Assessment of antibacterial activity of 2.5% NaOCl,chitosan nano-particles against Enterococcus faecalis contaminating root canals with and without diode laser irradiation: an in vitro study

Objective: This study was done to evaluate the antibacterial effect of chitosan nano-particles (CNPs) root canal irrigant as a new alternative to Sodium hypochlorite (NaOCl) for disinfection of root canals inoculated with Enterococcus faecalis, with and without laser activation.

Methodology: Sixty single rooted human premolars were decoronated, prepared and had their apical foramina sealed. E. faecalis were incubated in the root canals for 15 days. The teeth were then randomly divided into two experimental groups (n?=?30) according to the disinfection protocol used. In Group I: disinfection was performed using the irrigant solutions only (Saline, 2.5% NaOCl, CNPs). Whereas in Group II, disinfection was done using the same irrigants followed by Diode laser at (980-nm) at 2 W output for 5?×?5?s. Intra-canal bacterial samples were taken before and after canal disinfection to determine the CFU count.

Results: In group I, 2.5% NaOCl was as effective as CNP in eradication and significantly more effective than Saline (p?=?0.008) in eradication of E. faecalis. In Group II, either 2.5% NaOCl or CNP in combination with diode laser irradiation showed a similarly high effect in bacterial eradication.

Conclusions: Within the parameters used in this study, a combination therapy consisting of irrigation followed by diode laser irradiation should be utilized as an effective treatment modality for eliminating E. faecalis from root canal systems.     

Activation of ethylenediaminetetraacetic acid by a 940 nm diode laser for enhanced removal of smear layer

Laser enhancement of ethylenediaminetetraacetic acid with cetrimide (EDTAC) has previously been shown to increase removal of smear layer, for middle‐infrared erbium lasers. This study evaluated the efficiency of EDTAC activation using a near‐infrared‐pulsed 940 nm laser delivered by plain fibre tips into 15% EDTAC or 3% hydrogen peroxide. Root canals in 4 groups of 10 single roots were prepared using rotary files, with controls for the presence and absence of smear layer. After laser treatment (80 mJ pulse^?1, 50 Hz, 6 cycles of 10 s), roots were split and the apical, middle and coronal thirds of the canal were examined using scanning electron microscopy, with the area of dentine tubules determined by a validated quantitative image analysis method. Lasing EDTAC considerably improved smear layer removal, while lasing into peroxide gave minimal smear layer removal. The laser protocol used was more effective for smear layer removal than the ‘gold standard’ protocol using EDTAC with sodium hypochlorite (NaOCl). In addition, lasers may also provide a benefit through photothermal disinfection. Further research is needed to optimise irrigant activation protocols using near‐infrared diode lasers of other wavelengths.     

三波长肝储备功能检测系统的设计

背景：术前评估肝脏储备功能可以让医生得到充分的肝脏信息,从而制定下一步的治疗计划。吲哚青绿排泄试验因为其具有简单、创伤少等优点,被证明是一种有效的预测患者肝储备功能的方法。目的：设计基于吲哚青绿排泄法的便携式肝储备功能测试系统。方法：依据组织对红外光吸收的不同以及脉动选择不同波长LED,选择ARM9平台,设计外围硬件以及探头,并在Window CE系统下设计系统的软件程序,进行整机效果验证。结果与结论：便携式肝储备功能测试系统可以无创、实时的提供吲哚青绿15min滞留率以及血氧饱和度等人体信息,系统采用三波长LED照射手指,并利用光电传感器采集透过手指的光强,软件方面采用数字滤波器及自学习阈值法去除干扰信号。实验证明该系统信号可靠、稳定,效果良好,具有实用性。     

三种光疗法治疗寻常性痤疮疗效观察

目的：评价光动力学疗法（PDT）,强脉冲光（IPL）和红蓝光（LED）治疗中、重度寻常性痤疮的疗效。方法：将90例中、重度痤疮患者随机分为三组：PDT治疗组,IPL治疗组和LED红蓝光治疗组。分别于治疗前、治疗中期（治疗1个月）和末次治疗结束后评价疗效。结果：治疗中期评价时,PDT、IPL、LED治疗组总有效率分别为93.3%、60.0%和36.7%,平均皮损减少率分别为90.4%、69.0%和39.8%。要达到炎症性皮损痊愈,PDT组平均需要（3±1.52）个治疗周期,IPL组（6±2.15）个治疗周期,LED组（9±3.34）个治疗周期。结论：光疗法治疗中、重度痤疮疗效显著,PDT组疗法效果优于IPL和LED组,副作用少,有很好应用前景,而长期疗效有待进一步观察。     

Simultaneous separation of antihyperlipidemic drugs by green ultrahigh-performance liquid chromatography–diode array detector method: Improving the health of liquid chromatography

Statins in combination with fibrates show beneficial effects on the lipoprotein profile of patients because they have positive complimentary effects on lipid profile. A new green ultrahigh-performance liquid chromatography–diode array detector method for simultaneous analysis of simvastatin (SMV) and fenofibrate (FNF) in standard form, marketed formulations, and self-emulsifying drug delivery system formulations was developed and validated in the present investigation. The method utilized C₁₈ as stationary phase and a combination of methanol:water (8:2) as an eluent. It was found that selected eluent provided short run time (2.5 minutes), better peak symmetry and satisfactory values of other chromatographic parameters such as resolution (Rs = 2.325), capacity factor (k, 3.0 and 4.2 for SMV and FNF, respectively), selectivity (α =1.4), and number of theoretical plates (N, 4265 and 5285 for SMV and FNF, respectively). An excellent linear relationship (r² 0.998 and 0.997 for SMV and FNF, respectively) was observed for linear regression data for the calibration plots. The developed system was validated for accuracy, precision, robustness (˃ 2% for both drugs) and recovery (98–102% for both drugs). Results obtained from the statistical treatment of the values obtained for different parameters proved that the method is suitable, reproducible, and selective for the simultaneous analysis of SMV and FNF in bulk, marketed, and self-emulsifying drug delivery system formulations. The replacement of commonly applied toxic solvents with innocuous and environmentally benign solvents provides a better option than the more toxic processes in drug analysis.     

Transcanalicular laser-assisted dacryocystorhinostomy with diode laser

This article compares the efficacy of transcanalicular laser assisted dacryocystorhinostomy (TL DCR) with conventional external dacryocystorhinostomy (Ex DCR). All patients were randomly divided into two groups – Group A included patients who underwent TL DCR and Group B included patients who underwent Ex DCR. 168 operations were done in a total of 163 patients; 79 patients in group A and 84 patients in group B. The overall success rate was 90.12% in group A and 95.40% in group B. The mean total surgical time was 17.41 min in group A and 49.49 min in group B. The duration of stay in hospital was about 3 hours for group A and about 48 hours for group B. Intra and post operative complications were more in group B than in group A. TL DCR can offer a minimally invasive technique with comparable results and better patient satisfaction than Ex DCR.     

Optical suppression of experimental seizures in rat brain slices

Purpose:   To determine if a small ultraviolet emitting diode (UV LED) could release sufficient γ-aminobutyric acid (GABA) from a caged precursor to suppress paroxysmal activity in rat brain slices.
Methods:   Electrophysiologic recordings were obtained from rat brain slices bathed with caged GABA: 4-[[(2H-benzopyran-2-one-7-amino-4-methoxy)carbonyl]amino]butanoic acid (BC204), at concentrations between 3 and 30 μ m . Seizure-like activity was induced by perfusing slices with extracellular medium lacking magnesium and containing 4-aminopyridine (4-AP; 100 μ m ). A small, high-power UV LED was used to uncage BC204 and determine whether an increase in ambient GABA could alter normal or paroxysmal activity in the slice.
Results:   UV LED illumination, in the absence of BC204, had no effect on CA1 population spikes or seizure-like activity. The light did induce a small temperature elevation (<0.15°C) over the current intensities and exposure durations used in these experiments. In the presence of BC204, UV light decreased the CA1 population spike and seizure-like activity. The BC204 effect can be best accounted for by release of GABA: The reduction of population spikes and seizure-like activity was blocked by the GABA antagonist picrotoxin, and BC204 illumination produced a membrane polarization that reversed at the expected potential for GABA_A receptors.
Discussion:   These experiments establish that illumination of a low concentration of caged GABA with a tiny UV LED can release sufficient GABA to attenuate seizure-like activity in brain slices. Because our seizure model is very severe, it is probable that this technique would have a robust effect in human focal epilepsy.