Bionic manta underwater vehicles will play an essential role in future oceans and can perform tasks,such as long-duration reconnaissance and exploration,due to their efficient propulsion.The manta wings’deformation i...Bionic manta underwater vehicles will play an essential role in future oceans and can perform tasks,such as long-duration reconnaissance and exploration,due to their efficient propulsion.The manta wings’deformation is evident during the swimming process.To improve the propulsion performance of the unmanned submersible,the study of the deformation into the bionic pectoral fin is necessary.In this research,we designed and fabricated a flexible bionic pectoral fin,which is based on the Fin Ray®effect with active and passive deformation(APD)capability.The APD fin was actively controlled by two servo motors and could be passively deformed to variable degrees.The APD fin was moved at 0.5 Hz beat frequency,and the propulsive performance was experimentally verified of the bionic pectoral fins equipped with different extents of deformation.These results showed that the pectoral fin with active–passive deformed capabilities could achieve similar natural biological deformation in the wingspan direction.The average thrust(T)under the optimal wingspan deformation is 61.5%higher than the traditional passive deformed pectoral fins.The obtained results shed light on the design and optimization of the bionic pectoral fins to improve the propulsive performance of unmanned underwater vehicles(UUV).展开更多
A robotic fish driven by oscillating fins, 'Cownose Ray-I', is developed, which is in dorsoventrally flattened shape without a tail. The robotic fish is composed of a body and two lateral fins. A three-factor ...A robotic fish driven by oscillating fins, 'Cownose Ray-I', is developed, which is in dorsoventrally flattened shape without a tail. The robotic fish is composed of a body and two lateral fins. A three-factor kinematic model is established and used in the design of a mechanism. By controlling the three kinematic parameters, the robotic fish can accelerate and maneuver. Forward velocity is dependent on the largest amplitude and the number of waves in the fins, while the relative contribution of fin beat frequency to the forward velocity of the robotic fish is different from the usual result. On the other hand, experimental results on maneuvering show that phase difference has a stronger effect on swerving than the largest amplitude to some extent. In addition, as propulsion waves pass from the trailing edge to the leading edge, the robotic fish attains a backward velocity of 0. 15 m·s^(-1).展开更多
In present,there are increasing interests in the research on mechanical and control system of underwater vehicles.These ongoing research efforts are motivated by more pervasive applications of such vehicles including ...In present,there are increasing interests in the research on mechanical and control system of underwater vehicles.These ongoing research efforts are motivated by more pervasive applications of such vehicles including seabed oil and gas explorations, scientific deep ocean surveys,military purposes,ecological and water environmental studies,and also entertainments. However,the performance of underwater vehicles with screw type propellers is not prospective in terms of its efficiency and maneuverability.The main weaknesses of this kind of propellers are the production of vortices and sudden generation of thrust forces which make the control of the position and motion difficult. On the other hand,fishes and other aquatic animals are efficient swimmers,posses high maneuverability,are able to follow trajectories,can efficiently stabilize themselves in currents and surges,create less wakes than currently used underwater vehicle, and also have a noiseless propulsion.The fish's locomotion mechanism is mainly controlled by its caudal fin and paired pectoral fins.They are classified into Body and/or Caudal Fin(BCF)and Median and/or paired Pectoral Fins(MPF).The study of highly efficient swimming mechanisms of fish can inspire a better underwater vehicles thruster design and its mechanism. There are few studies on underwater vehicles or fish robots using paired pectoral fins as thruster.The work presented in this paper represents a contribution in this area covering study,design and implementation of locomotion mechanisms of paired pectoral fins in a fish robot.The performance and viability of the biomimetic method for underwater vehicles are highlighted through in-water experiment of a robotic fish.展开更多
Generally the underwater bio-robots take the tail fin as propulsor, and combined with pectoral fin they can manoeuvre agilely and control their position and movement at will. In nature, a lot of fishes realize to susp...Generally the underwater bio-robots take the tail fin as propulsor, and combined with pectoral fin they can manoeuvre agilely and control their position and movement at will. In nature, a lot of fishes realize to suspend itself in water to go forward and to move back up by the pectoral fin moving complexly. So that it is significant theoretically and valuable for practical application to investigate the propulsive principle and hydrodynamic performance of pectoral fin, and find the method utilizing the pectoral fin to manoeuvre the underwater bio-robot agilely. In this paper, a two degree of freedom （DoF） motion model is established for a rigid pectoral fin, and the hydrodynamic performances of the pectoral fin are studied by use of the pectoral fin propulsive experimental platform developed by Harbin Engineering University, simultaneously the hydrodynamic performance of the pectoral fin is analyzed when some parameters change. Then, through the secondary development of FLUENT （CFD code） software, the hydrodynamic performances of rigid pectoral fin in viscous flows are calculated and the results are compared with the latest experimental results. The research in this paper will provide the theoretical reference for the design of the manoeuvring system imitating pectoral fin, at the same time will become the foundation for the development of the small underwater bio-robot.展开更多
At a temperature of 23.0 - 24.8℃, the mixed feeding of Japanese anchovy larvae was initiated 24 h before the yolk-sac was exhausted. The point of no return （PNR） was reached on the 6th day after hatching. On the 4t...At a temperature of 23.0 - 24.8℃, the mixed feeding of Japanese anchovy larvae was initiated 24 h before the yolk-sac was exhausted. The point of no return （PNR） was reached on the 6th day after hatching. On the 4th day after hatching, the pectoral angle appeared in both fed and unfed anchovy larvae although it was more evident and sharper in the starved and the PNR stage larvae than in the fed ones. According to observations of larvae collected in the sea, the pectoral angles were evident not only in the larvae of 3.62 - 7.44 mm in standard length, but also in the larvae of 2.70 mm in standard length with remnants of yolk. The pectoral angles became diffuse when the larvae reached 7.84 mm and vanished at 9.86 mm. The pectoral angle cannot be used as a criterion to distinguish healthy from starving larvae.展开更多
Background: Pectoral nerves (PECS) block has been reported to be effective for a perioperative analgesia for breast cancer surgery. In addition, we may consider that the PECS block is also effective for motor function...Background: Pectoral nerves (PECS) block has been reported to be effective for a perioperative analgesia for breast cancer surgery. In addition, we may consider that the PECS block is also effective for motor function in postoperative period. Therefore, we investigated the effect of PECS block for motor function in postoperative period. Methods: This study selected the patients performed the breast cancer surgery between April and September, 2015. The study surveyed the difficulty of movement of the upper limbs at postoperative day 5 (D5) and postoperative month 6 (M6) by performing telephone survey. We counted the number of patients who complained of the difficulty of movement of the upper limbs. All results were compared using the chi- squared test. P < 0.05 was considered statistically significant. Results: 93 patients received only general anesthesia (G group). 85 patients received PECS block with general anesthesia (P group). The number of the P group at D5 was 2 patients. On the other hand, the number of the G group was 15 patients (P = 0.042). In the same way, the number of the P group M6 was no patient. On the other hand, the number of the G group was 10 patients (P = 0.043). Conclusion: A PECS block is effective for motor function recovery in the early postoperative period after breast cancer surgery.展开更多
An agonistic display by a white shark was observed and photographed during a cage dive at Guadalupe Island in November 2015. Exhibiting exaggerated pectoral fin depression, agonistic behaviors have been previously obs...An agonistic display by a white shark was observed and photographed during a cage dive at Guadalupe Island in November 2015. Exhibiting exaggerated pectoral fin depression, agonistic behaviors have been previously observed and described in several shark species. This account may be the first record of a white shark in close proximity to a caged diver, exhibiting strong pectoral fin depression significantly dipped, in the mid-agonistic display. Such displays should be considered as aggressive and potentially life-threatening by those using the ocean for recreational or professional purposes.展开更多
Background and Aims: Pectoral nerve blocks gained increasing recognition for adequate postoperative pain relief following breast surgery. Traditionally, anaesthetist administered preoperatively under ultrasound guidan...Background and Aims: Pectoral nerve blocks gained increasing recognition for adequate postoperative pain relief following breast surgery. Traditionally, anaesthetist administered preoperatively under ultrasound guidance, which added significantly to the total procedure time. We studied the effectiveness of intraoperative direct vision pectoral nerve block and reduction of total theatre time. Methods: We provided questionnaires to the eligible patients who underwent a mastectomy and or axillary node clearance from August 2018 to May 2019. All the patients had an intra-operative pectoral 1 and serratus plane (Pecs) block. Participants documented pain score twice daily, episodes of nausea or vomiting and type and dose of analgesia for the first seven postoperative days. We compiled and grouped the results into postoperative days 1 - 2 and 3 - 7 for data analysis. Results: Patients reported generally low levels of pain, with a median pain score of 1.75 out of 10 for postoperative days 1 - 2 (IQR 4). The score decreased to 0.7 for days 3 - 7 postoperatively (IQR 3) suggesting that most patients had generally minimal levels of pain apart from a few outliers. The average injection time for PECs blocks was 5 minutes, significantly less than USS guided techniques of 20 - 30 minutes. Conclusions: Our data suggest that nerve blocks under direct vision offer satisfactory efficacy in postoperative analgesia with minimal nausea and vomiting. This is in addition to substantial benefits in operative efficiency and reduction of total procedure time.展开更多
Dear Editor,Exaptation is defined as characters evolved for other usages(or for no function at all)and later“coopted”for their current role(Gould and Vrba,1982).Exaptation has occurred in many organisms,sometimes as...Dear Editor,Exaptation is defined as characters evolved for other usages(or for no function at all)and later“coopted”for their current role(Gould and Vrba,1982).Exaptation has occurred in many organisms,sometimes as an outcome of organ specialization for adaptation.This process is exemplified in the family Triglidae,commonly known as gurnards or sea robins.展开更多
Fish pectoral fin movement involves primarily a drag-based and a lift-based mechanisms to produce thrust. A numerical study on a pectoral fin rowing propulsion model based on the drag-based mechanism is presented in t...Fish pectoral fin movement involves primarily a drag-based and a lift-based mechanisms to produce thrust. A numerical study on a pectoral fin rowing propulsion model based on the drag-based mechanism is presented in this article. The propulsive mechanism of the pectoral fin rowing model is related with the voriticity and pressure in the flow field. The relationship between the thrust and kinematic parameters and the wake-captured problem are analyzed. It is shown that a high thrust is produced in the power stroke, mainly due to the backward translation acceleration, the anticlockwise angular acceleration and the absence of stall in the uniform translation. Moreover, the flow control mechanism and the effect of dynamic flexible deformation are further analyzed. To properly choose controllable factors and adopt an appropriate dynamic deformation can improve the propulsive performance.展开更多
Automatic pectoral muscle removal on medio-lateral oblique (MLO) view of mammogram is an essential step for many mammographic processing algorithms. However,it is still a very difficult task since the sizes,the shapes...Automatic pectoral muscle removal on medio-lateral oblique (MLO) view of mammogram is an essential step for many mammographic processing algorithms. However,it is still a very difficult task since the sizes,the shapes and the intensity contrasts of pectoral muscles change greatly from one MLO view to another. In this paper,we propose a novel method based on a discrete time Markov chain (DTMC) and an active contour model to automatically detect the pectoral muscle boundary. DTMC is used to model two important characteristics of the pectoral muscle edge,i.e.,continuity and uncertainty. After obtaining a rough boundary,an active contour model is applied to refine the detection results. The experimental results on images from the Digital Database for Screening Mammography (DDSM) showed that our method can overcome many limitations of existing algorithms. The false positive (FP) and false negative (FN) pixel percentages are less than 5% in 77.5% mammograms. The detection precision of 91% meets the clinical requirement.展开更多
The numerical simulation of the self-propelled motion of a fish with a pair of rigid pectoral fins is presented.A Navier-Stokes equation solver incorporating with the multi-block and overset grid method is developed t...The numerical simulation of the self-propelled motion of a fish with a pair of rigid pectoral fins is presented.A Navier-Stokes equation solver incorporating with the multi-block and overset grid method is developed to deal with the multi-body and moving body problems.The lift-based swimming mode is selected for the fin motion.In the lift-based swimming mode,the fin can generate great thrust and at the same time have no generation of lift force.It can be found when a pair of rigid pectoral fins generates the hydrodynamic moment,it may also generate a lateral force opposite to the centripetal direction,which has adverse effect on the turn motion of the fish.Furthermore,the periodic vortex structure generation and shedding,and their effects on the generation of hydrodynamic force are also demonstrated in this article.展开更多
Fluid dynamics of a self-propelled biomimetic underwater vehicle(BUV)with pectoral fins is investigated by an immersed boundary(IB)method.Typically,the BUV with a pair of pectoral fins starts from rest and attains a c...Fluid dynamics of a self-propelled biomimetic underwater vehicle(BUV)with pectoral fins is investigated by an immersed boundary(IB)method.Typically,the BUV with a pair of pectoral fins starts from rest and attains a constant mean velocity as the mean longitudinal force is zero.The capability and accuracy of the IB method to deal with the interaction between the fluid and complex moving body are firstly validated.Then we carry out a parametric study to understand the effect of key governing parameters on the dynamic response of the BUV.It is found that with the increase of motion frequency or rolling amplitude,the pectoral fin propulsors can induce larger forward velocity so that the BUV takes less time to attain its stable periodic swimming state.Although the pectoral fin is a very complicated lifting surface,a linear relationship between forward Reynolds number(final swimming velocity is used as velocity scale)and frequency Reynolds number(product of motion frequency and fin chord length is used as velocity scale)can be established when the frequency Reynolds number is above a critical value.A linear relationship between forward Reynolds number and rolling amplitude is also found within the studied range of rolling amplitude.Furthermore,a small-density-ratio BUV is sensitive to the surrounding flow with more rapid evolution process of self-propulsion.Whereas,BUV with a large density ratio is more stable.The implications of the hydrodynamic analysis on the bio-inspired engineering design of BUV with pectoral fins are also discussed.展开更多
Background Broilers stand out as one of the fastest-growing livestock globally,making a substantial contribution to animal meat production.However,the molecular and epigenetic mechanisms underlying the rapid growth an...Background Broilers stand out as one of the fastest-growing livestock globally,making a substantial contribution to animal meat production.However,the molecular and epigenetic mechanisms underlying the rapid growth and development of broiler chickens are still unclear.This study aims to explore muscle development patterns and regulatory networks during the postnatal rapid growth phase of fast-growing broilers.We measured the growth performance of Cornish(CC)and White Plymouth Rock(RR)over a 42-d period.Pectoral muscle samples from both CC and RR were randomly collected at day 21 after hatching(D21)and D42 for RNA-seq and ATAC-seq library construction.Results The consistent increase in body weight and pectoral muscle weight across both breeds was observed as they matured,with CC outpacing RR in terms of weight at each stage of development.Differential expression analysis identified 398 and 1,129 genes in the two dimensions of breeds and ages,respectively.A total of 75,149 ATAC-seq peaks were annotated in promoter,exon,intron and intergenic regions,with a higher number of peaks in the promoter and intronic regions.The age-biased genes and breed-biased genes of RNA-seq were combined with the ATAC-seq data for subsequent analysis.The results spotlighted the upregulation of ACTC1 and FDPS at D21,which were primarily associated with muscle structure development by gene cluster enrichment.Additionally,a noteworthy upregulation of MUSTN1,FOS and TGFB3 was spotted in broiler chickens at D42,which were involved in cell differentiation and muscle regeneration after injury,suggesting a regulatory role of muscle growth and repair.Conclusions This work provided a regulatory network of postnatal broiler chickens and revealed ACTC1 and MUSTN1 as the key responsible for muscle development and regeneration.Our findings highlight that rapid growth in broiler chickens triggers ongoing muscle damage and subsequent regeneration.These findings provide a foundation for future research to investigate the functional aspects of muscle development.展开更多
A mechanical design method of mbet fish is introduced in this paper. Based on this method, an autonomous 3-Dimension （3D） locomotion mbet fish with two pectoral fins and a caudal fin is developed. The pectoral fin m...A mechanical design method of mbet fish is introduced in this paper. Based on this method, an autonomous 3-Dimension （3D） locomotion mbet fish with two pectoral fins and a caudal fin is developed. The pectoral fin mechanism has 3 degrees of freedom （3-DOFs）, which enables the mbet fish to realize yawing and pitching motions by controlling two pectoral fins. And the eandal fin mechanism is designed based on fish body wave curve fitting. The forward velocity can be adjusted by changing the eandal mechanism＇ s oscillating frequency. Finally a physical implementation of the robot fish and experimental results are given.展开更多
We investigated the efficacy of ultrasound-guided pectoral nerves (PECS) block for modified radical mastectomy surgery retrospectively. Methods: We measured that pain scores and the use of additional analgesic drugs w...We investigated the efficacy of ultrasound-guided pectoral nerves (PECS) block for modified radical mastectomy surgery retrospectively. Methods: We measured that pain scores and the use of additional analgesic drugs were recorded in the postoperative care unit within 24 hours after the operation. Postoperative complications (i.e., nausea and vomiting) were noted. Results: Patients who received the PECS block under general anesthesia (PECS group) reported lower visual analog scale pain scores at 0, 1, 2, 4, 6, 12, 24 hours after the operation than patients who did not receive PECS block under general anesthesia (control group). Moreover, the use of additional analgesic drugs during the first 24 hours after surgery was lower in the PECS group than in the control group. While in the postoperative care unit, the PECS group had less nausea and vomiting than the control group. Conclusion: The PECS block provides effective postoperative analgesia within the first 24 hours after breast cancer surgery.展开更多
The natural distributional range of the cobitid loach Lepidocephalichthys alkaia is extended into Yunnan Province, China. The modified sexually dimorphic pectoral fin in males of L. alkaia is described.
基金supported by the National Key Research and Development Program(Grant no.2022YFC2805200,2020YFB1313200)the National Natural Science Foundation of China(Grant no.52001260,52201381,52371338)Ningbo Natural Science Foundation(Grant no.2022J062).
文摘Bionic manta underwater vehicles will play an essential role in future oceans and can perform tasks,such as long-duration reconnaissance and exploration,due to their efficient propulsion.The manta wings’deformation is evident during the swimming process.To improve the propulsion performance of the unmanned submersible,the study of the deformation into the bionic pectoral fin is necessary.In this research,we designed and fabricated a flexible bionic pectoral fin,which is based on the Fin Ray®effect with active and passive deformation(APD)capability.The APD fin was actively controlled by two servo motors and could be passively deformed to variable degrees.The APD fin was moved at 0.5 Hz beat frequency,and the propulsive performance was experimentally verified of the bionic pectoral fins equipped with different extents of deformation.These results showed that the pectoral fin with active–passive deformed capabilities could achieve similar natural biological deformation in the wingspan direction.The average thrust(T)under the optimal wingspan deformation is 61.5%higher than the traditional passive deformed pectoral fins.The obtained results shed light on the design and optimization of the bionic pectoral fins to improve the propulsive performance of unmanned underwater vehicles(UUV).
基金The supports of National Natural Science Foundation of China (No.50405006)the supports of the innovation foundation of graduate students of National University of Defense Technology (No.B060302) are also gratefully acknowledged
文摘A robotic fish driven by oscillating fins, 'Cownose Ray-I', is developed, which is in dorsoventrally flattened shape without a tail. The robotic fish is composed of a body and two lateral fins. A three-factor kinematic model is established and used in the design of a mechanism. By controlling the three kinematic parameters, the robotic fish can accelerate and maneuver. Forward velocity is dependent on the largest amplitude and the number of waves in the fins, while the relative contribution of fin beat frequency to the forward velocity of the robotic fish is different from the usual result. On the other hand, experimental results on maneuvering show that phase difference has a stronger effect on swerving than the largest amplitude to some extent. In addition, as propulsion waves pass from the trailing edge to the leading edge, the robotic fish attains a backward velocity of 0. 15 m·s^(-1).
文摘In present,there are increasing interests in the research on mechanical and control system of underwater vehicles.These ongoing research efforts are motivated by more pervasive applications of such vehicles including seabed oil and gas explorations, scientific deep ocean surveys,military purposes,ecological and water environmental studies,and also entertainments. However,the performance of underwater vehicles with screw type propellers is not prospective in terms of its efficiency and maneuverability.The main weaknesses of this kind of propellers are the production of vortices and sudden generation of thrust forces which make the control of the position and motion difficult. On the other hand,fishes and other aquatic animals are efficient swimmers,posses high maneuverability,are able to follow trajectories,can efficiently stabilize themselves in currents and surges,create less wakes than currently used underwater vehicle, and also have a noiseless propulsion.The fish's locomotion mechanism is mainly controlled by its caudal fin and paired pectoral fins.They are classified into Body and/or Caudal Fin(BCF)and Median and/or paired Pectoral Fins(MPF).The study of highly efficient swimming mechanisms of fish can inspire a better underwater vehicles thruster design and its mechanism. There are few studies on underwater vehicles or fish robots using paired pectoral fins as thruster.The work presented in this paper represents a contribution in this area covering study,design and implementation of locomotion mechanisms of paired pectoral fins in a fish robot.The performance and viability of the biomimetic method for underwater vehicles are highlighted through in-water experiment of a robotic fish.
基金supported by the National Natural Science Foundation of China (Grant Nos .50579007 and 50879014)the Specialized Research Fund for the Doctoral Program of Higher Education (Grant No.200802170010)
文摘Generally the underwater bio-robots take the tail fin as propulsor, and combined with pectoral fin they can manoeuvre agilely and control their position and movement at will. In nature, a lot of fishes realize to suspend itself in water to go forward and to move back up by the pectoral fin moving complexly. So that it is significant theoretically and valuable for practical application to investigate the propulsive principle and hydrodynamic performance of pectoral fin, and find the method utilizing the pectoral fin to manoeuvre the underwater bio-robot agilely. In this paper, a two degree of freedom （DoF） motion model is established for a rigid pectoral fin, and the hydrodynamic performances of the pectoral fin are studied by use of the pectoral fin propulsive experimental platform developed by Harbin Engineering University, simultaneously the hydrodynamic performance of the pectoral fin is analyzed when some parameters change. Then, through the secondary development of FLUENT （CFD code） software, the hydrodynamic performances of rigid pectoral fin in viscous flows are calculated and the results are compared with the latest experimental results. The research in this paper will provide the theoretical reference for the design of the manoeuvring system imitating pectoral fin, at the same time will become the foundation for the development of the small underwater bio-robot.
文摘At a temperature of 23.0 - 24.8℃, the mixed feeding of Japanese anchovy larvae was initiated 24 h before the yolk-sac was exhausted. The point of no return （PNR） was reached on the 6th day after hatching. On the 4th day after hatching, the pectoral angle appeared in both fed and unfed anchovy larvae although it was more evident and sharper in the starved and the PNR stage larvae than in the fed ones. According to observations of larvae collected in the sea, the pectoral angles were evident not only in the larvae of 3.62 - 7.44 mm in standard length, but also in the larvae of 2.70 mm in standard length with remnants of yolk. The pectoral angles became diffuse when the larvae reached 7.84 mm and vanished at 9.86 mm. The pectoral angle cannot be used as a criterion to distinguish healthy from starving larvae.
文摘Background: Pectoral nerves (PECS) block has been reported to be effective for a perioperative analgesia for breast cancer surgery. In addition, we may consider that the PECS block is also effective for motor function in postoperative period. Therefore, we investigated the effect of PECS block for motor function in postoperative period. Methods: This study selected the patients performed the breast cancer surgery between April and September, 2015. The study surveyed the difficulty of movement of the upper limbs at postoperative day 5 (D5) and postoperative month 6 (M6) by performing telephone survey. We counted the number of patients who complained of the difficulty of movement of the upper limbs. All results were compared using the chi- squared test. P < 0.05 was considered statistically significant. Results: 93 patients received only general anesthesia (G group). 85 patients received PECS block with general anesthesia (P group). The number of the P group at D5 was 2 patients. On the other hand, the number of the G group was 15 patients (P = 0.042). In the same way, the number of the P group M6 was no patient. On the other hand, the number of the G group was 10 patients (P = 0.043). Conclusion: A PECS block is effective for motor function recovery in the early postoperative period after breast cancer surgery.
文摘An agonistic display by a white shark was observed and photographed during a cage dive at Guadalupe Island in November 2015. Exhibiting exaggerated pectoral fin depression, agonistic behaviors have been previously observed and described in several shark species. This account may be the first record of a white shark in close proximity to a caged diver, exhibiting strong pectoral fin depression significantly dipped, in the mid-agonistic display. Such displays should be considered as aggressive and potentially life-threatening by those using the ocean for recreational or professional purposes.
文摘Background and Aims: Pectoral nerve blocks gained increasing recognition for adequate postoperative pain relief following breast surgery. Traditionally, anaesthetist administered preoperatively under ultrasound guidance, which added significantly to the total procedure time. We studied the effectiveness of intraoperative direct vision pectoral nerve block and reduction of total theatre time. Methods: We provided questionnaires to the eligible patients who underwent a mastectomy and or axillary node clearance from August 2018 to May 2019. All the patients had an intra-operative pectoral 1 and serratus plane (Pecs) block. Participants documented pain score twice daily, episodes of nausea or vomiting and type and dose of analgesia for the first seven postoperative days. We compiled and grouped the results into postoperative days 1 - 2 and 3 - 7 for data analysis. Results: Patients reported generally low levels of pain, with a median pain score of 1.75 out of 10 for postoperative days 1 - 2 (IQR 4). The score decreased to 0.7 for days 3 - 7 postoperatively (IQR 3) suggesting that most patients had generally minimal levels of pain apart from a few outliers. The average injection time for PECs blocks was 5 minutes, significantly less than USS guided techniques of 20 - 30 minutes. Conclusions: Our data suggest that nerve blocks under direct vision offer satisfactory efficacy in postoperative analgesia with minimal nausea and vomiting. This is in addition to substantial benefits in operative efficiency and reduction of total procedure time.
基金supported by the National Key Research and development Program of China(2022YFC3400300)the National Natural Science Foundation of China(32122021,32370452,32100367)+3 种基金the Postdoctoral Fellowship Program of CPSF(GZC20233518)the Fundamental Research Funds for the Central Universities(G2022KY05107)NWPU Scientific Research Initiation Grant(23GH02027)the Financial Fund of the Ministry of Agriculture and Rural Affairs,China(125C0505)。
文摘Dear Editor,Exaptation is defined as characters evolved for other usages(or for no function at all)and later“coopted”for their current role(Gould and Vrba,1982).Exaptation has occurred in many organisms,sometimes as an outcome of organ specialization for adaptation.This process is exemplified in the family Triglidae,commonly known as gurnards or sea robins.
基金supported by the National Natural Science Foundation of China (Grant No. 10502033)the Shanghai Leading Academic Discipline Project (Grant No. B206)
文摘Fish pectoral fin movement involves primarily a drag-based and a lift-based mechanisms to produce thrust. A numerical study on a pectoral fin rowing propulsion model based on the drag-based mechanism is presented in this article. The propulsive mechanism of the pectoral fin rowing model is related with the voriticity and pressure in the flow field. The relationship between the thrust and kinematic parameters and the wake-captured problem are analyzed. It is shown that a high thrust is produced in the power stroke, mainly due to the backward translation acceleration, the anticlockwise angular acceleration and the absence of stall in the uniform translation. Moreover, the flow control mechanism and the effect of dynamic flexible deformation are further analyzed. To properly choose controllable factors and adopt an appropriate dynamic deformation can improve the propulsive performance.
基金Project (No. 60505009) supported by the National Natural Science Foundation of China
文摘Automatic pectoral muscle removal on medio-lateral oblique (MLO) view of mammogram is an essential step for many mammographic processing algorithms. However,it is still a very difficult task since the sizes,the shapes and the intensity contrasts of pectoral muscles change greatly from one MLO view to another. In this paper,we propose a novel method based on a discrete time Markov chain (DTMC) and an active contour model to automatically detect the pectoral muscle boundary. DTMC is used to model two important characteristics of the pectoral muscle edge,i.e.,continuity and uncertainty. After obtaining a rough boundary,an active contour model is applied to refine the detection results. The experimental results on images from the Digital Database for Screening Mammography (DDSM) showed that our method can overcome many limitations of existing algorithms. The false positive (FP) and false negative (FN) pixel percentages are less than 5% in 77.5% mammograms. The detection precision of 91% meets the clinical requirement.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.50739004,11072154)the Foundation of State Key Laboratory of Ocean Engineering,Shanghai Jiao Tong University (Grant No.GKZD 010053-11)supported by the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning (Grant No.2008007)
文摘The numerical simulation of the self-propelled motion of a fish with a pair of rigid pectoral fins is presented.A Navier-Stokes equation solver incorporating with the multi-block and overset grid method is developed to deal with the multi-body and moving body problems.The lift-based swimming mode is selected for the fin motion.In the lift-based swimming mode,the fin can generate great thrust and at the same time have no generation of lift force.It can be found when a pair of rigid pectoral fins generates the hydrodynamic moment,it may also generate a lateral force opposite to the centripetal direction,which has adverse effect on the turn motion of the fish.Furthermore,the periodic vortex structure generation and shedding,and their effects on the generation of hydrodynamic force are also demonstrated in this article.
基金National Natural Science Foundation of China(Grant Nos.51809059,51709136)Project funded by China Postdoctoral Science Foundation(Grant No.2018M631915).
文摘Fluid dynamics of a self-propelled biomimetic underwater vehicle(BUV)with pectoral fins is investigated by an immersed boundary(IB)method.Typically,the BUV with a pair of pectoral fins starts from rest and attains a constant mean velocity as the mean longitudinal force is zero.The capability and accuracy of the IB method to deal with the interaction between the fluid and complex moving body are firstly validated.Then we carry out a parametric study to understand the effect of key governing parameters on the dynamic response of the BUV.It is found that with the increase of motion frequency or rolling amplitude,the pectoral fin propulsors can induce larger forward velocity so that the BUV takes less time to attain its stable periodic swimming state.Although the pectoral fin is a very complicated lifting surface,a linear relationship between forward Reynolds number(final swimming velocity is used as velocity scale)and frequency Reynolds number(product of motion frequency and fin chord length is used as velocity scale)can be established when the frequency Reynolds number is above a critical value.A linear relationship between forward Reynolds number and rolling amplitude is also found within the studied range of rolling amplitude.Furthermore,a small-density-ratio BUV is sensitive to the surrounding flow with more rapid evolution process of self-propulsion.Whereas,BUV with a large density ratio is more stable.The implications of the hydrodynamic analysis on the bio-inspired engineering design of BUV with pectoral fins are also discussed.
基金supported by the National Key Research and Development Program of China(2022YFF1000204)the National Natural Science Foundation of China(32102535)the Key Research and Development Program of Hainan province(ZDYF2023XDNY036)。
文摘Background Broilers stand out as one of the fastest-growing livestock globally,making a substantial contribution to animal meat production.However,the molecular and epigenetic mechanisms underlying the rapid growth and development of broiler chickens are still unclear.This study aims to explore muscle development patterns and regulatory networks during the postnatal rapid growth phase of fast-growing broilers.We measured the growth performance of Cornish(CC)and White Plymouth Rock(RR)over a 42-d period.Pectoral muscle samples from both CC and RR were randomly collected at day 21 after hatching(D21)and D42 for RNA-seq and ATAC-seq library construction.Results The consistent increase in body weight and pectoral muscle weight across both breeds was observed as they matured,with CC outpacing RR in terms of weight at each stage of development.Differential expression analysis identified 398 and 1,129 genes in the two dimensions of breeds and ages,respectively.A total of 75,149 ATAC-seq peaks were annotated in promoter,exon,intron and intergenic regions,with a higher number of peaks in the promoter and intronic regions.The age-biased genes and breed-biased genes of RNA-seq were combined with the ATAC-seq data for subsequent analysis.The results spotlighted the upregulation of ACTC1 and FDPS at D21,which were primarily associated with muscle structure development by gene cluster enrichment.Additionally,a noteworthy upregulation of MUSTN1,FOS and TGFB3 was spotted in broiler chickens at D42,which were involved in cell differentiation and muscle regeneration after injury,suggesting a regulatory role of muscle growth and repair.Conclusions This work provided a regulatory network of postnatal broiler chickens and revealed ACTC1 and MUSTN1 as the key responsible for muscle development and regeneration.Our findings highlight that rapid growth in broiler chickens triggers ongoing muscle damage and subsequent regeneration.These findings provide a foundation for future research to investigate the functional aspects of muscle development.
基金Supported by the National Natural Science Foundation of China （No. 50475179） and the National High Technology, Research and Development Program of China （No. 2006AAllz225）.
文摘A mechanical design method of mbet fish is introduced in this paper. Based on this method, an autonomous 3-Dimension （3D） locomotion mbet fish with two pectoral fins and a caudal fin is developed. The pectoral fin mechanism has 3 degrees of freedom （3-DOFs）, which enables the mbet fish to realize yawing and pitching motions by controlling two pectoral fins. And the eandal fin mechanism is designed based on fish body wave curve fitting. The forward velocity can be adjusted by changing the eandal mechanism＇ s oscillating frequency. Finally a physical implementation of the robot fish and experimental results are given.
文摘We investigated the efficacy of ultrasound-guided pectoral nerves (PECS) block for modified radical mastectomy surgery retrospectively. Methods: We measured that pain scores and the use of additional analgesic drugs were recorded in the postoperative care unit within 24 hours after the operation. Postoperative complications (i.e., nausea and vomiting) were noted. Results: Patients who received the PECS block under general anesthesia (PECS group) reported lower visual analog scale pain scores at 0, 1, 2, 4, 6, 12, 24 hours after the operation than patients who did not receive PECS block under general anesthesia (control group). Moreover, the use of additional analgesic drugs during the first 24 hours after surgery was lower in the PECS group than in the control group. While in the postoperative care unit, the PECS group had less nausea and vomiting than the control group. Conclusion: The PECS block provides effective postoperative analgesia within the first 24 hours after breast cancer surgery.
基金Foundation items： This study was financially supported by an International Biodiversity Assessment Project of the Chinese Academy of Sciences （GJHZ201317）ACKNOWLEDGEMENTS The author is indebted to Tao Qin of KIZ for his enthusiastic support during the survey to Dehong that yielded the specimen KIZ 2015000184 and subsequent}y prompted further research.
文摘The natural distributional range of the cobitid loach Lepidocephalichthys alkaia is extended into Yunnan Province, China. The modified sexually dimorphic pectoral fin in males of L. alkaia is described.
