Functional ultrasound imaging of the human spinal cord

Utilizing the first in-human functional ultrasound imaging (fUSI) of the spinal cord, we demonstrate the integration of spinal functional responses to electrical stimulation. We record and characterize the hemodynamic responses of the spinal cord to a neuromodulatory intervention commonly used for treating pain and increasingly used for the restoration of sensorimotor and autonomic function. We found that the hemodynamic response to stimulation reflects a spatiotemporal modulation of the spinal cord circuitry not previously recognized. Our analytical capability offers a mechanism to assess blood flow changes with a new level of spatial and temporal precision in vivo and demonstrates that fUSI can decode the functional state of spinal networks in a single trial, which is of fundamental importance for developing real-time closed-loop neuromodulation systems. This work is a critical step toward developing a vital technique to study spinal cord function and effects of clinical neuromodulation.

Comparative antibacterial effects of ginger and marjoram extract versus conventional irrigants on mature Enterococcus faecalis biofilms: An in vitro study

Background

This study evaluated antibacterial effects of Ginger and Marjoram extract compared with Routine Intracanal Irrigants on Mature Enterococcus faecalis Biofilms.

Material and Methods

Sixty-six extracted human teeth, were randomly assigned to four groups 5.25% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), chloroform extract of marjoram (Origanum majorana), and oil extract of ginger (Zingiber officinale), and two positive and negative control groups (n=11). Samples were contaminated with E. faecalis, except the negative control group. Then the root canals were irrigated with solutions above, after which dental debris was collected from each tooth separately, followed by culturing on plates containing BHI agar. The bacterial counts were finally determined with a colony counting machine.

Results

No bacterial growth was detected in the NaOCl, CHX, and negative control groups. However, some bacterial growth was observed in the ginger and marjoram groups. All four solutions successfully eliminated E. faecalis biofilms compared to the positive control group. Significant difference in the median bacterial growth between the ginger and marjoram groups and the positive control group (P<0.001) has been shown. There was no significant difference in median bacterial growth between the ginger and marjoram groups (P=0.94).

Conclusions

Chloroform extract of marjoram and oil extract of ginger were effective in eliminating 6-week-old biofilms of E. faecalis in vitro; however, their effect was not as favorable as CHX and NaOCl. These herbal extracts yielded promising results in the present study; therefore, they can be used as intracanal irrigants instead of chemical agents. Key words:Biofilm, Chlorhexidine, E. faecalis, Ginger, Marjoram, Sodium hypochlorite.

Closed-loop MOEMS accelerometer

In this paper, a closed-loop micro-opto-electro-mechanical system (MOEMS) accelerometer based on the Fabry-Pérot (FP) interferometer is presented. The FP cavity is formed between the end of a cleaved single-mode optical fiber and the cross-section of a proof mass (PM) which is suspended by four U-shaped springs. The applied acceleration tends to move the PM in the opposite direction. The arrays of fixed and movable comb fingers produce an electrostatic force which keeps the PM in its resting position. The voltage that can provide this electrostatic force is considered as the output of the sensor. Using a closed-loop detection method it is possible to increase the measurement range without losing the resolution. The proposed sensor is fabricated on a silicon-on-insulator wafer using the bulk micromachining method. The results of the sensor characterization show that the accelerometer has a linear response in the range of ±5 g. In the closed-loop mode, the sensitivity and bias instability of the sensor are 1.16 V/g and 40 µg, respectively.

Polymeric piezoresistive airflow sensor to monitor respiratory patterns

Monitoring human respiratory patterns is of great importance as it gives essential information for various medical conditions, e.g. sleep apnoea syndrome and chronic obstructive pulmonary disease and asthma, etc. Herein, we have developed a polymeric airflow sensor based on nanocomposites of vertically grown graphene nanosheets (VGNs) with polydimethylsiloxane (PDMS) and explored their applications in monitoring human respiration. The sensing performance of the VGNs/PDMS nanocomposite was characterized by exposing to a range of airflow rates (20-130 l min-1), and a linear performance with high sensitivity and low response time (mostly below 1 s) was observed. To evaluate the experimental results, finite-element simulation models were developed in the COMSOL Multiphysics package. The piezoresistive properties of VGNs/PDMS thin film and fluid-solid interaction were thoroughly studied. Laser Doppler vibrometry measures of sensor tip displacement closely approximated simulated deflection results and validated the dynamic response of the sensor. By comparing the proposed sensor and some other airflow sensors in the literature, it is concluded that the VGNs/PDMS airflow sensor has excellent features in terms of sensor height, detection range and sensitivity. The potential application of the VGNs/PDMS airflow sensor in detecting the respiration pattern of human exercises like walking, jogging and running has been demonstrated.

Axial accuracy and signal enhancement in acoustic-resolution photoacoustic microscopy by laser jitter effect correction and pulse energy compensation

In recent years, photoacoustic imaging has found vast applications in biomedical imaging. Photoacoustic imaging has high optical contrast and high ultrasound resolution allowing deep tissue non-invasive imaging beyond the optical diffusion limit. Q-switched lasers are extensively used in photoacoustic imaging due to the availability of high energy and short laser pulses, which are essential for high-resolution photoacoustic imaging. In most cases, this type of light source suffers from pulse peak-power energy variations and timing jitter noise, resulting in uncertainty in the output power and arrival time of the laser pulses. These problems cause intensity degradation and temporal displacement of generated photoacoustic signals which in turn deteriorate the quality of the acquired photoacoustic images. In this study, we used a high-speed data acquisition system in combination with a fast photodetector and a software-based approach to capture laser pulses precisely in order to reduce the effect of timing jitter and normalization of the photoacoustic signals based on pulse peak-powers simultaneously. In the experiments, maximum axial accuracy enhancement of 14 µm was achieved in maximum-amplitude projected images on XZ and YZ planes with ±13.5 ns laser timing jitter. Furthermore, photoacoustic signal enhancement of 77% was obtained for 75% laser pulses peak-power stability.

1146 Interaction Of Mild Cognitive Impairment And Late-life Depression In Actigraphy And Self Report Of Sleep Problems

Introduction

Late-life depression has been proposed as a precursor to amnestic Mild Cognitive Impairment (aMCI), the prodrome of Alzheimer’s disease. Both conditions are associated with sleep and cognitive problems. We hypothesized that MCI and current depressive symptoms would co-occur more frequently, but express distinct sleep phenotypes.

Methods

Independently living older adults (N=80), age 62-90 (M=71.78, SD=5.98), were recruited from a geriatric psychiatry clinic and the community for a home sleep study. A clinical decision board and neurocognitive battery were used to determine MCI status. Participants completed the CES-D and depression history interview where endorsement of current depression was considered positive. Sleep was examined with wrist actigraphy for 7 days. Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), Stanford Sleepiness Scale (SSS) provided subjective sleep quality.

Results

Based on these criteria, 41.2% of the sample were determined to be MCI (n=33); the remainder were deemed normative for age (NC; n=47). Chi-square analyses showed a higher frequency of MCI were positive for current depression than expected (14.2%; p=0.017). Repeated-measures MANOVA, using current depression symptoms and MCI as factors, revealed MCI was associated with longer sleep latency (p=0.035) and wake bout time (p=0.039); whereas, current depression was associated with longer sleep latency, more fragmentation/WASO, and lower sleep efficiency (p’s&lt;0.05), self-report of poorer daytime dysfunction (p=0.005), and greater daytime sleepiness (p=0.001). MCI x current depression interactions were found for sleep latency (p=0.029); and PSQI sleep disturbances (p=0.005) and sleep medication (p=0.025).

Conclusion

Despite distinct sleep disordered phenotypes, the interaction of MCI and current depression is associated with delayed sleep onset, use sleep medication and report of sleep disturbances.

Support

This project was sponsored by: NASA, Maine Space Consortium; AG 056176, AG 053164 Vice President for Research, U. Maine; Maine Technology Institute; DoD Phase I SBIR and R44AG059536-01 SBIR Phase II Award.

Varicocelectomy with primary gubernaculum veins closure: A randomised clinical trial

To evaluate the effect of microsurgical inguinal varicocelectomy with testicular delivery on semen parameters. A total of 416 patients, diagnosed with grade III varicocele, were randomised into two groups. One group underwent microsurgical inguinal varicocelectomy without testicular delivery. For the other group, testicular delivery and ligation of gubernacular and all collateral veins were performed. A semen analysis was performed before and 6 months after the procedure. Mean age of the patients in the case and control groups was 27.3 ± 6.1 years and 25.9 ± 4.6 years respectively (p = .1). The total number of recurrence after 6 months in the conventional and testicular delivery groups was 13 (6.5%) and 3 (1.5%) (p < .05). No case of hydrocele formation was observed in any of the groups. All sperm parameters were improved 6 months after the surgery in both groups. But comparing the mean improved difference between the two groups revealed a significant difference in improvement in sperm motility for patients who had undergone varicocelectomy with testicular delivery (p = .05). Microsurgical inguinal varicocelectomy is a safe and efficient technique with a minimum chance of post-operative complications and recurrence and also may have role in improvement of sperm motility compared with conventional techniques.

Comparison of surgical outcomes and cosmetic results between standard and mini laparoscopic pyeloplasty in children younger than 1 year of age

OBJECTIVE

To evaluate safety, efficacy, and cosmetic results after mini laparoscopic (mL) pyeloplasty and standard (sL) pyeloplasty in children younger than 1 year of age with ureteropelvic junction obstruction (UPJO).

MATERIALS AND METHODS

From August 2009 to March 2011, 20 sL pyeloplasties were performed in pediatric patients younger than 1 year of age; afterwards, 20 patients younger than 1 year of age underwent mini laparoscopic (mL) pyeloplasty from June 2011 to August 2012. The patients were followed by urine culture and ultrasonography at 3 and 6 months after surgery. Cosmetic appearance was assessed in all patients in both groups group 3 months after surgery using the Patient Scar Assessment Questionnaire.

RESULTS

Peri and postoperative results revealed that operative time (total and anastomosis of ureteropelvic junction), hospital stay, and overall complication rate were significantly lower in mL than in sL. Persistent hydronephrosis in follow-up imaging and recurrence of obstruction was not observed in any cases. Mean appearance score and consciousness score showed significantly better results in the mL group.

CONCLUSION

We believe that mL pyeloplasty in infant cases with UPJO is more cosmetically pleasing and less invasive than sL pyeloplasty and has similar functional outcomes.

Determination of lead and cadmium content in sausages from Iran

The contents of lead and cadmium in five major brands of six types of cooked beef sausages consumed in Iran were determined by a graphite furnace atomic absorption spectrometer (GFAAS) after hydrogen peroxide/nitric acid digestion. The metal content in the samples, expressed in µg kg(-1) wet weight, varied from 24.0 to 158.7 with an average of 53.5 for lead and from 2.2 to 13.5 with an average of 5.7 for cadmium. The highest lead and cadmium concentrations were obtained from a German sausage (158.7 µg kg(-1); brand B) and hot dog (13.5 µg kg(-1); brand D), respectively. The results indicate that the sausages from Iran have concentrations below the permitted levels for these heavy metals. The daily dietary intakes and the percentage contribution of the two considered metals to the provisional tolerable weekly intake (PTWI) were calculated for sausages.

Dissociative electron attachment to gas-phase glycine

By using a high-resolution electron energy monochromator low-energy electron attachment to gas-phase glycine (H2NCH2COOH, or G) has been studied by means of mass spectrometric detection of the product anions. In the same way as for several other biologically relevant molecules no stable parent anion was formed by free electron attachment. The largest dissociative electron attachment (DEA) cross-section, approximately 5x10(-20) m2, was observed for (G-H)-+H at an electron energy of 1.25 eV. Glycine and formic acid (HCOOH) have several common features, because a precursor ion can be characterized by electron attachment to the unoccupied pi* orbital of the -COOH group. At higher incident electron energies several smaller fragment anions are formed. Except for H-, which could not be observed in this study, there was good agreement with an earlier investigation by Gohlke et al.

Acyclovir in the treatment of recurrent respiratory papillomatosis: a preliminary report

INTRODUCTION

In this study, we evaluate the effect of acyclovir in the treatment of recurrent respiratory papillomatosis (RRP), in addition to CO2 surgery.

MATERIALS AND METHODS

We include 12 patients who had aggressive RRP and required at least three prior endoscopic surgeries in this study. Acyclovir treatment started the day after the surgery. During the planned treatment period of 6 months, patients older than 5 years were asked to take the daily dose of 800 mg, and those younger than 5 years were asked to take 400 mg.

RESULTS

Nine of 12 patients were disease free during the follow-up periods, which ranged from 14 to 25 months with a mean of 18 months. Only 3 patients who used the drug inadequately required reoperation.

CONCLUSION

Because of the specific viral origin of RRP, we hope that addition of acyclovir to surgery will preclude or at least decrease the number of recurrences in this potentially fatal disease.