In 2021,Cempaka,a tiny tropical cyclone,made landfall in China.As the TC intensified prior to landfall,the tropical cyclone size measured with precipitation decreased significantly.A numerical simulation was conducted...In 2021,Cempaka,a tiny tropical cyclone,made landfall in China.As the TC intensified prior to landfall,the tropical cyclone size measured with precipitation decreased significantly.A numerical simulation was conducted to examine the possible processes modulating the storm size.Azimuthally mean potential vorticity(PV)was found to decrease mainly in the middle to upper troposphere between 50-and 80-km radii.The PV budget results indicate that the advection and generation of mean PV associated with asymmetric processes,rather than the symmetric processes,primarily contributed to the decrease in mean PV.These asymmetric processes leading to a negative PV tendency were likely associated with inactive outer rainbands.In contrast,the tangential winds simultaneously expanded radially outward,possibly related to inner-core diabatic heating.The findings here emphasize the importance of outer rainband activity in tropical cyclone size change.展开更多
AIM:To evaluate the efficacy and safety of combining posterior scleral contraction(PSC)with intravitreal perfluoropropane(C_(3)F_(8))injection in high myopia with macular hole retinal detachment(MHRD).METHODS:A total ...AIM:To evaluate the efficacy and safety of combining posterior scleral contraction(PSC)with intravitreal perfluoropropane(C_(3)F_(8))injection in high myopia with macular hole retinal detachment(MHRD).METHODS:A total of 22 participants(22 eyes)with high myopia[axial length(AL)≥26.5 mm]and MHRD who underwent PSC combined with intravitreal C_(3)F_(8)injection,with at least 6mo of follow-up were retrospectively recruited.Outcome measures included best-corrected visual acuity(BCVA),AL,optical coherence tomography(OCT)findings,and adverse events.Retinal recovery was categorized as type Ⅰ(macular hole bridging with retinal reattachment)or type Ⅱ(reattachment without hole bridging).RESULTS:The mean age of participants was 62.1±8.8y and mean follow-up duration was 9.18±4.21mo.Complete retinal reattachment was observed in 11 eyes(50%)at postoperative day 1,19 eyes(86.3%)at week 1,and all 22 eyes at month 1.Ten eyes(45.5%)achieved type Ⅰ recovery and 12 eyes(54.5%)achieved type Ⅱ.Mean BCVA improved from 1.68±0.84 logMAR before surgery to 1.21±0.65 logMAR after surgery(P<0.001),and AL was significantly reduced compared to baseline(29.07±2.05 vs 30.8±2.2 mm;P<0.001).No serious complications were reported.CONCLUSION:PSC combined with intravitreal C_(3)F_(8)injection is a safe and effective treatment for MHRD in highly myopic eyes,especially for retinal detachment limited within the vascular arcade.展开更多
In this manuscript,the notion of a hesitant fuzzy soft fixed point is introduced.Using this notion and the concept of Suzuki-type(μ,ν)-weak contraction for hesitant fuzzy soft set valued-mapping,some fixed point res...In this manuscript,the notion of a hesitant fuzzy soft fixed point is introduced.Using this notion and the concept of Suzuki-type(μ,ν)-weak contraction for hesitant fuzzy soft set valued-mapping,some fixed point results are established in the framework of metric spaces.Based on the presented work,some examples reflecting decision-making problems related to real life are also solved.The suggested method’s flexibility and efficacy compared to conventional techniques are demonstrated in decision-making situations involving uncertainty,such as choosing the best options in multi-criteria settings.We noted that the presented work combines and generalizes two major concepts,the idea of soft sets and hesitant fuzzy set-valued mapping from the existing literature.展开更多
In this study,we explore some of the best proximity point results for generalized proximal contractions in the setting of double-controlled metric-type spaces.A non-trivial example is given to elucidate our analysis,a...In this study,we explore some of the best proximity point results for generalized proximal contractions in the setting of double-controlled metric-type spaces.A non-trivial example is given to elucidate our analysis,and some novel results are derived.The discovered results generalize previously known results in the context of a double controlled metric type space environment.This article’s proximity point results are the first of their kind in the realm of controlled metric spaces.To build on the results achieved in this article,we present an application demonstrating the usability of the given results.展开更多
Any composition sequential mapping, periodic composition mapping of a complete non-empty metric space M into M with geometric mean contraction ratio less than 1 ( simplifying as 'g-contraction mapping' ) has a...Any composition sequential mapping, periodic composition mapping of a complete non-empty metric space M into M with geometric mean contraction ratio less than 1 ( simplifying as 'g-contraction mapping' ) has a unique fixed point in M . Applications of the theorem to the proof of existence and uniqueness of the solutions of a set of non-linear differential equations and a coupled integral equations of symmetric bending of shallow shell of revolution are given.展开更多
The spontaneous oscillatory contraction（SPOC） of myofibrils is the essential property inherent to the contractile system of muscle. Muscle contraction results from cyclic interactions between actin filament and myos...The spontaneous oscillatory contraction（SPOC） of myofibrils is the essential property inherent to the contractile system of muscle. Muscle contraction results from cyclic interactions between actin filament and myosin II which is a dimeric motor protein with two heads. Taking the two heads of myosin II as an indivisible element and considering the effects of cooperative behavior between the two heads on rate constants in the mechanochemical cycle, the present work proposes the tenstate mechanochemical cycle model for myosin II dimer. The simulations of this model show that the proportion of myosin II in different states periodically changes with time, which results in the sustained oscillations of contractive tension, and serves as the primary factor for SPOC. The good fit of this model to experimental results suggests that the cooperative interaction between the two heads of myosin II dimer may be one of the underlying mechanisms for muscle contraction.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.
A new branch of hypergraph theory-directed hyperaph theory and a kind of new methods-dicomposition contraction(DCP, PDCP and GDC) methods are presented for solving hypernetwork problems.lts computing time is lower tha...A new branch of hypergraph theory-directed hyperaph theory and a kind of new methods-dicomposition contraction(DCP, PDCP and GDC) methods are presented for solving hypernetwork problems.lts computing time is lower than that of ECP method in several order of magnitude.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
In this article, we introduce a new type of contraction named almost type α-F-Z-weak contraction, which comes from a combination of F-contraction, Z-contraction, and almost contraction, and then we provide sufficient...In this article, we introduce a new type of contraction named almost type α-F-Z-weak contraction, which comes from a combination of F-contraction, Z-contraction, and almost contraction, and then we provide sufficient conditions for the existence and uniqueness of fixed point of such contractions in complete metric spaces and give some related fixed point results. In addition, some related fixed point results can derive from our main results.展开更多
For a graphlike manifold whose contraction is a generalized cuneate figure,we deribve a formula in this paper to compute the number of homeomorphism classes of it by using twist operations and the combinatorial theory.
Thick-skinned contractional salt structures are widely developed in the western Kuqa depression, northern Tarim basin. To understand the mechanisms that govern the development of these structures, physical experiments...Thick-skinned contractional salt structures are widely developed in the western Kuqa depression, northern Tarim basin. To understand the mechanisms that govern the development of these structures, physical experiments are conducted and the results show that they are largely governed by the activities of basement faults and the forming of paleo-uplifts and basement slopes. The model materials in this study are dry sand, vaseline and plasticene （or hard foam）, simulating the suprasalt, salt, and subsalt layers respectively. The experiments show that, due to the activities of basement faults and the forming of the paleo-uplifts, salt bodies usually accumulate and thicken significantly on the middle top of the paleo-uplifts which are constrained by the pre-exiting boundary faults. The development of large-scale thrust faults and salt nappes is favored by the basement slops with larger dips. The experiments also conclude that differential structural deformation could occur between the subsalt and suprasalt layers because of the presence of salt layers. Their geometries and the locations of structural highs are different, despite of the great similarities in the uplifted areas. The pierced salt diapir is not observed in the experiments, which indicates that the contractional shortening does not effectively accelerate the development of the salt diapir.展开更多
AIM: To investigate the effects of areca on the contractile activity of isolated colonic muscle strips in rats and mechanism involved. METHODS: Each strip (LMPC, longitudinal muscle of proximal colon; CMPC, circular m...AIM: To investigate the effects of areca on the contractile activity of isolated colonic muscle strips in rats and mechanism involved. METHODS: Each strip (LMPC, longitudinal muscle of proximal colon; CMPC, circular muscle of proximal colon; LMDC, longitudinal muscle of distal colon; CMDC, circular muscle of distal colon.) was suspended in a tissue chamber containing 5 mL Krebs solution (37 degrees C), bubbled continuously with 950 mL.L(-1) O(2) and 50 mL.L(-1) CO(2). The mean contractile amplitude (A), the resting tension (T), and the contractile frequency (F) were simultaneously recorded on recorders. RESULTS: Areca dose dependently increased the mean contractile amplitude, the resting tension of proximal and distal colonic smooth muscle strips in rats (P【0.05). It also partly increased the contractile frequency of colonic smooth muscle strips in rats (P【0.05). The effects were partly inhibited by atropine (the resting tension of LMPC decreased from 0.44 +/- 0.12 to 0.17 +/- 0.03; the resting tension of LMDC decreased from 0.71 +/- 0.14 to 0.03 +/- 0.01; the mean contractile amplitude of LMPC increased from -45.8 +/- 7.2 to -30.5 +/- 2.9; the motility index of CMDC decreased from 86.6 +/- 17.3 to 32.8 +/- 9.3; P【0.05 vs areca), but the effects were not inhibited by hexamethonium (P】0.05). CONCLUSION: Areca stimulated the motility of isolated colonic smooth muscle strips in rats. The stimulation of areca might be relevant with M receptor partly.展开更多
The uterine tetanic contraction and uterine artery blood flow reduction are possible reasons for primary dysmenorrhea(PD). In the present study, we aimed to evaluate the uterine relaxant effect and the influence on ut...The uterine tetanic contraction and uterine artery blood flow reduction are possible reasons for primary dysmenorrhea(PD). In the present study, we aimed to evaluate the uterine relaxant effect and the influence on uterine artery blood velocity of Ge-Gen Decoction(GGD), a well-known Chinese herbal formula. In female ICR mice, uterine contraction was induced by oxytocin exposure following estradiol benzoate pretreatment, and the uterine artery blood velocity was detected by Doppler ultrasound. Histopathological examination of the uterine tissue samples were performed by H&E staining. Ex vivo studies demonstrated that oxytocin, posterior pituitary, or acetylcholine induced contractions in isolated mouse uterus. GGD inhibited both spontaneous and stimulated contractions. In vivo study demonstrated that GGD significantly reduced oxytocin-induced writhing responses with a maximal inhibition of 87%. Further study demonstrated that GGD normalized oxytocin-induced abnormalities of prostaglandins F_2 alpha(PGF_(2α)) and Ca^(2+) in mice. In addition, injection of oxytocin induced a decrease in uterine artery blood flow velocity. Pretreatment with GGD reversed the oxytocin response on blood flow velocity. Histopathological examination showed pretreatment with GGD alleviated inflammation and edema in the uterus when compared with the model group. Both ex vivo and in vivo results indicated that GGD possessed a significant spasmolytic effect on uterine tetanic contraction as well as improvement on uterine artery blood velocity which may involve PGF_(2α) and Ca^(2+) signaling, suggesting that GGD may have a clinic potential in PD therapy.展开更多
AIM To investigate the effect of metformin on activated hepatic stellate cells(HSCs) and the possible signaling pathways involved. METHODS A fibrotic mouse model was generated by intraperitoneal injection of carbon te...AIM To investigate the effect of metformin on activated hepatic stellate cells(HSCs) and the possible signaling pathways involved. METHODS A fibrotic mouse model was generated by intraperitoneal injection of carbon tetrachloride(CCl_4) and subsequent treatment with or without metformin. The level of fibrosis was detected by hematoxylin-eosin staining, Sirius Red staining, and immunohistochemistry. The HSC cell line LX-2 was used for in vitro studies. The effect of metformin on cell proliferation(CCK8 assay),motility(scratch test and Transwell assay), contraction(collagen gel contraction assay), extracellular matrix(ECM) secretion(Western blot), and angiogenesis(ELISA and tube formation assay) was investigated. We also analyzed the possible signaling pathways involved by Western blot analysis.RESULTS Mice developed marked liver fibrosis after intraperitoneal injection with CCl_4 for 6 wk. Metformin decreased the activation of HSCs, reduced the deposition of ECM, and inhibited angiogenesis in CCl_4-treated mice. Platelet-derived growth factor(PDGF) promoted the fibrogenic response of HSCs in vitro, while metformin inhibited the activation, proliferation, migration, and contraction of HSCs, and reduced the secretion of ECM. Metformin decreased the expression of vascular endothelial growth factor(VEGF) in HSCs through inhibition of hypoxia inducible factor(HIF)-1α in both PDGF-BB treatment and hypoxic conditions, and it down-regulated VEGF secretion by HSCs and inhibited HSC-based angiogenesis in hypoxic conditions in vitro. The inhibitory effects of metformin on activated HSCs were mediated by inhibiting the Akt/mammalian target of rapamycin(m TOR) and extracellular signal-regulated kinase(ERK) pathways via the activation of adenosine monophosphate-activated protein kinase(AMPK).CONCLUSION Metformin attenuates the fibrogenic response of HSCs in vivo and in vitro, and may therefore be useful for the treatment of chronic liver diseases.展开更多
AIM:To investigate the effects of sulfated cholecystokinin octapeptide (CCK-8S) on the contractile activity of guinea-pig proximal colon.METHODS:Proximal colonic smooth muscle (PCSM) strips were obtained from adult fe...AIM:To investigate the effects of sulfated cholecystokinin octapeptide (CCK-8S) on the contractile activity of guinea-pig proximal colon.METHODS:Proximal colonic smooth muscle (PCSM) strips were obtained from adult female guinea pigs and contractile response of PCSM strips was recorded using a polyphysiograph.PCSM cells were isolated by enzymatic digestion.Resting potential (RP),action potential (AP),large conductance potassium channel currents (IBKCa) and L-type calcium currents (ICa-L) were recorded by patch-clamp techniques.RESULTS:(1) CCK-8S (10-7 mol/L) enhanced the mean contractile amplitude of colonic circular muscle and longitudinal muscle (LM) strips by 56.53% ± 11.92%(P=0.038) and 65.93% ± 12.98% (P=0.019),respectively,as well as the mean frequency of LM by 31.69% ± 13.58% (P=0.023),which were significantly attenuated by pretreating strips with devazepide,nifedipine,iberiotoxin,thapsigargin (TG) and BAPTA-AM (BA) respectively;(2) CCK-8S (10-7 mol/L) increased the AP amplitude by 38.6% ± 3.2% (P=0.015),decreased AP duration by 36.9% ± 8.7% (P=0.026),and depolarized the RP from-61.3 ± 2.7 mV to-29.8 ± 5.9 mV (P=0.032);and (3) Compared with the normal control group,CCK-8S (10-7 mol/L) enhanced the peak current of IBKCa by 18.7% ± 2.1% (from 916 ± 183 pA to 1088 ± 226 pA;at +60 mV;P=0.029),which was inhibited by respective pretreatment with iberiotoxin and devazepide.Additionally,CCK-8S (10-7 mol/L) intensif ied the peak current of ICa-L by 40% (from 60 ± 8 pA to 84 ± 11 pA;at +10 mV;P=0.012),compared to the normal control group,which was apparently suppressed by respective pretreatment with nifedipine,devazepide,TG and BA.In the respective presence of heparin and staurosporine,CCK-8S did not signif icantly enhance IBKCa and ICa-L.CONCLUSION:The results suggest that CCK-8S promotes guinea-pig proximal colon contraction by CCK1 receptors,following activation of the inositol triphosphate-protein kinase C signal transduction pathway.展开更多
We describe a rapid anterior capsule contraction following phacoemulsifiction and intraocular lens(IOL) implantation in an old woman with high myopia. The patient with high myopia complicated with cataract received ph...We describe a rapid anterior capsule contraction following phacoemulsifiction and intraocular lens(IOL) implantation in an old woman with high myopia. The patient with high myopia complicated with cataract received phacoemulcification and IOL implantation bilaterally .The best-corrected visual acuity (BCVA) improved from 0.1 to 0.4 in the right eye and 0.5 in the left eye 1 week after surgeries.5 weeks after surgery of the right eye and 4 weeks after surgery of the left eye, the patient complained blurred vision in the right eye. BCVA of the right eye was 0.06 and that of the left was 0.1. Slit-lamp examination revealed anterior capsule contraction in both eyes and a fully closed capsulorhexis opening in the right eye. The IOLs were centered but almost completely enclosed, with numerous linear fibrous folds radiating from the hick central fibrosis. We surgically excised the central part of the anterior capsule of the eyes with microscissors, resulting again in BCVA of 0.4 and 0.5 in the right and left eyes respectively. Anterior capsule contraction might appear much earlier than three months after phacoemulsification and IOL implantation surgery in case of high myopia complicated with cataract. Patients with high myopia receive cataract and IOL surgery should be monitored carefully for the rapid development of anterior capsule contraction.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
AIM:To clarify the effects of anti-hypertensive drugs on esophageal contraction and determine their possi-ble relationship with gastro-esophageal reflux disease.METHODS:Thirteen healthy male volunteers were enrolled. ...AIM:To clarify the effects of anti-hypertensive drugs on esophageal contraction and determine their possi-ble relationship with gastro-esophageal reflux disease.METHODS:Thirteen healthy male volunteers were enrolled. Esophageal body peristaltic contractions and lower esophageal sphincter (LES) pressure were measured using high resolution manometry. All subjects were randomly examined on four separate occasions following administrations of nifedipine,losartan,and atenolol,as well as without any drug administration.RESULTS:Peristaltic contractions by the esophageal body were separated into three segments by two troughs. The peak peristaltic pressures in the mid and lower segments of the esophageal body under atenolol administration were signifi cantly higher than those without medication in a supine position. On the other hand,peristaltic pressures under nifedipine administration were lower than those observed without drug ad-ministration. Losartan did not change esophageal body peristalsis. Atenolol elevated LES pressure and slowed peristaltic wave transition,while the effects of nifedip-ine were the opposite. CONCLUSION:Among the anti-hypertensive drugs tested,atenolol enhanced esophageal motor activity,which was in contrast to nifedipine.展开更多
The lattice-oxygen-mediated mechanism is considered as a reasonable mechanism for the electrochemical catalytic oxygen evolution reaction(OER)of NiFe layered double hydroxides(LDHs).A NiFe LDH with distinct lattice co...The lattice-oxygen-mediated mechanism is considered as a reasonable mechanism for the electrochemical catalytic oxygen evolution reaction(OER)of NiFe layered double hydroxides(LDHs).A NiFe LDH with distinct lattice contraction and microcrystallization was synthesized via a simple one-step method using sodium gluconate.The lattice contraction is attributed to the interaction of carbon in sodium gluconate and iron in NiFe LDH.The NiFe LDH with optimized microcrystallization and lattice contraction shows a low overpotential of 217 mV at a current density of 10 mA cm^(−2) and excellent durability of 20 h at a high current density of 100 mA cm^(−2).The results revealed that a contractive metal–oxygen bond could boost the intrinsic activity of active sites and the microcrystallization promotes an increase in the number of active sites in terms of unit area.The chemical environment of oxygen elemental characterization and resistance at different chronopotentiometry times confirm that the lattice oxygen element is indeed involved in the process of OER,supporting the lattice-oxygen-mediated mechanism of NiFe LDH.Density functional theory calculations reveal that contractive metal–oxygen bonds induced a reduction of the adsorption energy barrier of intermediate products,thus improving the intrinsic catalytic activity.The special characteristics of microcrystallization and lattice contraction of NiFe LDH provide a strategy to improve both the number and the intrinsic activity of active sites in a versatile manner.展开更多
基金jointly supported by the National Natural Science Foundation of China[grant numbers U2342202 and 42175005]the Qing Lan Project[grant number R2023Q06]。
文摘In 2021,Cempaka,a tiny tropical cyclone,made landfall in China.As the TC intensified prior to landfall,the tropical cyclone size measured with precipitation decreased significantly.A numerical simulation was conducted to examine the possible processes modulating the storm size.Azimuthally mean potential vorticity(PV)was found to decrease mainly in the middle to upper troposphere between 50-and 80-km radii.The PV budget results indicate that the advection and generation of mean PV associated with asymmetric processes,rather than the symmetric processes,primarily contributed to the decrease in mean PV.These asymmetric processes leading to a negative PV tendency were likely associated with inactive outer rainbands.In contrast,the tangential winds simultaneously expanded radially outward,possibly related to inner-core diabatic heating.The findings here emphasize the importance of outer rainband activity in tropical cyclone size change.
文摘AIM:To evaluate the efficacy and safety of combining posterior scleral contraction(PSC)with intravitreal perfluoropropane(C_(3)F_(8))injection in high myopia with macular hole retinal detachment(MHRD).METHODS:A total of 22 participants(22 eyes)with high myopia[axial length(AL)≥26.5 mm]and MHRD who underwent PSC combined with intravitreal C_(3)F_(8)injection,with at least 6mo of follow-up were retrospectively recruited.Outcome measures included best-corrected visual acuity(BCVA),AL,optical coherence tomography(OCT)findings,and adverse events.Retinal recovery was categorized as type Ⅰ(macular hole bridging with retinal reattachment)or type Ⅱ(reattachment without hole bridging).RESULTS:The mean age of participants was 62.1±8.8y and mean follow-up duration was 9.18±4.21mo.Complete retinal reattachment was observed in 11 eyes(50%)at postoperative day 1,19 eyes(86.3%)at week 1,and all 22 eyes at month 1.Ten eyes(45.5%)achieved type Ⅰ recovery and 12 eyes(54.5%)achieved type Ⅱ.Mean BCVA improved from 1.68±0.84 logMAR before surgery to 1.21±0.65 logMAR after surgery(P<0.001),and AL was significantly reduced compared to baseline(29.07±2.05 vs 30.8±2.2 mm;P<0.001).No serious complications were reported.CONCLUSION:PSC combined with intravitreal C_(3)F_(8)injection is a safe and effective treatment for MHRD in highly myopic eyes,especially for retinal detachment limited within the vascular arcade.
基金funded by National Science,Research and Innovation Fund(NSRF)King Mongkut's University of Technology North Bangkok with Contract No.KMUTNB-FF-68-B-46.
文摘In this manuscript,the notion of a hesitant fuzzy soft fixed point is introduced.Using this notion and the concept of Suzuki-type(μ,ν)-weak contraction for hesitant fuzzy soft set valued-mapping,some fixed point results are established in the framework of metric spaces.Based on the presented work,some examples reflecting decision-making problems related to real life are also solved.The suggested method’s flexibility and efficacy compared to conventional techniques are demonstrated in decision-making situations involving uncertainty,such as choosing the best options in multi-criteria settings.We noted that the presented work combines and generalizes two major concepts,the idea of soft sets and hesitant fuzzy set-valued mapping from the existing literature.
文摘In this study,we explore some of the best proximity point results for generalized proximal contractions in the setting of double-controlled metric-type spaces.A non-trivial example is given to elucidate our analysis,and some novel results are derived.The discovered results generalize previously known results in the context of a double controlled metric type space environment.This article’s proximity point results are the first of their kind in the realm of controlled metric spaces.To build on the results achieved in this article,we present an application demonstrating the usability of the given results.
文摘Any composition sequential mapping, periodic composition mapping of a complete non-empty metric space M into M with geometric mean contraction ratio less than 1 ( simplifying as 'g-contraction mapping' ) has a unique fixed point in M . Applications of the theorem to the proof of existence and uniqueness of the solutions of a set of non-linear differential equations and a coupled integral equations of symmetric bending of shallow shell of revolution are given.
基金Project supported by Research Program of Science and Technology at Universities of Inner Mongolia Autonomous Region,China(Grant Nos.NJZY16493and NJZC17458)
文摘The spontaneous oscillatory contraction（SPOC） of myofibrils is the essential property inherent to the contractile system of muscle. Muscle contraction results from cyclic interactions between actin filament and myosin II which is a dimeric motor protein with two heads. Taking the two heads of myosin II as an indivisible element and considering the effects of cooperative behavior between the two heads on rate constants in the mechanochemical cycle, the present work proposes the tenstate mechanochemical cycle model for myosin II dimer. The simulations of this model show that the proportion of myosin II in different states periodically changes with time, which results in the sustained oscillations of contractive tension, and serves as the primary factor for SPOC. The good fit of this model to experimental results suggests that the cooperative interaction between the two heads of myosin II dimer may be one of the underlying mechanisms for muscle contraction.
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A new branch of hypergraph theory-directed hyperaph theory and a kind of new methods-dicomposition contraction(DCP, PDCP and GDC) methods are presented for solving hypernetwork problems.lts computing time is lower than that of ECP method in several order of magnitude.
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.
文摘In this article, we introduce a new type of contraction named almost type α-F-Z-weak contraction, which comes from a combination of F-contraction, Z-contraction, and almost contraction, and then we provide sufficient conditions for the existence and uniqueness of fixed point of such contractions in complete metric spaces and give some related fixed point results. In addition, some related fixed point results can derive from our main results.
文摘For a graphlike manifold whose contraction is a generalized cuneate figure,we deribve a formula in this paper to compute the number of homeomorphism classes of it by using twist operations and the combinatorial theory.
文摘Thick-skinned contractional salt structures are widely developed in the western Kuqa depression, northern Tarim basin. To understand the mechanisms that govern the development of these structures, physical experiments are conducted and the results show that they are largely governed by the activities of basement faults and the forming of paleo-uplifts and basement slopes. The model materials in this study are dry sand, vaseline and plasticene （or hard foam）, simulating the suprasalt, salt, and subsalt layers respectively. The experiments show that, due to the activities of basement faults and the forming of the paleo-uplifts, salt bodies usually accumulate and thicken significantly on the middle top of the paleo-uplifts which are constrained by the pre-exiting boundary faults. The development of large-scale thrust faults and salt nappes is favored by the basement slops with larger dips. The experiments also conclude that differential structural deformation could occur between the subsalt and suprasalt layers because of the presence of salt layers. Their geometries and the locations of structural highs are different, despite of the great similarities in the uplifted areas. The pierced salt diapir is not observed in the experiments, which indicates that the contractional shortening does not effectively accelerate the development of the salt diapir.
基金the Natural Scientific Foundation of Shandong Province,No.Y2001C06
文摘AIM: To investigate the effects of areca on the contractile activity of isolated colonic muscle strips in rats and mechanism involved. METHODS: Each strip (LMPC, longitudinal muscle of proximal colon; CMPC, circular muscle of proximal colon; LMDC, longitudinal muscle of distal colon; CMDC, circular muscle of distal colon.) was suspended in a tissue chamber containing 5 mL Krebs solution (37 degrees C), bubbled continuously with 950 mL.L(-1) O(2) and 50 mL.L(-1) CO(2). The mean contractile amplitude (A), the resting tension (T), and the contractile frequency (F) were simultaneously recorded on recorders. RESULTS: Areca dose dependently increased the mean contractile amplitude, the resting tension of proximal and distal colonic smooth muscle strips in rats (P【0.05). It also partly increased the contractile frequency of colonic smooth muscle strips in rats (P【0.05). The effects were partly inhibited by atropine (the resting tension of LMPC decreased from 0.44 +/- 0.12 to 0.17 +/- 0.03; the resting tension of LMDC decreased from 0.71 +/- 0.14 to 0.03 +/- 0.01; the mean contractile amplitude of LMPC increased from -45.8 +/- 7.2 to -30.5 +/- 2.9; the motility index of CMDC decreased from 86.6 +/- 17.3 to 32.8 +/- 9.3; P【0.05 vs areca), but the effects were not inhibited by hexamethonium (P】0.05). CONCLUSION: Areca stimulated the motility of isolated colonic smooth muscle strips in rats. The stimulation of areca might be relevant with M receptor partly.
基金supported by a grant from Ministry of Education,the New Teachers’Fund for Ph.D Stations(Program No.20110096120011)2011’Program for Excellent Scientific and Technological Innovation Team of Jiangsu Higher Education
文摘The uterine tetanic contraction and uterine artery blood flow reduction are possible reasons for primary dysmenorrhea(PD). In the present study, we aimed to evaluate the uterine relaxant effect and the influence on uterine artery blood velocity of Ge-Gen Decoction(GGD), a well-known Chinese herbal formula. In female ICR mice, uterine contraction was induced by oxytocin exposure following estradiol benzoate pretreatment, and the uterine artery blood velocity was detected by Doppler ultrasound. Histopathological examination of the uterine tissue samples were performed by H&E staining. Ex vivo studies demonstrated that oxytocin, posterior pituitary, or acetylcholine induced contractions in isolated mouse uterus. GGD inhibited both spontaneous and stimulated contractions. In vivo study demonstrated that GGD significantly reduced oxytocin-induced writhing responses with a maximal inhibition of 87%. Further study demonstrated that GGD normalized oxytocin-induced abnormalities of prostaglandins F_2 alpha(PGF_(2α)) and Ca^(2+) in mice. In addition, injection of oxytocin induced a decrease in uterine artery blood flow velocity. Pretreatment with GGD reversed the oxytocin response on blood flow velocity. Histopathological examination showed pretreatment with GGD alleviated inflammation and edema in the uterus when compared with the model group. Both ex vivo and in vivo results indicated that GGD possessed a significant spasmolytic effect on uterine tetanic contraction as well as improvement on uterine artery blood velocity which may involve PGF_(2α) and Ca^(2+) signaling, suggesting that GGD may have a clinic potential in PD therapy.
基金Supported by National Natural Science Foundation of China,No.81370590
文摘AIM To investigate the effect of metformin on activated hepatic stellate cells(HSCs) and the possible signaling pathways involved. METHODS A fibrotic mouse model was generated by intraperitoneal injection of carbon tetrachloride(CCl_4) and subsequent treatment with or without metformin. The level of fibrosis was detected by hematoxylin-eosin staining, Sirius Red staining, and immunohistochemistry. The HSC cell line LX-2 was used for in vitro studies. The effect of metformin on cell proliferation(CCK8 assay),motility(scratch test and Transwell assay), contraction(collagen gel contraction assay), extracellular matrix(ECM) secretion(Western blot), and angiogenesis(ELISA and tube formation assay) was investigated. We also analyzed the possible signaling pathways involved by Western blot analysis.RESULTS Mice developed marked liver fibrosis after intraperitoneal injection with CCl_4 for 6 wk. Metformin decreased the activation of HSCs, reduced the deposition of ECM, and inhibited angiogenesis in CCl_4-treated mice. Platelet-derived growth factor(PDGF) promoted the fibrogenic response of HSCs in vitro, while metformin inhibited the activation, proliferation, migration, and contraction of HSCs, and reduced the secretion of ECM. Metformin decreased the expression of vascular endothelial growth factor(VEGF) in HSCs through inhibition of hypoxia inducible factor(HIF)-1α in both PDGF-BB treatment and hypoxic conditions, and it down-regulated VEGF secretion by HSCs and inhibited HSC-based angiogenesis in hypoxic conditions in vitro. The inhibitory effects of metformin on activated HSCs were mediated by inhibiting the Akt/mammalian target of rapamycin(m TOR) and extracellular signal-regulated kinase(ERK) pathways via the activation of adenosine monophosphate-activated protein kinase(AMPK).CONCLUSION Metformin attenuates the fibrogenic response of HSCs in vivo and in vitro, and may therefore be useful for the treatment of chronic liver diseases.
基金Supported by National Natural Science Foundation of China,No. 30871148
文摘AIM:To investigate the effects of sulfated cholecystokinin octapeptide (CCK-8S) on the contractile activity of guinea-pig proximal colon.METHODS:Proximal colonic smooth muscle (PCSM) strips were obtained from adult female guinea pigs and contractile response of PCSM strips was recorded using a polyphysiograph.PCSM cells were isolated by enzymatic digestion.Resting potential (RP),action potential (AP),large conductance potassium channel currents (IBKCa) and L-type calcium currents (ICa-L) were recorded by patch-clamp techniques.RESULTS:(1) CCK-8S (10-7 mol/L) enhanced the mean contractile amplitude of colonic circular muscle and longitudinal muscle (LM) strips by 56.53% ± 11.92%(P=0.038) and 65.93% ± 12.98% (P=0.019),respectively,as well as the mean frequency of LM by 31.69% ± 13.58% (P=0.023),which were significantly attenuated by pretreating strips with devazepide,nifedipine,iberiotoxin,thapsigargin (TG) and BAPTA-AM (BA) respectively;(2) CCK-8S (10-7 mol/L) increased the AP amplitude by 38.6% ± 3.2% (P=0.015),decreased AP duration by 36.9% ± 8.7% (P=0.026),and depolarized the RP from-61.3 ± 2.7 mV to-29.8 ± 5.9 mV (P=0.032);and (3) Compared with the normal control group,CCK-8S (10-7 mol/L) enhanced the peak current of IBKCa by 18.7% ± 2.1% (from 916 ± 183 pA to 1088 ± 226 pA;at +60 mV;P=0.029),which was inhibited by respective pretreatment with iberiotoxin and devazepide.Additionally,CCK-8S (10-7 mol/L) intensif ied the peak current of ICa-L by 40% (from 60 ± 8 pA to 84 ± 11 pA;at +10 mV;P=0.012),compared to the normal control group,which was apparently suppressed by respective pretreatment with nifedipine,devazepide,TG and BA.In the respective presence of heparin and staurosporine,CCK-8S did not signif icantly enhance IBKCa and ICa-L.CONCLUSION:The results suggest that CCK-8S promotes guinea-pig proximal colon contraction by CCK1 receptors,following activation of the inositol triphosphate-protein kinase C signal transduction pathway.
文摘We describe a rapid anterior capsule contraction following phacoemulsifiction and intraocular lens(IOL) implantation in an old woman with high myopia. The patient with high myopia complicated with cataract received phacoemulcification and IOL implantation bilaterally .The best-corrected visual acuity (BCVA) improved from 0.1 to 0.4 in the right eye and 0.5 in the left eye 1 week after surgeries.5 weeks after surgery of the right eye and 4 weeks after surgery of the left eye, the patient complained blurred vision in the right eye. BCVA of the right eye was 0.06 and that of the left was 0.1. Slit-lamp examination revealed anterior capsule contraction in both eyes and a fully closed capsulorhexis opening in the right eye. The IOLs were centered but almost completely enclosed, with numerous linear fibrous folds radiating from the hick central fibrosis. We surgically excised the central part of the anterior capsule of the eyes with microscissors, resulting again in BCVA of 0.4 and 0.5 in the right and left eyes respectively. Anterior capsule contraction might appear much earlier than three months after phacoemulsification and IOL implantation surgery in case of high myopia complicated with cataract. Patients with high myopia receive cataract and IOL surgery should be monitored carefully for the rapid development of anterior capsule contraction.
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Supported by The Grants-in-Aid from Science Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan, No. 19590724
文摘AIM:To clarify the effects of anti-hypertensive drugs on esophageal contraction and determine their possi-ble relationship with gastro-esophageal reflux disease.METHODS:Thirteen healthy male volunteers were enrolled. Esophageal body peristaltic contractions and lower esophageal sphincter (LES) pressure were measured using high resolution manometry. All subjects were randomly examined on four separate occasions following administrations of nifedipine,losartan,and atenolol,as well as without any drug administration.RESULTS:Peristaltic contractions by the esophageal body were separated into three segments by two troughs. The peak peristaltic pressures in the mid and lower segments of the esophageal body under atenolol administration were signifi cantly higher than those without medication in a supine position. On the other hand,peristaltic pressures under nifedipine administration were lower than those observed without drug ad-ministration. Losartan did not change esophageal body peristalsis. Atenolol elevated LES pressure and slowed peristaltic wave transition,while the effects of nifedip-ine were the opposite. CONCLUSION:Among the anti-hypertensive drugs tested,atenolol enhanced esophageal motor activity,which was in contrast to nifedipine.
基金National Natural Science Foundation of China,Grant/Award Numbers:51874357,51872333,U20A20123。
文摘The lattice-oxygen-mediated mechanism is considered as a reasonable mechanism for the electrochemical catalytic oxygen evolution reaction(OER)of NiFe layered double hydroxides(LDHs).A NiFe LDH with distinct lattice contraction and microcrystallization was synthesized via a simple one-step method using sodium gluconate.The lattice contraction is attributed to the interaction of carbon in sodium gluconate and iron in NiFe LDH.The NiFe LDH with optimized microcrystallization and lattice contraction shows a low overpotential of 217 mV at a current density of 10 mA cm^(−2) and excellent durability of 20 h at a high current density of 100 mA cm^(−2).The results revealed that a contractive metal–oxygen bond could boost the intrinsic activity of active sites and the microcrystallization promotes an increase in the number of active sites in terms of unit area.The chemical environment of oxygen elemental characterization and resistance at different chronopotentiometry times confirm that the lattice oxygen element is indeed involved in the process of OER,supporting the lattice-oxygen-mediated mechanism of NiFe LDH.Density functional theory calculations reveal that contractive metal–oxygen bonds induced a reduction of the adsorption energy barrier of intermediate products,thus improving the intrinsic catalytic activity.The special characteristics of microcrystallization and lattice contraction of NiFe LDH provide a strategy to improve both the number and the intrinsic activity of active sites in a versatile manner.
