Progress in the experimental and computational methods of work function evaluation of materials: A review.

The work function, which determines the behaviour of electrons in a material, remains a crucial factor in surface science to understand the corrosion rates and interfacial engineering in making photosensitive and electron-emitting devices. The present article reviews the various experimental methods and theoretical models employed for work function measurement along with their merits and demerits are discussed. Reports from the existing methods of work function measurements that Kelvin probe force microscopy (KPFM) is the most suitable measurement technique over other experimental methods. It has been observed from the literature that the computational methods that are capable of predicting the work functions of different metals have a higher computational cost. However, the stabilized Jellium model (SJM) has the potential to predict the work function of transition metals, simple metals, rare-earth metals and inner transition metals. The metallic plasma model (MPM) can predict polycrystalline metals, while the density functional theory (DFT) is a versatile tool for predicting the lowest and highest work function of the material with higher computational cost. The high-throughput density functional theory and machine learning (HTDFTML) tools are suitable for predicting the lowest and highest work functions of extreme material surfaces with cheaper computational cost. The combined Bayesian machine learning and first principle (CBMLFP) is suitable for predicting the lowest and highest work functions of the materials with a very low computational cost. Conclusively, HTDFTML and CBMLFP should be used to explore the work functions and surface energy in complex materials.

The validity and reliability of the functional rating index for evaluating low back pain in athletes.

The purpose of the present study was to determine the reliability and validity of the Functional Rating Index (FRI) for athletes with low back pain (LBP). In this cross-sectional and prospective cohort study, the validated Persian FRI (PFRI) was tested in 100 athletes with LBP and 50 healthy athletes. From the athletes with LBP, data were recollected among 50 athletes with a 7-day interval to examine test-retest reliability. The content validity was excellent, and the athletes with LBP responded to all items with no floor or ceiling effects. The discriminative validity was supported by a statistically significant difference in PFRI total scores between the athletes with LBP and healthy athletes. The concurrent criterion validity was good (rho = 0.72). The construct, convergent validity was good (r = 0.83). The internal consistency reliability estimate was high (Cronbach's α = 0.90). Factor analysis demonstrated a single-factor structure with an explained variance of 52.22%. The test-retest reliability was excellent, indicated by an ICC(agreement) of 0.97, and the agreement observed in the Bland and Altman plot demonstrated no systematic bias. It is concluded that the PFRI has excellent psychometric properties for assessing athletes with LBP.

The relationship between symptoms, clinical tests and nerve conduction study findings in carpal tunnel syndrome.

Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy. The aim of the present study was to determine the relationship between patients reported symptoms and clinical tests with electrodiagnostic findings. Three hundred and nine patients with a mean age of 48.35 +/- 12.26 (range = 19-81 years) participated. Patients were assessed clinically and electrophysiologically. The main outcome measures were CTS related symptoms of pain and paraesthesia, Tinel sign, Phalen's test, distal sensory latency, and distal motor latency. The symptoms of presence of pain and diurnal paraesthesia showed a statistical relationship with the distal sensory latency. No relationship was found between the Tinel sign and either the distal sensory latency or the distal motor latency. Furtheremore, no relationship could be shown between Phalen 60 s, Phalen 45 s and distal sensory and motor latency. The Phalen 30 s had a significant relationship with both sensory and motor distal latency. The findings of this study indicate that both CTS related symptoms of pain, diurnal paraesthesia, and Phalen 30 s are associated with electrodiagnostic tests.

The correlation between Modified Ashworth Scale scores and the new index of alpha motoneurones excitability in post-stroke patients.

The Modified Ashworth Scale (MAS) is currently a widely used clinical scale to evaluate muscle spasticity. However, it lacks reliability and the validity, of the MAS as a clinical measure of muscle spasticity has been challenged. The aim of the present study was to examine the validity of the MAS in patients with wrist flexor spasticity after stroke by using the Hslope/Mslope (Hslp/Mslp) ratio as the new index of alpha motoneuron excitability. Twenty-seven adult patients (14 women and 13 men) with first ever stroke resulting in hemiplegia with a mean (SD, range) age of 57.9 (11.6, 37-75) were included in the study. The main outcome measures were the MAS for the clinical assessment of spasticity, and the Hslp/Mslp for the neurophysiological evaluation. There was not a significant correlation between the MAS scores and Hslp/Mslp ratio (r = 0.38, p > 0.05). The mean of the Hslp/Mslp did not show a hierarchical increase with the MAS scores. The findings indicate that the MAS is not a valid and ordinal level measure of muscle spasticity.

Neurophysiological examination of the Modified Modified Ashworth Scale (MMAS) in patients with wrist flexor spasticity after stroke.

The Modified Modified Ashworth Scale (MMAS) is a clinical test for the measurement of spasticity. The aim of the present study was to examine the validity of the MMAS in patients with wrist flexor spasticity after stroke. 27 adult patients (14 women and 13 men) with first ever stroke resulting in hemiplegia with a mean (SD, range) age of 57.9 (11.6, 37-75) were included in the study. The outcome measures were the MMAS for the clinical assessment of spasticity, the Hslope/Mslope (Hslp/Mslp), and the H(max)/M(max) ratio for the neurophysiological evaluation. The mean of the Hslp/Mslp and the H(max)/M(max) were higher in patients with worse MMAS grades but the differences were not statistically significant. There was a significant positive correlation between the MMAS scores and Hslp/Mslp ratio as the new index of alpha motoneurone excitability or traditional index of H(max)/M(max) ratio (r = 0.39, p = 0.04). It is concluded that the MMAS to be a valid measure of spasticity after stroke.

Therapeutic ultrasound in the treatment of ankle plantarflexor spasticity in a unilateral stroke population: a randomized, single-blind, placebo-controlled trial.

Spasticity is a common and disabling symptom associated with Upper Motor Neuron Syndrome. The current methods of treatment for muscle spasticity have been claimed as unsatisfactory. Therapeutic ultrasound (US) is a common therapeutic modality in physiotherapy used for treating a wide variety of disorders. The aim of present study was to quantify the effects of continuous US on ankle plantarflexor spasticity in a randomized, single-blind, placebo-controlled trial. Twelve stroke patients (6 women and 6 men) randomly allocated to ultrasound (n = 6) or placebo (n = 6) groups. The patients were treated with either US or sham US for three days per week, every other day for 15 treatment sessions. The primary efficacy measures were the H-reflex and the Ashworth Scale (AS). In experimental group there was a significant reduction in the Hmax/Mmax ratio (p = 0.03). The Hmax/Mmax ratio was increased in the placebo group patients (p > 0.05). The difference between two groups was statistically significant (p = 0. 02). In both groups there was a reduction in the posttreatment AS scores. The Ashworth scores demonstrated statistically significant changes in the US group (p = 0.04). There was no statistical difference, however, when these two groups were compared (p > 0.05). Results from the present study show that treatment with US can reduce HmaxlMmax ratio as a measure of alpha motoneuron excitability and spasticity measure of AS in stroke patients with ankle plantarflexor spasticity.

A preliminary study into the criterion validity of the Modified Modified Ashworth Scale using the new measure of the alpha motoneuron excitability in spastic hemiplegia.

The Modified Ashworth Scale (MAS) is the most widely used clinical test for the measurement of muscle spasticity. This scale that suffers from limitations and lack of reliability and validity has recently been remodified. The aim of the present study is to investigate the criterion validity of the new Modified MAS(MMAS) in the upper limb in post-stroke hemiplegia, using the Hslope/Mslope (Hslp/Mslp) as a novel index of alpha motor neuron excitability. Prior to the validity study, the reliability of the MMAS was evaluated in 30 hemiplegic patients. The raters agreed on 23 patients (0. 76%). The MMAS had good inter-rater reliability (K= 0.63, SE = 0.11, p < 0.001) for the assessment of wrist flexors spasticity in hemiplegic patients. 12 adult patients (7 women and 5 men) with first ever stroke resulting in hemiplegia with a mean age of 58.9 +/- 11.9 years (range, 37-73) were included in the validity study. The outcome measures were the MMAS for the clinical assessment of spasticity, and the HslopelMslope and the Hmax/Mmax ratio for the electrophysiological evaluation. The results showed an increase in mean rank of Hslp / Mslp in patients with a score of 1, 2 or 3 on the MMAS. However, the difference among the groups was not significant (p > 0.05). There was also no relationship between the clinical scale of MMAS and either the traditional [Hmax / Mmax ratio (r = -0.06)] or the new index [Hslp / Mslp (r = 0.24)] of spinal excitability. This preliminary study recruited a small number of patients, and failed to confirm a linear correlation between these variables. A study with a large number of patients is suggested to clarify the outcome.

The effect of Bobath approach on the excitability of the spinal alpha motor neurones in stroke patients with muscle spasticity.

A clinical study was performed to evaluate the efficacy of the Bobath approach on the excitability of the spinal alpha motor neurones in patients with poststroke spasticity. Ten subjects ranging in age from 37 through 76 years (average 60 years) with ankle plantarflexor spasticity secondary to a stroke were recruited and completed the trial. They had physiotherapy according to Bobath concept for ten treatment sessions, three days per week. Two repeated measures, one before and another after treatment, were taken to quantify clinical efficacy. The effect of this type of therapy on the excitability of alpha motor neurones (aMN) was assessed by measuring the latency of the Hoffmann reflex (H-reflex) and the Hmax/Mmax ratio. The original Ashworth scale and ankle range of motion were also measured. The mean HmaxlMmax ratio on the affected side at baseline was high in the study patients. However, there were no statistically significant differences in the HmaxlMmax ratio or in the H-reflex latency between the baseline values and those recorded after therapy intervention. Before treatment, the HmaxlMmax ratio was significantly higher in the affected side than in the unaffected side. However, it was similar at both sides after treatment. Following treatment, the significant reduction in spasticity was clinically detected as measured with the original Ashworth scale. The ankle joint active and passive range of motion was significantly increased. In conclusion, Bobath therapy had a statistically significant effect on the excitability of the aMN in the affected side compared to the unaffected side in stroke patients with muscle spasticity.

A randomized, single blind placebo controlled clinical trial on the effect of continuous ultrasound on low back pain.

Low back pain (LBP) is a very common problem in primary care and a major cause of disability. There is no evidence for the efficacy of therapeutic modalities such as ultrasound in LBP In a randomized, single blind placebo controlled clinical trial, we aimed to evaluate the effect of continuous ultrasound (US) in patients with non specific LBP Of the fifty eight patients recruited, 10 patients (8 women and 2 men) randomly allocated to ultrasound (n=5) or placebo controlled (n=5) groups. The patients were treated by either US or sham-US for ten sessions, three days per week, every other day. The outcome measures were Functional Rating Index (FRI), Hmax/Mmax ratio and range of motion (ROM), which were measured at baseline, after 5 treatment sessions and at the end of treatment. To analyze the data, The Mann Whitney U test and Wilcoxon Signed Rank test were used. After treatment, both US and placebo groups showed statistically significant decrease in FRI scores indicating improvement in functional ability (p = 0.042 and p = 0.043, respectively). The mean changes of FRI during the second five treatment sessions and after the end of treatment was significantly better in the US group than in the placebo group (p = 0.016 and p = 0.032, respectively). Before and after treatment, the mean H reflex latency and Hmax/Mmax ratio, right and left side were similar in the groups (p > 0.05), and no significant changes were observed in the treatment groups (p > 0.05). After treatment, the extension and lateral flexion range of motion significantly increased in the US group (p = 0.04), but the back movements in the placebo group did not show significant changes (p > 0.05). The present study supports the significant effect of US on LBP, and suggests that US may improve the functional ability of patients with non specific low back pain.

The effect of physiotherapeutic ultrasound on muscle spasticity in patients with hemiplegia: a pilot study.

BACKGROUND: Spasticity is one part of the upper motor neuron syndrome. Untreated spasticity not only causes loss of motor control that results in functional disability, but can easily lead to joint contractures as well. Physical therapy plays an important role in the management of patients with spasticity. Among the modalities, Therapeutic ultrasound has become an important modality for treatment of various conditions including spasticity. OBJECTIVES: The aim of this study is to determine the effect of ultrasound on spasticity. METHODS: In this before-after study, four adult patients (mean age: 57.5 +/- 14.43) with first ever stroke and resulting in hemiplegia participated in the study. The outcome measures were the Ashworth Scale for the assessment of spasticity, ankle passive and active range of motion, and the Hmax: Mmax ratio. RESULTS: The mean of Ashworth scores, Hmax:Mmax ratio, and passive range of motion in ankle joint improved after treatment with ultrasound, but it was not statistically significant (p > 0.05). CONCLUSIONS: The study did not show a significant decrease in spasticity after ultrasound therapy. A study with a large number of patients and a control group would clarify the effects of ultrasound on spasticity.

An information processing model for schizophrenia.

A disorder of information processing must be present for a person to receive the diagnosis of schizophrenia, and is present when schizophrenic symptoms occur along with other diseases. We created a model for this disorder that resolves some paradoxic findings and suggests directions for future study. Basically, schizophrenics have a deficiency in information processing that can be characterized as conscious, serial, and limited in channel capacity. In contrast, those processes that seem automatic, unconscious, parallel, and almost unlimited in capacity seem to be normal or supernormal.