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1.
Immunosenescence is characterized by age-associated changes in immunological functions. Although age- and autoimmune-related sialadenitis cause dry mouth (xerostomia), the roles of immunosenescence and cellular senescence in the pathogenesis of sialadenitis remain unknown. We demonstrated that acquired immune cells rather than innate immune cells infiltrated the salivary glands (SG) of aged mice. An analysis of isolated epithelial cells from SG revealed that the expression levels of the chemokine CXCL13 were elevated in aged mice. Senescence-associated T cells (SA-Ts), which secrete large amounts of atypical pro-inflammatory cytokines, are involved in the pathogenesis of metabolic disorders and autoimmune diseases. The present results showed that SA-Ts and B cells, which express the CXCL13 receptor CXCR5, accumulated in the SG of aged mice, particularly females. CD4+ T cells derived from aged mice exhibited stronger in vitro migratory activity toward CXCL13 than those from young mice. In a mouse model of Sjögren’s syndrome (SS), SA-Ts also accumulated in SG, presumably via CXCL12-CXCR4 signaling. Collectively, the present results indicate that SA-Ts accumulate in SG, contribute to the pathogenesis of age- and SS-related sialadenitis by up-regulating chemokines in epithelial cells, and have potential as therapeutic targets for the treatment of xerostomia caused by these types of sialadenitis.  相似文献   
2.
The neural mechanisms to reflex dilation elicited by electro-acupuncture stimulation were investigated in anesthetized rats. Two needles, with 160 microns diameter and about 5 mm apart, were inserted into the skin and underlying muscle of a hindpaw. Repetitive 20 Hz, 0.5 ms electrical pulses at various intensities were used for stimulation for 30s. The pupil size was magnified about 44 times via a microscope and was continuously recorded on a videotape. Electro-acupuncture stimulation at more than 0.5 up to 6 mA induced stimulus intensity-dependent pupil dilation. These responses were abolished by the severance of the sciatic and saphenous nerve of the stimulated hindlimb. Compound action potentials were recorded from the distal cut end of the tibial of a saphenous nerve following electro-acupuncture stimulation of the hindpaw. The mean threshold of the compound action potentials of the myelinated fibers in saphenous nerves was 0.18 mA, while that of unmyelinated fibers was 3.0 mA. The mean threshold of the compound action potentials of the myelinated fibers in the tibial nerve was 0.20 mA of unmyelinated fibers was 3.3 mA. Severance of bilateral trunks did not affect the response, while severance of the third cranial nerves abolished the responses. In conclusion, electro-acupuncture stimulation applied to the hindpaws of the anesthetized rats induced excitation of myelinated or of both myelinated and unmyelinated afferent fibers of the tibial and saphenous nerve, and involved a reflex response of pupil dilation through the third cranial parasympathetic efferent nerve.  相似文献   
3.
The polarimetric angular memory effect is applied to obtain the average topographic height of a rough surface. This novel effect improves the height sensitivity while maintaining a good degree of correlation between the sensors. By using a reference flat surface, the interferometric phase is linearly related to the mean topographic height. The combination of angular memory and wideband frequency interferometry (AMFI) is realized and offers a means to design a robust interferometric system. Extension of the technique to the pulse scattering problem is studied through the two-frequency mutual coherence function, and its time-domain transform provides an equivalent way to obtain the mean topographic height by combining both spatial and temporal diversity. Millimeter-wave (MMW) experiments are conducted with rough surfaces of different statistics and scattering media of different types (gravel, sand, and rough surfaces) to prove the effectiveness of the technique  相似文献   
4.
Toggle-flip-flop (T-FF) is one of the most important high-Tc superconducting single-flux quantum (HTS SFQ) circuit components and has been designed and fabricated by using YBa2Cu3 O7-delta ramp-edge junction technology. The circuit layout of the T-FF was improved to suppress the junction critical current (Ic) spread in the circuit. Test circuits, which include a T-FF with a single output for evaluating the logic operation and measuring the operating frequency, were fabricated and their operation characteristics were investigated. The T-FF circuit with a single output was successfully operated and finite direct current (dc) supply current margins were obtained at temperatures from 27 to 34 K. Moreover, the maximum operating frequency of the T-FF was estimated to be 360 GHz at 4.2 K and 114 GHz at 41 K. In addition, reduction of dc supply current margins due to thermal noise was also investigated. According to the numerical simulation in which parasitic inductances were taken into account, the narrowest margin in the T-FF circuit wider than plusmn10% was maintained with a bit-error rate (BER) of 10-6 up to 40 K  相似文献   
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6.
OBJECTIVE: To determine the pharmacokinetics and absolute bioavailability of ciprofloxacin in 12 critically ill patients receiving continuous enteral feeding. Design: a prospective, cross-over study. SETTING: 12-bed surgical intensive care unit in a University Hospital. PATIENTS: 12 stable critically ill patients on mechanical ventilation and receiving continuous enteral feeding (Normoreal fibres) without diarrhea or excessive residual gastric contents ( < 200 ml/4 h). None had gastro-intestinal disease, renal insufficiency (estimated creatinine clearance > or = 50 ml/min) or was receiving medications that could interfere with ciprofloxacin absorption or metabolism. MEASUREMENTS AND MAIN RESULTS: The study was carried out after the fourth (steady state) b. i. d. intravenous (i. v.) 1-h infusion of 400 mg and the second b. i. d. nasogastric (NG) dose of 750 mg (crushed tablet in suspension). Plasma concentrations were measured by high-performance liquid chromatography. The median (range) peak concentration after i. v. infusion was 4.1 (1.5-7.4) mg/l, and that after NG administration was 2.3 (0.7-5.8) mg/l, occurring 1.25 (0.75-3.33) h after dosing. The median [range] areas under plasma concentration-time curves were similar for the two administration routes (10.3 [3.3-34.6] and 8.4 [3.6-53.4] for i.v. infusion and NG administration, respectively). Ciprofloxacin bioavailability ranges from 31 to 82 % (median, 44%). CONCLUSIONS: In tube-fed critically ill patients, a switch to the NG ciprofloxacin after initial i. v. therapy to simplify the treatment of severe infections is restricted to those for whom serial assessments of ciprofloxacin levels are routinely available.  相似文献   
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8.
Crystallization processes of amorphous Fe–Si layers have been investigated using transmission electron microscopy (TEM). Si(1 1 1) substrates were irradiated with 120 keV Fe ions at ?150 °C to a fluence of 1.0 × 1017 cm2. An Fe-rich amorphous layer embedded in an amorphous Si was formed in the as-irradiated sample. Plan-view TEM observations revealed that a part of the amorphous Fe–Si layer crystallized to the metastable α-FeSi2 after thermal annealing at 350 °C for 8 h. The lattice parameter of c-axis decreased with thermal annealing. It was considered that the change in the lattice parameter originates from the decrease of the Fe occupancy at (0, 0, 1/2) and its equivalent positions in the unit cell of the metastable α-FeSi2.  相似文献   
9.
In this article, a genetic algorithm is applied to an optimization problem of material composition for a plate of step-formed functionally graded materials. The step-formed functionally graded plate is analyzed as a laminated composite plate made of numerous layers with homogeneous and different isotropic material properties. First, the onedimensional transient temperature distribution for a laminated plate is analyzed theoret ically. In addition, the thermal stress components for such an infinitely long plate are formulated under the mechanical condition of being traction-free. As a numerical example, a plate composed of zirconium oxide and titanium alloy is considered. In addition, for the optimization problem of minimizing the thermal stress distribution, the numerical calculations are made using a genetic algorithm without supposing a distribution function of material composition and the optimal material composition of each layer is determined taking into account the effect of the temperature dependency of material properties. Furthermore, the results obtained when a distribution function isn't specified and the results found when a distribution function is specified are compared.  相似文献   
10.
We have performed high-dose Fe ion implantation into Si and characterized ion-beam-induced microstructures as well as annealing-induced ones using transmission electron microscopy (TEM) and grazing-incidence X-ray diffraction (GIXRD). Single crystals of Si(1 0 0) substrate were irradiated at 623 K with 120 keV Fe+ ions to a fluence of 4 × 1017 cm−2. The irradiated samples were then annealed in a vacuum furnace at temperatures ranging from 773 K to 1073 K. Cross-sectional TEM observations and GIXRD measurements revealed that a layered structure is formed in the as-implanted specimen with ε-FeSi, β-FeSi2 and damaged Si, as component layers. A continuous β-FeSi2 layer was formed on the topmost layer of the Si substrate after thermal annealing.  相似文献   
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