Effects of a passive upper extremity exoskeleton for overhead tasks

Overhead work is a major cause of upper extremity work-related musculoskeletal disorders (WMSD). In this paper, the potential effects of a Passive Upper-Limb Exoskeleton (PULE) were evaluated in the tasks of overhead works. This proposed PULE has a higher degree of freedom and does not impede the user's upper limb movements. Fifteen male volunteers participated in the study by performing the repeated overhead bolt installation tasks. The electromyographic (EMG) values of anterior deltoid (AD), mid deltoid (MD), descending trapezius (TR), and triceps (TB) of the left and right arms of the participants were measured at three different overhead task heights with Intervention (with/without the PULE). Moreover, the rankings of perceived discomfort (RPD) obtained on the neck, shoulders, upper arms, forearms, upper back, waists, and legs were rated for each participant. The preliminary experiment results show that the initial nEMG of right anterior deltoid (AD) decreased by 38.5%, median nEMG values decreased by 45.1%, and total RPD decreased by 52.4%. The use of the PULE could bring the benefits of less upper extremity muscle contraction and lower RPD compared to the non-use, which may potentially reduce or slow down the level of upper extremity WMSD across the overhead work.     

Trapezius muscle rest time during standardised computer work--a comparison of female computer users with and without self-reported neck/shoulder complaints.

Work related musculoskeletal disorders (WMSDs) in the shoulder/neck area are a common and increasing problem among European computer workers, especially women. Long-term low-level workloads with low degree of muscle rest are a potential risk factor for developing WMSDs. The purpose of the present study of female computer users (age 45-65 years) in Denmark and Sweden was to investigate if subjects with self-reported neck/shoulder complaints (cases, N=35) show less trapezius muscle relative rest time (RRT) than controls (N=44) when performing standardised short-term computer work tasks in controlled laboratory conditions. Surface electromyography (EMG) signals were recorded bilaterally from the upper trapezius muscles during a type, edit, precision and colour word stress task. Besides RRT, 10th percentile RMS values were calculated. On the average, 15 of the cases and 18 of the controls showed analysable EMG files per task. For the colour word stress task, the results showed lower RRT values and higher 10th percentile RMS amplitude levels among cases compared to controls. No such signs could be found for the other tasks performed. The present results indicate an increased motor response to a psychological stressor among subjects with self-reported neck/shoulder complaints.     

A computational study of injury severity and pattern sustained by overweight drivers in frontal motor vehicle crashes

The objective of this study was to examine the role of body mass and subcutaneous fat in injury severity and pattern sustained by overweight drivers. Finite element models were created to represent the geometry and properties of subcutaneous adipose tissue in the torso with data obtained from reconstructed magnetic resonance imaging data-sets. The torso adipose tissue models were then integrated into the standard multibody dummy models together with increased inertial parameters and sizes of the limbs to represent overweight occupants. Frontal crash simulations were carried out considering a variety of occupant restraint systems and regional body injuries were measured. The results revealed that differences in body mass and fat distribution have an impact on injury severity and pattern. Even though the torso adipose tissue of overweight subjects contributed to reduce abdominal injury, the momentum effect of a greater body mass of overweight subjects was more dominant over the cushion effect of the adipose tissue, increasing risk of other regional body injuries except abdomen. Through statistical analysis of the results, strong correlations (p < 0.01) were found between body mass index and regional body injuries except neck injury. The analysis also revealed that a greater momentum of overweight males leads to greater forward torso and pelvic excursions that account for higher risks (p < 0.001) of head, thorax and lower extremity injury than observed in non-overweight males. The findings have important implications for improving the vehicle and occupant safety systems designed for the increasing global obese population.     

Neck and shoulder muscle activity of orthodontists in natural environments

Work related musculoskeletal disorders (WMSDs) are common among dentists and possibly caused by prolonged static load. The aim of this study was to assess the contraction pattern of neck and shoulder muscles of orthodontists in natural environments.Electromyographic (EMG) activity of right sternocleidomastoid and trapezius muscles were recorded by means of portable recorders in eight orthodontists during working conditions, and both active and resting non-working conditions. Recordings were analysed in terms of contraction episode (CE) count, amplitude, and duration.The sternocleidomastoid and trapezius muscles contracted about 40–70 times per hour in the natural environment. Their EMG activity pattern mainly consisted of short-lasting, low-amplitude CEs. The counts and amplitude of sternocleidomastoid CEs did not differ across vocational and non-vocational conditions. The number and amplitude of trapezius CEs were slightly but significantly higher during the vocational condition. There were highly significant (p < 0.001) differences in duration of CEs across conditions, with two to threefold increase in the average duration of trapezius muscle contractions found in the vocational setting.During orthodontic work, operators commonly hold muscular contractions for significantly longer periods than are encountered in non-vocational settings. This behaviour may be associated causally with the increases seen in WMSDs through proposed pathophysiological mechanisms occurring at the motor unit level. Our findings may also be valid for other occupations characterised by seated static postures with precision hand and wrist movements.     

Evaluation of Novel EMG Biofeedback for Postural Correction During Computer Use

Postural correction is an effective rehabilitation technique used to treat chronic neck and shoulder pain, and is aimed toward reducing the load on the surrounding muscles by adopting a neutral posture. The objective of this investigation was to evaluate the effectiveness of real-time high-density surface EMG (HDsEMG) biofeedback for postural correction during typing. Twenty healthy participants performed a typing task with two forms of postural feedback: (1) verbal postural coaching and (2) verbal postural coaching plus HDsEMG biofeedback. The interface used activity from two HDsEMG arrays placed over the trapezius designed to shift trapezius muscle activity inferiorly. The center of gravity across both arrays was used to quantify the spatial distribution of trapezius activity. Planar angles taken from upper extremity reflective markers quantified cervicoscapular posture. During the biofeedback condition, trapezius muscle activity was located 12.74 ± 3.73 mm more inferior, the scapula was 2.58 ± 1.18° more adducted and 0.23 ± 0.24° more depressed in comparison to verbal postural coaching alone. The results demonstrate the short-term effectiveness of a real-time HDsEMG biofeedback intervention to achieve postural correction, and may be more effective at creating an inferior shift in trapezius muscle activity in comparison to verbal postural coaching alone.     

Temporal changes in motor variability during prolonged lifting/lowering and the influence of work experience

Existing research indicates that repetitive motions are strongly correlated with the development of work-related musculoskeletal disorders (WMSDs). Resulting from the redundant degrees-of-freedom in the human body, there are variations in motions that occur while performing a repetitive task. These variations are termed motor variability (MV), and may be beneficial for reducing WMSD risks. To better understand the potential role of MV in preventing injury risk, we evaluated the effects of fatigue on MV using data collected during a lab-based prolonged, repetitive lifting/lowering task. We also investigated whether experienced workers used different motor control strategies than novices to adapt to fatigue. MV of the whole-body center-of-mass (COM) and box trajectory were quantified using cycle-to-cycle standard deviation, sample entropy, and goal equivalent manifold (GEM) methods. In both groups, there were significantly increased variations of the COM with fatigue, and with a more substantial increase in a direction that did not affect task performance. Fatigue deteriorated the task goal and made it more difficult for participants to maintain their performance. Experienced workers also had higher MV than novices. Based on these results, we conclude that flexible motor control strategies are employed to reduce fatigue effects during a prolonged repetitive task.     

Firing statistics of inhibitory neuron with delayed feedback. I. Output ISI probability density

Activity of inhibitory neuron with delayed feedback is considered in the framework of point stochastic processes. The neuron receives excitatory input impulses from a Poisson stream, and inhibitory impulses from the feedback line with a delay. We investigate here, how does the presence of inhibitory feedback affect the output firing statistics. Using binding neuron (BN) as a model, we derive analytically the exact expressions for the output interspike intervals (ISI) probability density, mean output ISI and coefficient of variation as functions of model's parameters for the case of threshold 2. Using the leaky integrate-and-fire (LIF) model, as well as the BN model with higher thresholds, these statistical quantities are found numerically. In contrast to the previously studied situation of no feedback, the ISI probability densities found here both for BN and LIF neuron become bimodal and have discontinuity of jump type. Nevertheless, the presence of inhibitory delayed feedback was not found to affect substantially the output ISI coefficient of variation. The ISI coefficient of variation found ranges between 0.5 and 1. It is concluded that introduction of delayed inhibitory feedback can radically change neuronal output firing statistics. This statistics is as well distinct from what was found previously (Vidybida and Kravchuk, 2009) by a similar method for excitatory neuron with delayed feedback.     

Puppy Temperament Assessments Predict Breed and American Kennel Club Group but Not Adult Temperament

Puppy assessments for companion dogs have shown mixed long-term reliability. Temperament is cited among the reasons for surrendering dogs to shelters. A puppy temperament test that reliably predicts adult behavior is one potential way to lower the number of dogs given to shelters. This study used a longitudinal design to assess temperament in puppies from 8 different breeds at 7 weeks old (n = 52) and 6 years old (n = 34) using modified temperament tests, physiological measures, and a follow-up questionnaire. For 7-week-old puppies, results revealed (a) puppy breed was predictable using 3 variables, (b) 4 American Kennel Club breed groups had some validity based on temperament, (c) temperament was variable within litters of puppies, and (d) certain measures of temperament were related to physiological measures (heart rate). Finally, puppy temperament assessments were reliable in predicting the scores of 2 of the 8 adult dog temperament measures. However, overall, the puppy temperament scores were unreliable in predicting adult temperament.     

Who shall I say is calling? Validation of a caller recognition procedure in Bornean flanged male orangutan (Pongo pygmaeus wurmbii) long calls

Acoustic individual discrimination has been demonstrated for a wide range of animal taxa. However, there has been far less scientific effort to demonstrate the effectiveness of automatic individual identification, which could greatly facilitate research, especially when data are collected via an acoustic localization system (ALS). In this study, we examine the accuracy of acoustic caller recognition in long calls (LCs) emitted by Bornean male orangutans (Pongo pygmaeus wurmbii) derived from two data-sets: the first consists of high-quality recordings taken during individual focal follows (N = 224 LCs by 14 males) and the second consists of LC recordings with variable microphone-caller distances stemming from ALS (N = 123 LCs by 10 males). The LC is a long-distance vocalization. We therefore expect that even the low-quality test-set should yield caller recognition results significantly better than by chance. Automatic individual identification was accomplished using software originally developed for human speaker recognition (i.e. the MSR identity toolbox). We obtained a 93.3% correct identification rate with high-quality recordings, and 72.23% with recordings stemming from the ALS with variable microphone-caller distances (20–420 m). These results show that automatic individual identification is possible even though the accuracy declines compared with the results of high-quality recordings due to severe signal degradations (e.g. sound attenuation, environmental noise contamination, and echo interference) with increasing distance. We therefore suggest that acoustic individual identification with speaker recognition software can be a valuable tool to apply to data obtained through an ALS, thereby facilitating field research on vocal communication.     

Effects of an active warm-up on variation in bench press and back squat (upper and lower body measures)

The present study investigated the magnitude of diurnal variation in back squat and bench press using the MuscleLab linear encoder over three different loads and assessed the benefit of an active warm-up to establish whether diurnal variation could be negated. Ten resistance-trained males underwent (mean ± SD: age 21.0 ± 1.3?years, height 1.77 ± 0.06?m, and body mass 82.8 ± 14.9?kg) three sessions. These included control morning (M, 07:30?h) and evening (E, 17:30?h) sessions (5-min standardized warm-up at 150?W, on a cycle ergometer), and one further session consisting of an extended active warm-up morning trial (M_E, 07:30?h) until rectal temperature (T_rec) reached previously recorded resting evening levels (at 150?W, on a cycle ergometer). All sessions included handgrip, followed by a defined program of bench press (at 20, 40, and 60?kg) and back squat (at 30, 50, and 70?kg) exercises. A linear encoder was attached to an Olympic bar used for the exercises and average force (AF), peak velocity (PV), and time to peak velocity (tPV) were measured (MuscleLab software; MuscleLab Technology, Langesund, Norway) during the concentric phase of the movements. Values for T_rec were higher in the E session compared to values in the M session (Δ0.53?°C, P < 0.0005). Following the extended active warm-up in the morning (M_E), T_rec and T_m values were no different to the E values (P < 0.05). Values for T_m were lower in the M compared to the E condition throughout (P < 0.05). There were time-of-day effects for hand grip with higher values of 6.49% for left (P = 0.05) and 4.61% for right hand (P = 0.002) in the E compared to the M. Daily variations were apparent for both bench press and back squat performance for AF (3.28% and 2.63%), PV (13.64% and 11.50%), and tPV (?16.97% and ?14.12%, where a negative number indicates a decrease in the variable from morning to evening). There was a main effect for load (P < 0.0005) such that AF and PV values were larger at higher masses on the bar than lower ones and tPV was smaller at lower masses on the bar than at higher masses for both bench press and back squat. We established that increasing T_rec in the M–E values did not result in an increase of any measures related to bench press and back squat performance (P > 0.05) to increase from M to E levels. Therefore, MuscleLab linear encoder could detect meaningful differences between the morning and evening for all variables. However, the diurnal variation in bench press and back squat (measures of lower and upper body force and power output) is not explained by time-of-day oscillations in T_rec.     

Daily rhythms in activity and mRNA abundance of enzymes involved in glucose and lipid metabolism in liver of rainbow trout,Oncorhynchus mykiss. Influence of light and food availability

ABSTRACT

We have investigated the magnitude of diurnal variation in back squat and bench press performance using the MuscleLab force velocity transducer. Thirty resistance-trained males (mean ± SD: age 21.7 ± 1.4 years; body mass 80.5 ± 4.5 kg; height 1.79 ± 0.06 m) underwent two sessions at different times of day: morning (M, 07:30 h) and evening (E, 17:30 h). Each session included a period when rectal temperature (T_rec) was measured at rest, a 5-min standardized 150 W warm-up on a cycle ergometer, then defined programme of bench press (at 20, 40 and 60 kg) and back squat (at 30, 50 and 70 kg) exercises. A linear encoder was attached to an Olympic bar used for the exercises and average force (AF), peak velocity (PV) and time-to-peak velocity (tPV) were measured (MuscleLab software; MuscleLab Technology, Langesund, Norway) during the concentric phase of the movements. Values for T_rec at rest were higher in the evening compared to morning values (0.48°C, P < 0.0005). Daily variations were apparent for both bench press and back squat performance for AF (1.9 and 2.5%), PV (8.3 and 12.7%) and tPV (?16.6 and ?9.8%; where a negative number indicates a decrease in the variable from morning to evening). There was a main effect for load where AF and tPV increased and PV decreased from the lightest load to the heaviest for both bench press and back squat (47.1 and 80.2%; 31.7 and 57.7%; ?42.1 and ?73.9%; P < 0.0005 where a negative number indicates a decrease in the variable with increasing load). An interaction was found only for tPV, such that the tPV occurs earlier in the evening than the morning at the highest loads (60 and 70 kg) for both bench press and back squat, respectively (mean difference of 0.32 and 0.62 s). In summary, diurnal variation in back squat and bench press was shown; and the tPV in complex multi-joint movements occurs earlier during the concentric phase of exercise when back squat or bench press is performed in the evening compared to the morning. This difference can be detected using a low cost, portable and widely available commercial instrument and enables translation of past laboratory/tightly controlled experimental research in to main-stream coaching practice.     

Towards automatic measurement of anteversion and neck–shaft angles in human femurs using CT images

Automatic assessment of human femur morphology may provide useful clinical information with regard to hip and knee surgery, prosthesis design and management of hip instability. To this end, neck–shaft and anteversion angles are usually used. We propose a full automatic method to estimate these angles in human femurs. Multislice CT images from 18 dried bones were analysed. The algorithm fits 3D cylinders to different regions of the bone to estimate the angles. A manual segmentation and a conventional angle assessment were used for validation. We found anteversion angle as 20 ± 7° and neck–shaft angle as 130 ± 9°. Mean distances from femur surface to cylinders were 5.5 ± 0.6, 3.5 ± 0.6 and 2.4 ± 0.4 mm for condyles, diaphysis and neck regions, respectively. Automatic and conventional angles were positively correlated (r²>0.85). Manual and automatic segmentations did not differ. The method was fast and 100% reproducible. A robust in vivo segmentation algorithm should be integrated to advance towards a clinically compliant methodology.     

Prediction of digestible and metabolisable energy in soybean meals produced from soybeans of different origins fed to growing pigs

The objective of this experiment was to determine the digestible energy (DE) and metabolisable energy (ME) in 22 sources of soybean meal (SBM) produced from soybeans from different countries and subsequently to establish equations for predicting the DE and ME in SBM based on their chemical composition. The 22 sources of SBM were all processed in Chinese crushing plants, but the soybeans used originated from China (n = 6), the US (n = 6), Brazil (n = 7) or Argentina (n = 3). The basal diet was a corn-based diet and 22 additional diets were formulated by mixing corn and 24.3% of each source of SBM. The average DE and ME in SBM from China, the US, Brazil and Argentina were 15.73, 15.93, 15.64 and 15.90 MJ/kg and 15.10, 15.31, 14.97 and 15.42 MJ/kg, respectively, and no differences among countries were observed. From a stepwise regression analysis, a series of DE and ME prediction equations were generated. The best-fit equations for SBM were DE = 38.44–0.43 crude fibre ?0.98 gross energy +0.11 acid detergent fibre (R² = 0.67, p < 0.01) and ME = 2.74 + 0.97 DE ?0.06 crude protein (R² = 0.79, p < 0.01). In conclusion, there were no differences in the DE and ME of SBM among the different soybean sources used in this experiment. The DE and ME of SBM of different origin can be predicted based on their chemical composition when fed to growing pigs.     

Investigation Into the Humaneness of Slaughter Methods for Guinea Pigs (Cavia porcelus) in the Andean Region

Guinea pigs (Cavia porcelus) are an important source of nonhuman animal protein in the Andean region of South America. Specific guidelines regarding the welfare of guinea pigs before and during slaughter have yet to be developed. This study critically assessed the humaneness of 4 different stunning/slaughter methods for guinea pigs: cervical neck dislocation (n = 60), electrical head-only stunning (n = 83), carbon dioxide (CO₂) stunning (n = 21), and penetrating captive bolt (n = 10). Following cervical neck dislocation, 97% of guinea pigs had at least 1 behavioral or cranial/spinal response. Six percent of guinea pigs were classified as mis-stunned after electrical stunning, and 1% were classified as mis-stunned after captive bolt. Increased respiratory effort was observed during CO₂ stunning. Apart from this finding, there were no other obvious behavioral responses that could be associated with suffering. Of the methods assessed, captive bolt was deemed the most humane, effective, and practical method of stunning guinea pigs. Cervical neck dislocation should not be recommended as a slaughter method for guinea pigs.     

An integrated genetic linkage map of the laboratory rat

The laboratory rat, Rattus novegicus, is a major model system for physiological and pathophysiological studies, and since 1966 more than 422,000 publications describe biological studies on the rat (NCBI/Medline). The rat is becoming an increasingly important genetic model for the study of specific diseases, as well as retaining its role as a major preclinical model system for pharmaceutical development. The initial genetic linkage map of the rat contained 432 genetic markers (Jacob et al. 1995) out of 1171 developed due to the relatively low polymorphism rate of the mapping cross used (SHR × BN) when compared to the interspecific crosses in the mouse. While the rat genome project continues to localize additional markers on the linkage map, and as of 11/97 more than 3,200 loci have been mapped. Current map construction is using two different crosses (SHRSP × BN and FHH × ACI) rather than the initial mapping cross. Consequently there is a need to provide integration among the different maps. We set out to develop an integrated map, as well as increase the number of markers on the rat genetic map. The crosses available for this analysis included the original mapping cross SHR × BN reciprocal F2 intercross (448 markers), a GH × BN intercross (205 markers), a SS/Mcw × BN intercross (235 markers), and a FHH/Eur × ACI/Hsd intercross (276 markers), which is also one of the new mapping crosses. Forty-six animals from each cross were genotyped with markers polymorphic for that cross. The maps appear to cover the vast majority of the rat genome. The availability of these additional markers should facilitate more complete whole genome scans in a greater number of strains and provide additional markers in specific genomic regions of interest. Received: 3 December 1997 / Accepted: 20 February 1998     

Drinking water biofilm assessment of total and culturable bacteria under different operating conditions

Abstract

Monitoring of biofilms subjected to different operating conditions was performed using a flow cell system. The system was fed by chlorine-free tap water, with and without added nutrients (0.5 mg l^?1 carbon, 0.1 mg l^?1 nitrogen and 0.01 mg l^?1 phosphorus), and biofilms were grown on polyvinyl chloride (PVC) and stainless steel (SS) coupons, both in laminar and turbulent flow. The parameters analysed were culturable cells, using R2A, and total bacteria, which was assessed using the 4,6-diamino-2-phenylindole (DAPI) staining method. The impact of the different operating conditions in the studied parameters was established using Multivariate Analysis of Variance (MANOVA). From the most relevant to the least relevant factor, the total and culturable bacteria in biofilms increased due to the addition of nutrients to water (F = 20.005; p < 0.001); the use of turbulent (Re = 11000) instead of laminar (Re = 2000) hydrodynamic flows (F = 9.173; p < 0.001); and the use of PVC instead of SS as the support material (F = 2.848; p = 0.060). Interactions between these conditions, namely between surface and flow (F = 8.235; p < 0.001) and also flow and nutrients (F = 5.498; p < 0.05) have also proved to significantly influence biofilm formation. This work highlights the need for a deeper understanding of how the large spectrum of conditions interact and affect biofilm formation potential and accumulation with the final purpose of predicting the total and culturable bacteria attached to real drinking water distribution pipes based on the system characteristics.     

Night shift work and osteoporosis among female blue-collar workers in Poland - a pilot study

ABSTRACT

Osteoporosis is an important public health problem worldwide. Although a number of factors that affect bone structure have been described; thus far, the current knowledge of occupational factors that may have an influence on bone tissue metabolism is strongly limited. Published studies indicate night shift work and the related circadian rhythm disruption may be considered as plausible underlying factors. The aim of the present study was to assess the potential association between night shift work and bone mineral density (BMD) among female blue-collar workers in Poland. A cross-sectional study was carried out among 194 female blue-collar workers >40 years of age employed in industrial plants. The operating system of work consisted of three work shifts clockwise rotation: morning (06:00–14:00 h), afternoon (14:00–22:00 h), and night (22:00–06:00 h), with five consecutive shifts per week followed by a free weekend. A questionnaire survey, based on a Polish version of The European vertebral osteoporosis study (EVOS) questionnaire, a validated instrument, was administered. Data on current job characteristics, job seniority, and lifetime duration of night shift work were also collected. BMD of the lumbar spine and hip (both total femur and femoral neck) was measured using dual-energy X-ray absorptiometry. Multivariate linear regression models were run, with bone mineralization parameters as dependent variables, as well as night work characteristics and important confounders. Statistical analysis was performed separately for premenopausal and postmenopausal women. The analyses adjusted for confounders did not reveal any significant differences between current or lifetime experience of night shift work and BMD among both premenopausal and postmenopausal women. However, the outcomes supported the well-established correlation with factors, such as age, BMI, and menopausal status. BMD at the three sites measured was significantly associated with BMI (p < .001) and inversely associated with age (p < .001) in the total study population. Postmenopausal women had significantly lower BMD than did premenopausal women (p < .001). The study findings indicate that in the population of Polish female blue-collar workers, the system of work does not seem to be associated with the development of osteoporosis.     

Prediction of tree species composition in fine root mixed samples using near-infrared reflectance spectroscopy

Fine roots ( ≤ 2 mm diameter) are of great value when investigating belowground interactions among different plant species and soil nutrient cycling in forest ecosystems. However, fine root separation and species identification are labor-intensive and time-consuming processes. This study aimed to evaluate the aptitude of near-infrared reflectance spectroscopy (NIRS) in predicting tree species composition in fine root mixed samples. The coniferous species Cunninghamia lanceolata and Pinus massoniana, the deciduous species Alniphyllum fortunei and Liquidambar formosana, and the evergreen broadleaved species Cyclobalanopsis glauca represent the five subtropical tree species selected for this investigation. To obtain near-infrared reflectance spectral data, 20 samples taken in the field and 70 artificially mixed samples of the five species were produced after root samples were oven-dried and ground. Calibration was performed with partial least squares regression and leave-one-out cross-validation. Root mass proportions of the mixed samples showed good predictive capacity for C. lanceolata, P. massoniana, and C. glauca with low root mean square error of prediction ( < 6.82%) and high determination coefficients (R²>0.944). Predictions for A. fortunei and L. formosana were acceptable with R²>0.819. NIRS shows potential in predicting tree species composition with suitable accuracy.     

A DFT study on graphene,SiC, BN,and AlN nanosheets as anodes in Na-ion batteries

A great concern exists about the lifetime, cost, low-temperature performance, and safety of Li-ion batteries. Na-ion batteries (NIB) are an alternative to the Li-ion batteries due to the wide availability of sodium, its low cost, and nontoxicity. Here, we examined the Na and Na⁺ adsorption on nanosheets of carbon (graphene), AlN, BN, and SiC to explore their potential use as an anode in NIBs. The interaction of atomic Na was found to play the main role in producing different nanosheet cell voltages. Unlike the graphene and SiC nanosheets, the lone pairs on the surface of the AlN and BN nanosheets hinder the Na adsorption and significantly increase the cell voltage. The order of magnitude of the nanosheet cell voltage as an anode in NIBs is as follows: AlN (1.49 V)?>?BN (1.46 V) >?>?C (0.69 V)?>?SiC (0.61 V). The AlN and BN nanosheets may be appropriate compounds for NIBs and their cell voltages are comparable with carbon nanotubes.     

DNA Electrochemical Sensor for Detection of PRSS1 Point Mutation Based on Restriction Endonuclease Technique

To construct a restriction endonuclease based biosensor technology for PRSS1 genotyping. We designed a thiol-modified hairpin probe where the neck has EcoRI endonuclease recognition sites according to the PRSS1 gene c.410 C>T (p.T137 M) mutation and it was fixed on the gold electrode. Different charge generated by the binding of MB to phosphate groups of DNA before and after hybridization was used for distinguishing the different genotypes and quantity. This showed that the novel sensor can better distinguish the complementary sequence, single-base mismatches, and completely noncomplementary sequences, and the linear range for the logarithm was Y = –0.0242 X + 0.1574, R = 0.9912(Y = current, X = log target DNA concentration); the detection limit for DNA detection is estimated to be 50 fM.