those with a delay in diagnosis of 15 to 30 days, and 95% (20/21) in the cases with a delay in diagnosis of over 30 days after aspirating the foreign bodies.
A series of novel N-（1-aryl-3-phenyl-pyrazol-4-yl）methylene-2-（halo-o-hydroxyphenyl）hydrazide derivatives was synthesized and the antibacterial activity of each of them was evaluated. The supposed ...reaction mechanism of acquiring compounds 3a--3d is that catalytic activity is enhanced by the electron-donating groups of the first phenyl ring while decreased by electron-withdrawing groups of that ring. The result of preliminary bioassay shows that the lowest minimal inhibitory concentration（MIC） of the title compounds against Escherichia coli is 2 ℃g/mL. MIC values against Monilia albiean and Staphloeoeeus aureus are as low as 4 ~g/mL. They will be a series of potential antibacterial compounds against fungi and gram-negative bacteria.
Phys. Rev. Applied 20, 014014 (2023) Greenberger-Horne-Zeilinger and W states feature genuine tripartite
entanglement that cannot be converted into each other by local operations and
classical ...communication. Here, we present a dissipative protocol for
deterministic interconversion between Greenberger-Horne-Zeilinger and W states
of three neutral $^{87}$Rb atoms arranged in an equilateral triangle of a
two-dimensional array. With three atomic levels and diagonal van der Waals
interactions of Rydberg atoms, the interconversion between tripartite entangled
states can be efficiently accomplished in the Floquet-Lindblad framework
through the periodic optical pump and dissipation engineering. We evaluate the
feasibility of the existing methodology using the experimental parameters
accessible to current neutral-atom platforms. We find that our scheme is robust
against typical noises, such as laser phase noise and geometric imperfections
of the atom array. In addition, our scheme can integrate the Gaussian soft
quantum control technique, which further reduces the overall conversion time
and increases the resilience to timing errors and interatomic distance
fluctuations. The high-fidelity and robust tripartite entanglement
interconversion protocol provides a route to save physical resources and
enhance the computational efficiency of quantum networks formed by neutral-atom
arrays.
Abstract Objectives To evaluate whether cigarette smoking in Chinese urban areas was respectively associated with exposure to tobacco advertising and smoking bans in households, workplaces, and ...public places. Methods Participants were 4735 urban residents aged 15 years and older, who were identified through multi-stage quota-sampling conducted in six Chinese cities. Data were collected on individual sociodemographics and smoking status, and regional tobacco control measures. The sample was characterized in terms of smoking prevalence, and multilevel logistic models were employed to analyze the association between smoking and tobacco advertising and environmental smoking restrictions, respectively. Results Smoking prevalence was 30%. Multilevel logistic regression analysis showed that smoking was positively associated with exposure to tobacco advertising, and negatively associated with workplace and household smoking bans. Conclusions The association of smoking with both tobacco advertising and environmental smoking bans further justifies implementation of comprehensive smoking interventions and tobacco control programs in China.
Compacted loess is widely used as fills of road embankments in loess regions of northern China.Generally, densely-compacted loess can satisfy the requirements of embankment strength and ...postconstruction deformation. However, uneven subsidence, pavement cracks and other related damages can affect the integrity of loess subgrade after several years of operation,and even cause some hazards, especially in North China, where the strong freeze-thaw erosion occurs. In this study, cyclic freeze-thaw tests for both densely and loosely compacted loess samples were performed to determine the variation in engineering properties such as volume, void ratio, collapsible settlement,microstructure, and the related mechanisms were addressed. The experimental results showed that an obvious water migration and redistribution occurred within the samples during freeze-thaw cycles. Ice lenses and fissures could be identified in the upper frozen layers of the samples. After freeze-thaw cycles,the dry densities of the upper layers of samples changed significantly due to strong freeze-thaw erosion. The dry densities decreased for the dense sample and increased for the loose sample. It can be found that dense samples become loose, while loose samples became dense with the increasing number of freeze-thaw cycles. Their related void ratios changed reversely. Both void ratios tended to fall into a certain range, which verified the concept of a residual void ratio proposed by Viklander. The loosening process of densely compacted samples involves the formation of large pores, volume increase and density reduction as well as the related changes in mechanical properties because freeze-thaw cycles may be important contribution to problems of loess road embankments.Adverse effects of freeze-thaw cycles, therefore,should be taken into account in selecting loess parameters for the stability evaluation of road embankment in seasonally frozen ground regions.
不同光固化模式和乙醇湿粘接对牙本质粘结性能的影响 Mu-zi LI Jin-rui WANG Hong LIU Xia WANG Kang GAN Xiu-ju LIU De-li NIU Xiao-qing SONG
浙江大学学报：B卷英文版,
2016, Letnik:
17, Številka:
9
Journal Article
Recenzirano
目的：探究不同光固化模式和乙醇湿粘接对牙本质粘结强度及耐久性的影响,为临床应用提供理论指导。创新点：率先将乙醇湿粘接技术和不同光固化模式有机结合,成功筛选出了提高牙本质粘结性能的有效策略。方法：将Single Bond 2（SB）组、Gluma Comfort ...Bond（GB）组和N-Bond（NB）组分别分为6个亚组：高光照射模式、乙醇预处理＋高光照射模式、软启动照射模式、乙醇预处理＋软启动照射模式、标准照射模式和乙醇预处理＋标准照射模式。按照分组粘结,水储24小时和6个月后,应用万能测试机分别检测微拉伸强度,体视显微镜观察微拉伸试件断裂类型和扫描电镜观察混合层形态。结论：乙醇湿粘接技术可以改善混合层质量,从而提高其粘结强度和改善粘结耐久性;软启动光照模式和标准光照模式可以形成更好的混合层质量,获得更高的牙本质粘结强度和更好的粘结耐久性。
PDF
