Antibacterial effect of water-soluble chitosan on representative dental pathogens Streptococcus mutans and Lactobacilli brevis

Dental caries is still a major oral health problem in most industrialized countries. The development of dental caries primarily involves Lactobacilli spp. and Streptococcus mutans. Although antibacterial ingredients are used against oral bacteria to reduce dental caries, some reports that show partial antibacterial ingredients could result in side effects. OBJECTIVES: The main objective is to test the antibacterial effect of water-soluble chitosan while the evaluation of the mouthwash appears as a secondary aim. MATERIAL AND METHODS: The chitosan was obtained from the Application Chemistry Company (Taiwan). The authors investigated the antibacterial effects of water-soluble chitosan against oral bacteria at different temperatures (25-37ºC) and pH values (pH 5-8), and evaluated the antibacterial activities of a self-made water-soluble chitosan-containing mouthwash by in vitro and in vivo experiments, and analyzed the acute toxicity of the mouthwashes. The acute toxicity was analyzed with the pollen tube growth (PTG) test. The growth inhibition values against the logarithmic scale of the test concentrations produced a concentrationresponse curve. The IC50 value was calculated by interpolation from the data. RESULTS: The effect of the pH variation (5-8) on the antibacterial activity of water-soluble chitosan against tested oral bacteria was not significant. The maximal antibacterial activity of water-soluble chitosan occurred at 37ºC. The minimum bactericidal concentration (MBC) of water-soluble chitosan on Streptococcus mutans and Lactobacilli brevis were 400 µg/mL and 500 µg/mL, respectively. Only 5 s of contact between water-soluble chitosan and oral bacteria attained at least 99.60% antibacterial activity at a concentration of 500 µg/mL. The water-soluble chitosan-containing mouthwash significantly demonstrated antibacterial activity that was similar to that of commercial mouthwashes (>;99.91%) in both in vitro and in vivo experiments. In addition, the alcohol-free mouthwash exhibited no cytotoxicity and no oral stinging. To the best of our knowledge, this was the first study to combine in vitro and in vivo investigations to analyze the antibacterial properties of water-soluble chitosan-containing mouthwash. CONCLUSIONS: This study illustrated that water-soluble chitosan may be a viable alternative to commercial mouthwashes in the future

An Output-Recurrent-Neural-Network-Based Iterative Learning Control for Unknown Nonlinear Dynamic Plants

We present a design method for iterative learning control system by using an output recurrent neural network (ORNN). Two ORNNs are employed to design the learning control structure. The first ORNN, which is called the output recurrent neural controller (ORNC), is used as an iterative learning controller to achieve the learning control objective. To guarantee the convergence of learning error, some information of plant sensitivity is required to design a suitable adaptive law for the ORNC. Hence, a second ORNN, which is called the output recurrent neural identifier (ORNI), is used as an identifier to provide the required information. All the weights of ORNC and ORNI will be tuned during the control iteration and identification process, respectively, in order to achieve a desired learning performance. The adaptive laws for the weights of ORNC and ORNI and the analysis of learning performances are determined via a Lyapunov like analysis. It is shown that the identification error will asymptotically converge to zero and repetitive output tracking error will asymptotically converge to zero except the initial resetting error

Septic Shock after Conservative Management for Placenta Accreta

SummaryObjectiveThe rate of placenta accreta has risen in the last three decades due to the increasing rate of cesarean section. Placenta accreta usually results in severe postpartum hemorrhage requiring massive blood transfusion and postpartum hysterectomy. Conservative treatment is an alternative in selected patients to preserve fertility and decrease postpartum hemorrhage, but the risks of conservative treatment have seldom been described.Case ReportA 39-year-old woman with placenta accreta diagnosed during cesarean section was treated conservatively. Persistent puerperal fever with leukocytosis developed during the postpartum period in spite of long-term antibiotic treatment. Evacuation of the retained placenta resulted in septic shock, which occurred immediately after dilatation and curettage. An uneventful recovery was achieved after use of strong antibiotics and fluid challenge.ConclusionAt present, there is no consensus about the optimal treatment for placenta accreta. Conservative treatment appears to be an alternative in selected patients, but the complications such as sepsis should be carefully identified and appropriately managed

An Output-Recurrent-Neural-Network-Based Iterative Learning Control for Unknown Nonlinear Dynamic Plants

We present a design method for iterative learning control system by using an output recurrent neural network (ORNN). Two ORNNs are employed to design the learning control structure. The first ORNN, which is called the output recurrent neural controller (ORNC), is used as an iterative learning controller to achieve the learning control objective. To guarantee the convergence of learning error, some information of plant sensitivity is required to design a suitable adaptive law for the ORNC. Hence, a second ORNN, which is called the output recurrent neural identifier (ORNI), is used as an identifier to provide the required information. All the weights of ORNC and ORNI will be tuned during the control iteration and identification process, respectively, in order to achieve a desired learning performance. The adaptive laws for the weights of ORNC and ORNI and the analysis of learning performances are determined via a Lyapunov like analysis. It is shown that the identification error will asymptotically converge to zero and repetitive output tracking error will asymptotically converge to zero except the initial resetting error

The effects of rear-wheel camber on the kinematics of upper extremity during wheelchair propulsion

BACKGROUND: The rear-wheel camber, defined as the inclination of the rear wheels, is usually used in wheelchair sports, but it is becoming increasingly employed in daily propulsion. Although the rear-wheel camber can increase stability, it alters physiological performance during propulsion. The purpose of the study is to investigate the effects of rear-wheel cambers on temporal-spatial parameters, joint angles, and propulsion patterns. METHODS: Twelve inexperienced subjects (22.3±1.6 yr) participated in the study. None had musculoskeletal disorders in their upper extremities. An eight-camera motion capture system was used to collect the three-dimensional trajectory data of markers attached to the wheelchair-user system during propulsion. All participants propelled the same wheelchair, which had an instrumented wheel with cambers of 0°, 9°, and 15°, respectively, at an average velocity of 1 m/s. RESULTS: The results show that the rear-wheel camber significantly affects the average acceleration, maximum end angle, trunk movement, elbow joint movement, wrist joint movement, and propulsion pattern. The effects are especially significant between 0° and 15°. For a 15° camber, the average acceleration and joint peak angles significantly increased (p < 0.01). A single loop pattern (SLOP) was adopted by most of the subjects. CONCLUSIONS: The rear-wheel camber affects propulsion patterns and joint range of motion. When choosing a wheelchair with camber adjustment, the increase of joint movements and the base of support should be taken into consideration

The Liquid Sensor Using Thin Film Bulk Acoustic Resonator with C-Axis Tilted AlN Films

Dual-mode thin film bulk acoustic resonator (TFBAR) devices are fabricated with c-axis tilted AlN films. To fabricate dual-mode TFBAR devices, the off-axis RF magnetron sputtering method for the growth of tilted piezoelectric AlN thin films is adopted. In this report, the AlN thin films are deposited with tilting angles of 15° and 23°. The frequency response of the TFBAR device with 23° tilted AlN thin film is measured to reveal its ability to provide dual-mode resonance. The sensitivities of the longitudinal and shear modes to mass loading are calculated to be 2295 Hz cm2/ng and 1363 Hz cm2/ng with the mechanical quality factors of 480 and 287, respectively. The sensitivities of the longitudinal and shear modes are calculated to be 0 and 15 Hz cm2/μg for liquid loading

Co-Overexpression of Cyclooxygenase-2 and Microsomal Prostaglandin E Synthase-1 Adversely Affects the Postoperative Survival in Non-small Cell Lung Cancer

IntroductionCyclooxygenase (COX)-2 and microsomal prostaglandin E synthase (mPGES)-1 have been found to be overexpressed in non-small cell lung cancer (NSCLC). The aim of this study was to investigate the expression profiles of COX-2 and mPGES-1 and their correlation with the clinical characteristics and survival outcomes in patients with resected NSCLC.Methods/ResultsSeventy-nine paired adjacent normal-tumor matched samples were prospectively procured from patients undergoing surgery for NSCLC. The protein levels of COX-2 and mPGES-1 were assessed by Western blot analysis. Overexpression in the tumor sample was defined as more than twofold increase in protein expression compared with the corresponding adjacent normal tissue. Co-overexpression of COX-2 and mPGES-1 were further confirmed by immunohistochemistry. COX-2 was overexpressed in 58% and mPGES-1 in 70% of the tumor samples (p < 0.0001). Co-overexpression of mPGES-1 and COX-2 was noted in 43%, and they were unrelated to each other (p = 0.232). Co-overexpression of both proteins was significantly associated with less tumor differentiation (p = 0.046), tumor size larger than 5 cm (p = 0.038), and worse survival status during the follow-up (p = 0.036). Multivariate analysis showed that in addition to overall stage, co-overexpression of both proteins adversely affected the overall (hazard ratio, 2.40; p = 0.045) and disease-free survivals (hazard ratio, 2.27; p = 0.029).ConclusionsOverexpression of either COX-2 or mPGES-1 is common but unrelated in NSCLC. Co-overexpression of both COX-2 and mPGES-1 adversely affects postoperative overall and disease-free survivals