Three Hertz postural leg tremor impairs posture maintenance in multiple system atrophy-cerebellar type.

BACKGROUND: Three-Hz postural leg tremor has recently been identified as highly prevalent in patients with the cerebellar type of multiple system atrophy, but its impact on posture maintenance remains poorly understood. PATIENTS AND METHODS: Thirty-seven patients with spinocerebellar ataxia and 58 others with cerebellar type of multiple system atrophy were given Synapsys posturography examinations. Fifty-three healthy controls were also tested. Low, medium, and high-frequency sway were recorded to compute energy values. Frequency shift and postural strategy predominance were evaluated from the postural sway distributions, mainly from the proportions of higher frequency values among the total values. The trajectories of postural sway components were evaluated with the generalized additive mixed model. Distributions of the components and their relationships with falls and tremors were assessed through repeated measures correlation analysis. RESULTS: As the test difficulty increased, the standard controls showed slight increases in the energy values at every frequency. Distributions of the higher frequency (>0.5 Hz) values increased escalatingly with test difficulty, illustrating frequency shifts and hip strategy predominance. Medium and high-frequency values were strongly and positively inter-correlated in normal stances, but this was not observed among the spinocerebellar ataxia or multiple system atrophy patients. Unlike normal stances, the proportion of medium frequency values was negatively related to the total value among the spinocerebellar ataxia and multiple system atrophy patients, implying a failure of frequency shift in response to perturbation. Medium frequency proportions were also inversely correlated with tremors among the multiple system atrophy patients. CONCLUSIONS: The observed synchronized changes in medium and high-frequency postural sway indicate that they constitute a complete hip strategy for posture control. The strategy was rigid in those with spinocerebellar ataxia but completely disrupted in those with multiple system atrophy. Three Hertz postural leg tremors destabilize the ankle joints and interfere with postural adjustment among those with multiple system atrophy.

Biotransformation of cyproterone acetate, drospirenone, and megestrol acetate in agricultural soils: Kinetics, microbial community dynamics, transformation products, and mechanisms.

The occurrence of biologically active synthetic progestins in agricultural soils is of growing concern due to their potential to disrupt the endocrine function of aquatic fish in nearby surface waters. This study investigated the biotransformation outcomes of cyproterone acetate (CPA), drospirenone (DRO), and megestrol acetate (MGA) in four agricultural soils. The biotransformation data were fitted to a first-order decay model (R2 = 0.93-0.99), with half-lives and first-order decay coefficients ranging from 76.2-217 h and 9.10 × 10-3-3.20 × 10-3 (h-1), respectively. Abundant biotransformation products (TPs) were generated during incubation, with the number and yields varying across the four soils. 1,2-Dehydrogenation was the main transformation pathway of DRO in the four soils (yields of 32.3-214 %). Similarly, 1,2-dehydrogenation was the most relevant transformation pathway of MGA in the four soils (yields of 21.8-417 %). C3 reduction was the major transformation pathway of CPA in soils B, C, and D (yields of 114-245 %). Hydrogenation (yield of 133 %) and hydroxylation (yield of 21.0 %) were the second major transformation pathway of CPA in soil B and C, respectively. In particular, several TPs exhibited progestogenic and antimineralocorticoid activity, as well as genotoxicity. The high-throughput sequencing indicated that interactions between microorganisms and soil properties may affect biotransformation. Spearman correlation and bidirectional network correlation analysis further revealed that soil properties can directly interfere with the soil sorption capacity for the progestins, thus affecting biotransformation. In particular, soil properties can also limit or promote biotransformation and the formation of TPs (i.e., biotransformation pathways) by affecting the relative abundances of relevant microorganisms. The results of this study indicate that the ecotoxicity of synthetic progestins and related TPs can vary across soils and that the assessment of environmental risks associated with these compounds requires special consideration of both soil properties and microbial communities.

Synergistic benefits of lime and 3,4-dimethylpyrazole phosphate application to mitigate the nitrous oxide emissions from acidic soils.

Acidic soils cover approximately 50 % of the arable land with high N2O emission potential. 3,4-dimethylpyrazole phosphate (DMPP) inhibits N2O emission from soils; however, its efficiency is affected by acidity. Liming is used for soil conditioning to ameliorate the effects of acidity. In the present study, we investigated the effects of liming on the efficiency of DMPP in inhibiting N2O emission in acidic soils and the mechanisms involved. We evaluated the impact of liming, DMPP, and combined application and its microbial responses in two acidic soils from Zengcheng (ZC) and Shaoguan (SG) City, Guangdong Province, China. Soils were subjected to four treatments: un-limed soil (low soil pH) + urea (LU), un-limed soil + urea + DMPP (LD), limed soil (high soil pH) + urea (HU), and limed soil + urea + DMPP (HD) for analyses of the mineral N, N2O emissions, and full-length 16S and metagenome sequencing. The results revealed that, HU significantly decreased and increased the N2O emission by 17.8 % and 235.0 % in ZC and SG, respectively, compared with LU. This was caused by a trade-off between N2O production and consumption after liming, where microbial communities and N-cycling functional genes show various compositions in different acidic soils. LD reduced N2O emission by 23.5 % in ZC, whereas decreased 1.5 % was observed in SG. Interestingly, DMPP efficiency considerably improved after liming in two acidic soils. Compared with LU, HD significantly reduced N2O emissions by 61.2 % and 48.5 % in ZC and SG, respectively. Synergy of mitigation efficiency was observed by lime and DMPP application, which was attributed to the changes in the dominant nitrifiers and the increase in N2O consumption by denitrifiers. The combined application of lime and DMPP is a high-efficiency strategy for N2O mitigation can ensure agricultural sustainability in acidic arable soils with minimal environmental damage.

Metagenomic analysis insights into the influence of 3,4-dimethylpyrazole phosphate application on nitrous oxide mitigation efficiency across different climate zones in Eastern China.

Excessive nitrogen (N) fertilization in agroecological systems increases nitrous oxide (N2O) emissions. 3,4-dimethylpyrazole phosphate (DMPP) is used to mitigate N2O losses. The influence of DMPP efficiency on N2O mitigation was clearly affected by spatiotemporal heterogeneity. Using field and incubation experiments combined with metagenomic sequencing, we aimed to investigate DMPP efficiency and the underlying microbial mechanisms in dark-brown (Siping, SP), fluvo-aquic (Cangzhou, CZ; Xinxiang, XX), and red soil (Wenzhou, WZ) from diverse climatic zones. In the field experiments, the DMPP efficiency in N2O mitigation ranged from 51.6% to 89.9%, in the order of XX, CZ, SP, and WZ. The DMPP efficiency in the incubation experiments ranged from 58.3% to 93.9%, and the order of efficiency from the highest to lowest was the same as that of the field experiments. Soil organic matter, total N, pH, texture, and taxonomic and functional α-diversity were important soil environment and microbial factors for DMPP efficiency. DMPP significantly enriched ammonia-oxidizing archaea (AOA) and nitrite-oxidizing bacteria (NOB), which promoted N-cycling with low N2O emissions. Random forest (RF) and regression analyses found that an AOA (Nitrosocosmicus) and NOB (Nitrospina) demonstrated important and positive correlation with DMPP efficiency. Moreover, genes associated with carbohydrate metabolism were important for DMPP efficiency and could influenced N-cycling and DMPP metabolism. The similar DMPP efficiency indicated that the variation in DMPP efficiency was significantly due to soil physicochemical and microbial variations. In conclusion, filling the knowledge gap regarding the response of DMPP efficiency to abiotic and biotic factors could be beneficial in DMPP applications, and in adapting more efficient strategies to improve DMPP efficiency and mitigate N2O emissions in multiple regions.

Organic amendments alter microbiota assembly to stimulate soil metabolism for improving soil quality in wheat-maize rotation system.

Straw retention (SR) and organic fertilizer (OF) application contribute to improve soil quality, but it is unclear how the soil microbial assemblage under organic amendments mediate soil biochemical metabolism pathways to perform it. This study collected soil samples from wheat field under different application of fertilizer (chemical fertilizer, as control; SR, and OF) in North China Plain, and systematically investigated the interlinkages among microbe assemblages, metabolites, and physicochemical properties. Results showed that the soil organic carbon (SOC) and permanganate oxidizable organic carbon (LOC) in soil samples followed the trend as OF > SR > control, and the activity of C-acquiring enzymes presented significantly positive correlation with SOC and LOC. In organic amendments, bacteria and fungi community were respectively dominated by deterministic and stochastic processes, while OF exerted more selective pressure on soil microbe. Compared with SR, OF had greater potential to boost the microbial community robustness through increasing the natural connectivity and stimulating fungal taxa activities in inter-kingdom microbial networks. Altogether 67 soil metabolites were significantly affected by organic amendments, most of them belonged to benzenoids (Ben), lipids and lipid-like molecules (LL), and organic acids and derivatives (OA). These metabolites were mainly derived from lipid and amino acid metabolism pathways. A list of keystone genera such as stachybotrys and phytohabitans were identified as important to soil metabolites, SOC, and C-acquiring enzyme activity. Structural equation modeling showed that soil quality properties were closely associated with LL, OA, and PP drove by microbial community assembly and keystone genera. Overall, these findings suggested that straw and organic fertilizer might drive keystone genera dominated by determinism to mediate soil lipid and amino acid metabolism for improving soil quality, which provided new insights into understanding the microbial-mediated biological process in amending soil quality.

Biotransformation kinetics and pathways of typical synthetic progestins in soil microcosms.

Gestodene (GES), altrenogest (ALT), and medroxyprogesterone acetate (MPA) are three potent synthetic progestins detected in agricultural soils; however, their biotransformation outcomes in soils remain unclear. This study explored the biotransformation of these progestins in five agricultural soils with different physicochemical properties. The biotransformation data were well-described by a first-order decay model (R2 = 0.83-0.99), with estimated half-lives ranging between 12.1 and 188 h. Amplicon sequencing indicated that the presence of progestins changed the bacterial richness and community structure in the soils. Linear correlation, canonical correlation, and two-way correlation network analysis revealed that soil properties can affect biotransformation rates by interfering with progestin-soil interactions or with keystone taxa in soils. The clustermap demonstrated the formation of abundant transformation products (TPs). Isomerization and C4(5) hydrogenation were the major transformation pathways for GES (yields of ∼ 13.7 % and ∼ 10.6 %, respectively). Aromatic dehydrogenation was the major transformation pathway for ALT (yield of ∼ 17.4 %). The C17 hydrolysis with subsequent dehydration and hydrogenation was the major transformation pathway for MPA (yield of ∼ 196 %). In particular, some TPs exhibited progestagenic, androgenic, or estrogenic activity. This study highlights the importance of evaluating the ecotoxicity of progestin and TP mixtures for better understanding their risks in the environment.

Changes in hip joint contact stress during a gait cycle based on the individualized modeling method of "gait-musculoskeletal system-finite element".

OBJECTIVE: To construct a comprehensive simulation method of "gait-musculoskeletal system (MS)-finite element (FE)" for analysis of hip joint dynamics characteristics and the changes in the contact stress in the hip throughout a gait cycle. METHODS: Two healthy volunteers (male and female) were recruited. The 3D gait trajectories during normal walking and the CT images including the hip and femur of the volunteers were obtained. CT imaging data in the DICOM format were extracted for subjected 3D hip joint reconstruction. The reconstructed 3D model files were used to realize the subject-specific registration of the pelvis and thigh segment of general musculoskeletal model. The captured marker trajectory data were used to drive subject-specific musculoskeletal model to complete inverse dynamic analysis. Results of inverse dynamic analysis were exported and applied as boundary and load settings of the hip joint finite element in ABAQUS. Finally, the finite element analysis (FEA) was performed to analyze contact stress of hip joint during a gait cycle of left foot. RESULTS: In the inverse dynamic analysis, the dynamic changes of the main hip-femoral muscle force with respect to each phase of a single gait cycle were plotted. The hip joint reaction force reached a maximum value of 2.9%BW (body weight) and appeared at the end of the terminal stance phase. Twin peaks appeared at the initial contact phase and the end of the terminal stance phase, respectively. FEA showed the temporal changes in contact stress in the acetabulum. In the visual stress cloud chart, the acetabular contact stress was mainly distributed in the dome of the acetabulum and in the anterolateral area at the top of the femoral head during a single gait cycle. The acetabular contact area was between 293.8 and 998.4 mm2, and the maximum contact area appear at the mid-stance phase or the loading response phase of gait. The maximum contact stress of the acetabulum reached 6.91 MPa for the model 1 and 6.92 MPa for the model 2 at the terminal stance phase. CONCLUSIONS: The "Gait-MS-FE" technology is integrated to construct a comprehensive simulation framework. Based on human gait trajectories and their CT images, individualized simulation modeling can be achieved. Subject-specific gait in combination with an inverse dynamic analysis of the MS provides pre-processing parameters for FE simulation for more accurate biomechanical analysis of hip joint.

Fertilizer stabilizers reduce nitrous oxide emissions from agricultural soil by targeting microbial nitrogen transformations.

Nitrous oxide (N2O) is a pollutant released from agriculture soils following N fertilizer application. N stabilizers, such as N-(n-butyl) thiophosphoric triamide (NBPT) and 3,4-dimethylpyrazole phosphate (DMPP) could mitigate these N2O emissions when applied with fertilizer. Here, field experiments were conducted to investigate the microbial mechanisms by which NBPT and DMPP mitigate N2O emissions following urea application. We determined dynamic N2O emissions and inorganic N concentrations for two wheat seasons and combined this with metagenomic sequencing. Application of NBPT, DMPP, and both NBPT and DMPP together with urea decreased mean N2O accumulative emissions by 77.8, 91.4 and 90.7%, respectively, compared with urea application alone, mainly via repressing the increase in NO2- concentration after N fertilization. Sequencing results indicated that urea application enriched microorganisms that were positively correlated with N2O production, whereas N stabilizers enriched microorganisms that were negatively correlated with N2O production. Furthermore, compared to urea application alone, NBPT with urea reduced the abundances of genes related to denitrification, including napA/nasA, nirS/nirK, and norBC, resulting in a higher soil NO3- pool. Conversely, DMPP application, either alone or together with NBPT, decreased the abundance of genes involved in ammonia oxidation and denitrification, including amoCAB, hao, napA/nasA, nirS/nirK, and norBC, and maintained a greater soil NH4+ pool. Both N stabilizers resulted in similar abundances of nirABD-which is related to NO2- reducers-as when no N fertilizer was applied, which could prevent NO2- accumulation, consequently mitigating N2O emissions. These findings suggest that the high effectiveness of N stabilizers on mitigating N2O emissions could be attributed to changes to soil microbial communities and N-cycling functional genes to control the by-product or intermediate products of microbial N-cycling processes in agricultural soils.

Effect of opposing needling on motor cortex excitability in healthy participants and in patients with post-stroke hemiplegia: study protocol for a single-blind, randomised controlled trial.

BACKGROUND: Opposing needling has an obvious curative effect in the treatment of post-stroke hemiplegia; however, the mechanism of the opposing needling in the treatment of post-stroke hemiplegia is still not clear. The purpose of this study is to investigate the effect of opposing needling on the excitability of primary motor cortex (M1) of healthy participants and patients with post-stroke hemiplegia, which may provide insight into the mechanisms of opposing needling in treating post-stroke hemiplegia. METHODS: This will be a single-blind, randomised, sham-controlled trial in which 80 healthy participants and 40 patients with post-stroke hemiplegia will be recruited. Healthy participants will be randomised 1:1:1:1 to the 2-Hz, 50-Hz, 100-Hz, and sham electroacupuncture groups. Patients with post-stroke hemiplegia will be randomised 1:1 to the opposing needling or conventional treatment groups. The M1 will be located in all groups by using neuroimaging-based navigation. The stimulator coil of transcranial magnetic stimulation (TMS) will be moved over the left and right M1 in order to identify the TMS hotspot, followed by a recording of resting motor thresholds (RMTs) and motor-evoked potentials (MEPs) of the thenar muscles induced by TMS before and after the intervention. The primary outcome measure will be the percent change in the RMTs of the thenar muscles at baseline and after the intervention. The secondary outcome measures will be the amplitude (µV) and latency (ms) of the MEPs of the thenar muscles at baseline and after the intervention. DISCUSSION: The aim of this trial is to explore the effect of opposing needling on the excitability of M1 of healthy participants and patients with post-stroke hemiplegia. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR1900028138 . Registered on 13 December 2019.

Ethephon Reduces Maize Nitrogen Uptake but Improves Nitrogen Utilization in Zea mays L.

Increasing use of plant density or/and nitrogen (N) application has been introduced to maize production in the past few decades. However, excessive planting density or/and use of fertilizer may cause reduced N use efficiency (NUE) and increased lodging risks. Ethephon application improves maize lodging resistance and has been an essential measure in maize intensive production systems associated with high plant density and N input in China. Limited information is available about the effect of ethephon on maize N use and the response to plant density under different N rates in the field. A three-year field study was conducted with two ethephon applications (0 and 90 g ha-1), four N application rates (0, 75, 150, and 225 kg N ha-1), and two plant densities (6.75 plants m-2 and 7.5 plants m-2) to evaluate the effects of ethephon on maize NUE indices (N agronomic efficiency, NAE; N recovery efficiency, NRE; N uptake efficiency, NUpE; N utilization efficiency, NUtE; partial factor productivity of N, PFPN), biomass, N concentration, grain yield and N uptake, and translocation properties. The results suggest that the application of ethephon decreased the grain yield by 1.83-5.74% due to the decrease of grain numbers and grain weight during the three experimental seasons. Meanwhile, lower biomass, NO 3 - and NH 4 + fluxes in xylem bleeding sap, and total N uptake were observed under ethephon treatments. These resulted in lower NAE and NUpE under the ethephon treatment at a corresponding N application rate and plant density. The ethephon treatment had no significant effects on the N concentration in grains, and it decreased the N concentration in stover at the harvesting stage, while increasing the plant N concentration at the silking stage. Consequently, post-silking N remobilization was significantly increased by 14.10-32.64% under the ethephon treatment during the experimental periods. Meanwhile, NUtE significantly increased by ethephon.

3-Hz Postural Tremor in MSA-C and SCA: Revisiting an Old but Underestimated Cerebellar Sign by Posturography.

The aim of this study is to evaluate the prevalence and electrophysiological features of 3-Hz postural tremor in multiple system atrophy-cerebellar type and spinocerebellar ataxia. A static posturography examination was administered to 37 persons with spinocerebellar ataxia, 58 others with the cerebellar type of multiple system atrophy, and 53 healthy controls. During the sensory organization tests of 5 multiple system atrophy patients, surface electromyograms were recorded from bilateral tibialis anterior and medial gastrocnemius muscles. The patients with multiple system atrophy had, on average, significantly higher scores on the International Cooperative Ataxia Rating Scale and significantly greater prevalence of cross sign. Almost 80% of them fell during the posturography testing compared with two-thirds of the spinocerebellar ataxia patients. Twenty-seven percent of the spinocerebellar ataxia patients and 82.8% of those with multiple system atrophy displayed postural tremor with a frequency of approximately 3 Hz. The tremor's frequency tended to be lower in the spinocerebellar ataxia patients. The surface electromyography revealed highly coherent tremor activity at about 3 Hz in the patients' bilateral tibialis anterior and alternating firing in the bilateral antagonist muscles. Combining cross sign with a subject's static score of the International Cooperative Ataxia Rating Scale and occurrence of the tremor produced an indicator able to differentiate the two conditions with a sensitivity of 87.9% and a specificity of 89.2%. The area under the receiver operating characteristics curve for the indicator was 0.942. Three-hertz postural tremor is relatively characteristic of cerebellar type of multiple system atrophy and appears at an early stage of the disease. Identification of the tremor by posturography will facilitate its diagnosis.

[Effect of Fu's subcutaneous needling on thickness and elasticity of affected muscles in shoulder neck pain based on ultrasonic elastography].

OBJECTIVE: To observe the effect of Fu's subcutaneous needling on thickness and elasticity of affected muscles in subjects with shoulder neck pain by ultrasonic elastography. METHODS: A total of 30 subjects with upper trapezius pain and local tenderness, or stiffness and funicular nodules were observed randomly, right shoulders were as observation group and left shoulders were as control group. Simple resistance training was adopted in the control group. At the same time of the resistance training, sweeping technique of Fu's subcutaneous needling was adopted at the local tenderness or the stiffness and funicular nodules of upper trapezius in the observation group. The treatment was given once in both groups. Before and immediately after treatment, thickness and elasticity of bilateral upper trapezius and supraspinatus were observed by ultrasonic elastography, and the variations of visual analogue scale (VAS) score were observed in the two groups. RESULTS: Compared before treatment, the elasticity of upper trapezius and supraspinatus were decreased after treatment in both groups (P<0.05), and those in the observation group were lower than the control group (P<0.05). Compared before treatment, the VAS scores after treatment were decreased in both groups (P<0.05), and that in the observation group was lower than the control group (P<0.05). CONCLUSION: Fu's subcutaneous needling can increase the elasticity and release the muscular tension of affected muscles, and relieve pain in subjects with shoulder neck pain.

Top-Down Inhibitory Mechanisms Underlying Auditory-Motor Integration for Voice Control: Evidence by TMS.

The dorsolateral prefrontal cortex (DLPFC) has been implicated in auditory-motor integration for accurate control of vocal production, but its precise role in this feedback-based process remains largely unknown. To this end, the present event-related potential study applied a transcranial magnetic stimulation (TMS) protocol, continuous theta-burst stimulation (c-TBS), to disrupt cortical activity in the left DLPFC as young adults vocalized vowel sounds while hearing their voice unexpectedly shifted upwards in pitch. The results showed that, as compared to the sham condition, c-TBS over left DLPFC led to significantly larger vocal compensations for pitch perturbations that were accompanied by significantly smaller cortical P2 responses. Source localization analyses revealed that this brain activity pattern was the result of reduced activation in the left superior frontal gyrus and right inferior parietal lobule (supramarginal gyrus). These findings demonstrate c-TBS-induced modulatory effects of DLPFC on the neurobehavioral processing of vocal pitch regulation, suggesting that disrupting prefrontal function may impair top-down inhibitory control mechanisms that prevent speech production from being excessively influenced by auditory feedback, resulting in enhanced vocal compensations for feedback perturbations. This is the first study that provides direct evidence for a causal role of the left DLPFC in auditory feedback control of vocal production.