Search

No consensus on standardized technique of enterostomy creation has been made meanwhile high heterogeneity of surgical procedure exists in 'stoma creation' chapters of textbooks or atlases of colorectal surgery. The present article reviews the anatomy of tendinous aponeurotic fibers which is crucial for abdominal wall tension and integrity. Through empirical practice we hypothesize a procedure of enterostomy creation basied on abdominal wall tension plus anchor suture for fascia fixation which could theoretically decrease short-term stoma complication rates and long-term parastomal hernia rates. Surgical techniques are as followed: (1) preoperative stoma site mark for de-functioning ileostomy should be positioned at the lateral border of rectus abdominis muscle (RAM) to decrease the difficulty of stoma reversal and for permanent colostomy should be placed overlying the RAM to promote adhesion; (2)Optimal circular removal or lineal opening of skin, and avoid dissection of subcutaneous tissue; (3) Lineal dissection of natural strong fascia (rectus sheath) at stoma site and blunt separation of muscular fibers. The tunnel of the fascia should be made with appropriate size without undue tension. To prevent the formation of dead space, additional suturing at fascia layer is unnecessary. (4) Anchor suture for fascia fixation at two ends of fascia opening could be considered to avoid delayed fascia disruption and parastomal hernia. (5) After pull-through of ileum or colon loop, 4-8 interrupted seromuscular sutures could be placed to attach loop to skin. For ileostomy, self-eversion of mucosa can be successful in vast majority of cases and a Brooke ileostomy is not necessary. The efficacy and safety of this procedure should be tested in future trials.肠造口手术技术细节尚无统一标准，外科学教材中的手术原则存在较大异质性。在回顾腹壁结构和腱膜的精细解剖基础上，结合作者们的实践经验，尝试提出一种基于腹壁张力和筋膜锁定缝合的肠造口技术。技术操作细节为：（1）临时性造口选择右腹直肌外缘，永久性造口选择左侧腹直肌内促进粘连；（2）皮肤行适合尺寸的圆形开孔（临时性也可一字型），皮下组织和深筋膜行钝性分离；（3）沿腹外斜肌腱膜纤维方向切开筋膜层，钝性扩开肌肉组织，腹横筋膜层水平切开小口后，扩张腹壁隧道至适合尺寸，临时性造口肠袢能恰好无阻力地提出腹壁为适宜，永久性造口稍有阻力为适宜，但均不要预留运针空间以免致死腔形成；（4）永久性造口可考虑在筋膜切线两端单纯或8字锁定缝合，避免慢性筋膜撕裂；（5）肠壁提出后，与皮肤简单固定4~8针；通常临时性回肠造口黏膜可自行翻出，无需外翻缝合；永久性造口可视情况黏膜外翻缝合。理论上讲，该技术可降低术后短期并发症和远期造口疝的发生率。期待能够在未来的研究中，验证该技术的安全性和有效性。.

Hyperalgesia is an occult complication during the treatment of cancer pain, not only related to opioids, but also pertaining to the tumor itself and cancer therapeutic drugs. Yet it is often ignored by clinicians. Patients with cancer pain who were treated with opioids often have sensory abnormalities presented with reduced pain threshold and increased sensitivity to nociceptive stimuli. This phenomenon is clinically called opioid-induced hyperalgesia (OIH). However, due to the complexity of pathogenesis and the lack of clinical diagnostic criteria, the pain management of cancer patients is still facing great challenges. Therefore, this article focuses on the clinical diagnosis, pathogenesis, prevention and treatment of hyperalgesia related to cancer pain treatment, in order to provide a basis for optimal use of opioids in the future.痛觉过敏常常隐匿于癌痛治疗过程中，不仅与阿片类药物相关，也与肿瘤本身以及肿瘤治疗药物相关，但常常受到临床医生忽视。接受阿片类药物治疗的癌痛患者常出现痛阈降低，并对各种伤害性刺激敏感性增高，这种现象在临床上称之为阿片类药物引起的痛觉过敏（OIH）。由于其发病机制复杂且缺乏临床诊断标准，因此导致癌症患者的疼痛管理面临极大挑战。本文从癌痛治疗相关痛觉过敏的临床诊断、发生机制和防治的最新研究进展进行论述，以期为阿片类药物的优化使用提供依据。.

Background & Aims Tenofovir disoproxil fumarate (TDF) is the preferred treatment to prevent maternal transmission of HBV, owing to its efficacy and safety. However, data are lacking on the long-term safety outcomes in children following fetal exposure to TDF. Methods Children participating in a prospective, multisite trial of maternal TDF treatment during late pregnancy were recruited for follow-up visits once a year. Growth parameters, serum biochemistry, HBV serology, and bone mineral density (BMD) by dual-energy x-ray absorptiometery scan were measured. Results One hundred and twenty-eight children, 71 in the TDF and 57 in the control group, completed 255 follow-up visits at the age of 2 to 7 (median, 4.08) years. No differences in z-scores for weight-for-age (0.26 ± 0.90 vs. 0.22 ± 0.99, p = 0.481), z-scores for height-for-age (0.20 ± 1.02 vs. 0.25 ± 0.98, p = 0.812), and estimated glomerular filtration rate (169.12 ± 50.48 vs. 169.06 ± 34.46 ml/min/1.73m2, p = 0.479) were detected. After adjustment for age, sex and HBV status by multiple linear regression, children in the TDF and control group had comparable levels of serum calcium, phosphorus, bone-specific alkaline phosphatase, calcidiol and BMD of lumbar spines (0.55 ± 0.01 vs. 0.57 ± 0.01 g/cm2, p = 0.159) and left hip (0.56 ± 0.01 vs. 0.56 ± 0.01 g/cm2, p = 0.926). Conclusions Children of HBV-infected mothers who did or did not receive tenofovir disoproxil fumarate treatment during late pregnancy had comparable long-term growth, renal function, and bone development up to 6–7 years after delivery. Clinical trial number NCT01312012 ( ClinicalTrials.gov ) Lay summary Currently there are insufficient long-term safety data in children born to mothers who took antiviral agents during pregnancy to prevent mother-to-infant transmission of hepatitis B virus (HBV). In this study, we found that children of HBV-infected mothers who did or did not receive tenofovir disoproxil fumarate treatment during late pregnancy had comparable long-term growth, renal function, and bone development up to 6-7 years after delivery.

As students transition into tertiary blended learning environments, their digital literacy in terms of technical capabilities have potential to impact on their access to digital resources. The first foundational year of STEM degrees includes compulsory courses across a broad range of scientific areas, each of which incorporates online technology in a discipline-specific manner. Given the diversity of online resources that STEM students need to access across their first-year coursework, this study applies learning analytical methods to determine whether students’ perceived level of digital literacy has an effect on their navigation of learning management systems (LMS) and overall academic performance. The frequency and nature of LMS interactivity were examined across four first-year STEM courses offered in the same semester at a single institution, using a K-means cluster analysis to group student responses. It was observed that high achieving students accessed LMS resources more frequently than mid or low-achieving students across all four STEM courses. Students’ perceived level of digital literacy was collected via survey (n = 282), and students were sorted high (n = 106) and low-level (n = 176) of perceived digital literacy—HDL and LDL, respectively. HDL students were not consistently found in the high-achieving academic group and did not perform better in their overall grade when compared to LDL students. LDL students were observed to perform better in specific online assessment tasks, which may be attributed to their increased frequency of LMS interactivity. These findings highlight the delicate balance between students’ perceived level of digital literacy, motivation for engaging with online learning environments, and academic performance.

The difficulty of transanal total mesorectal excision (TME) is to find the correct dissection plane of perirectal space. As a complex new surgical procedure, the fascial anatomic landmarks of transanal approach operation are more likely to be ignored. It is often found that dissection plane is false after the secondary injury occurs during the operation, which results in the damage of pelvic autonomic nerves. Meanwhile, the mesorectum is easily damaged if the dissection plane is too close to the rectum. Thus, the safety of oncologic outcomes could be limited by difficulty achieving adequate TME quality. The promotion and development of the theory of perirectal fascial anatomy provides a new thought for researchers to design a precise approach for transanal endoscopic surgery. Transanal total mesorectal excision based on fascial anatomy offers a solution to identify the transanal anatomic landmarks precisely and achieves pelvic autonomic nerve preservation. In this paper, the authors focus on the surgical experience of transanal total mesorectal excision based on the theory of perirectal fascial anatomy, and discuss the feature of perirectal fascial anatomy dissection and technique of pelvic autonomic nerve preservation during transanal approach operation.经肛全直肠系膜切除术的难点在于寻找直肠周围间隙的正确分离平面，作为一种复杂的新术式，实施过程中经肛操作的筋膜解剖标志容易被忽略，待出现术中副损伤时才发现游离平面有误，从而导致盆腔自主神经受损；若是游离平面过于靠近直肠，可能造成直肠系膜受损，则无法实现完整的TME标本质量，从而导致肿瘤学安全无法得到保证。膜解剖理论的推动与发展，为经肛腔镜手术的精准实施提供了一种新的思路。基于膜解剖的经肛全直肠系膜切除术可精确识别经肛操作解剖标志并加以神经保护，为上述难题提供了一个解决方案。本中心以直肠周围筋膜解剖的理论为基础，结合经肛腔镜全直肠系膜切除手术经验，探讨经肛操作中直肠周围筋膜分离的特点和盆腔自主神经保护的技巧。.

Course-integrated Undergraduate Research Experiences (CUREs) involve large numbers of students in real research. We describe a late-year microbiology CURE in which students use yeast to address a research question around beer brewing or synthesizing biofuel; the interdisciplinary student-designed project incorporates genetics, bioinformatics, biochemistry, analytical chemistry, and microbiology. Students perceived significant learning gains around multiple technical and "becoming a scientist" aspects of the project. The project is demanding for both the students and the academic implementers. We examine the rich landscape of support and interaction that this CURE both encourages and requires while also considering how we can support the exercise better and more sustainably. The findings from this study provide a picture of a CURE implementation that has begun to reach the limits of both the students' and the academics' capacities to complete it. © 2018 by The International Union of Biochemistry and Molecular Biology, 2018.

The modulation p-doping technique has emerged as an effective way to optimize the carrier dynamics process of quantum dot (QD) structures. Here, the laser structures based on the 1.3 μm multiple-layer InAs/GaAs QD were fabricated with and without modulation p-doping. The carrier relaxation rate was increased after modulation p-doping, as demonstrated by transient absorption spectroscopy. The higher relaxation rate in p-doped QDs could be explained by more rapid carrier–carrier scattering process originating from increasing of the hole quasi-Fermi-level movement that increases the probability of occupancy of the valence states. In addition, the lasing behavior of Fabry–Perot lasers with and without modulation p-doping was investigated and compared. It was found that the ground state (GS) lasing in the absence of facet coating was successfully achieved in a p-doped laser diode with short cavity length (400 μm), which can be attributed to the higher GS saturation gain caused by p-doping. With assistance of a designed TiO2/SiO2 facet coating whose central wavelength (∼1480 nm) is far beyond the lasing wavelength of 1310 nm, the GS lasing could be realized in a laser diode with short cavity lengths (300 μm) under continuous wave operation at room temperature, implying great potential for the development of low-cost and high-speed directly modulated lasers.

In this study, the unsteady drag produced by the interaction of a shock wave with a single- and a double-sphere model is measured using imbedded accelerometers. The shock wave is generated in a horizontal circular shock tube with an inner diameter of 200 mm. The effect of the shock Mach number and the dimensionless distance between spheres is investigated. The time-history of the drag coefficient is obtained based on Fast Fourier Transformation (FFT) band-block filtering and polynomial fitting of the measured acceleration. The measured peak values of the drag coefficient, with the associated uncertainty, are reported.

© FEMS 2018. All rights reserved. The American Society for Microbiology's curricular guidelines for Introductory Microbiology highlighted key laboratory skills in the isolation, visualization and identification of microorganisms as core learning objectives in the discipline. Since the publication of these guidelines in 2012, there has been a paucity of diagnostic assessment tools in the literature that can be used to assess competencies in the microbiology laboratory. This project aimed to establish a laboratory competency examination for introductory microbiology, with tasks specifically aligned to laboratory skills and learning outcomes outlined in curricular guidelines for microbiology. A Laboratory Competency Examination assessing student skills in light microscopy, Gram-staining, pure culture, aseptic technique, serial dilution, dilution calculations and pipetting was developed at The University of Queensland, Australia. The Laboratory Competency Examination was field-tested in a large introductory microbiology subject (~400 students), and student performance and learning gains data were collected from 2016 to 2017 to evaluate the validity of the assessment. The resulting laboratory assessment is presented as an endpoint diagnostic tool for assessing laboratory competency that can be readily adapted towards different educational contexts.

To report a case of abscess formation in bilateral ovarian endometriomas after failure of mifepristone-induced abortion.A-36-year-old multiparous woman with bilateral ovarian endometriomas conceived spontaneously and received mifepristone to induce an abortion at 35 days' gestation. Fever and lower abdominal pain occurred 28 days after the abortion. The patient then underwent surgical curettage for an incomplete abortion complicated by endometritis. Her symptoms and signs became aggravated, and computed tomography showed a large ovarian abscess. She underwent laparoscopic drainage of the abscess plus the enucleation of the ovarian endometriomas, and received intravenous antibiotic treatment. She resumed menstruation one month later and was doing well at the 11-month follow-up.This case demonstrates the importance of combining antibiotic therapy with mifepristone to induce abortions in women with known ovarian endometriomas.

Clinical microbiology testing is crucial for the diagnosis and treatment of community and hospital-acquired infections. Laboratory scientists need to utilize technical and problem-solving skills to select from a wide array of microbial identification techniques. The inquiry-driven laboratory training required to prepare microbiology graduates for this professional environment can be difficult to replicate within undergraduate curricula, especially in courses that accommodate large student cohorts. We aimed to improve undergraduate scientific training by engaging hundreds of introductory microbiology students in an Authentic Large-Scale Undergraduate Research Experience (ALURE). The ALURE aimed to characterize the microorganisms that reside in the healthy human oral cavity—the oral microbiome—by analyzing hundreds of samples obtained from student volunteers within the course. Students were able to choose from selective and differential culture media, Gram-staining, microscopy, as well as polymerase chain reaction (PCR) and 16S rRNA gene sequencing techniques, in order to collect, analyze, and interpret novel data to determine the collective oral microbiome of the student cohort. Pre- and postsurvey analysis of student learning gains across two iterations of the course (2012–2013) revealed significantly higher student confidence in laboratory skills following the completion of the ALURE (p < 0.05 using the Mann-Whitney U-test). Learning objectives on effective scientific communication were also met through effective student performance in laboratory reports describing the research outcomes of the project. The integration of undergraduate research in clinical microbiology has the capacity to deliver authentic research experiences and improve scientific training for large cohorts of undergraduate students. Editor's Note: The ASM advocates that students must successfully demonstrate the ability to explain and practice safe laboratory techniques. For more information, read the laboratory safety section of the ASM Curriculum Recommendations: Introductory Course in Microbiology and the Guidelines for Biosafety in Teaching Laboratories, available at www.asm.org. The Editors of JMBE recommend that adopters of the protocols included in this article follow a minimum of Biosafety Level 2 practices.

Course-integrated Undergraduate Research Experiences (CUREs) involve large numbers of students in real research. We describe a late-year microbiology CURE in which students use yeast to address a research question around beer brewing or synthesizing biofuel; the interdisciplinary student-designed project incorporates genetics, bioinformatics, biochemistry, analytical chemistry, and microbiology. Students perceived significant learning gains around multiple technical and "becoming a scientist" aspects of the project. The project is demanding for both the students and the academic implementers. We examine the rich landscape of support and interaction that this CURE both encourages and requires while also considering how we can support the exercise better and more sustainably. The findings from this study provide a picture of a CURE implementation that has begun to reach the limits of both the students' and the academics' capacities to complete it. © 2018 by The International Union of Biochemistry and Molecular Biology, 46(3):213-222, 2018.

Inquiry-driven learning, research internships and course-based undergraduate research experiences all represent mechanisms through which educators can engage undergraduate students in scientific research. In life sciences education, the benefits of undergraduate research have been thoroughly evaluated, but limitations in infrastructure and training can prevent widespread uptake of these practices. It is not clear how faculty members can integrate complex laboratory techniques and equipment into their unique context, while finding the time and resources to implement undergraduate research according to best practice guidelines. This review will go through the trends and patterns in inquiry-based undergraduate life science projects with particular emphasis on molecular biosciences-the research-aligned disciplines of biochemistry, molecular cell biology, microbiology, and genomics and bioinformatics. This will provide instructors with an overview of the model organisms, laboratory techniques and research questions that are adaptable for semester-long projects, and serve as starting guidelines for course-based undergraduate research.

Phase transitions, dielectric permittivity, and conductivity of (Bi1-xBax)(Fe1-xTix)O3 (x = 0.05 and 0.1) [BFO-(Ba,Ti)] multiferroic ceramics have been studied as functions of temperature and frequency. In situ synchrotron x-ray diffraction revealed rhombohedral–cubic transitions in the temperature ranges 760–780°C in BFO-5%(Ba,Ti), and 720–750°C in BFO-10%(Ba,Ti). A one-dimensional barrier model with intrinsic barriers B every lattice constant a and extrinsic barriers B + Δ is introduced to describe the dielectric response and conductivity. This work revealed that (Ba,Ti) substitutions can enhance the intrinsic barriers and reduce the hopping rate of charge carriers, thereby giving the desired effect of decreasing the conductivity.

In this paper, we propose a new design of flow channel and stack arrangement based on the numerical study considering the effect of the flow channel design on the stack performance and analyze the thermal stress of a planar anode-supported solid oxide fuel cell stack. We also attempt to simplify the cell stack design without affecting its performance and propose an easier sealing method of cell stacks through the study of the thermal stress distribution. The results indicate that the new design, created by changing the cathode flow channel to a porous current collector, with a 6.3% increase in power density, an 8.6% increase in electrical efficiency. Both more uniform flow and current density distribution can be obtained as compared with a conventional counter-flow design. In addition, we propose a new design direction of cell stack, which could be simpler and easier to fabricate, in which material can easily undertake the resulting stress based on the thermal stress analysis.

[1] A novel approach for estimating marine boundary layer cloud base height (CBH) is proposed based on calculated boundary layer lapse rates, collocated cloud top height (CTH), cloud top, and ocean surface temperatures from the A-Train satellite constellation. The method takes advantage of the assumption that decreases of temperature within and below water clouds may follow the different constant apparent lapse rates in the same region, respectively. The CBHs derived from the new method compare well with the coincident CBH product from the active sensors of Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) and CloudSat. The correlation coefficient, the mean difference, and the standard deviation are 0.79 (0.54), 0.02 km (0.03 km), and ±0.35 km (±0.54 km), respectively, when CTH is derived from CALIPSO data (or Moderate Resolution Imaging Spectroradiometer retrieval). Besides the relatively small bias, the most important advantage of this method compared to previous CBH retrieval techniques is that it is independent of boundary layer cloud types, optical thickness, and illumination.

This paper presents a robust fault-tolerant H ∞ approach for the development of the energy management strategy (EMS) for a parallel hybrid electric vehicle (PHEV). The objective is to determine the power split ratio between engine and battery that maintains the state of energy (SOE) of the battery within a reasonable range to prevent the battery from undesirable breakdown under the situation of existence of battery fault. The system model which consists of the engine part; the electric motor part and the battery part (here a equivalent circuit model) is given first. Then the control system structure with weighting functions, taking into account the battery fault and the control signal limit, is given. Finally, the controller is derived and some simulations for a specific PHEV are included.

Molecular cloning skills are an essential component of biological research, yet students often do not receive this training during their undergraduate studies. This can be attributed to the complexities of the cloning process, which may require many weeks of progressive design and experimentation. To address this issue, we incorporated an immersive 12-week undergraduate research experience into an upper-level molecular microbiology course. Students completed two 6-week modules where the entire molecular cloning process was carried out for two sets of novel genes implicated in distinct biological processes, microbial cell division and bacterial pathogenesis. The first module trained students in molecular cloning experimental skills, and the second facilitated the application of these skills within a new biological context. Students designed and optimized primers targeted against specific genes, andthen PCR amplified, purified, and quantified the DNA of their gene of interest. Using a variety of strategies, students inserted these genes into expression plasmids to produce GFP and His-tag fusion proteins; this was tested through restriction digestion or colony PCR and verified by gel electrophoresis. At the end of each module, students were assessed on comprehension of biological concepts, professional laboratory note-keeping and scientific communication, and proficiencies in experimental procedures. The recombinant plasmids produced by the students directly contributed to ongoing research projects, and the molecular cloning skills learnt are applicable to many career and study options in molecular biology. Overall, this research experience trained students in professional molecular biology and microbiology practice and engages them in producing real-world research outcomes.

This paper presents an observer-based fault estimation method for the Li-ion battery used for hybrid electric vehicles (HEVs) propulsions, where battery ageing is treated as a fault. First, the nominal equivalent electric circuit (EEC) battery model and the extended one combining the effects of temperature and fault variations are given. Then the principle of fault estimation is stated, the fault observer with the general H ∞ configuration is depicted, some weighting functions for performance description are given. Finally, the fault observer is derived and simulation results both in frequency domain and time domain are given. The simulation results illustrate the availability of the proposed observer which owns excellent robustness performance with respect to disturbances, e.g., electrical current and temperature variations.

Hollow single crystal Fe3O4 submicrospheres, which exhibit excellent magnetic properties, have been synthesized by a simple solvothermal process. These Fe3O4 particles have nanocrystallites with an average diameter of about 300 nm and are constructed with a hollow sphere structure that has an inside diameter of about 70 nm. The growth of the hollow Fe3O4 submicrospheres involves the cooperation of Ostwald ripening and oriented re-aggregation with increasing reaction time. As the oriented aggregation continues, adjacent nanocrystals fuse together along the (311) direction and the final product is formed as hollow spheres. Optional re-aggregation of the Fe3O4 hollow spheres may happen in the EG and N2H4·H2O solution. The synthesized Fe3O4 particles show different magnetic properties and can be adjustable with morphological variation.

Dielectric permittivity and loss of BiFeO3 (BFO) and 5 mol% lanthanum-substituted BFO [(Bi0.95La0.05)FeO3 or BFO-5% La] ceramics have been carried out as functions of temperature and frequency. A frequency-dependent and broad dielectric shoulder and maximum were observed in BFO and BFO-5% La near 600-700 K. These dielectric responses are likely due to the magnetoelectric coupling while the antiferromagnetic-paramagnetic transition takes place near the Neel temperature. As an approximation, a barrier model with intrinsic barriers B (in temperature unit) every lattice constant a and extrinsic barriers B +Δ every distance d is introduced to describe the low-frequency upturn in dielectric loss in the high-temperature region. Good qualitative fits are obtained for BFO and BFO-5% La. This work suggests that 5 mol% La substitution can enhance dielectric response and considerably reduce electric conductivity.

Magnetization, grain size, x-ray diffraction, and dielectric permittivity of BiFeO3 (BFO) and 5 mol% lanthanum-substitution BFO [(Bi0.9BLa0.05)FeO3] ceramics have been carried out as a function of sintering temperature (910-950°C) BFO ceramic exhibits an antiferromagnetic behavior, whose magnetization curve is linear with the field at room temperature. A weak ferromagnetic behavior occurs in (Bi0.9BLa0.05)FeO3 (BLFO) ceramics at room temperature, in which remanent magnetization increases from 0.008 to 0.14 as sintering temperature raises from 910 to 950°C. This phenomenon can be correlated with the growth of grain size of BLFO ceramics, which grows with increasing sintering temperature. The dielectric permittivities of BFO and BLFO are about 33 and 57 at room temperature, respectively. The dielectric losses (tan δ) of BFO and BLFO ceramics vary respectively in the ranges of ~0.2-0.4 and ~0.002-0.004 below 150°C, indicating that 5 mol% La-substitution can efficiently reduce electric conductivity. A frequency-dependent and broad dielectric maximum was observed in both BFO and BLFO ceramics upon heating. This dielectric response is likely triggered by the antiferromagnetic-paramagnetic transition near the Neel temperature.

Magnetization, grain size, structure, and temperature-dependent dielectric permittivity of BiFeO3, (BiFeO3,0.95(BaTiO3)0.05 -(BaTiO3)0.05(5%BTO-BFO), and (Bi0.95Ba0.05)(Fe0.95Ti0.05)O3[5%(Ba, Ti)-BFO] ceramics have been carried out. BFO and 5%BTO-BFO exhibit an typical antiferromagnetic behavior, whose magnetization curve is linear with magnetic field at room temperature. The magnetic hysteresis loop of 5%(Ba,Ti)-BFO ceramic shows a weak ferromagnetic behavior with a small remanent magnetization of about 0.01 emu/g possibly due to a higher density in the grain matrix. This result also implies that the A-and B-site substitutions with Ba2+ and Ti4+ could efficiently suppress the spiral magnetic modulation. The magnetic susceptibilities of BFO, 5%BTO-BFO, and 5%(Ba,Ti)-BFO ceramics are about 1.9 × 10-5, 5.43 × 10-6, and 8.67 × 10-6 emu/gOe, respectively. Frequency-dependent dielectric maxima were observed in BFO, 5%BTO-BFO, and 5%(Ba,Ti)-BFO ceramics upon heating. This dielectric response is likely triggered by the antiferromagnetic-paramagnetic transition near the Neel temperature.

Current−voltage characteristics of hydrocarbon coated on ZnSe nanowire annealed by current-induced Joule heating have been studied via an in situ transmission electron microscope (TEM) technique. The major feature of the measured current−voltage curves is the presence of negative conductance due to a remarkable drop of current at the early stage of the graphitization which decreases the density of the band tail states resulting from hydrogen that escaped from various C-Hn clusters and the sp3 and sp2 coordinated carbon networks. At the later stage of graphitization, the current began to increase rapidly due to sp3 coordination transformation into sp2 coordination, which effectively narrowed the band gap. Finally, a linear relationship between the current and voltage appeared as a result of a phase transition from the amorphous hydrocarbon to graphite, leading to the semiconductor to conductor transition. The details revealed in the measured current−voltage curve strongly suggest that the electrical proper...

3-phosphorylated phosphoinositides (3-PtdIns) orchestrate endocytic trafficking pathways exploited by intracellular pathogens such as Salmonella to gain entry into the cell. To infect the host, Salmonellae subvert its normal macropinocytic activity, manipulating the process to generate an intracellular replicative niche. Disruption of the PtdIns(5) kinase, PIKfyve, be it by interfering mutant, siRNA-mediated knockdown or pharmacological means, inhibits the intracellular replication of Salmonella enterica serovar typhimurium in epithelial cells. Monitoring the dynamics of macropinocytosis by time-lapse 3D (4D) videomicroscopy revealed a new and essential role for PI(3,5)P2 in macropinosome-late endosome/lysosome fusion, which is distinct from that of the small GTPase Rab7. This PI(3,5)P2-dependent step is required for the proper maturation of the Salmonella-containing vacuole (SCV) through the formation of Salmonella-induced filaments (SIFs) and for the engagement of the Salmonella pathogenicity island 2-encoded type 3 secretion system (SPI2-T3SS). Finally, although inhibition of PIKfyve in macrophages did inhibit Salmonella replication, it also appears to disrupt the macrophage's bactericidal response.

The present paper investigates the tensile behaviour of alloy 718 sheets processed after electron beam welding (EBW). The alloy 718 sheets were pretreated in three conditions: as received, solution and precipitation pretreatments. Metallographic and fractographic examination on the specimens were conducted with optical microscope, scanning and transmission electron microscopes. Experimental results show that cracks propagate through all of the fusion zones during tensile test. The intermetallic laves phase, which precipitates along the fine columnar grain boundary in the fusion zone, offers a preferred crack propagation path, especially for the precipitation pretreated weld. The static ductility of precipitation-treated weld decreases significantly after EBW. This was attributed to high precipitation density of laves phase along the columnar grain boundary. Relatively high tensile strength and ductility of as-received and solution-pretreated welds can be obtained by using two sequential welding pa...

Background Barbed suture suspension has gained popularity as an inexpensive, “non-surgical” facial rejuvenation procedure. Initial studies on this procedure have reported minimal complications. Objective In this article, we review and evaluate several cases involving complications resulting from barbed suture suspension. Methods Four case histories of patients who required removal of suspension sutures because of symptomatic suture, failure, settling, or infection are summarized. The suspension sutures involved were examined after removal and compared to suture withdrawn through bovine muscle. Results Two patients reported chronic foreign body sensation. One patient had facial weakness. One patient had obvious dimpling. One patient had localized infection resulting from suture placement. On removal, the barbs on the suspension sutures appeared to be reflected against the direction of lift. Additionally, some sutures were clearly mobile. Forced withdrawal of new suture through bovine muscle did not result in similar anteversion of suture barbs. This would suggest the barb orientation noted at surgery was not the result of the removal process. Identification can be difficult, as the suture in some cases is clear. Once the sutures had been identified, they were easily pulled out without the need for additional surgical access. Conclusions Suture suspension may gradually fail due to eversion of suture barbs or migration through tissues. Although the complication rate for this technique has been reported to be low, we believe that surgeons performing this procedure should be aware the rate may be higher than indicated in the literature.

We present experimental evidence of in situ fabrication of multi-walled carbon nanotube junctions via electron beam induced deposition. The tip-to-tip interconnection of the nanotubes involves the alignment of two nanotubes via a piezodriven nanomanipulator and nano-welding by electron beam deposition. Hydrocarbon contamination from the pump oil vapour of the vacuum system of the TEM chamber was used as the solder; this is superior to the already available metallic solders because its composition is identical to the carbon nanotube. The hydrocarbon deposition, with perfect wettability, on the nanotubes establishes strong mechanical binding between the two nanotubes to form an integrated structure. Consequently, the nanotubes cross-linked by the hydrocarbon solder produce good electrical and mechanical connections. The joint dimension was determined by the size of the electron beam, which results in a sound junction with well-defined geometry and the smallest junction size obtained so far. In situ electric measurement showed a linear current-voltage property for the multi-walled nanotube junction.

24 Mb deletion of 6q22.1--q23.2 in an infant with pulmonary atresia, ventricular septal defect, microcephaly, developmental delay and facial dysmorphism.

The I - V behaviour of a single semiconducting ZnSe nanowire with a diameter of about 20 nm has been studied by means of electric measurement under inspection with a transmission electron microscope. The experimental results showed not only an exponential relation between the current and applied bias voltage, but also the existence of a high contact resistance with characteristic features consistent with Schottky potential barriers at the gold electrodes and the semiconducting ZnSe nanowire contacts. These Schottky barriers with asymmetrical characteristics may result from different orientations of gold grains that have different work functions. The threshold bias voltages for breakdown of the Schottky barriers examined at the Au - ZnSe nanowire contacts were about - 2.5 and 1.6 V respectively.

A new method for the preparation of Fe(2)O(3) nanoparticle/SiO(2) microsphere composites is described, in which fine alpha-Fe(2)O(3) nanocrystals were prepared by forced hydrolysis of FeCl(3) aqueous solution. The structure and optical spectra of these alpha-Fe(2)O(3) nanocrystals have been studied. Their visible optical absorption can be enhanced by their adsorptions on the surface of SiO(2) microspheres and thereafter simple packing of these microspheres to the aggregated structures. The size-dependent photogenerated surface photovoltage spectra (SPS) of these composites were studied, and quantum confinement effects of the SPS properties were observed. The transport of photoinduced charges between nanocrystals with intrinsic electronic nature of confined states accounts for this phenomenon. These results are helpful in understanding the relationship among d-d transition and charge-transfer transition in transition metal oxides and find applications in photovoltaic devices.

Twenty-one Candida albicans isolates from three HIV-infected patients were collected over a period of 3 years and characterized for fluconazole susceptibility, infectivity and genetic relatedness. Fluconazole resistance was found in five isolates, four exhibited dose-dependent susceptibility and the remainder were fully susceptible to this agent. Pulsed-field gel electrophoresis of SfiI restriction digests of the genomic DNA from the isolates revealed that isolates from the same swab specimen were identical despite differences in susceptibility to fluconazole and isolates recovered over time from the three patients retained clonally related DNA fingerprints within each patient. This small-scale study confirms the persistence of oral colonization of C. albicans strains in HIV-infected patients. Clinical data also suggests that the primary infecting strain may become a persistent colonist in the oral cavity once the immune function of the patient has been restored.

This paper presents a hybrid knowledge-based decision support system for enterprise mergers and acquisitions. The HKDSS system provides not only practical merger and acquisition procedures, related regulations, and legal problems but also feasible solutions or actions through the performance of rule-based reasoning. The hybrid system integrates a database, case base, rule base and model base to create a tool that managers can use to deal with decision-making problems via the Internet. Rules in the rule base are explained here in detail to illustrate the process of reasoning, and four practical cases in the case base also used to show how a case can be dealt with as a new case arrives. In order to evaluate a business's value, a discounted free cash flow model and economic profit model in the model base have been developed. Finally, a scenario analysis is employed to show how the user can deal with an uncertain growth rate and present value.

The thermal conductivities of three types of single-wall carbon nanotubes are studied using the homogeneous non-equilibrium Green–Kubo method based on the Brenner potential. The thermal conductivity of a carbon nanotube is found to have dependence on its chirality. The thermal conductivities of three types of nanotube seem to have similar temperature dependence. The thermal conductivity of the chiral nanotube is lower than that of the other two types of nanotube.

Monolayer-isolated silver (Ag) nanodots with the average diameter down to 7 nm are synthesized on Al2O3/Si substrate by vacuum electron-beam evaporation followed by annealing at 400 degreesC in N-2 ambient. Metal-insulator-silicon (MIS) structures with Ag nanodots embedded in Al2O3 gate dielectric are fabricated. Clear electron storage effect with the flatband voltage shift of 1.3 eV is observed through capacitance-conductance and conductance-voltage measurements. Our results demonstrate the feasibility of applying Ag nanodots for nanocrystal floating-gate memory devices. (C) 2004 Elsevier B.V. All rights reserved.

Large area, self-assembled Au-Si alloy nanocones are synthesized by vacuum electron-beam evaporation method at 450 degreesC. The formation mechanism is discussed based on the stress effect, interface energy, and Au-Si alloying process. The electron field emission properties of the self-assembled nanocones are studied based on current-voltage measurements and the Fowler-Nordheim equation. Low turn-on field (10 V/mum) with relatively high current density is obtained due to the nanocone-shaped structures with relatively rough morphology. The process temperature is lower than the melting point of ordinary glass. So our method is of great significance to the low-cost vacuum field emission devices fabrication. (C) 2003 Elsevier B.V. All rights reserved.

The magneto-optical Kerr effect of single-walled carbon nanotubes (SWNTs) film in the Terahertz region is theoretically studied by means of the Drude model. The calculation shows a new oscillation occurring near the plasma frequency as the origin of the magneto-optical Kerr effect for the single-walled nanotubes film. We propose that the amplitude of this near plasma frequency oscillation is directly proportional to the external magnetic field and its period increases with increasing cyclotron frequency. We consider these features of this oscillation of SWNTs are related to the Landau energy of SWNTs. The reflectivity and figure of merit (FOM) spectrum also reveal that this oscillation is the dominant mechanism for the magneto-optical Kerr effect of SWNTs film. Meanwhile, the shift and large enhancement of Kerr rotation under different external magnetic fields is explained. (C) 2004 Elsevier Ltd. All rights reserved.

A theoretical investigation for the conductivity of single walled nanotube films is carried out with an effective medium model in the Terahertz region. The results are compared with the recent experiment and a decrease of the real conductivity with increasing frequency is predicted. Meanwhile, the off-diagonal components of the dielectric function of single-walled carbon nanotube films based on the magnetooptical effects are also shown. (C) 2003 MAIK "Nauka / Interperiodica".

A theoretical investigation for the magneto-optical Kerr effect of InSb in Terahertz region is carried out. The results show an enhancement of Kerr effect both at room temperature and a low temperature in Terahertz region. The enhancement of Kerr spectrum due to the plasma edge effect is put forward. Meanwhile, the magneto-optical Kerr effect spectrum of InSb in the different external magnetic fields are discussed. The peak shifts of the Kerr rotation under different external magnetic fields and temperatures are discussed.

Background: Reshaping of the face with age is a result of volume change and loss of support. It is not well understood which tissues are involved in this process. Recent publications suggest that adult bone growth may have a significant role. Objective: We report a longitudinal cephalometric analysis of midfacial growth in adults to determine the role of bone in facial aging. Methods: The Behrents modification of the Bolton Cephalometric study in patients up to age 83 was reviewed. A trigonometric analysis targeted orbital and anterior maxillary growth. Results: Facial bone growth is shown to continue throughout adulthood. Anterior descent creates increased bone projection. Conclusions: The appearance of facial aging is caused by attrition of soft tissue volume and loss of support. The deficiency of maxillary bone projection seen in some patients, with tear trough depression and negative vector eyelid (polar bear), preexists adulthood and is unmasked with age.

High-vacuum electron-beam evaporation method is used for large area, metal-nucleated germanium (Ge) nanodots and nanocones on Si3N4/Si preparation. Nanodot and nanocone arrays with uniform size in bulk-quantity are synthesized using titanium (Ti) nanocrystals as nucleating center at 750degreesC with different Ge deposition amount, respectively. The morphology evolution from nanodot to nanocone is studied by atomic force microscopy (AFM). The structure of the prepared sample is characterized by X-ray diffraction (XRD) and Raman scattering. Ge nanocones formed by this convenient fabrication process could have potential applications on nanoelectronics and vacuum electron field emission. (C) 2003 Elsevier Science Ltd. All rights reserved.

Quaternary InAlGaN film has been grown directly on top of low-temperature-deposited GaN buffer layer by low-pressure metalorganic vapor phase epitaxy. High-resolution X-ray diffraction and photoluminescence (PL) results show that the film has good crystal quality and optical property. Temperature-dependent PL and time-resolved PL (TRPL) have been employed to study the carriers recombination dynamics in the film. The TRPL signals can be well fitted as a stretched exponential function exp[-(t/tau)(beta)] from 14 to 250 K, indicating that the emission is attributed to the radiative recombination of excitons localized in disorder quantum nanostructures such as quantum disks originating from indium (In) clusters or In composition fluctuation. The cross-sectional high-resolution electron microscopy measurement further proves that there exist the disorder quantum nanostructures in the quaternary. By investigating the dependence of the exponential parameter beta on the temperature, it is shown that the multiple trapping-detrapping mechanism dominates the diffusion among the localized states. The localized states are considered to have two-dimensional density of states (DOS) at 250 K, since radiative recombination lifetime tau(r) increases linearly with increasing temperature. (C) 2002 Elsevier Science B.V. All rights reserved.

A new method, high-vacuum electron-beam co-evaporation is used to prepare silicon nanocrystals (Si NCs) embedded in Al2O3 dielectric matrix in the form of thin films. Silicon and Al2O3 are co-evaporated by two electron guns at the same time at room temperature with the pressure below 1×10−5 Pa. After evaporation, annealing in N2 ambient at 500 and 800 °C for 1 h is performed. X-ray diffraction and atomic force microscopy are used to estimate the diameter of the Si NCs and check the morphology of the co-evaporation film respectively. X-ray photoelectron spectroscopy is used to investigate the chemical state of Si and Al in the as-prepared and annealed samples. Electrical properties of the Si NCs are investigated and resonant tunneling due to three dimensional quantum confinements is observed at room temperature.