Ghrelin causes interdigestive contractions of the stom- ach in rats. However, it remains unknown whether ghrelin causes interdigestive contractions in the small intestine. Four strain gauge transducers were implanted ...Ghrelin causes interdigestive contractions of the stom- ach in rats. However, it remains unknown whether ghrelin causes interdigestive contractions in the small intestine. Four strain gauge transducers were implanted on the antrum, duodenum, proximal and distal jejunum. After an overnight fast, gastrointestinal （GI） contrac- tions were recorded in freely moving conscious rats. Spontaneous phase m-like contractions were observed at every 13-16 min in rat GI tract. The fasted motor patterns were replaced by the fed motor pattern imme- diately after food intake. Two minutes after finishing the spontaneous phase Ill-like contractions in the antrum, acyl ghrelin （0.8, 2.4 and 8.0 μg/kg per min） was con- tinuously infused for 30 min. Three-five minutes after the starting ghrelin infusion, augmented phase Ⅲ-like contractions were observed at the antrum, duodenum, and jejunum. Ghrelin infusion （0.8, 2.4 and 8.0μg/kg per min） significantly increased motility index of phase Ⅲ-like contractions at the antrum and jejunum in a dose dependent manner, compared to that of saline in- jection. Thus, it is likely that exogenously administered ghrelin causes phase Ⅲ-like contraction at the antrum, which migrates to the duodenum and jejunum. The possible role of 5-HT, in addition to ghrelin, in mediating intestinal migrating motor complex （MMC）, is discussed.展开更多
Recent studies have shown that premature ventricular contractions （PVCs） could enlarge the heart, but its risk factors are incompletely understood as a single 24-hour recording cannot reflect the true PVC burden due...Recent studies have shown that premature ventricular contractions （PVCs） could enlarge the heart, but its risk factors are incompletely understood as a single 24-hour recording cannot reflect the true PVC burden due to day-to-day variability. Our purpose was to investigate the effect of burden and origin sites on left ventricular （LV） function in patients with PVCs by 7-day Holter electrocardiography （ECG）. From May 2012 to August 2013, 112 consecutive patients with PVCs were recruited from the authors＇ affiliated hospital. All patients received 2-dimensional transthoracic echocardiography, 12-lead routing ECG and 7-days Holter ECG. Serum N-terminal pro- brain natriuretic peptide （NT-proBNP） levels were measured. A total of 102 participants with PVCs were included in the final analysis. Origin of PVCs from the tricuspid annulus had the highest burden and NT-proBNP level. LV papillary muscle had a higher LV ejection fraction （EF） level and a lower LV end-systolic dimension （ESD） than other PVC foci （P〈0.05）. The high burden group had a higher LV end-diastolic dimension （EDD） and LVESD but lower LVEF than the other two groups （P〈0.05）. Female, older age, physical work, and history of PVCs had a significantly positive correlation with symptoms. Male, older age, physical work, and high burden were positive predictors of enlarged LVEDD, LVESD and higher serum NT-proBNP level, but lower LVEF. Seven-day dynamic ECG Holter monitor showed the true PVC burden on patients with PVCs. PVCs with a lower burden or origin from the LV papillary muscle and the fascicle were relatively benign, while PVCs with a higher burden or origin from the tricuspid annulus may lead to cardiac dysfunction.展开更多
AIM: To investigate the presence or absence of high amplitude propagating contractions (HAPC), as well as the other measures of colonic motility, in persons with spinal cord injury (SCI). METHODS: Prolonged colonic am...AIM: To investigate the presence or absence of high amplitude propagating contractions (HAPC), as well as the other measures of colonic motility, in persons with spinal cord injury (SCI). METHODS: Prolonged colonic ambulatory manometric studies were performed on 14 male volunteers: 8 with SCI (mean age, 59 ± 13 years; mean duration of injury, 13 ± 4 years) and 6 healthy able-bodied controls (mean age, 57 ± 10 years). A solid-state manometry catheter was endoscopically clipped to the splenic flexure. Recording was performed for > 24 h after manometric catheter placement. RESULTS: HAPC were absent in individuals with SCI during pre-sleep, sleep, and post-sleep phases. HAPC were significantly increased after awakening in non-SCI controls (0.8 ± 0.2 HAPC/h vs 10.5 ± 2.0 HAPC/h, P < 0.005). The motility index was lower in those with SCI than in controls preand post-sleep (SCI vs non-SCI: Pre-sleep, 2.4 ± 0.4 vs 8.8 ± 1.9, P < 0.01; Post-sleep, 4.3 ± 0.8 vs 16.5 ± 4.5, P < 0.05). However, a sleepinduced depression of colonic motility was observed in both the SCI and non-SCI groups (Pre-sleep vs Sleep, non-SCI: 8.8 ± 1.9 vs 2.1 ± 0.9, P < 0.002; SCI: 2.4 ± 0.4 vs 0.2 ± 0.03, P < 0.001), with the motility index of those with SCI during sleep not significantly different than that of the controls. CONCLUSION: HAPC were not observed in individuals with SCI preor post-sleep. A sleep-induced depression in general colonic motility was evident in SCI and control subjects.展开更多
Background:The steady-state increase in muscle force generating potential following a lengthening contraction is called residual force enhancement(RFE).In this study,we aimed to test for differences in torque,electrom...Background:The steady-state increase in muscle force generating potential following a lengthening contraction is called residual force enhancement(RFE).In this study,we aimed to test for differences in torque,electromyographic activity(EMG),and the associated neuromuscular efficiency(NME)between isometric voluntary contractions of elbow flexors preceded and not preceded by a lengthening contraction.The dependence of such differences on(i)stretch amplitude,(ii)the region of the force-length(FxL)relationship where contraction occurs,and(iii)the individual's ability to produce(negative)work during the stretch was investigated.Methods:Sixteen healthy adults participated in the study.Elbow flexor torque,angle,and biceps brachii EMG for purely isometric contractions(reference contractions)and for isometric contractions preceded by active stretches of 20°and 40°were measured at the ascending,plateau,and descending regions of subject-specific FxL curves.All contractions were performed in an isokinetic dynamometer.Two-factor(stretch×FxL region)repeated measures analysis of variance ANOVAs was used to analyze the effect of active stretch on EMG,torque,and NME across conditions.The relationships between mechanical work during stretch-calculated as the torque-angular displacement integral-and the changes in EMG,torque,and NME were analyzed using Pearson correlation.Results:In general,torque,EMG,and NME following active stretches differed from the values observed for the purely isometric reference contractions.While although the detailed effects of active stretch on torque and EMG differed between regions of the FxL relationship,NME increased by about 19%for all muscle lengths.Up to 30%of the interindividual variability in torque generating potential change in response to active stretching was accounted for by differences in(negative)work capacity between subjects.Conclusion:Our results suggest that(i)RFE contributes to"flatten"the elbow flexor torque-angle relationship,favoring torque production at lengths where the purely isometric torques are reduced substantially,and(ii)RFE contributes to a reduction in energy cost of torque production during isometric contractions for the entire operating range.展开更多
In 2011, Berinde and Borcut [6] introduced the notion of tripled fixed point in partially ordered metric spaces. In our paper, we give some new tripled fixed point theorems by using a generalization of Meir-Keeler con...In 2011, Berinde and Borcut [6] introduced the notion of tripled fixed point in partially ordered metric spaces. In our paper, we give some new tripled fixed point theorems by using a generalization of Meir-Keeler contraction：展开更多
Contractions of the Lie algebras d = u(2), f = u(1 ,1) to the oscillator Lie algebra l are realized via the adjoint action of SU(2,2) when d, l, f are viewed as subalgebras of su(2,2). Here D, L, F are the correspondi...Contractions of the Lie algebras d = u(2), f = u(1 ,1) to the oscillator Lie algebra l are realized via the adjoint action of SU(2,2) when d, l, f are viewed as subalgebras of su(2,2). Here D, L, F are the corresponding (four-dimensional) real Lie groups endowed with bi-invariant metrics of Lorentzian signature. Similar contractions of (seven-dimensional) isometry Lie algebras iso(D), iso(F) to iso(L) are determined. The group SU(2,2) acts on each of the D, L, F by conformal transformation which is a core feature of the DLF-theory. Also, d and f are contracted to T, S-abelian subalgebras, generating parallel translations, T, and proper conformal transformations, S (from the decomposition of su(2,2) as a graded algebra T + Ω + S, where Ω is the extended Lorentz Lie algebra of dimension 7).展开更多
[Objectives]To explore the efficacy of Danshen Injection combined with phosphocreatine disodium in treating frequent premature contractions during pregnancy and its effect on maternal and infant outcomes.[Methods]A to...[Objectives]To explore the efficacy of Danshen Injection combined with phosphocreatine disodium in treating frequent premature contractions during pregnancy and its effect on maternal and infant outcomes.[Methods]A total of 200 pregnant women with normal pregnancy and frequent premature contractions who were treated in the outpatient department of internal medicine in Women and Children's Hospital of Hubei Province and Xinzhou District People's Hospital of Wuhan Central Hospital during September 2015 and October 2018 were selected and randomly divided into the control group and observation group,100 cases for each group.The observation group was treated with Danshen Injection combined with phosphocreatine disodium,and the control group was treated with phosphocreatine disodium alone.The course of treatment in both groups was one week.During the treatment,the changes of heart rate,heart rhythm,electrocardiogram and 24-h dynamic electrocardiogram(DCG)of both groups were observed.[Results]After treatment,the clinical efficacy of the observation group was better than that of the control group,and the difference was statistically significant(P<0.01).There were no adverse drug reactions in both groups.However,in the control group,non-sustained ventricular tachycardia(NSVT)was found in 24-h dynamic electrocardiogram(DCG)of 2 pregnant women with premature ventricular contraction.The pregnancy process was smooth,with full-term natural delivery and no fetal malformation.There was no significant difference in gestational age and neonatal weight between the two groups(P>0.05).However,there was a statistically significant difference in Apgar score between the two groups(P<0.05).During the 6-month postpartum follow-up,the mother and child were unharmed,and examination of repeated electrocardiograms showed that the conditions were normal.[Conclusions]Danshen Injection combined with phosphocreatine disodium has better efficacy in the treatment of frequent premature contractions during pregnancy and the maternal and infant outcomes than the treatment with phosphocreatine disodium alone,and it has good safety and can prevent premature contractions from progressing to tachyarrhythmias.展开更多
Monitoring foetal health is important to appropriately plan pregnancy management and delivery. Cardiotocography (CTG) is one of the most employed diagnostic techniques. Because CTG interpretation still lacks of comple...Monitoring foetal health is important to appropriately plan pregnancy management and delivery. Cardiotocography (CTG) is one of the most employed diagnostic techniques. Because CTG interpretation still lacks of complete reliability, new methods of interpretation and parameters are necessary to further support physicians’ decisions. To this aim, indexes related to variability of foetal heart rate (FHRV) are particularly studied. Frequency components of FHRV and their modifications can be analysed by applying a time-frequency approach, which allows for a distinct understanding of the spectral components related to foetal reactions to internal and external stimuli and their change over time. Being uterine contractions (UC) strong stimuli for the foetus and his autonomic nervous system (ANS), it is worth exploring the FHRV response to UC. This study analysed modifications of FHRV frequency characteristics with respect to 108 UC (relative to 35 healthy foetuses). Results showed a statistically significant (t-test, p < 0.01) power increase of the FHRV in both LF and HF bands in correspondence of the contractions. Moreover, we observed a shift to higher values of the maximum frequency contained in the signal corresponding to the power increase. Such modifications of the FHRV power spectrum can be a sign of ANS reaction and therefore represent additional, objective information about foetal reactivity and health during labour.展开更多
Objectives: To determine the feasibility of measuring intra-uterine pressure prior to placental delivery, using a novel minimally invasive method. Design: A prospective exploratory physiological study. Methods: Thirty...Objectives: To determine the feasibility of measuring intra-uterine pressure prior to placental delivery, using a novel minimally invasive method. Design: A prospective exploratory physiological study. Methods: Thirty-six low risk women undergoing normal vaginal delivery were randomly allocated to four groups. Group A received 600 mcg rectal misoprostol;group B received 600 mcg oral misoprostol;group C received 10 international units oxytocin intramuscularly after delivery of the anterior shoulder;group D received intramuscular oxytocin, 30 minutes after delivery of the baby. A calibrated catheter-tip intrauterine pressure transducer was used to measure the intrauterine pressure. This was introduced into the placenta via the umbilical vein, and recorded on a standard tocograph. Results: It was technically easy to introduce the catheter through the umbilical vessels in all mothers. On assessment of the tocograms, it was possible to interpret 95 out of 108 recordings (88%). Conclusions: This study demonstrated the simplicity of a novel, minimally invasive method of measuring the duration and frequency of postpartum uterine contractions prior to delivery of the placenta.展开更多
In order to detect and assess the muscle fatigue state with the surface electromyography(sEMG) characteristic parameters,this paper carried out a series of isometric contraction experiments to induce the fatigue on th...In order to detect and assess the muscle fatigue state with the surface electromyography(sEMG) characteristic parameters,this paper carried out a series of isometric contraction experiments to induce the fatigue on the forearm muscles from four subjects,and recorded the sEMG signals of the flexor carpi ulnaris.sEMG's median frequency(MDF) and mean frequency(MF) were extracted by short term Fourier transform(STFT),and the root mean square(RMS) of wavelet coefficients in the frequency band of 5—45 Hz was obtained by continuous wavelet transform(CWT).The results demonstrate that both MDF and MF show downward trends within 1 min; however,RMS shows an upward trend within the same time.The three parameters are closely correlated with absolute values of mean correlation coefficients greater than 0.8.It is suggested that the three parameters above can be used as reliable indicators to evaluate the level of muscle fatigue during isometric contractions.展开更多
This study is aimed at assessing muscle fatigue during a static contraction using multifractal analysis and found that the surface electromyographic （SEMG） signals characterized multiffactality during a static contr...This study is aimed at assessing muscle fatigue during a static contraction using multifractal analysis and found that the surface electromyographic （SEMG） signals characterized multiffactality during a static contraction. By applying the method of direct determination ofthef（a） singularity spectrum, the area of the multifractal spectrum of the SEMG signals was computed. The results showed that the spectrum area significantly increased during muscle fatigue. Therefore the area could be used as an assessor of muscle fatigue. Compared with the median frequency （MDF）--the most popular indicator of muscle fatigue, the spectrum area presented here showed higher sensitivity during a static contraction. So the singularity spectrum area is considered to be a more effective indicator than the MDF for estimating muscle fatigue.展开更多
AIM： To study the direct correlation between gastric dysrhythrnias and in vivo gastric muscle tone. METHODS： Five healthy dogs were implanted with 4 pairs of electrodes along the greater curvature, with a strain gau...AIM： To study the direct correlation between gastric dysrhythrnias and in vivo gastric muscle tone. METHODS： Five healthy dogs were implanted with 4 pairs of electrodes along the greater curvature, with a strain gauge （SG） being sutured parallel to the distal electrodes （2 cm above the pylorus）. Intravenous vasopressin was given to induce gastric dysrhythrnia. The percentage of regular slow waves and SG energy were calculated. RESULTS： （1） the regularity of gastric rnyoelectric activity （GMA） was reduced during and after infusion of vasopressin; （2） SG energy was significantly decreased during the infusion of vasopressin; （3） the decrease in SG energy was well correlated with the reduction in GMA regularity; （4） SG energy was negatively correlated with bradygastria and tachygastria. CONCLUSION： Vasopressin inhibits gastric contractions and impairs gastric slow waves; gastric dysrhythrnias are associated with the reduced antral muscle contractions, and are indicative of antral hypornotility.展开更多
The forced lengthening of an activated skeletal muscle has been termed an eccentric contraction(EC).This review highlights the mechanically unique nature of the EC and focuses on the specific disruption of proteins wi...The forced lengthening of an activated skeletal muscle has been termed an eccentric contraction(EC).This review highlights the mechanically unique nature of the EC and focuses on the specific disruption of proteins within the cell known as cytoskeletal proteins.The major intermediate filament cytoskeletal protein,desmin,has been the focus of work in this area because changes to desmin occur within minutes of ECs and because desmin has been shown to play both a mechanical and biologic role in a muscle's response to EC.It is hoped that these types of studies will assist in decreasing the incidence of muscle injury in athletes and facilitating the development of new therapies to treat muscle injuries.展开更多
In this paper, we discuss the concept of fixed point curve for linear interpolations of weakly inward contractions and establish necessary condition for a nonex- pansive mapping to have approximate fixed point property.
In this paper, we introduce a new class U of 3-dimensional real functions, use U and a 2-dimensional real function ? to construct a new implicit-linear contractive condition and obtain some existence theorems of commo...In this paper, we introduce a new class U of 3-dimensional real functions, use U and a 2-dimensional real function ? to construct a new implicit-linear contractive condition and obtain some existence theorems of common fixed points for two mappings on partially ordered 2-metric spaces and give a sufficient condition under which there exists a unique common fixed point. The obtained results goodly generalize and improve the corresponding conclusions in references.展开更多
This paper proposes a modified iterative algorithm using a viscosity approximation method with a weak contraction.The purpose is to find a common element of the set of common fixed points of an infinite family of none...This paper proposes a modified iterative algorithm using a viscosity approximation method with a weak contraction.The purpose is to find a common element of the set of common fixed points of an infinite family of nonexpansive mappings and the set of a finite family of equilibrium problems that is also a solution to a variational inequality.Under suitable conditions,some strong convergence theorems are established in the framework of Hilbert spaces.The results presented in the paper improve and extend the corresponding results of Colao et al.（Colao,V.,Acedo,G.L.,and Marino,G.An implicit method for finding common solutions of variational inequalities and systems of equilibrium problems and fixed points of infinite family of nonexpansive mappings.Nonlinear Anal.71,2708–2715（2009））,Plubtieng and Punpaeng（Plubtieng,S.and Punpaeng,R.A general iterative method for equilibrium problems and fixed point problems in Hilbert spaces.J.Math.Anal.Appl.336,455–469（2007））,Colao et al.（Colao,V.,Marino,G.,and Xu,H.K.An iterative method for finding common solutions of equilibrium problem and fixed point problems.J.Math.Anal.Appl.344,340–352（2008））,Yao et al.（Yao,Y.,Liou,Y.C.,and Yao,J.C.Convergence theorem for equilibrium problems and fixed point problems of infinite family of nonexpansive mappings.Fixed Point Theory Application 2007,Article ID 64363（2007）DOI 10.1155/2007/64363）,and others.展开更多
Fixed point theory is one of the most important subjects in the setting of metric spaces since fixed point theorems can be used to determine the existence and the uniqueness of solutions of such mathematical problems....Fixed point theory is one of the most important subjects in the setting of metric spaces since fixed point theorems can be used to determine the existence and the uniqueness of solutions of such mathematical problems.It is known that many problems in applied sciences and engineering can be formulated as functional equations.Such equations can be transferred to fixed point theorems in an easy manner.Moreover,we use the fixed point theory to prove the existence and uniqueness of solutions of such integral and differential equations.Let X be a non-empty set.A fixed point for a self-mapping T on X is a point𝑒𝑒∈𝑋𝑋that satisfying T e=e.One of the most challenging problems in mathematics is to construct some iterations to faster the calculation or approximation of the fixed point of such problems.Some mathematicians constructed and generated some new iteration schemes to calculate or approximate the fixed point of such problems such as Mann et al.[Mann(1953);Ishikawa(1974);Sintunavarat and Pitea(2016);Berinde(2004b);Agarwal,O’Regan and Sahu(2007)].The main purpose of the present paper is to introduce and construct a new iteration scheme to calculate or approximate the fixed point within a fewer number of steps as much as we can.We prove that our iteration scheme is faster than the iteration schemes given by Sintunavarat et al.[Sintunavarat and Pitea(2016);Agarwal,O’Regan and Sahu(2007);Mann(1953);Ishikawa(1974)].We give some numerical examples by using MATLAB to compare the efficiency and effectiveness of our iterations scheme with the efficiency of Mann et al.[Mann(1953);Ishikawa(1974);Sintunavarat and Pitea(2016);Abbas and Nazir(2014);Agarwal,O’Regan and Sahu(2007)]schemes.Moreover,we introduce a problem raised from Newton’s law of cooling as an application of our new iteration scheme.Also,we support our application with a numerical example and figures to illustrate the validity of our iterative scheme.展开更多
In patients suffering from neurogenic detrusor overactivity, continence can be regained by conditional stimulation of the dorsal genital nerve (DGN);that is applying electrical stimulation to the DGN at the onset of a...In patients suffering from neurogenic detrusor overactivity, continence can be regained by conditional stimulation of the dorsal genital nerve (DGN);that is applying electrical stimulation to the DGN at the onset of an involuntary contraction. For this scheme to work, a sensor capable of reliably detecting the onset of bladder contractions is needed. This article reviews the methods proposed for or associated with detection of bladder contractions, and their applicability to onset detection is assessed. Fourteen methods are described in this review;bladder pressure, urethral sphincter EMG and anal sphincter EMG are the most promising options for onset detection. For all three modalities, however, further research is needed before clinical application becomes viable.展开更多
We developed an eccentric contraction induced electrical stimulation (ES) training system. The purpose of this study was to investigate whether the eccentric contraction induced ES enhance the knee extension torque co...We developed an eccentric contraction induced electrical stimulation (ES) training system. The purpose of this study was to investigate whether the eccentric contraction induced ES enhance the knee extension torque compared with typical ES. Twenty-two young untrained men (age: 23 ± 3 years) in the acute response trial (single training) and seven untrained men in the long period training trial (for 6 weeks) were studied. We measured muscle thickness and knee extension torque evoked by ES with eccentric contraction training system (ES + ECC) or ES alone for the quadriceps muscle of men. The levels of pain and discomfort were evaluated using numeric rating scale (NRS) and heart rate variability. The knee extension torque of ES + ECC was higher than that of ES alone in the acute response trial. There were no significant differences in the levels of pain and discomfort between ES and ES + ECC. Additionally, ES + ECC training for 6 weeks was effective on the quadriceps muscle thickness and knee extension torque. In contrast, the ES alone training failed to increase muscle thickness and knee extension torque. These results suggest that eccentric contraction induced ES would have the potential to become an effective intervention to promote muscle strengthening.展开更多
Past eccentric contraction (ECC)-induced muscle injury reduces the severity of symptoms of subsequent muscle injury;this phenomenon is known as a repeated bout effect (RBE). It has been reported that increases in the ...Past eccentric contraction (ECC)-induced muscle injury reduces the severity of symptoms of subsequent muscle injury;this phenomenon is known as a repeated bout effect (RBE). It has been reported that increases in the duration of the interval between the first and second bouts are linked to weakening of the RBE. However, the histology following the attenuation of the RBE remains unclear. We examined the sustained effects of the second bout with regard to myofiber permeability and muscle force. Sixty-four male rats were randomly assigned to eight groups that varied in the number of exercise sessions and the duration of the interval between the first and second bouts: the non-ECC (Control);the single-injury (Post 1st bout);groups that were allowed to recover for 1, 2, and 4 weeks after a single injury (Pre 2nd bout_1w, Pre 2nd bout_2w, and Pre 2nd bout_4w);and groups that were subjected to second injuries 1, 2, and 4 weeks after the first (Post 2nd bout_1w, Post 2nd bout_2w, and Post 2nd bout_4w). The tibialis anterior was electrically stimulated in each ECC group. Twenty-four hours before muscle sampling, Evans blue dye (EBD) (a marker of myofiber damage) was administered. The maximal isometric contraction tension was measured immediately before sampling. The number of EBD-positive (+) fibers was determined via histological analysis. An RBE was revealed by functional examination at the 1- and 2-week and histological examination at the 1-, 2-, and 4-week time points (P < 0.05). In terms of myofiber permeability, prolongation of the interval before the second bout weakened this effect (P < 0.05). Experiments with 1-, 2-, and 4-week intervals indicated that prolongation of the interval before the second bout weakened the RBE with regard to myofiber permeability.展开更多
文摘Ghrelin causes interdigestive contractions of the stom- ach in rats. However, it remains unknown whether ghrelin causes interdigestive contractions in the small intestine. Four strain gauge transducers were implanted on the antrum, duodenum, proximal and distal jejunum. After an overnight fast, gastrointestinal （GI） contrac- tions were recorded in freely moving conscious rats. Spontaneous phase m-like contractions were observed at every 13-16 min in rat GI tract. The fasted motor patterns were replaced by the fed motor pattern imme- diately after food intake. Two minutes after finishing the spontaneous phase Ill-like contractions in the antrum, acyl ghrelin （0.8, 2.4 and 8.0 μg/kg per min） was con- tinuously infused for 30 min. Three-five minutes after the starting ghrelin infusion, augmented phase Ⅲ-like contractions were observed at the antrum, duodenum, and jejunum. Ghrelin infusion （0.8, 2.4 and 8.0μg/kg per min） significantly increased motility index of phase Ⅲ-like contractions at the antrum and jejunum in a dose dependent manner, compared to that of saline in- jection. Thus, it is likely that exogenously administered ghrelin causes phase Ⅲ-like contraction at the antrum, which migrates to the duodenum and jejunum. The possible role of 5-HT, in addition to ghrelin, in mediating intestinal migrating motor complex （MMC）, is discussed.
基金supported by the innovation project in Jiangsu province,Chinathe Program for Development of Innovative Research Team in the First Affiliated Hospital of NJMU(IRT-004)
文摘Recent studies have shown that premature ventricular contractions （PVCs） could enlarge the heart, but its risk factors are incompletely understood as a single 24-hour recording cannot reflect the true PVC burden due to day-to-day variability. Our purpose was to investigate the effect of burden and origin sites on left ventricular （LV） function in patients with PVCs by 7-day Holter electrocardiography （ECG）. From May 2012 to August 2013, 112 consecutive patients with PVCs were recruited from the authors＇ affiliated hospital. All patients received 2-dimensional transthoracic echocardiography, 12-lead routing ECG and 7-days Holter ECG. Serum N-terminal pro- brain natriuretic peptide （NT-proBNP） levels were measured. A total of 102 participants with PVCs were included in the final analysis. Origin of PVCs from the tricuspid annulus had the highest burden and NT-proBNP level. LV papillary muscle had a higher LV ejection fraction （EF） level and a lower LV end-systolic dimension （ESD） than other PVC foci （P〈0.05）. The high burden group had a higher LV end-diastolic dimension （EDD） and LVESD but lower LVEF than the other two groups （P〈0.05）. Female, older age, physical work, and history of PVCs had a significantly positive correlation with symptoms. Male, older age, physical work, and high burden were positive predictors of enlarged LVEDD, LVESD and higher serum NT-proBNP level, but lower LVEF. Seven-day dynamic ECG Holter monitor showed the true PVC burden on patients with PVCs. PVCs with a lower burden or origin from the LV papillary muscle and the fascicle were relatively benign, while PVCs with a higher burden or origin from the tricuspid annulus may lead to cardiac dysfunction.
基金Supported by The Department of Veterans Affairs Rehabilitation Research and Development Service Center of Excellencefor the Medical Consequences of Spinal Cord Injury (B4162C)
文摘AIM: To investigate the presence or absence of high amplitude propagating contractions (HAPC), as well as the other measures of colonic motility, in persons with spinal cord injury (SCI). METHODS: Prolonged colonic ambulatory manometric studies were performed on 14 male volunteers: 8 with SCI (mean age, 59 ± 13 years; mean duration of injury, 13 ± 4 years) and 6 healthy able-bodied controls (mean age, 57 ± 10 years). A solid-state manometry catheter was endoscopically clipped to the splenic flexure. Recording was performed for > 24 h after manometric catheter placement. RESULTS: HAPC were absent in individuals with SCI during pre-sleep, sleep, and post-sleep phases. HAPC were significantly increased after awakening in non-SCI controls (0.8 ± 0.2 HAPC/h vs 10.5 ± 2.0 HAPC/h, P < 0.005). The motility index was lower in those with SCI than in controls preand post-sleep (SCI vs non-SCI: Pre-sleep, 2.4 ± 0.4 vs 8.8 ± 1.9, P < 0.01; Post-sleep, 4.3 ± 0.8 vs 16.5 ± 4.5, P < 0.05). However, a sleepinduced depression of colonic motility was observed in both the SCI and non-SCI groups (Pre-sleep vs Sleep, non-SCI: 8.8 ± 1.9 vs 2.1 ± 0.9, P < 0.002; SCI: 2.4 ± 0.4 vs 0.2 ± 0.03, P < 0.001), with the motility index of those with SCI during sleep not significantly different than that of the controls. CONCLUSION: HAPC were not observed in individuals with SCI preor post-sleep. A sleep-induced depression in general colonic motility was evident in SCI and control subjects.
文摘Background:The steady-state increase in muscle force generating potential following a lengthening contraction is called residual force enhancement(RFE).In this study,we aimed to test for differences in torque,electromyographic activity(EMG),and the associated neuromuscular efficiency(NME)between isometric voluntary contractions of elbow flexors preceded and not preceded by a lengthening contraction.The dependence of such differences on(i)stretch amplitude,(ii)the region of the force-length(FxL)relationship where contraction occurs,and(iii)the individual's ability to produce(negative)work during the stretch was investigated.Methods:Sixteen healthy adults participated in the study.Elbow flexor torque,angle,and biceps brachii EMG for purely isometric contractions(reference contractions)and for isometric contractions preceded by active stretches of 20°and 40°were measured at the ascending,plateau,and descending regions of subject-specific FxL curves.All contractions were performed in an isokinetic dynamometer.Two-factor(stretch×FxL region)repeated measures analysis of variance ANOVAs was used to analyze the effect of active stretch on EMG,torque,and NME across conditions.The relationships between mechanical work during stretch-calculated as the torque-angular displacement integral-and the changes in EMG,torque,and NME were analyzed using Pearson correlation.Results:In general,torque,EMG,and NME following active stretches differed from the values observed for the purely isometric reference contractions.While although the detailed effects of active stretch on torque and EMG differed between regions of the FxL relationship,NME increased by about 19%for all muscle lengths.Up to 30%of the interindividual variability in torque generating potential change in response to active stretching was accounted for by differences in(negative)work capacity between subjects.Conclusion:Our results suggest that(i)RFE contributes to"flatten"the elbow flexor torque-angle relationship,favoring torque production at lengths where the purely isometric torques are reduced substantially,and(ii)RFE contributes to a reduction in energy cost of torque production during isometric contractions for the entire operating range.
基金supported by Università degli Studi di Padermo,Local Project R.S.ex 60\char37
文摘In 2011, Berinde and Borcut [6] introduced the notion of tripled fixed point in partially ordered metric spaces. In our paper, we give some new tripled fixed point theorems by using a generalization of Meir-Keeler contraction：
文摘Contractions of the Lie algebras d = u(2), f = u(1 ,1) to the oscillator Lie algebra l are realized via the adjoint action of SU(2,2) when d, l, f are viewed as subalgebras of su(2,2). Here D, L, F are the corresponding (four-dimensional) real Lie groups endowed with bi-invariant metrics of Lorentzian signature. Similar contractions of (seven-dimensional) isometry Lie algebras iso(D), iso(F) to iso(L) are determined. The group SU(2,2) acts on each of the D, L, F by conformal transformation which is a core feature of the DLF-theory. Also, d and f are contracted to T, S-abelian subalgebras, generating parallel translations, T, and proper conformal transformations, S (from the decomposition of su(2,2) as a graded algebra T + Ω + S, where Ω is the extended Lorentz Lie algebra of dimension 7).
基金the Project of National Natural Science Foundation of China(81370337&81970331).
文摘[Objectives]To explore the efficacy of Danshen Injection combined with phosphocreatine disodium in treating frequent premature contractions during pregnancy and its effect on maternal and infant outcomes.[Methods]A total of 200 pregnant women with normal pregnancy and frequent premature contractions who were treated in the outpatient department of internal medicine in Women and Children's Hospital of Hubei Province and Xinzhou District People's Hospital of Wuhan Central Hospital during September 2015 and October 2018 were selected and randomly divided into the control group and observation group,100 cases for each group.The observation group was treated with Danshen Injection combined with phosphocreatine disodium,and the control group was treated with phosphocreatine disodium alone.The course of treatment in both groups was one week.During the treatment,the changes of heart rate,heart rhythm,electrocardiogram and 24-h dynamic electrocardiogram(DCG)of both groups were observed.[Results]After treatment,the clinical efficacy of the observation group was better than that of the control group,and the difference was statistically significant(P<0.01).There were no adverse drug reactions in both groups.However,in the control group,non-sustained ventricular tachycardia(NSVT)was found in 24-h dynamic electrocardiogram(DCG)of 2 pregnant women with premature ventricular contraction.The pregnancy process was smooth,with full-term natural delivery and no fetal malformation.There was no significant difference in gestational age and neonatal weight between the two groups(P>0.05).However,there was a statistically significant difference in Apgar score between the two groups(P<0.05).During the 6-month postpartum follow-up,the mother and child were unharmed,and examination of repeated electrocardiograms showed that the conditions were normal.[Conclusions]Danshen Injection combined with phosphocreatine disodium has better efficacy in the treatment of frequent premature contractions during pregnancy and the maternal and infant outcomes than the treatment with phosphocreatine disodium alone,and it has good safety and can prevent premature contractions from progressing to tachyarrhythmias.
文摘Monitoring foetal health is important to appropriately plan pregnancy management and delivery. Cardiotocography (CTG) is one of the most employed diagnostic techniques. Because CTG interpretation still lacks of complete reliability, new methods of interpretation and parameters are necessary to further support physicians’ decisions. To this aim, indexes related to variability of foetal heart rate (FHRV) are particularly studied. Frequency components of FHRV and their modifications can be analysed by applying a time-frequency approach, which allows for a distinct understanding of the spectral components related to foetal reactions to internal and external stimuli and their change over time. Being uterine contractions (UC) strong stimuli for the foetus and his autonomic nervous system (ANS), it is worth exploring the FHRV response to UC. This study analysed modifications of FHRV frequency characteristics with respect to 108 UC (relative to 35 healthy foetuses). Results showed a statistically significant (t-test, p < 0.01) power increase of the FHRV in both LF and HF bands in correspondence of the contractions. Moreover, we observed a shift to higher values of the maximum frequency contained in the signal corresponding to the power increase. Such modifications of the FHRV power spectrum can be a sign of ANS reaction and therefore represent additional, objective information about foetal reactivity and health during labour.
文摘Objectives: To determine the feasibility of measuring intra-uterine pressure prior to placental delivery, using a novel minimally invasive method. Design: A prospective exploratory physiological study. Methods: Thirty-six low risk women undergoing normal vaginal delivery were randomly allocated to four groups. Group A received 600 mcg rectal misoprostol;group B received 600 mcg oral misoprostol;group C received 10 international units oxytocin intramuscularly after delivery of the anterior shoulder;group D received intramuscular oxytocin, 30 minutes after delivery of the baby. A calibrated catheter-tip intrauterine pressure transducer was used to measure the intrauterine pressure. This was introduced into the placenta via the umbilical vein, and recorded on a standard tocograph. Results: It was technically easy to introduce the catheter through the umbilical vessels in all mothers. On assessment of the tocograms, it was possible to interpret 95 out of 108 recordings (88%). Conclusions: This study demonstrated the simplicity of a novel, minimally invasive method of measuring the duration and frequency of postpartum uterine contractions prior to delivery of the placenta.
基金Supported by the National Natural Science Foundation of China(No.81222021 and No.31011130042)the National Key Technology R&D Program of the Ministry of Science and Technology of China(No.2012BAI34B02)
文摘In order to detect and assess the muscle fatigue state with the surface electromyography(sEMG) characteristic parameters,this paper carried out a series of isometric contraction experiments to induce the fatigue on the forearm muscles from four subjects,and recorded the sEMG signals of the flexor carpi ulnaris.sEMG's median frequency(MDF) and mean frequency(MF) were extracted by short term Fourier transform(STFT),and the root mean square(RMS) of wavelet coefficients in the frequency band of 5—45 Hz was obtained by continuous wavelet transform(CWT).The results demonstrate that both MDF and MF show downward trends within 1 min; however,RMS shows an upward trend within the same time.The three parameters are closely correlated with absolute values of mean correlation coefficients greater than 0.8.It is suggested that the three parameters above can be used as reliable indicators to evaluate the level of muscle fatigue during isometric contractions.
基金Project (No. 2005CB724303) supported by the National Basic Re-search Program (973) of China
文摘This study is aimed at assessing muscle fatigue during a static contraction using multifractal analysis and found that the surface electromyographic （SEMG） signals characterized multiffactality during a static contraction. By applying the method of direct determination ofthef（a） singularity spectrum, the area of the multifractal spectrum of the SEMG signals was computed. The results showed that the spectrum area significantly increased during muscle fatigue. Therefore the area could be used as an assessor of muscle fatigue. Compared with the median frequency （MDF）--the most popular indicator of muscle fatigue, the spectrum area presented here showed higher sensitivity during a static contraction. So the singularity spectrum area is considered to be a more effective indicator than the MDF for estimating muscle fatigue.
文摘AIM： To study the direct correlation between gastric dysrhythrnias and in vivo gastric muscle tone. METHODS： Five healthy dogs were implanted with 4 pairs of electrodes along the greater curvature, with a strain gauge （SG） being sutured parallel to the distal electrodes （2 cm above the pylorus）. Intravenous vasopressin was given to induce gastric dysrhythrnia. The percentage of regular slow waves and SG energy were calculated. RESULTS： （1） the regularity of gastric rnyoelectric activity （GMA） was reduced during and after infusion of vasopressin; （2） SG energy was significantly decreased during the infusion of vasopressin; （3） the decrease in SG energy was well correlated with the reduction in GMA regularity; （4） SG energy was negatively correlated with bradygastria and tachygastria. CONCLUSION： Vasopressin inhibits gastric contractions and impairs gastric slow waves; gastric dysrhythrnias are associated with the reduced antral muscle contractions, and are indicative of antral hypornotility.
文摘The forced lengthening of an activated skeletal muscle has been termed an eccentric contraction(EC).This review highlights the mechanically unique nature of the EC and focuses on the specific disruption of proteins within the cell known as cytoskeletal proteins.The major intermediate filament cytoskeletal protein,desmin,has been the focus of work in this area because changes to desmin occur within minutes of ECs and because desmin has been shown to play both a mechanical and biologic role in a muscle's response to EC.It is hoped that these types of studies will assist in decreasing the incidence of muscle injury in athletes and facilitating the development of new therapies to treat muscle injuries.
文摘In this paper, we discuss the concept of fixed point curve for linear interpolations of weakly inward contractions and establish necessary condition for a nonex- pansive mapping to have approximate fixed point property.
文摘In this paper, we introduce a new class U of 3-dimensional real functions, use U and a 2-dimensional real function ? to construct a new implicit-linear contractive condition and obtain some existence theorems of common fixed points for two mappings on partially ordered 2-metric spaces and give a sufficient condition under which there exists a unique common fixed point. The obtained results goodly generalize and improve the corresponding conclusions in references.
基金supported by the Natural Science Foundation of Yibin University(No.2009Z3)
文摘This paper proposes a modified iterative algorithm using a viscosity approximation method with a weak contraction.The purpose is to find a common element of the set of common fixed points of an infinite family of nonexpansive mappings and the set of a finite family of equilibrium problems that is also a solution to a variational inequality.Under suitable conditions,some strong convergence theorems are established in the framework of Hilbert spaces.The results presented in the paper improve and extend the corresponding results of Colao et al.（Colao,V.,Acedo,G.L.,and Marino,G.An implicit method for finding common solutions of variational inequalities and systems of equilibrium problems and fixed points of infinite family of nonexpansive mappings.Nonlinear Anal.71,2708–2715（2009））,Plubtieng and Punpaeng（Plubtieng,S.and Punpaeng,R.A general iterative method for equilibrium problems and fixed point problems in Hilbert spaces.J.Math.Anal.Appl.336,455–469（2007））,Colao et al.（Colao,V.,Marino,G.,and Xu,H.K.An iterative method for finding common solutions of equilibrium problem and fixed point problems.J.Math.Anal.Appl.344,340–352（2008））,Yao et al.（Yao,Y.,Liou,Y.C.,and Yao,J.C.Convergence theorem for equilibrium problems and fixed point problems of infinite family of nonexpansive mappings.Fixed Point Theory Application 2007,Article ID 64363（2007）DOI 10.1155/2007/64363）,and others.
文摘Fixed point theory is one of the most important subjects in the setting of metric spaces since fixed point theorems can be used to determine the existence and the uniqueness of solutions of such mathematical problems.It is known that many problems in applied sciences and engineering can be formulated as functional equations.Such equations can be transferred to fixed point theorems in an easy manner.Moreover,we use the fixed point theory to prove the existence and uniqueness of solutions of such integral and differential equations.Let X be a non-empty set.A fixed point for a self-mapping T on X is a point𝑒𝑒∈𝑋𝑋that satisfying T e=e.One of the most challenging problems in mathematics is to construct some iterations to faster the calculation or approximation of the fixed point of such problems.Some mathematicians constructed and generated some new iteration schemes to calculate or approximate the fixed point of such problems such as Mann et al.[Mann(1953);Ishikawa(1974);Sintunavarat and Pitea(2016);Berinde(2004b);Agarwal,O’Regan and Sahu(2007)].The main purpose of the present paper is to introduce and construct a new iteration scheme to calculate or approximate the fixed point within a fewer number of steps as much as we can.We prove that our iteration scheme is faster than the iteration schemes given by Sintunavarat et al.[Sintunavarat and Pitea(2016);Agarwal,O’Regan and Sahu(2007);Mann(1953);Ishikawa(1974)].We give some numerical examples by using MATLAB to compare the efficiency and effectiveness of our iterations scheme with the efficiency of Mann et al.[Mann(1953);Ishikawa(1974);Sintunavarat and Pitea(2016);Abbas and Nazir(2014);Agarwal,O’Regan and Sahu(2007)]schemes.Moreover,we introduce a problem raised from Newton’s law of cooling as an application of our new iteration scheme.Also,we support our application with a numerical example and figures to illustrate the validity of our iterative scheme.
文摘In patients suffering from neurogenic detrusor overactivity, continence can be regained by conditional stimulation of the dorsal genital nerve (DGN);that is applying electrical stimulation to the DGN at the onset of an involuntary contraction. For this scheme to work, a sensor capable of reliably detecting the onset of bladder contractions is needed. This article reviews the methods proposed for or associated with detection of bladder contractions, and their applicability to onset detection is assessed. Fourteen methods are described in this review;bladder pressure, urethral sphincter EMG and anal sphincter EMG are the most promising options for onset detection. For all three modalities, however, further research is needed before clinical application becomes viable.
文摘We developed an eccentric contraction induced electrical stimulation (ES) training system. The purpose of this study was to investigate whether the eccentric contraction induced ES enhance the knee extension torque compared with typical ES. Twenty-two young untrained men (age: 23 ± 3 years) in the acute response trial (single training) and seven untrained men in the long period training trial (for 6 weeks) were studied. We measured muscle thickness and knee extension torque evoked by ES with eccentric contraction training system (ES + ECC) or ES alone for the quadriceps muscle of men. The levels of pain and discomfort were evaluated using numeric rating scale (NRS) and heart rate variability. The knee extension torque of ES + ECC was higher than that of ES alone in the acute response trial. There were no significant differences in the levels of pain and discomfort between ES and ES + ECC. Additionally, ES + ECC training for 6 weeks was effective on the quadriceps muscle thickness and knee extension torque. In contrast, the ES alone training failed to increase muscle thickness and knee extension torque. These results suggest that eccentric contraction induced ES would have the potential to become an effective intervention to promote muscle strengthening.
文摘Past eccentric contraction (ECC)-induced muscle injury reduces the severity of symptoms of subsequent muscle injury;this phenomenon is known as a repeated bout effect (RBE). It has been reported that increases in the duration of the interval between the first and second bouts are linked to weakening of the RBE. However, the histology following the attenuation of the RBE remains unclear. We examined the sustained effects of the second bout with regard to myofiber permeability and muscle force. Sixty-four male rats were randomly assigned to eight groups that varied in the number of exercise sessions and the duration of the interval between the first and second bouts: the non-ECC (Control);the single-injury (Post 1st bout);groups that were allowed to recover for 1, 2, and 4 weeks after a single injury (Pre 2nd bout_1w, Pre 2nd bout_2w, and Pre 2nd bout_4w);and groups that were subjected to second injuries 1, 2, and 4 weeks after the first (Post 2nd bout_1w, Post 2nd bout_2w, and Post 2nd bout_4w). The tibialis anterior was electrically stimulated in each ECC group. Twenty-four hours before muscle sampling, Evans blue dye (EBD) (a marker of myofiber damage) was administered. The maximal isometric contraction tension was measured immediately before sampling. The number of EBD-positive (+) fibers was determined via histological analysis. An RBE was revealed by functional examination at the 1- and 2-week and histological examination at the 1-, 2-, and 4-week time points (P < 0.05). In terms of myofiber permeability, prolongation of the interval before the second bout weakened this effect (P < 0.05). Experiments with 1-, 2-, and 4-week intervals indicated that prolongation of the interval before the second bout weakened the RBE with regard to myofiber permeability.
