Nuclear Magnetic Resonance Chemical Shift as a Probe for Single-Molecule Charge Transport

Existing modelling tools, developed to aid the design of efficient molecular wires and to better understand their charge-transport behaviour and mechanism, have limitations in accuracy and computational cost. Further research is required to develop faster and more precise methods that can yield information on how charge transport properties are impacted by changes in the chemical structure of a molecular wire. In this study, we report a clear semilogarithmic correlation between charge transport efficiency and nuclear magnetic resonance chemical shifts in multiple series of molecular wires, also accounting for the presence of chemical substituents. The NMR data was used to inform a simple tight-binding model that accurately captures the experimental single-molecule conductance values, especially useful in this case as more sophisticated density functional theory calculations fail due to inherent limitations. Our study demonstrates the potential of NMR spectroscopy as a valuable tool for characterising, rationalising, and gaining additional insights on the charge transport properties of single-molecule junctions.

Effect of Diabetes Mellitus on the Spectrum of Uropathogens and the Antimicrobial Resistance in Patients with Urinary Tract Infection

Patients with diabetes mellitus frequently experience urinary tract infections (UTIs). In the present study, we looked at how glycemic control affects diabetic patients' rates of UTI, the causing pathogens, the presence of multi-drug-resistant (MDR) and extensively drug-resistant organisms, and the infections' relation to diabetes. Diabetes patients' midstream urine samples were included, after collecting and identifying the organisms, disc diffusion antibiotic sensitivity tests were conducted. The HbA1c was measured for all patients. A total of 500 diabetic patients provided urine samples for this study, and 189 (37.2%) of them had UTIs. Compared to 59 patients with managed glycemia, 130 individuals in the uncontrolled glycemic group experienced the most UTI cases. In both diabetic groups, females had a significantly higher prevalence of UTI than males (88.4% and 11.6%, respectively). The most common bacterial isolate, E. coli, displayed 58.4% MDR. Regardless of age or gender, glycemic control in diabetes patients is essential for decreasing UTI rates.

Potential Role of microRNAs in Response to Aeromonas Infection in Fish

The genus Aeromonas is a widespread pathogen that includes more than 30 Gram-negative species, many of which are opportunistic bacteria. Aeromonas species are naturally distributed in various aquatic sources. Infectious processes in marine animals such as fish usually develop under stressful conditions, and when their immune systems are weakened. MicroRNAs (miRNAs/miRs) are short, non-coding RNAs that post-transcriptionally regulate gene expression. Their diverse biological functions, such as influencing cell development, proliferation, differentiation, tumorigenesis, metabolism, and apoptosis have been studied in various animals. Fish is the most important source of aquatic nutrients throughout the world, and its market is constantly growing. Overpopulation in aquaculture brings infectious diseases that threaten the development of aquaculture around the world. There is extensive evidence that microRNAs are involved in modulating infectious processes and regulating the inflammatory response to major bacterial fish infections, including Aeromonas. Here, we review the current literature on the fish microRNA repertoire and outline the physiological roles assigned to microRNAs to provide a foundation for future research during Aeromonas infection. Understanding the interaction between microRNAs and Aeromonas may provide clues to a remarkable strategy for preventing Aeromonas infections in fish.

Improving postharvest life, quality and bioactive compounds of strawberry fruits using spermine and spermidine

Small fruits such as strawberries, are a good source of natural antioxidants. In recent decades, many efforts have been made to increase the shelf life of strawberries and maintain its nutritional value in post-harvest conditions. In the present study, the effects of spermine (Spm) and spermidine (Spd) (0, 1.0 and 1.5 mM) on the post-harvest life and quality of strawberry fruits during the 3rd, 6th, and 12th days of storage, were investigated. Applications of Spm and Spd decreased the rate of weight loss, fruit decay, soluble solids content, fruit juice pH and taste index during the storage period in compared to the control. However, titratable acids and vitamin C contents, tissue stiffness, phenolic compounds and antioxidant activity increased in compared to the control. These growth regulators prevented the aging and loss of bioactive compounds of the fruit by increasing the antioxidant activity and preventing the destruction of the fruit tissue. Among the studied treatments, applications of 1.5 mM of Spm and Spd were the most effective treatments to enhance the storage life and quality characters of strawberry fruits.

Evaluation of Mandibular Movements in Patients with Bell's Palsy Using Kinematic Variables

Background

Since the function of muscles, and subsequently the mandibular joint, is affected in patients with Bell's palsy, therefore, the evaluation of facial muscles and mandibular function in these patients can be effective in diagnosis, prevention, and treatment planning. The present study aimed to evaluate the degree of displacement and range of motion (ROM) of the mandible and the ability of the facial symmetrical muscles of patients with Bell's palsy.

Methods

This was a quasi-experimental comparative study. The variables evaluated were mandibular movement in a vertical direction and side-to-side displacement. Ten patients with Bell's palsy and 10 healthy eligible volunteers participated in the present study. Three mobile video cameras (to record jaw movements), 9 color markers, Kinovea software, House-Brackmann index, Toledo protocol, and a specialized patient questionnaire were used. Descriptive and inferential statistics were used for data analysis, the Kolmogorov-Smirnov test was used to investigate the normality of data distribution, and independent samples the t test and paired samples t test were used to compare means.

Results

The maximum lateral on the sound side was 12.40 and 4.49 mm during lateral movements of the patients' mandible, while this value was between 12.30 and 3 mm on the involved side. There is a difference between the affected side and the nonaffected side in terms of the mean lateral movements of the patients' mandible. However, this difference in the mean ROM on both sides is not statistically significant. The maximum mouth opening in healthy individuals during mandibular movements was between 40 and 60 mm, while this value was between 25 and 50 mm in the patients with Bell's palsy. This study shows a significant difference (P = 0.007) between patients and healthy individuals in terms of the mean of maximum mouth opening ( P < 0.05).

Conclusion

The results of this study showed that the ROM of temporomandibular joint (TMJ) of the patient is the same as that of normal subjects, but the side-to-side motion is more than normal which should be considered in rehabilitation treatments. The present study emphasizes the need to implement a mandibular kinematic evaluation protocol in patients with bell's palsy to prevent damage to the TMJ in the long term.

http://medrehab.sbmu.ac.ir/article_1101715_d7641b2cbbd4f9e28db58f78a16fcd8c.pdf?lang=en

Background and Aims: Running sport is one of the basic and medal-winning sports. For success in this sport, it requires to improve the performance of athletes in young ages. This study aims to assess the effect of eight weeks of two plyometric and resistance training methods on selected biomechanical variables (flexibility, balance, power, and speed) of adolescent male runners. Methods: This is a quasi-experimental study with a pre-test/post-test design using a control group. The study population consists of all adolescent male runners aged 12-17 years attending the training sessions of youth teams active in the league competitions in Tehran, Iran. Of these, 45 were selected and randomly divided into three groups of plyometric training (n=15), resistance training (n=15) and control (n=15). The training programs were presented to the training groups for eight weeks, three sessions per week, each for 45 minutes, while the control group participated in their routine training of their teams. The Sargent jump test was used to evaluate their power; the 30-m sprint test was used to evaluate their speed; the star excursion balance test was used to evaluate their dynamic balance, and the sit and reach test was used to evaluate their flexibility. To analyze the collected data, descriptive statistics (mean and standard deviation) and analysis of covariance and Bonferroni post hoc test were used in SPSS software, version 24. Results: The eight weeks of two plyometric and resistance training methods had a significant effect on the selected biomechanical variables of adolescent male runners in the training groups compared to the control group. The results of post hoc test showed that the plyometric training was more effective than the resistance training. Conclusion: Plyometric and resistance training methods can be helpful in improving the physical performance of adolescent male runners and increase their records.

The relationship between vertical stiffness during bilateral and unilateral hopping tests performed with different strategies and vertical jump performances

Vertical stiffness has been highlighted as a potential determinant of performance and may be estimated across a range of different performance tasks. The aim of the current study was to investigate the relationship between vertical stiffness determined during 9 different hopping tests and performance of vertical jumps. Twenty healthy, active males performed vertical hopping tests with three different strategies (self-selected, maximal, and controlled) and three different limb configurations (bilateral, unilateral preferred, and unilateral non-preferred), resulting in nine different variations, during which vertical stiffness was determined. In addition, participants performed squat jump (SQJ) and countermovement jump (CMJ) during which jump height, CMJ stiffness, and eccentric utilization ratio (EUR) were determined. Vertical stiffness in bilateral and unilateral preferred tasks performed with a self-selected and maximal, but not controlled, strategy was associated with stiffness in the CMJ (r = 0.61-0.64; p < 0.05). However, stiffness obtained during unilateral preferred and non-preferred hopping with self-selected strategy was negatively associated with performance in SQJ and CMJ tasks (r = -0.50 to -0.57; p < 0.05). These findings suggest that high levels of vertical stiffness may be disadvantageous to static vertical jumping performance. In addition, unilateral hopping with a self-selected strategy may be the most appropriate task variation if seeking to determine relationships with vertical jumping performance. HighlightsStiffness obtained during unilateral hopping with a preferred strategy was negatively associated with vertical jumping performancesStiffness obtained during hopping with preferred and maximal strategies was associated with stiffness obtained during a countermovement jumpIn this population, hopping stiffness may therefore be reflective of an individual's countermovement jump strategyHigh levels of stiffness may be disadvantageous to static-start vertical jumping.

Center of pressure excursion and muscle activation during gait initiation in individuals with and without chronic ankle instability

The aim of the current study was to determine differences in center of pressure (COP)excursion and muscle activation during gait initiation (GI) in those with and without chronic ankle instability (CAI). Thirty-four participants, 17 per group, volunteered to participate. Participants were asked to stand barefoot on a force plate before initiating gait upon hearing an auditory cue. Reaction time, anticipatory postural adjustment phase time, as well as normalized peak COP excursion during the anticipatory postural adjustment phase was calculated. Response time of Soleus and Tibialis Anterior muscles were concurrently recorded via electromyography. The results demonstrate a longer reaction time and shorter anticipatory postural adjustment phase time in the CAI group (p < 0.05). No significant between group differences in peak normalized COP excursion were noted (p > 0.05). Muscle onset patterns differed between groups as those with CAI demonstrated earlier Soleus activation compared to the control group (p < 0.05). The results suggest that those with CAI have an altered GI motor control strategy as evidenced by reduced or absent Soleus muscle inhibition during APA phase of GI relative to controls. The APA phase is controlled by the secondary motor area, therefore, the presence of motor control alterations in CAI patients may be due to a supra-spinal alterations.

Comparison of four methods for determining the cut-off frequency of accelerometer signals in able-bodied individuals and ACL ruptured subjects

BACKGROUND

Selecting the appropriate cut-off frequency to filter triaxial accelerometric data is a challenging issue in gait analyses. It reduces soft tissues artifacts and the variability in the kinematic data waveform from able-bodied and physically impaired gaits.

RESEARCH QUESTION

Are cut-off frequencies estimated by four filtering methods similar along each axis of a triaxial accelerometer and for able-bodied subjects and those with an anterior cruciate ligament rupture (ACLR)?

METHODS

After walking on a treadmill, the cut-off frequency for the tibial accelerations was calculated using 95 and 99 per cent of the energy spectrum (E), residual analysis (RA) and, the method (Yu) proposed by Yu et al. [1]. The coefficient of variation was used to express the variability of the cut-off frequencies estimated by the four methods. t-Test and repeated measure ANOVA were applied to examine the effects of healthiness and acceleration axis on cut-off frequencies.

RESULTS

On average, E95 and E99 gave the lowest and the highest cut-off frequencies respectively. The results demonstrated the effect of ACL injury and axes on the cut-off frequencies, especially on the RA method. There was a significant difference in the cut-off frequencies between healthy and ACLR subjects for the vertical axis with the RA method and for the anterior-posterior (AP) axis with the Yu method. Similar cut-off frequencies were obtained for all axes with the E99 method for within groups' comparison. The E95 and E99 methods gave the least and most variable outputs respectively. Significant within group differences between cut off frequencies calculated by four methods, led to disappearing peaks in the more fluctuating portion of the acceleration data.

SIGNIFICANCE

A single cut-off frequency is not recommended for all individuals and axes. In cases where a single cut-off frequency is necessary for all individuals or axes, RA or E99 methods are suggested respectively.

The effects of general fatigue induced by incremental exercise test and active recovery modes on energy cost, gait variability and stability in male soccer players

The aerobic endurance is considered an important physiological capacity of soccer players which is examined by Incremental Exercise Test (IET). However, it is not clear how general fatigue induced by IET influences physiological and biomechanical gait features in soccer players and how players recover optimally at post-IET. Here, the effect of general fatigue induced by IET on energy cost, gait variability and stability in soccer players was investigated. To identify an optimal recovery mode, the effect of walking at Preferred Walking Speed (PWS), running at Individual Ventilation Threshold (IVT) (two active recovery modes), and Rest (a passive recovery mode) on aforementioned features were studied. Nine male players walked 4-min at PWS on a treadmill prior IET (PreT), which was followed by four 4-min walking trials (PosT-0, 1, 2, and 3) with three 4-min recovery intervals (PWS, IVT, or Rest) between them, in three sessions (one for each recovery mode) in a random order. Energy cost, gait variability and stability were examined at PreT (baseline), and at PosT-0, 1, 2, and 3 (intervals of respectively 0-4, 8-12, 16-20, 24-28 min at post-IET). Gait variability was assessed by the standard deviation of trunk angle and gait stability was assessed by the local dynamic stability of trunk angular velocity. Gait stability was not affected by IET, despite increases in gait variability and energy cost. Different from IVT, PWS and Rest recovery modes reduced energy cost at post-IET. Gait variability and energy cost recovered at PosT-1 and PosT-2, suggesting that 8-12 and 16-20 min recovery intervals, respectively, were required for returning to their baselines. No preference for active over passive recovery was found in terms of gait variability and energy cost.