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Aim Preterm premature rupture of membranes (PPROM) is common in preterm births. Fetal inflammatory response syndrome (FIRS) is present in nearly 50% of PPROM cases. We created a risk score to predict FIRS using maternal factors after PPROM. Methods We conducted a retrospective study of singleton pregnancies complicated by PPROM that resulted in delivery at 23-35 weeks of gestation. Antepartum maternal factors and umbilical cord blood interleukin-6 (IL-6) data were analyzed. FIRS was defined as IL-6 > 11 pg/mL. Results Umbilical cord blood IL-6 and maternal blood data within 24 h before parturition were available for 158 cases; 66 were diagnosed with FIRS (41.8%; median IL-6, 57.55 pg/mL). We created a risk score (FIRS score) comprising expected delivery weeks (≤30 weeks), maternal C-reactive protein (≥1.2 mg/dL), maternal white blood cell count (≥13 000/μL), corticosteroid use (none) and PROM latency period (≥3 days) from the multivariate logistic regression model predicting FIRS. Receiver operating characteristic curve analysis of the score produced the following results: area under the curve, 0.82; 95% CI, 0.76-0.89; cut-off value, 7.5; sensitivity, 89%; specificity, 63%; positive predictive value, 63% and negative predictive value, 89%. The probability of FIRS according to the categories of the FIRS score was 11% for those with a score of 0-7, 50% for a score of 8-15, and 88% for a score of 16-22. Conclusion The devised maternal risk score could predict FIRS and be helpful to decide the delivery timing for the cases of PPROM.

Objective. This study aimed to clarify the effects of cesarean delivery on neonatal respiratory morbidity when women had preterm premature rupture of membranes.Methods. This retrospective study included women with preterm premature rupture of membranes who delivered from 23 weeks to 33 weeks of gestation between January 2009 and December 2014. Neonatal outcomes were compared between infants delivered by cesarean section and those delivered vaginally. The primary outcome was respiratory distress syndrome (RDS). Neonatal intubation and mechanical ventilation periods were secondary outcomes. Propensity score matching was used to compare outcomes between cesarean and vaginal delivery cases.Results.There were 101 cesarean deliveries and 89 vaginal deliveries. A comparison of the presence or absence of neonatal complications based on the delivery type indicated a higher occurrence of RDS with cesarean deliveries (P=0.025). The intubation and mechanical ventilation periods were not significantly longer in neonates delivered via cesarean section.Conclusions.Cesarean delivery is a risk factor for neonatal RDS in women with preterm premature rupture of membranes. Trials identifying long-term neonatal prognoses are needed to further develop optimal management strategies in such cases.

Near infrared spectroscopy (NIRS) is often used during the tablet coating process to assess coating thickness. As the coating process proceeds, the increase and decrease in NIRS signal from both the coating formulation and tablet core has been related to coating thickness. Partial least-squares models are often generated relating NIRS spectra to reference coating thickness measurements for in-line and/or at-line monitoring of the coating process. This study investigated the effect of the reference coating thickness measurements on the accuracy of the model. The two primary reference techniques used were weight gain-based coating thickness and terahertz-based coating thickness. Most NIRS coating thickness models currently use weight gain-based reference values; however, terahertz-time-of-flight spectroscopy (THz-TOF) offers a more direct reference coating thickness measurement. Results showed that the accuracy of the NIRS coating thickness model significantly improved when terahertz-based coating thickness measurements were used as reference when compared to weight gain-based coating thickness measurements. Therefore, the application of THz-TOF as a reference method is further demonstrated.

We experienced a case of pregnancy after hysterosalpingogram and residual lipiodol in the extraperitoneal space. Initially, we suspected a metallic remnant, however, analysis by mass spectrometer confirmed that it was a remnant of lipiodol.

Film coating of nifedipine tablets is commonly performed to reduce photo-degradation. The coating thickness of these tablets is a primary dictating factor of photo-stability. Terahertz spectroscopy enables accurate measurement of coating thickness. This study identifies a method to determine an end-point of a photo-protective coating process by using coating thickness measurements from terahertz time of flight spectroscopy (THz-TOF). For this method, nifedipine tablets, at different coating thicknesses, were placed in a photostability chamber. The illumination conditions of the coated tablets were adjusted based on the time duration of these tablets inside the chamber. A multiple linear regression model was developed with the coating thickness estimates from THz-TOF and illumination conditions information to predict the amount of drug remaining after photo-degradation (percent label claim). The prediction error of this model was 1.03 % label claim in the range of 88.4 to 100.6 % label claim. According to this model, acceptable levels of photo-protection in illumination conditions of up to approximately 700,000 lux hours was achieved at the end of the coating process (approximately 50 µm coating thickness) performed in this study. These results suggest THz-TOF as a viable process analytical technology tool for process understanding and end-point determination of a photo-protective coating process.

This paper presents a terahertz (THz) optical sampling technique and discusses some industrial applications in semiconductor manufacturing and failure analysis. The use of ultrashort pulse fiber lasers and specific electro-optical or opto-electrical conversion devices such as photoconductive switches enable time-domain analysis of sub-picosecond pulses, paving the way to new industrial applications.

In this paper, an experimental study was conducted using terahertz (THz) spectroscopy to assess the electromagnetic properties in the THz range of various materials that can be found in oil and gas fields. This includes the absorbance, transmittance, and refraction properties of crude oil (i.e., PS65 oil in this paper), water, solid contaminants, and various mixtures of these contents. The first set of experiments was conducted to assess the effects of temperature on THz absorbance. This revealed that the temperature does not have a substantial effect on the absorbance coefficient. On the other hand, other experiments indicated that the absorbance coefficient is much higher for solid contaminants particles than for either crude oil or water. In addition, when solid contaminants are mixed with the crude oil, the absorbance coefficient varies with respect to the way the solid contaminants are distributed within the sample and increase proportionally to the amount of solid contaminants. In case of crude oil–water mixture, it is found that the absorbance coefficient increases as the water content increases. However, compared to solid contaminants, its absorbance value is much lower. The results obtained for THz spectrums and the corresponding principal component analysis graphs demonstrate the potential that THz-based devices would have in effectively measuring concentrations of solid and liquid multiphase flows, including solid contaminants which can hinder the quality of oil and gas flowing through the pipe. It would also help to monitor the quality of exported oil, which usually still contains water phase, in spite of series of oil–water separation process.

Refractive index is an important optical parameter that can be used to characterize the physicochemical properties of pharmaceutical solids. The complexity of most drugs and solid oral dosage systems introduces challenges for refractive index measurement methods. These challenges are highlighted, and different types of measurement methods are discussed in this review article. These measurements provide pharmaceutical scientists the opportunity to improve the drug-development process and enhance product quality. Pharmaceutical applications range from identification and quantification of drug crystallinity and polymorphism to mechanical strength assessment of tablets. This review article surveys the literature and evaluates the current and potential future characterization of pharmaceutical solids using refractive index measurements.

Background Infant flow biphasic nasal continuous positive airway pressure (Bi-NCPAP) and regular NCPAP (Re-NCPAP) are equally useful with respect to the rate of successful weaning from mechanical ventilation. It remains unclear, however, whether Bi-NCPAP or Re-NCPAP is more effective for reducing apnea of prematurity (AOP). Methods A multicenter randomized controlled study was conducted of 66 infants assigned to receive Bi-NCPAP and 66 assigned to receive Re-NCPAP for respiratory support after extubation. Primary outcome was the number of AOP events during the 48 h observation period after successful extubation, defined as no reintubation and no adverse events associated with the use of NCPAP during the observation period. The secondary outcome was successful extubation. Reintubation was at the discretion of the attending physician. Results Baseline characteristics were similar between the two groups. The number of AOP events during the 48 h observation period was significantly lower in infants with Bi-NCPAP than in those with Re-NCPAP (5.2 ± 6.5 vs 10.3 ± 10.9 per infant, respectively; P = 0.002). The rate of successful extubation tended to be greater in those with Bi-NCPAP than in those with Re-NCPAP (92.4%, 61/66 vs 80.3%, 53/66, respectively; P = 0.074). Adverse events occurred in only one of 132 infants: erosive dermatitis developed on the nose after application of Re-NCPAP. The risk of reintubation did not differ significantly between the two groups (7.6%, 5/66 for Bi-NCPAP vs 18.2%, 12/66 for Re-NCPAP; P = 0.117). Conclusions Bi-NCPAP was superior to Re-NCPAP for reduction of AOP following extubation.

International audience; In this paper, we report on fast identification of low-cost tags with a commercial terahertz (THz) spectrometer. These tags are designed and dedicated for anti-counterfeiting applications. One-dimensional pattern on a fully dielectric material were designed to enhance the robustness and complex the reverse engineering. Moreover, contrary to barcodes and RFID tags based on a planar surface pattern, this one is buried in the volume and can be then hidden in the product to identify as it is only made of dielectric material, without any metal. The generic tag consists of a quasi-periodic stack of two different polyethylene-based dielectric layers with different refractive indices and thicknesses. As we use THz wave, each layer remains thin (of the order of the wavelength), to get a tag whose thickness is in the millimeter range. We show that a reliable identification of the binary code encoded by the tag is possible in few tens of millisecond, with a bit error rate smaller than 1 percent.

As no terahertz signal is transmitted through opaque materials, reflection terahertz time-domain spectroscopy is obviously the dedicated setup. On the other hand, optical properties of transparent and thick samples are extracted more accurately with transmission terahertz time-domain spectroscopy. In this paper, we report the intrinsic frontier above or below which it is preferable to use either reflection or transmission setup for probing with the best accuracy possible a given sample.

Background The aim of this study was to investigate the relationship between prognosis and the changes in serum-ionized calcium concentration in neonates with hypoxic–ischemic encephalopathy (HIE) before and during brain hypothermia (BHT). Methods Serum samples were obtained from 16 HIE neonates who underwent BHT. All patients underwent developmental testing at 18 months of age. Results Mean serum-ionized calcium concentration in the poor outcome group (developmental quotient [DQ], 80; seven infants), both immediately before and after 6 h of BHT. Mean serum-ionized calcium concentration significantly decreased in both groups for 6 h, and the lowest adjusted serum-ionized calcium during 6 h of BHT was

Nanopolymorphic crystalline Hydroxyapatite (HA)-coated implants were different in surface property from conventional HA-coated implants subjected to previous clinical studies. The purposes of the present study were to retrospectively evaluate 10-years clinical outcome of the HA-coated implants (HA implants) with a comparison to the same system implants with anodic oxidized titanium surface (Ti implants).Cumulative survival rate (CSR) of HA or Ti implants placed in 183 patients (55±12.4 years old) over two decades was calculated with life table analysis. Differences in CSR at each interval year, sex, age, frequency of number of implant placement according to implant location and diameter were compared between both types of implants.Total 455 HA implants and 255 Ti implants were included. CSR at upper molar site was consistently higher in HA implants than Ti implants until 8 years after placement. The values after 10 years was 89.9% or 77.7% in HA or Ti implants, respectively. There were no significant differences in overall CSR at any interval year. HA implants were more distributed at upper molar site but less at lower molar site than Ti implants. Diameter of HA implants tended to be wider than Ti implants.Under limitation of this retrospective study, the nanopolymorphic crystalline HA-coated implants were more survived at upper molar site than anodic oxidized implants until 8 years after placement. This clinical outcome might attribute to differences in topographical and physicochemical characteristics between both types of implants.

The objective of this study was to compare osteoconductivity and biodegradation properties of an in-house fabricated beta-tricalcium phosphate (b-TCP)-collagen composite with those of Bio-Oss Collagen® (Osteohealth, Shirley, NY, USA) using a rat calvarial critical-size defect model.b-TCP-collagen composite material was fabricated by mixing b-TCP granules having a particle size of 0.15 to 0.8 mm and 75% porosity, with bovine dermis-derived soluble collagen sponge. The dry weight ratio of b-TCP granules-to-collagen ratios was 4:1. Bio-Oss Collagen or the b-TCP-collagen composite was used to fill a 5.0 mm-diameter calvarial defect in rats. The defects were evaluated by histological and histomorphological analyses of decalcified histological sections with hematoxylin and eosin staining 6 and 10 weeks, respectively, after surgery.The defect implanted with the b-TCP composite contained immature bone structures with dense connective tissue in contrast to the abundant fibrous tissue, but no trabecular structure was observed within the defect implanted with Bio-Oss Collagen at 6 weeks postoperatively. Eventually, the defect filled with the b-TCP composite was covered with dense, continuous, mature bone tissue with complete replacement of the graft material. However, in defects filled with Bio-Oss Collagen, only dense connective tissue, containing limited amounts of immature trabecular bone and abundant remnant Bio-Oss particles, was observed. Histomorphological analysis revealed that the b-TCP composite caused greater tissue augmentation with a larger volume of bone tissue observed in the defect and greater bioabsorption of remnant material than Bio-Oss Collagen.These results indicated that the b-TCP composite has greater osteoconductivity and better biodegradation properties than Bio-Oss Collagen; these properties of the b-TCP-collagen composite complimented bone formation and remodeling.

Although ammonium acid urate (AAU) calculi are extremely rare renal stone components, it was recently found that many urinary tract calculi that cause post-renal renal failure in rotavirus (RV) gastroenteritis are AAU calculi. The mechanism of AAU calculi development in RV gastroenteritis has not been fully elucidated. We analyzed data from eight RV gastroenteritis patients who transiently had AAU crystals in their urinary sediment. In these patients, formation of AAU crystals occurred earlier than the formation of AAU calculi. No difference was observed in serum and urine uric acid levels between RV gastroenteritis patients with or without AAU crystals. Interestingly, fractional excretion of sodium was extremely low among patients with AAU crystals. These results suggest that the formation of AAU crystals might not be due to excretion of uric acid, but excretion of sodium.

Purpose: The objective of this study was to compare osteoconductivity and biodegradation properties of an in-house fabricated beta-tricalcium phosphate (b-TCP)-collagen composite with those of Bio-Oss Collagen® (Osteohealth, Shirley, NY, USA) using a rat calvarial critical-size defect model. Materials and Methods: b-TCP–collagen composite material was fabricated by mixing b-TCP granules having a particle size of 0.15 to 0.8 mm and 75% porosity, with bovine dermis-derived soluble collagen sponge. The dry weight ratio of b-TCP granules-to-collagen ratios was 4:1. Bio-Oss Collagen or the b-TCP–collagen composite was used to fill a 5.0 mm–diameter calvarial defect in rats. The defects were evaluated by histological and histomorphological analyses of decalcified histological sections with hematoxylin and eosin staining 6 and 10 weeks, respectively, after surgery. Results: The defect implanted with the b-TCP composite contained immature bone structures with dense connective tissue in contrast to the abundant fibrous tissue, but no trabecular structure was observed within the defect implanted with Bio-Oss Collagen at 6 weeks postoperatively. Eventually, the defect filled with the b-TCP composite was covered with dense, continuous, mature bone tissue with complete replacement of the graft material. However, in defects filled with Bio-Oss Collagen, only dense connective tissue, containing limited amounts of immature trabecular bone and abundant remnant Bio-Oss particles, was observed. Histomorphological analysis revealed that the b-TCP composite caused greater tissue augmentation with a larger volume of bone tissue observed in the defect and greater bioabsorption of remnant material than Bio-Oss Collagen. Conclusion: These results indicated that the b-TCP composite has greater osteoconductivity and better biodegradation properties than Bio-Oss Collagen; these properties of the b-TCP–collagen composite complimented bone formation and remodeling.

A novel analytical method for the determination of pharmaceutical polymorphs was developed using terahertz spectroscopy. It was found out that each polymorph of a substance showed a specific terahertz absorption spectrum. In particular, analysis of the second derivative spectrum was enormously beneficial in the discrimination of closely related polymorphs that were difficult to discern by powder X-ray diffractometry. Crystal forms that were obtained by crystallization from various solvents and stored under various conditions were specifically characterized by the second derivative of each terahertz spectrum. Fractional polymorphic transformation for substances stored under stressed conditions was also identified by terahertz spectroscopy during solid-state stability test, but could not be detected by powder X-ray diffractometry. Since polymorphs could be characterized clearly by terahertz spectroscopy, further physicochemical studies could be conducted in a timely manner. The development form of compound examined was determined by the results of comprehensive physicochemical studies that included thermodynamic relationships, as well as chemical and physicochemical stability. In conclusion, terahertz spectroscopy, which has unique power in the elucidation of molecular interaction within a crystal lattice, can play more important role in physicochemical research. Terahertz spectroscopy has a great potential as a tool for polymorphic determination, particularly since the second derivative of the terahertz spectrum possesses high sensitivity for pharmaceutical polymorphs.

Metallic meshes work as band-pass filters in the terahertz (THz) region, with their transmission spectra acutely affected by the refractive index of the material inside and above the metallic-mesh openings. We used a metallic mesh for high-sensitivity observations by focusing on the “dip,” that is, a sudden change in transmittance that only appeared when the THz wave was obliquely incident onto the metallic mesh. Here we consider the interference between apertures of the metallic mesh in the diagonal direction and explain the dip using finite-difference time-domain (FDTD) electromagnetic simulations.

We report on a novel sensing method in the terahertz region using metallic mesh. Conventionally, the band-pass filter property of a metallic mesh can be adjusted by changing the mesh geometrical parameters. However, the band-pass filter parameters also depend on the refractive index of the medium in the vicinity of the mesh openings. To inspect this effect as a potential measurement principle, we calculated the electric field distribution around the metallic mesh and analyzed the frequency characteristics due to a sample attached to the metallic mesh using the Finite Difference Time Domain method. For bio-molecular sensing, the Electrospray Deposition method was applied in order to spray a uniform layer of protein over a metallic mesh. We observed a correlation between the quantity of protein and the transmission characteristics of the metallic mesh.

Infant flow biphasic nasal continuous positive airway pressure (Bi-NCPAP) and regular NCPAP (Re-NCPAP) are equally useful with respect to the rate of successful weaning from mechanical ventilation. It remains unclear, however, whether Bi-NCPAP or Re-NCPAP is more effective for reducing apnea of prematurity (AOP).A multicenter randomized controlled study was conducted of 66 infants assigned to receive Bi-NCPAP and 66 assigned to receive Re-NCPAP for respiratory support after extubation. Primary outcome was the number of AOP events during the 48 h observation period after successful extubation, defined as no reintubation and no adverse events associated with the use of NCPAP during the observation period. The secondary outcome was successful extubation. Reintubation was at the discretion of the attending physician.Baseline characteristics were similar between the two groups. The number of AOP events during the 48 h observation period was significantly lower in infants with Bi-NCPAP than in those with Re-NCPAP (5.2 ± 6.5 vs 10.3 ± 10.9 per infant, respectively; P = 0.002). The rate of successful extubation tended to be greater in those with Bi-NCPAP than in those with Re-NCPAP (92.4%, 61/66 vs 80.3%, 53/66, respectively; P = 0.074). Adverse events occurred in only one of 132 infants: erosive dermatitis developed on the nose after application of Re-NCPAP. The risk of reintubation did not differ significantly between the two groups (7.6%, 5/66 for Bi-NCPAP vs 18.2%, 12/66 for Re-NCPAP; P = 0.117).Bi-NCPAP was superior to Re-NCPAP for reduction of AOP following extubation.

Aim: Hypoxic–ischemic reperfusion injury causes either necrosis or apoptosis, and the influx of ionized calcium into cells is the major cause of both types of cell death. The aim of this study was to investigate whether or not the serum ionized calcium concentration in neonates with hypoxic–ischemic encephalopathy (HIE) could be used to predict their outcome. Methods: Serum samples were obtained shortly after birth from 20 HIE neonates who had not urinated or received treatment with calcium. Serum ionized calcium concentrations were adjusted for pH using a correction formula. Twelve neonates without any disease were selected as a control. The results were compared between nine HIE neonates who made a full recovery, 11 who died or had neurologic deficits, and 12 normal neonates. Results: Considered together, the two HIE groups had lower serum ionized calcium concentrations (1.05 ± 0.10 mmol/L) than the control group (1.22 ± 0.07 mmol/L; P

The volume change, ΔVh,, accompanying the hydrophobic hydration associated with the volume phase transition in Poly(N-isopropylacrylamide) gels was measured by a simple method. The hydration accompanies a negative ΔVh′−2.5 cm3/mol. The P-T phase diagram, the coexistence curve, for the gels was determined from the swelling ratio-pressure curves up to 350 MPa for various constant temperatures. The contour of the coexistence curve is shaped like an ellipsoid on the P-T plain, which is a feature peculiar to the reversible pressure-temperature denaturation of a protein. The thermodynamic analysis of the Clausius–Clapeyron relation for the measured ΔVh elucidates that the obtained coexistence curve represents the phase boundary between thermodynamic different phases like the two phases, native and denatured, of a protein and gives the transition enthalpy, ΔH, 5.2kJ/mol by estimate, which well coincides with the transition heat measured by a calorimetric method. Considering the volume-dependent free energy, Δvmi · P, for the mixing free energy of the gel, we can fit the calculated curve to the measured swelling ratio-pressure curve of PNIPA gels. The value of Δvmi changes the sign from negative to positive above around 100MPa. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 405–412, 2005

The swelling behavior of poly(N-isopropylacrylamide) (PNIPA) gels in seawater at high pressures up to ∼40 MPa is examined in terms of human activity at deep sea. The neutral gel in seawater undergoes a continuous volume transition at 26°C at atmospheric pressure. Addition of the ionic group (sodium acrylate) does not have much effect on the swelling properties of the gels in seawater except that the transition temperature is somewhat increased. At high constant pressures up to ∼40 MPa, the gels undergo a continuous volume transition at 26–28°C as the temperature varies. Normally, the gel takes a swollen state at deep sea. The ratio of the volume change associated with the transition is more than 10, which is 3 times larger than that obtained by changing the pressure at a constant temperature. The results suggest a possibility that the phase transition of PNIPA gels is utilized for producing mechanochemical energy at deep sea. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1069–1072, 2005

The volume phase transition of neutral poly( N -isopropylacrylamide) gels in aqueous solutions of pyridine was studied by means of depolarized Rayleigh and Raman scattering. The Rayleigh reorientational relaxation time, τ Ray , of pyridine, calculated from the half-width of the depolarized Rayleigh spectrum, attains a maximum at approximately x =0.2 at which the gel undergoes the abrupt volume change. As the gel shrinks, the ratio, I G / I S , of the intensity of the spectrum of the gel to that of the aqueous solution abruptly decreases, reflecting the decrease in the number of free pyridine in the gel network. A new Raman band, which shifts by 130 cm −1 , appears for the shrunken gels. This new band is assigned to the C–H stretching vibrations of pyridine bound to the PNIPA chains by the hydrogen-bonding interaction. As the gel shrinks, the intensity, I B , of the new Raman band abruptly increases, on the contrary, the intensity, I F , of the free pyridine band decreases. The intensity ratio, I F /( I F + I B ), which represents the number fraction of free pyridine in the network, excellently agrees with I G / I S . The results show that the hydrophilic solutes such as pyridine in PNIPA gels are bound by the hydrogen-bonding interaction between the solutes and the chains.

As the effects of supplementary oxygen on urinary excretion of 8-hydroxy-2'-deoxyguanosine (8-OHdG) are poorly understood, urinary 8-OHdG levels (ng/mg creatinine) were determined longitudinally on the postnatal day (PND) 1, 3, and 30 in 16 neonates with birth weight < 1000 g. No supplementary oxygen was required in 9 neonates during the first 24 h of life. Urinary 8-OHdG level on PND 1 was inversely correlated with birth weight in these 9 neonates (P = 0.0323) and was higher in four with birth weight < 750 g than five with birth weight > 750 g (41.0 +/- 6.9 vs. 5.6 +/- 2.7, respectively, P = 0.0200). Median urinary 8-OHdG on PND 1 of these 9 neonates was significantly lower than that of 7 neonates with oxygen (9.3 vs. 60.2, respectively), although there were no significant differences in clinical background, such as birth weight, between the two groups. Five of the 9 did not require supplemental oxygen at all during the first 30 days of life. Median urinary 8-OHdG levels were consistently significantly lower in the 5 neonates than in 11 neonates with oxygen transiently or persistently (9.3 vs. 54.6, 19.1 vs. 61.4, and 28.3 vs. 145 on PND 1, 3, and 30, respectively), although there were no differences in clinical background, such as birth weight, between the two groups. Urinary 8-OHdG on PND 30 was significantly positively correlated with supplemental oxygen dose on PND 30 (P < 0.0001), but not with birth weight in the 16 neonates. These results suggest that higher supplemental oxygen tension caused higher urinary 8-OHdG in this population.

We report on the observation of collective radiative decay, or superradiance, of cyclotron resonance (CR) in high-mobility two-dimensional electron gases in GaAs quantum wells using time-domain terahertz magnetospectroscopy. The decay rate of coherent CR oscillations increases linearly with the electron density in a wide range, which is a hallmark of superradiant damping. Our fully quantum mechanical theory provides a universal formula for the decay rate, which reproduces our experimental data without any adjustable parameter. These results firmly establish the many-body nature of CR decoherence in this system, despite the fact that the CR frequency is immune to electron-electron interactions due to Kohn's theorem., Comment: 5 pages, 4 figures

Equilibrium swelling curves of ionized polyacrylamide gels immersed in acetone–water mixtures were measured as a function of pressure up to pressures of 300 MPa. The gels, which shrank at atmospheric pressure, underwent an abrupt volume change (pressure-induced volume phase transition) from a shrunken state to a swollen state at the transition pressure. The transition pressure increased with an increase of acetone concentration. The pressure-induced volume phase transition can be interpreted by taking account of the free-energy change ΔV⋅P between swollen (hydrated) and shrunken (dehydrated) states. The ΔV represents the difference between the molar volume of water structured around hydrophilic groups of polyacrylamide chains and that of free water in the bulk mixtures. The estimated value of ΔV is −3.3 mL/mol, which qualitatively agrees with that obtained from the experiments of denaturation of proteins. The pressure-induced volume phase transition is generally expected in many hydrogels.

The time course of the changes in perilymphatic glutamate was determined during the application of kanamycin and ethacrynic acid, which are known to damage the hair cells in the inner ear. For the continuous recording of glutamate, the microdialysis technique combined with an enzyme-linked fluorometric assay was used. In guinea pigs receiving a loading dose of 800 mg/kg of kanamycin subcutaneously followed 3 h later by an i.v. injection of 40 mg/kg of ethacrynic acid, a marked glutamate release was clearly found about 2 h after the injection of ethacrynic acid. Injection of kanamycin or ethacrynic acid alone did not produce any change in the perilymphatic glutamate. The morphological changes induced by the administration of both drugs indicated that the collapsing hair cells might release glutamate into the perilymphatic space. The present findings provide additional evidence that glutamate acts as an aggravating factor in aminoglycoside-induced ototoxicity.

Foamed polystyrene boxes are widely used in low-temperature physical distribution today. They have, however, a big problem with the way they are disposed of after use. On the other hand, corrugated cardboard boxes, which are low-priced, lightweight, collapsible and less bulky, have almost no problems of disposal after use, although they cannot adequately keep the contents fresh because of their inferior heat insulation and water resistance. To find a solution to these problems, we have developed a heat insulating cardboard consisting of a corrugated foamed polystyrene sheet core covered with a paperboard liner on both sides. We have also established technology for continuous production of long-sized material with the purpose of commercializing it through mass production. Tests to determine the basic characteristics revealed that the new cardboard material is equal to conventional cardboard in calorific value when burned, as well as in usability and decorative capacity and that it displays far superior heat insulation and moisture resistance. In transport tests on cut flowers and a processed marine product, it was also confirmed that the new material excels in the performance of preserving the freshness of the contents. Furthermore, a recycling test proved that the material is recyclable as waste paper. Copyright © 1999 John Wiley & Sons, Ltd.

剣道が聴覚障害の原因になり得ることが指摘されているが, 個々の例で因果関係が証明された報告はない。 今回, 剣道の稽古直後に発症した一側性急性感音難聴が治療により回復した症例を経験した。 本例の難聴病態にはTTS (temporary threshold shift) が長時間かけて回復した機序が想定されるが, 剣道が直接の原因となった感音難聴臨床例として貴重な例である。 また, 本症例を契機に宮崎医科大学剣道部員学生ボランティア17例を対象に純音聴力検査を施行し, 面打ち前後のオージオグラムの変化を測定した。 面打ち前に高音域dip型聴力障害を示した例が2例あり, この2例にのみ面打ち後のTTSが陽性であった。 これは, 試験的面打ちによるTTSの評価が剣道家の 「剣道難聴」 受傷性判定に有用である可能性を示すものと考える。

Penetration and release of the rhodamine B probe into nonionic poly( N -isopropylacrylamide) (NIPA) gels were visualized by anti-Stokes fluorescence imaging. A sharp intensity boundary in fluorescence across the solution–gel surface was observed. This showed that NIPA gels adsorbed selectively a large amount of probe molecules due to hydrophobic interaction between the probe molecules and NIPA. Analyzing the intensity distributions in the gel by a formula based on Fickian diffusion, we calculated the diffusion coefficients of the probe molecules in the swollen and shrunken gels. The diffusion coefficients were discussed in terms of the hydrophobic interaction acting between rhodamine B molecules and NIPA.

Pressure-induced volume phase transitions in neutral and ionized N-isopropylacrylamide-water (NIPA) gels were investigated. When the pressure is increased, the gels which shrink at atmospheric pressure undergo two volume phase transitions. One is the continuous phase transition (for neutral gels) or the discontinuous phase transition (for ionized gels) from the shrunken state to the swollen state at low pressures of several tens MPa. Another is the gradual shrinking transition occurred in the high pressure region above 100 MPa. The former transition shows that the derivative of the pressure with respect to the volume at constant temperature, (∂P/∂V)T, is positive. The results are explained by considering the pressure effects on the hydrophobic interaction. The phase transition pressure increases with increase of the temperature, and the critical pressure and temperature exist. The P–T coexistence curve resembling the evaporation curve of a liquid–gas system is obtained. These pressure-induced phase transi...