Characterization of long-periodic layered structures by X-ray diffraction I: A system for small angle and intermediate angle X-ray diffraction using a reflection kratky camera

A high resolution camera has been developed for the small angle X-ray diffraction measurement of long-periodic layered structures such as Langmuir-Blodgett multilayers, superlattices and liquid crystals. A block collimation system known as a Kratky camera is used to produce a very narrow incident beam. The camera is mounted on a computer-controlled goniometer whose sample holder is rotated around a vertical Θ axis by a pulse motor. Measurements can be carried out in a θ-2θ scan, and also in θ or 2θ scans. Processing of the collected data includes smoothing, and correction for absorption, polarization factor and instrumental broadening. The performance of the present system has been demonstrated by observation of diffraction patterns of a Langmuir-Blodgett film of cadmium arachidate and a GaAs/AlAs superlattice.     

Hyperthermia and hypoxia increase tolerance of retinal ganglion cells to anoxia and excitotoxicity

PURPOSE: Knowledge of the mechanisms by which retinal ganglion cells are damaged may provide information required to develop novel treatments for diseases that cause retinal ganglion cell death. The authors investigated whether the expression of the 72-kDa heat shock protein in cultured rat retinal ganglion cells increases tolerance to hypoxic and excitotoxic injury. METHODS: Hyperthermia (42 degrees C for 1 hour) and sublethal hypoxia (9% O2 for 6 hours) were used to induce synthesis of the 72-kDa heat shock protein in cultured rat retinal ganglion cells and cultured retinal Müller cells. Induction of the 72-kDa heat shock protein was detected with immunocytochemical and immunoblot techniques. Survival of cultured retinal ganglion cells after exposure to anoxia (< 1% O2 for 6 hours) and glutamate (200 microns for 6 hours) was measured and compared to control cultures stressed previously by hyperthermia or sublethal hypoxia. The effect of quercetin, a blocker of heat shock protein synthesis, was evaluated in parallel experiments. RESULTS: Heat shock protein immunoreactivity was expressed in cultured retinal ganglion cells and Müller cells after hyperthermia and sublethal hypoxia. The mean (+/- standard deviation) retinal ganglion cell survival rates after exposure to anoxia (expressed as a percentage of untreated control cultures) in cells pretreated with sublethal hypoxia (83% +/- 17%) and hyperthermia (82% +/- 19%) were significantly greater than for cells that had no pretreatment (50% +/- 18%, P < 0.001). The mean (+/-standard deviation) retinal ganglion cell survival rate after exposure to glutamate in cells pretreated with sublethal hypoxia (82% +/- 19%) and hyperthermia (86% +/- 17%) were significantly greater than for cells that had no pretreatment (56% +/- 17%, P < 0.001). Inhibition of heat shock protein synthesis with quercetin abolished the protective effects of sublethal hypoxia and hyperthermia on cell survival after anoxia and glutamate exposure. CONCLUSIONS: The neuroprotective effect of hyperthermia and sublethal hypoxia suggests that heat shock proteins confer protection against ischemic and excitotoxic retinal ganglion cell death.     

Usefulness and limitations of ultrasonography in the initial evaluation of blunt abdominal trauma

BACKGROUND: In the assessment of blunt abdominal trauma, the reliability of ultrasonography (US) in identifying individual organ injuries remains uncertain, in spite of its usefulness in detecting hemoperitoneum. This study was designed to evaluate the overall diagnostic value of US, including identification of individual organ injuries. METHODS: The accuracy of US in the detection of intra-abdominal injuries and the identification of individual organ injuries was evaluated in 1,239 patients seen during a 15-year period. Accuracy was based on detection of intraperitoneal fluid, free air, or irregular parenchymal lesions. RESULTS: For the detection of injuries, US was 94.6% sensitive, 95.1% specific, and 94.9% accurate. Individual organ injuries were identified with sensitivities of 92.4, 90.0, 92.2, 71.4, and 34.7% for the liver, spleen, kidneys, pancreas, and intestine, respectively. CONCLUSION: US is reliable for the detection of injuries and the identification of solid-organ injuries despite its poor sensitivity for intestinal injuries.     

Synthesis and photovoltaic properties of soluble fulleropyrrolidine derivatives for organic solar cells

Organic solar cells made from bi-layer thin-film heterojunctions having poly((2-methoxy-5-(2′-ethylhexyloxy)-p-phenylene)vinylene) (MEH-PPV) as an electron donor and fulleropyrrolidine derivatives as an electron acceptor were investigated. We synthesized soluble fulleropyrrolidine derivatives substituted different chain lengths for the organic solar cell. Due to the high solubility and sufficiently long chain length of fulleropyrrolidine derivatives, though those are monomers, a thin film (about 80–90 nm) could be fabricated individually by the spin-coating method. The fill factor of the bi-layer device was achieved to be 0.46, which is higher than that of the single-layer device by a polymer/fulleropyrrolidine derivative blend film of 0.37, due to the decrease of the recombination.     

A quantitative evaluation of time-independent and time-dependent deformations of lead-free and lead-containing solder alloys

A method to separate plasticity and creep is discussed for a quantitative evaluation of the plastic, transient creep, and steady-state creep deformations of solder alloys. The method of separation employs an elasto-plastic-creep constitutive model comprised of the sum of the plastic, transient creep, and steady-state creep deformations. The plastic deformation is expressed by the Ramberg-Osgood law, the steady-state creep deformation by Garofalo’s creep law, and the transient creep deformation by a model proposed here. A method to estimate the material constants in the elasto-plastic-creep constitutive model is also proposed. The method of separation of the various deformations is applied to the deformation of the lead-free solder alloy Sn/3Ag/0.5Cu and the lead-containing solder alloy Sn/37Pb to compare the differences in the plastic, transient creep, and steady-state creep deformations. The method of separation provides a powerful tool to select the optimum lead-free solder alloys for solder joints of electronic devices.     

Laparoscopy-assisted devascularization of the lower esophagus and upper stomach in the management of gastric varices

Devascularization of the lower esophagus and the upper stomach is one method of treating patients with clinically significant gastric varices. We describe a new method of laparoscopically-assisted devascularization which has been applied in seven patients with esophagogastric varices. Three of the seven patients had an episode of gastric variceal bleeding, and the remaining four had moderate to large gastric varices with red color signs. The operative procedure was carried out without pneumoperitoneum by using an ordinary forceps and laparoscopic instruments through a small skin incision (3-5 cm); the abdominal wall was elevated with a U-shaped retractor. The operative field was obtained by laparoscopic and direct vision illuminated by laparoscopic light. The procedure time ranged from 100 to 180 minutes with minimal blood loss (70-320 g). No complications were encountered. All patients could be discharged within one week; postoperative pain was minimal and all patients returned to work early. Follow-up (mean 11.4 months) showed no recurrence of gastric varices although, due to an incomplete procedure in two cases, two patients were treated additionally by endoscopic injection of histoacryl.     

Synthesis of polychloroprene–silica composites by sol‐gel method in the presence of modified polychloroprene containing triethoxysilyl group

Triethoxysilyl‐modified polychloroprene (CR) latex was synthesized by the emulsion copolymerization of 2‐(3‐triethoxysilylpropyl)‐1,3‐butadiene with chloroprene. This latex was mixed with unmodified CR latex and tetraethoxysilane to obtain CR–silica composites by sol‐gel reaction in the latex. SEM observation showed that the silica particles in unvulcanized composites have various diameters ranging from 0.1 to 0.6 μ m, and their size became larger with the decrease of the silica content. Vulcanized CR–silica composites showed that the tensile modulus and tear strength improved with an increase of the amount of modified CR. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1545–1552, 2005     

Carcinoid somatostatinoma of the papilla of Vater: a case report

A 57 year-old Japanese man with a carcinoid somatostatinoma of the papilla of Vater is presented. He was found to have cholecystolithiasis without any symptoms. Physical examination showed no abnormal findings. Routine laboratory data gave normal results, except for glucose intolerance and an elevated somatostatin concentration. A yellowish papillary tumor was found at the papilla of Vater, and histological examination suggested the diagnosis of carcinoid. He underwent a pancreatoduodenectomy in March 1992. The gallbladder contained a single pure cholesterol stone. Histological, immunohistochemical, and electron microscopic studies resulted in the diagnosis of a carcinoid somatostatinoma of the papilla of Vater, without regional lymph node metastases. Post-operative pancreatic juice output from the total pancreatic duct drainage increased to more than 1000 mL/day. Although an anastomotic leakage of the pancreatojejunostomy was noted, the pancreatic fistula closed 8 weeks later. His postoperative somatostatin value was normal. He has been well for 54 months following surgery, without any signs of recurrence.     

Photoreaction of Titanium-Based Metal-organic Compounds for Ceramic Fine Patterning

The photoreaction of metal-organic compounds prepared by the chemical modification of metal alkoxides was investigated for the patterning of ceramic films. The chemical stability and photoreactivity of these compounds were found to be greatly influenced by the kind of chemical additive applied during the syntheses of the precursor solutions. In this study, the photoreaction of the precursor thin films prepared by the addition of alkanolamines was achieved by tuning the wavelength of the incident UV light. The decomposition of the organic moieties of the percursors was clearly observed in IR spectra during UV irradiation. Furthermore, the spectrum of the titania precursor film in the visible and ultraviolet regions (UV-vis) changed in accordance with the irradiation time. The photolithography of the titanium precursor pattern was successfully achieved by means of these techniques.     

Poly(ethylene oxide) macromonomers

Summary p-Vinylbenzyl-terninated poly(ethylene oxide) macromonomers (M₂) were radical-copolymerized with styrene (M₁) in benzene, tetrahydrofuran, and methyl isobutyl ketone at 60°C. Relative reactivity of the macromonomer toward polystyryl radical, as estimated by l/r₁ was found to decrease with increasing number-average degree of polymerization and also in a solvent which gives a higher [] of both polystyrene and the macromonomer. The results support our previous suggestion that a repulsion between the macromonomer and the propagating polymer radical can be a factor responsible for disturbing their mutual reaction.Part 1: Ref. 1, Part 2: Ref. 2