Primary coexistent adenocarcinoma and choriocarcinoma of the stomach. A case report and review of the literature

We report a case of primary gastric choriocarcinoma with liver metastasis. The mixed histologic patterns included adenocarcinoma, undifferentiated carcinoma, and choriocarcinoma. Immunohistologic staining for the beta-subunit of human chorionic gonadotrophin (beta-HCG) showed positive results in the choriocarcinoma, adenocarcinoma, and normal mucosal gland. However, positive HCG cells were present at different intensities in the choriocarcinoma, adenocarcinoma, and normal mucosal gland. The level of HCG was significantly increased in serum. This unusual tumor probably resulted from dedifferentiation of a primary adenocarcinoma or developed directly from the mucosal glands.     

Evaluation of drawing on 3D surfaces with haptics

We describe experiments for evaluating the speed and accuracy of a haptic drawing interface, particularly in terms of the effects of changing two haptic characteristics the magnitude of the friction force and the use of smooth, interpolated-normal force shading in combination with the effect of stereo displays and shadows. Because surface geometry affects the sense of touch, we studied the efficacy of the haptic interface in the context of varying geometric characteristics of the surface drawing task. We also found that stereo displays, in combination with haptics, can provide additional benefits for drawing in terms of reducing error and increasing speed for the drawing task. So the decision to introduce shadows in a VR system should be considered in the context of the expected task mix.     

Asterlingulatosides C and D, cytotoxic triterpenoid saponins from Aster lingulatus

Over the last few decades, European courses in which 'classical' tropical medicine (i.e. parasitology, entomology, and clinical aspects of tropical diseases) is taught have largely become anachronisms. Most countries in the tropics have their own medical schools and few have much need of expatriate doctors. There do, however, appear to be other ways in which Europeans may still help improve health in the tropics. One is to control the quality of the expatriate nurses who are still in demand in the tropics (often as cheaper, generally less demanding substitutes for doctors). This may be achieved by only training the best, insisting they spend some time after graduation gaining maturity before they leave for the tropics, ensuring they realise that their clinical skills will probably be inferior to their local counterparts in the tropics, and encouraging them to continue studying once abroad. The second way Europeans may help is to change the bias of their courses from teaching to training. There seems little doubt that the intellectual personalities of the brightest young men and women in the tropics often develop far better when they spend a period in a foreign environment, especially when they are allowed to function within a team, with trainees and trainers from other countries. Some 'international' courses may offer such benefits, especially if closely tailored to the needs of the trainees and their home countries.     

X-band HBT VCO with high-efficiency CB buffer amplifier

A monolithic AlGaAs-GaAs HBT VCO with common-base (CB) buffer amplifier was demonstrated at X-band. Overall efficiency of 30% was achieved with 93-mW output power at 9.8 GHz. The MMIC chip is only 1 mm×2 mm, including the monolithic varactor diode. The circuit design offers several unique advantages: (1) the CB buffer amplifier reduces the frequency-pull effect from the external load; (2) the design for the oscillation condition and the output impedance match for power are separated; and (3) the overall efficiency can be high. A step-by-step design procedure is discussed     

Miniature aperture-coupled microstrip antenna of very highpermittivity

A miniature aperture-coupled microstrip antenna of very high permittivity designed at 1.66 GHz is described. Superstrates of appropriate thickness are added on the substrate for gain enhancement. Its size is dramatically reduced and the electrical performance remains almost the same as compared with the conventional microstrip antenna of low dielectric constant. Experimental data for the return loss, radiation pattern and measured antenna gain are presented to validate the design     

Randomized controlled trial of open and closed haemorrhoidectomy

BACKGROUND: This study was a prospective randomized comparison of healing following open and closed haemorrhoidectomy. METHODS: Sixty-seven consecutive patients (mean(s.e.m.) age 45(1.7) years; 35 men, 32 women) with three prolapsed piles were randomized to open haemorrhoidectomy (n = 34) or closed haemorrhoidectomy (n = 33). RESULTS: Mean(s.e.m.) follow-up was 8.7(0.2) months. There were no differences in the linear analogue pain scores, analgesic requirements and length of hospitalization after open haemorrhoidectomy and closed haemorrhoidectomy. Complete wound healing took significantly longer after closed haemorrhoidectomy (mean(s.e.m.) 6.9(0.7) weeks) compared with open haemorrhoidectomy (4.9(0.4)weeks) (P < 0.05). This was related to wound dehiscence in eight patients. Complication rates, however, were similar except for prolonged serous discharge from unhealed wounds. The anal manometry findings after both procedures were equivalent. CONCLUSION: Open haemorrhoidectomy leads to faster and more reliable wound healing, although this did not result in less pain or fewer complications.     

Phonological skills are important in learning to read Chinese.

A4-year longitudinal study was conducted to examine the relationship between Chinese children's phonological skills and their success in reading. Initially, 100 Hong Kong Chinese children were tested on visual and phonological skills at the age of 3, before they could read. The findings showed that prereading phonological skills significantly predicted the children's reading performance in Chinese 2 and 3 years later, even after controlling for the effects of age, IQ, and mother's education. The main reason for this relationship is that phonological knowledge helps children to use the phonetic component in Chinese characters. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

FDTD microcavity simulations: design and experimental realizationof waveguide-coupled single-mode ring and whispering-gallery-mode diskresonators

We investigate the properties of high-Q, wide free-spectral-range semiconductor microcavity ring and disk resonators coupled to submicron-width waveguides. Key optical design parameters are characterized using finite-difference time-domain (FDTD) solutions of the full-wave Maxwell's equations. We report coupling efficiencies and resonant frequencies that include the effects of waveguide dispersion and bending and scattering losses. For diameters of 5 μm, the microcavity resonators can have Q's in the several thousands and a free spectral range of 6 THz (50 nm) in the 1.55 μm, wavelength range. Studies of the transmittance characteristics illustrate the transition from single-mode resonances to whispering-gallery-mode resonances as the waveguide width of the microring is increased to form a solid microdisk. We present nanofabrication results and experimentally measured transmission resonances of AlGaAs/GaAs microcavity resonators designed in part with this method     

A New Anomaly in Solid 4He

A new anomaly in the acoustic properties of solid⁴He has been observed when as little as a few parts per million of³He impurities are added. We show that the specific properties of the anomaly, can be explained by a continuous (second order) phase transition from a Bose condensed state above a critical temperature to a normal state below it. In this model the Bose particles which condense are long lived, thermally activated excitations.     

Slot antennas on photonic band gap crystals

The radiation patterns of a slot antenna placed on a photonic band gap crystal have been measured. We used a layer-by-layer photonic band gap crystal having a three-dimensional stop band between 12 and 15 GHz. The slot antenna radiation depends sensitively on the relative position and orientation of the slot in the surface unit cell of the photonic crystal. We have found configurations of the slot antenna with an increase of radiated power by 2-3 dB. The photonic band gap crystal can considerably improve the performance of a simple slot antenna