Effect of electrical muscle stimulation on cerebrovascular function and cognitive performance.

It is known that electrical muscle stimulation (EMS) can enhance physical function, but its impact on cognition and cerebral hemodynamics is not well understood. Thus, the purpose of this study was to investigate the effects of one EMS session on cerebrovascular function and cognitive performance. The 17 recruited young healthy participants undertook a 25-min session of EMS and a resting control session (Ctrl group) in a random order. Cerebral blood flow velocity (CBFv) in the middle and posterior cerebral arteries (right MCAv and left PCAv, respectively), cerebral oxygenation, cardiac output, and heart rate were measured throughout the sessions, whereas cognitive function was assessed before and after each experimental condition. MCAv, cardiac output, heart rate, and cerebral oxygenation were increased throughout the EMS session, whereas PCAv remained unchanged. In addition, EMS led to improved scores at the Rey auditory verbal learning test-part B and congruent Stroop task versus Ctrl. The present study demonstrates that a single session of EMS may improve cognitive performance and concomitantly increase CBFv and cerebral oxygenation. Therefore, EMS appears to be a valuable surrogate for voluntary exercise and could therefore be advantageously used in populations with severe physical limitations who would not be able to perform physical exercise otherwise.NEW & NOTEWORTHY This study is the first to demonstrate that one session of EMS applied to the quadriceps increases cerebral blood flow velocity and cerebral oxygenation, which are pivotal factors for brain health. Thus, EMS has the potential to be used as an interesting option in rehabilitation to increase cerebral perfusion and defend if not improve cognitive function sustainably for people with severe physical limitations who would not be able to perform physical exercise voluntarily.

Catalytic asymmetric Friedel-Crafts alkylation of unprotected indoles with nitroalkenes using a novel chiral Yb(OTf)3-pybox complex.

Chiral chloro-indeno pybox has served as a new ligand for the Yb(OTf)3-catalyzed asymmetric Friedel-Crafts alkylation reaction of indoles with nitroalkenes. The tunable nature of pybox ligands enables the rational design of catalysts for optimal performance in terms of both activity and stereoselectivity in a Friedel-Crafts-type reaction. Good to excellent yields and enantioselectivities were obtained for a relatively wide range of substrates, including sterically hindered compounds, under optimized reaction conditions.

Innovative spiral electrode configuration for enhancement of electrocoagulation-flotation.

The performance of electrocoagulation-flotation (ECF) process can profoundly be affected by the reactor design and electrode configuration. These may, in turn, influence the removal efficiency, flow hydrodynamic, floc formation, and flotation/settling characteristics. The present work aimed at developing a new spiral electrode configuration to enhance the ECF process. To do so, the impacts of parameters such as energy consumption, removal efficiency of the contaminants from industrial wastewater with a composition of turbidity, emulsified oil, and heavy metals (Si, Zn, Pb, Ni, Cu, Cr, and Cd), as well as stirring speed and foaming have been investigated. Comparison was also made between the experimental results of the new electrode configuration with the conventional rectangular cell with plate electrode configuration with the same volume and electrode surface area. The findings revealed that energy consumption of the spiral electrode configuration within the operating times of 10, 20, 30, 32, 48, and 70 min, was approximately 20% lower compared to that of the conventional ECF. Moreover, the maximum and minimum removal efficiency of 97% and 60% were obtained for turbidity and TOC for the stirring speed of 500 rpm and Reynolds number of 10,035, respectively. Finally, the formed gas bubbles tilted toward the center due to the enhanced flow hydrodynamic which resulted in substantial reduction of foam formation.

Suppression of seizure in childhood absence epilepsy using robust control of deep brain stimulation: a simulation study.

Deep brain stimulation (DBS) is a promising technique to relieve the symptoms in patients with intractable seizures. Although the DBS therapy for seizure suppression dates back more than 40 years, determining stimulation parameters is a significant challenge to the success of this technique. One solution to this challenge with application in a real DBS system is to design a closed-loop control system to regulate the stimulation intensity using computational models of epilepsy automatically. The main goal of the current study is to develop a robust control technique based on adaptive fuzzy terminal sliding mode control (AFTSMC) for eliminating the oscillatory spiking behavior in childhood absence epilepsy (CAE) dynamical model consisting of cortical, thalamic relay, and reticular nuclei neurons. To this end, the membrane voltage dynamics of the three coupled neurons are considered as a three-input three-output nonlinear state delay system. A fuzzy logic system is developed to estimate the unknown nonlinear dynamics of the current and delayed states of the model embedded in the control input. Chattering-free control input (continuous DBS pulses) without any singularity problem is the superiority of the proposed control method. To guarantee the bounded stability of the closed-loop system in a finite time, the upper bounds of the external disturbance and minimum estimation errors are updated online with adaptive laws without any offline tuning phase. Simulation results are provided to show the robustness of AFTSMC in the presence of uncertainty and external disturbances.

Optimization of Seating Position and Stimulation Pattern in Functional Electrical Stimulation Cycling: Simulation Study.

Two significant challenges facing functional electrical stimulation (FES) cycling are the low power output and early onset of muscle fatigue, mainly due to the non-physiological and superficial recruitment of motor units and weakness of the antagonistic muscles. Thus optimization of the cycling biomechanical properties and stimulation pattern to achieve maximum output power with minimum applied electrical stimulus is of great importance. To find the optimal seating position and stimulation pattern, the previous works either ignored the muscle's force-velocity and force-length properties or employed complicated muscle models which was a massive barrier to clinical experiments. In this work, an easy-to-use and precise muscle model in conjunction with Jacobian-based torque transfer functions were adopted to determine the optimal seating position, trunk angle, crank arm length, and stimulation intervals. Furthermore, the impact of muscle force-velocity factor in finding the optimal seating position and stimulation intervals was investigated. The simulation models showed the trivial effect of the force-velocity factor on the resulting optimal seating position of six healthy simulated subjects. This method can enhance the FES-cycling performance and shorten the time-consuming process of muscle model identification for optimization purposes.

A Distributed Automatic Control Framework for Simultaneous Control of Torque and Cadence in Functional Electrical Stimulation Cycling.

One of the major challenges facing functional electrical stimulation (FES) cycling is the design of an automatic control system that addresses the problem of disturbance with unknown bound and time-varying behavior of the muscular system. The previous methods for FES-cycling are based on the system modeling and require pre-adjustment of the control parameters which are based on the model parameters. These will degrade the FES-cycling performance and limit the clinical application of the methods. In this paper, a distributed cooperative control framework, which is based on an adaptive higher-order sliding mode (AHOSM) controller, is proposed for simultaneous control of torque and cadence in FES-cycling. The proposed control system is free-model which does not require any pre-adjustment of the control parameters and does not need the boundary of the disturbance to be known. Another major issue in FES-cycling is the stimulation pattern. In the paper, an automatic pattern generator is proposed which is capable of providing not only the regions of the crank angle in which each muscle group should be stimulated but also a specific gain for each muscle group. The results of the simulation studies and experiments on three spinal cord injuries showed that the proposed control strategy significantly increases the efficiency and tracking accuracy of motor-assisted FES-cycling in paraplegic patients and decreases the power consumption compared to HOSM controller with the fixed stimulation pattern. Reducing power consumption can slow down muscle fatigue and consequently increase cycling endurance. The average of cadence and torque tracking errors over three subjects using the proposed method are 5.77± 0.5% and 5.23± 0.8%, respectively.

Effects of diode and erbium lasers as an adjunct to scaling and root planing on clinical and immunological parameters in non-surgical periodontal treatment: a split-mouth randomized controlled clinical trial-"effects of lasers on immunological parameters".

This study evaluated the effects of diode and erbium lasers, as an adjunct to scaling and root planing (SRP), on clinical and immunological parameters in non-surgical periodontal therapy. In this split-mouth randomized controlled clinical trial, 17 participants with at least one periodontally involved tooth in each quadrant received oral hygiene instruction and full-mouth SRP. At baseline, probing pocket depth (PPD), clinical attachment level (CAL), bleeding on probing (BOP), and full-mouth plaque index (FMPI) were measured, and gingival crevicular fluid (GCF) sampling was performed. Next, one random quadrant in each participant received 940 nm diode laser (1 W, continuous-wave), and another quadrant received 2780 nm Er,Cr:YSGG laser (1.5 W, 30 Hz) irradiation. The GCF levels of interleukin (IL)-10 and matrix metalloproteinase (MMP)-13 were measured at baseline, and after 2 and 6 months using ELISA. The clinical parameters were also measured. Data were analyzed by repeated measures ANOVA. Significant clinical improvement was noted in all groups (P < 0.05). CAL in the control group was higher at 6 months than 2 months. The increase in IL-10 in erbium group was significantly greater than that in other groups (P < 0.001). The MMP-13 level was significantly lower in laser groups with greater reduction in erbium group (P < 0.001). Application of 940 nm diode and 2780 nm Er,Cr:YSGG lasers as an adjunct to SRP significantly decreased the GCF level of MMP-13, with no significant clinical advantage over SRP monotherapy. Application of 2780 nm Er,Cr:YSGG laser in addition to SRP increased the GCF level of IL-10.Trial registration numbers: IRCT20140318017053N11 and IRCT20140318017053N9.

In Vitro Effect of Photodynamic Therapy with Indocyanine Green Followed by 660 nm Photobiomodulation Therapy on Fibroblast Viability.

This in vitro study sought to assess the effect of repetitive PBMT on the viability of fibroblasts following aPDT with indocyanine green (ICG). In this in vitro experimental study, human gingival fibroblasts (HGFs) were obtained and incubated in a culture medium. After reaching 10 000 cells cm-2 , the cells were divided into five groups of control, aPDT with ICG and 808 nm (energy density of 24 J cm-2 ), PBMT immediately after aPDT, PBMT with 660 nm (energy density of 7.2 J cm-2 ) immediately and 24 h after aPDT and PBMT immediately and 24 and 48 h after aPDT in 48-well plates. Cell viability was evaluated using the methyl thiazolyl tetrazolium (MTT) assay after 1, 4 and 7 days of incubation. Statistical analyses were performed using one-way ANOVA. Cell viability significantly decreased in group 2 (P < 0.002). We observed no significant increase in cell viability at any time point in group 3 (P > 0.05). Cell viability significantly increased in groups 4 and 5 after the first day of incubation (P < 0.000). Emission of 660 nm as PBMT for two and three times along with passage of time would increase the viability of HGFs following aPDT with ICG.

Effect of two commercial acellular dermal scaffolds on biological behavior of human gingival fibroblasts.

Background: Periodontal regeneration is an essential goal of periodontal therapy. Acellular dermal matrix (ADM) has been recommended as an alternative to autogenous grafts. However, since it is devoid of cells and vasculature, there are concerns regarding the biological behavior of cells on ADM. This study aimed to assess the effects of two commonly used ADMs on biological behavior, i.e., attachment and proliferation, of human gingival fibroblasts (HGFs). Methods: This in vitro, experimental study was conducted on explanted and cultured HGFs. ADM types 1 and 2 (n=26; measuring 10×15 mm) were rinsed with saline solution, adapted to the bottom of 52 wells, exposed to HGFs with a cell density of 16,000 cells/mL, and incubated at 37°C for 12, 24, and 84 hours and seven days. Cell attachment was assessed 12 hours after incubation using 4>,6-diamidino-2-phenylindole (DAPI) and methyl-thiazol-diphenyl-tetrazolium (MTT) assay under a fluorescence microscope. Cell viability was assessed at 24 and 84 hours and one week using the MTT assay. Cells were then platinum-coated, and their morphology was evaluated under a scanning electron microscope (SEM). Data were analyzed using ANOVA. Results: HGFs were evaluated in 60 samples in three groups (n=20). Cell attachment was the same in the three groups, as shown by the MTT assay and DAPI test (P=0.6). Cell viability at one week was 3.73±0.02, 2.88±0.29, and 2.13±0.24 in the control, ADM 1, and ADM 2 groups, respectively. The difference was statistically significant (P=0.01). Conclusion: Both scaffolds were the same in terms of attachment of HGFs. However, ADM 1 was superior to ADM2 in terms of cell viability and morphology at one week. It was concluded that the quality of acellular dermal scaffolds could significantly influence cellular behaviors and tissue maturation.

Organocatalytic Oxa-Michael/Michael/Michael/Aldol Condensation Quadruple Domino Sequence: Asymmetric Synthesis of Tricyclic Chromanes.

An efficient and highly stereoselective one-pot, four-component synthesis of functionalized tricyclic chromanes has been achieved through an organocatalyzed quadruple domino reaction. The reaction sequence involves an oxa-Michael/Michael/Michael/aldol condensation between alcohols, 2 equiv of acrolein, and nitrochromenes to generate the pharmaceutically important tricyclic chromanes bearing three contiguous stereogenic centers including a chiral tetrasubstituted carbon center in good domino yields (30-70%) and excellent diastereo- and enantioselectivities (>20:1 dr and >99% ee).

N-Heterocyclic carbene-catalyzed [4+2] annulation of ß-methyl enals and cyclic trifluoromethyl ketimines for the asymmetric synthesis of dihydroquinazolinone derivatives.

The enantioselective oxidative N-heterocyclic carbene-catalyzed [4+2] annulation reaction of ß-methyl enals and cyclic trifluoromethyl ketimines has been developed. A series of biologically interesting dihydroquinazolinone derivatives bearing a trifluoromethyl group and a tetrasubstituted stereocenter are efficiently prepared with very good yields and excellent stereoselectivities.

N-Heterocyclic Carbene Catalyzed [3+2] Cycloaddition of Enals with Masked Cinnamates for the Asymmetric One-Pot Synthesis of Adipic Acid Derivatives.

A novel short entry to 3,4-disubstituted adipic acids has been developed by employing an asymmetric NHC-catalyzed [3+2] cycloaddition of enals with masked cinnammates in moderate to good yields and high stereoselectivities. The synthetic utility of the protocol was demonstrated by the basic conversion of the masked cyclopentanone intermediates to 3S,4S-disubstituted adipic acid precursors of pharmaceutically important gababutins.

N-Heterocyclic Carbene Catalyzed [4+2] Annulation of Enals via a Double Vinylogous Michael Addition: Asymmetric Synthesis of 3,5-Diaryl Cyclohexenones.

A strategy for the N-heterocyclic carbene (NHC) catalyzed asymmetric synthesis of 3,5-diaryl substituted cyclohexenones has been developed via oxidative [4+2] annulation of enals and alkenylisoxazoles. It is the first example of using NHC organocatalysis in a double vinylogous Michael type reaction, a challenging but highly desirable topic. This unprecedented protocol affords good yields as well as high to excellent diastereo- and enantioselectivities.

Organocatalytic Asymmetric Synthesis of Dihydroisoquinolinones via a One-Pot Aza-Henry-Hemiaminalization-Oxidation Sequence.

The asymmetric organocatalytic one-pot synthesis of trans-3,4-disubstituted 3,4-dihydroisoquinolin-1(2H)-ones is described. Starting from 2-(nitromethyl)benzaldehydes and various N-protected aldimines, 5 mol% of a quinine-based squaramide organocatalyst was used to synthesize the title compounds as virtually single diastereomers via an aza-Henry-hemiaminalization-oxidation sequence. Moderate to good yields (39-78%) and moderate to very good enantioselectivities (40-95% ee) were reached.

Highly efficient catalytic enantioselective Mannich reaction of malonates with N-tert-butoxycarbonyl imines by using Yb(OTf)3/pybox catalysts at room temperature.

Go Mannich! A highly efficient and enantioselective method for the direct asymmetric reaction of dibenzyl malonate with N-tert-butoxycarbonyl aldimines in the presence of Yb(OTf)3 and iPr-pybox complexes is described (see scheme; pybox = pyridine bisoxazoline).