Analysing the influence mechanism of the riblet protrusion height on turbulent drag components is more beneficial in organising the vortical structure over the riblet surface.Therefore, the Large Eddy Simulation(LES) ...Analysing the influence mechanism of the riblet protrusion height on turbulent drag components is more beneficial in organising the vortical structure over the riblet surface.Therefore, the Large Eddy Simulation(LES) is used to investigate the vortex structure over the riblet surface with different protrusion heights. Then, the variations of Reynolds stress and viscous shear stress in a turbulent channel are analysed. As a result, the drag reduction rate increases from3.4% when the riblets are completely submerged in the turbulent boundary layer to 7.9% when the protrusion height is 11.2. Further analysis shows that the protrusion height affects the streamwise vortices and the normal diffusivity of spanwise and normal vortices, thus driving the variation of Reynolds stress. Compared with the smooth surface, the vorticity strength and the number of streamwise vortices are weakened near the wall but increase in the logarithmic layer with increased protrusion height. Meanwhile, the normal diffusivity of spanwise vorticity decreases with the increase of protrusion height, and the normal diffusivity of normal vorticity is the smallest when the protrusion height is 11.2. Moreover, the protrusion height affects the velocity gradient of the riblet tip and riblet valley, thus driving the variation of viscous shear stress. With the increase of protrusion height, the velocity gradient of the riblet tip increases dramatically but decreases in the riblet valley.展开更多
Objective To observe the influence of acupuncture on the post-operative rehabilitation in patients undergoing vertebral pulp extraction due to lumbar intervertebral disc protrusion （LIDP） so as to evaluate its effic...Objective To observe the influence of acupuncture on the post-operative rehabilitation in patients undergoing vertebral pulp extraction due to lumbar intervertebral disc protrusion （LIDP） so as to evaluate its efficacy in the treatment of lumbago induced by LIDP. Methods A total of 69 patients undergoing vertebral pulp extraction were randomized into acupuncture group （ n = 35） and control group （ n = 34）. Patients of acupuncture group were treated with routine rehabilitation method and electroacupuncture （EA） stimulation on Zhìbiān （秩边 BL54） and Wěizhōng （委中 BL40）, acupuncture on Shènshū （ 肾俞 BL23）, Dàchángshū （大肠俞 BL25）, BL54, BL40, Jiájǐ （夹脊 EX-B 2）, Shàngliáo （上髎 BL31）, etc., and cupping on BL40, with 15 days being a therapeutic course and for average 7. 36 courses. Patients of control group were treated with simple rehabilitation method. Functional recovery state was judged before and after surgery by using the standards of Japanese Orthopedic Association （JOA）. Results The average recovery rates of 3 months, 6 months and one year after surgery were 49.93% ,90.31% and 95.08% separately in acupuncture group, and 26.24% ,63.42% and 71.36% successively in control group. The recovery rates of acupuncture group were significantly higher than those of control group at the same time-points （P〈0. 05）. Conclusion Acupuncture has a definite effect on promoting post-operative functional recovery in LIDP patients undergoing vertebral pulp extraction and spinal fusion.展开更多
Objective To observe the therapeutic effect of acupuncture combined with atomized herbal medicine in the treatment of protrusion of lumbar intervertebral disc. Methods A total of 211 patients with lumbar intervertebra...Objective To observe the therapeutic effect of acupuncture combined with atomized herbal medicine in the treatment of protrusion of lumbar intervertebral disc. Methods A total of 211 patients with lumbar intervertebral disc protrusion were randomized into two groups, with 106 cases being in trealment group and 105 in control group. The treatment was given once everyday, 12 days as one course of treatment. After two courses of treatment, the results were analyzed. Results The curative rate was 97.1% in the treatment group and 81.0% in the control group. Conclusion Acupuncture together with herbal medicine for the protrusion of lumbar intervetebral disc was better in effect than acupuncture only.展开更多
This paper presents an experimental investigation on the effect of protrusion radial position and height on the sealing performance and flow structure in the rotor-stator cavity. The rotormounted protrusions are assem...This paper presents an experimental investigation on the effect of protrusion radial position and height on the sealing performance and flow structure in the rotor-stator cavity. The rotormounted protrusions are assembled at three radial positions and are set to three heights. The cavity is equipped with three rim seals: a radial seal, an axial seal and a seal with double fins on the stator.The annulus Reynolds number is set at 4:39 ×10;and the rotational Reynolds number ranges from 7:51×10;to 1:20×10;. Heat and mass transfer analogy is applied. Pressure and CO;concentration are measured. The experimental results show that in cavities with different rim seals, radial distributions of the sealing efficiency, pressure and swirl ratio are basically the same. The sealing performance is improved by protrusions compared with the cavity without protrusion and improves with the increase of protrusion radial position and height. The effect of protrusion increases with the increase of the rotational Reynolds number. The windage loss and the flow resistance introduced by protrusions are investigated. It is found that induced windage loss and flow resistance decrease with the increase of protrusion radial position but increase with the protrusion height.展开更多
In this paper, the effect of different amount of protrusion on various parameters in rotor–stator system was experimentally studied by measuring CO_2 concentration and pressure, in order to obtain the optimal protrus...In this paper, the effect of different amount of protrusion on various parameters in rotor–stator system was experimentally studied by measuring CO_2 concentration and pressure, in order to obtain the optimal protrusion amount.The parameters of different dimensionless sealing flow were measured under the condition that the annulus Reynolds number was 4.39 × 10~5 and the rotating Reynolds number was 1.05 × 10~6.The results show that the change of the amount of protrusions has little effect on the static pressure in the cavity, and the static pressure change near the sealing ring is almost negligible.But the total pressure and sealing efficiency increase first and then decrease with the increase of the amount of protrusion.The variation of power consumption is the same.A complex vortex structure will appear at the high radius region when the protrusion is installed.On the other hand, the protrusion can effectively reduce the minimum sealing flow of the rotor–stator cavity.Furthermore, considering the sealing efficiency and power consumption,the best range of the protrusion amount is about 36.The ratio near this range can optimally balance the alleviation of the gas ingestion and the reduction of the power consumption.展开更多
The mechanical behaviors of filamentous actin (F-actin) bundles play an essential role in filopodial protrusions at the leading edge of crawling cells. These bundles consist of parallel actin filaments that are hexago...The mechanical behaviors of filamentous actin (F-actin) bundles play an essential role in filopodial protrusions at the leading edge of crawling cells. These bundles consist of parallel actin filaments that are hexagonally packed and interconnected via cross-linking proteins including α-actinin, filamin, and fascin. As pushing against the plasma membrane and/or external barriers, the actin bundles in filopodial protrusion inevitably encounter a compressive load. The bending stiffness and buckling stability of actin bundles are therefore important in determining the filopodia architecture and subsequent cell morphology. In this work, we employ a coarse-grained molecular dynamics model to investigate the buckling behaviors of cross-linked actin bundles under compression, which explicitly accounts for the properties of constituent filaments and the mechanical descriptions of cross-linkers. The bending stiffness of actin bundles exhibits a generic size effect depending on the number of filaments in the bundles, explicitly depending on the degree of inter-filament coupling. The distinct buckling modes are analyzed for bundles with different coupling states and strengths of cross-linkers. This study could clarify the stability and buckling mechanisms of parallelly packed actin bundles and the structure-function relations of mechanical components in filopodial protrusion.展开更多
Intravesical prostatic protrusion(IPP)has emerged as a new prostatic morphometric parameter of significance to aid the clinicians in various aspects of managing the patients with some diseases of the lower urinary tra...Intravesical prostatic protrusion(IPP)has emerged as a new prostatic morphometric parameter of significance to aid the clinicians in various aspects of managing the patients with some diseases of the lower urinary tract and the prostate.These include but may not be limited to its role in such conditions as:bladder outlet obstruction,trial without catheter,medical treatment effect,progression of lower urinary tract symptoms related to benign prostatic hypertrophy(LUTS/BPH),risk factor for bladder stone in BPH,overactive bladder,prostate carcinoma,and early urinary continence recovery after laparoscopic radical prostatectomy.In this review,I will try to summarize the different researchers’efforts on the potential practical application of this clinical tool.Technology is ever evolving to help us in the diagnosis and management of our patients.However,we as clinicians should contemplate their cost and possible suffering for the patient by wise and judicious utilization based on our clinical experience and tools.IPP seems to be one such promising clinical tool.展开更多
The windage loss caused by protrusion in a rotor–stator cavity has been studied in detail,and there are abundant fitting formulas that have been summarized to calculate the moment coefficients.Some other theorists ha...The windage loss caused by protrusion in a rotor–stator cavity has been studied in detail,and there are abundant fitting formulas that have been summarized to calculate the moment coefficients.Some other theorists have emphasized its effect on the sealing efficiency,proposing that installation of protrusion could alleviate gas ingestion.However,the protrusion shape which is an influential factor on the sealing efficiency has not been focused in previous research.Using the experimental method of measuring CO2 volume fraction,cavity pressure,and power consumption,we investigated the effects of several typical protrusion shapes on various parameters for two sealing structures,in order to obtain the optimal shape.Results showed that a variation of the protrusion shape had little impact on the static pressure,but the total pressure and the sealing efficiency increased in different degrees.Furthermore,even though the hexagon shape resulted in the highest sealing efficiency,we observed that the drop shape had the best overall performance in all of the eight models,which could result in higher efficiency of the turbine cavity.The combination of a radial seal structure and protrusion could improve sealing efficiency better.展开更多
The attachment of the DC arc on the anode is usually affected by surface morphology such as protrusions due to ablation or melting deformation.A three-dimensional thermodynamic and chemical non-equilibrium model is us...The attachment of the DC arc on the anode is usually affected by surface morphology such as protrusions due to ablation or melting deformation.A three-dimensional thermodynamic and chemical non-equilibrium model is used to numerically simulate the effect of artificially assumed surface protrusions on the arc anode attachment.The numerical simulation results show that the arc deflects toward the protrusions on the anode and attaches to them in a constricted mode,resulting in an increase in the temperature of the arc attachment region.The analysis shows that the presence of protrusion on the anode surface changes the electric field distribution,intensifies the degree of thermodynamic and chemical non-equilibrium in its vicinity,further influences the chemical kinetic process of the plasma around it,which is the main reason for the deflection of the arc toward the protrusions and the arc anode attachment in a constricted mode.In order to verify the numerical simulation results,verification experiments are also performed using similar size scale anode protrusion,and the results showed that the presence of protrusion can indeed cause the deflection of the arc and even cause the ablation of the protrusion.展开更多
Abstract Objective:Despite high-grade intravesical prostatic protrusion(IPP)being closely related to bladder outlet obstruction(BOO),up to 21%of patients with low IPP remain obstructed.This study evaluates the charact...Abstract Objective:Despite high-grade intravesical prostatic protrusion(IPP)being closely related to bladder outlet obstruction(BOO),up to 21%of patients with low IPP remain obstructed.This study evaluates the characteristics and urodynamic findings of men with small prostates and low IPP.Methods:One hundred and fourteen men aged>50 years old with lower urinary tract symptoms(LUTS)were assessed with symptoms,uroflowmetry,serum prostate-specific antigen(PSA),transabdominal ultrasound measurement of prostate volume(PV),IPP and post-void residual urine(PVRU).All patients underwent pressure flow studies.Patients with PV<30 mL and IPP10 mm were examined for parameters correlating with BOO or impaired detrusor contractility.Results:Thirty-six patients had PV<30 mL and IPP<10 mm.Nine patients(25.0%)had urodynamic BOO,all with normal bladder contractility.Fourteen patients(38.9%)had poor detrusor contractility and all had no BOO.PV,PVRU and IPP were significantly associated with BOO,with IPP showing greatest positive correlation.Both Qmax and IPP were significantly associated with detrusor contractility.At 5-year follow-up,most patients responded to medical therapy.Only three out of nine patients(33.3%)with BOO eventually underwent surgery,and all had a high bladder neck seen on the resectoscope.Only one patient(7.1%)with poor detrusor contractility eventually required surgery after repeat pressure flow study revealed BOO.Conclusion:In men with small prostates and low IPP,the presence of BOO is associated with higher PV,PVRU and IPP,and most respond well to medical management.BOO can possibly be explained by elevation of the bladder neck by a small subcervical adenoma.展开更多
BACKGROUND Bimaxillary protrusion is a clinically common dentofacial deformity,particularly among Chinese patients.This kind of malformation can severely affect facial esthetics and,even in mild cases,is difficult to ...BACKGROUND Bimaxillary protrusion is a clinically common dentofacial deformity,particularly among Chinese patients.This kind of malformation can severely affect facial esthetics and,even in mild cases,is difficult to correct without surgery.Unfortunately,many patients abandon treatment because of fear of surgery.Here,we describe a case of severe skeletal bimaxillary protrusion treated with nonsurgical orthodontic treatments,highlighting an alternative treatment option.CASE SUMMARY A 31-year-old woman wished to address a severe protrusion profile(approximately 8 mm overbite)and gummy smile.Cephalometric analysis and superimposition showed a severe skeletal class II pattern with a mandibular retrusion,and proclined and protrusive mandibular incisors.Panoramic radiograph showed a missing mandibular right third molar.A diagnosis of severe bimaxillary dentoalveolar protrusion was made.Taking into account the patient’s fear of orthognathic surgery,she accepted the proposed alternative treatment using micro-implants and a self-made four-curvature torquing auxiliary.The treatment allowed for maximal en masse anterior tooth retraction,proper relocation of incisors,and alleviation of the skeletal class II pattern.Esthetically,the patient’s lip protrusion was significantly decreased as was the overjet(from 10.5 mm to 1.8 mm),and the results remained stable throughout the 2-year followup.CONCLUSION Nonsurgical treatment using micro-implants and a four-curvature torquing auxiliary may benefit severe cases of skeletal bimaxillary protrusion in adults.展开更多
<strong>Background:</strong> Ultrasound is the main method of exploring the prostate. In benign prostatic hyperplasia (BPH), it provides important morphological information and assesses its impact, helping...<strong>Background:</strong> Ultrasound is the main method of exploring the prostate. In benign prostatic hyperplasia (BPH), it provides important morphological information and assesses its impact, helping to guide the treatment. <strong>Objective:</strong> To compare intravesical prostatic protrusion (IPP) and middle lobe volume by ultrasound in BPH. <strong>Method:</strong> This was a single center prospective, descriptive and analytical study, over a period of 6 months, including 95 patients, undergoing prostatic trans-abdominal ultrasound. Patients were selected by a single urologist for clinical suspicion of benign prostatic hypertrophy. The ultrasound examination was done by a single senior radiologist. <strong>Results:</strong> The mean age of the patients was 66.63 ± 11.55 years with ranges from 38 to 98 years. The prevalence of BPH was 76.84%. The rate of patient with middle lobe protrusion was 48.42%. The mean middle lobe volume was 11.29 ± 12.90 ml. More than half of the patients (50.91%) had an IPP stage 3 of. The mean bladder wall thickness was 6.08 ± 2.58 mm, with 50.53% being pathological. The post-voiding residue (PVR) was significant in 38.75% of patients. Renal repercussions were present in 17.89%. The correlation analysis did not note a statistical link between prostate volume and quality of life score (<em>p</em> > 0.05). There was a statistically significant correlation between IPP values and quality of life score (<em>p</em> = 00461), IPSS score (<em>p</em> = 0.0424) and PVR (<em>p</em> = 0.0395). For middle lobe volume, there was a correlation with PVR (<em>p</em> = 0.0018). There was no correlation with clinical impact (quality of life score and IPSS score). <strong>Conclusion:</strong> The IPP appears to be an easy element to measure and better than the volume of the prostate and the middle lobe in assessing the impact of BPH.展开更多
Objective： To investigate epidural fat distribution patterns in patients with lumbar intervertebral disc protrusion. Methods： Medical records were selected randomly from 30 patients whose diagnoses were consistent w...Objective： To investigate epidural fat distribution patterns in patients with lumbar intervertebral disc protrusion. Methods： Medical records were selected randomly from 30 patients whose diagnoses were consistent with the inclusion criteria of the study. Thickness of bilateral fat, the longest length of posterior fat, thickness of bilateral yellow ligament and the hernial distance of lumbar discs were measured by MRI at L3/L4, L4/L5 and L5/S 1 levels. According to clinical symptoms of lumbar intervertebral disc protrusion, the patients were divided into two groups at all space levels. All data were analyzed by statistical software. Results： The longest length of posterior epidural fat at the symptomatic levels was shorter than that at the non-symptomatic levels in each disc space. The symptomatic levels had no effect on the whole thickness of the lateral fat and lateral yellow ligaments. Conclusion： Epidural fat distribution in patients with lumbar intcrvertebral disc protrusion is different from that in normal adults. It is affected by the hernial distance of lumbar discs. The diagnostic criteria for spinal epidural lipomatosis in normal adults may therefore prove to be inappropriate for patients with lumbar intervertebral disc protrusion.展开更多
Objective:To explore the clinical effect of governor meridian moxibustion on lumbar intervertebral disc protrusion.Methods:Randomized controlled trials on treatment of lumbar intervertebral disc protrusion with govern...Objective:To explore the clinical effect of governor meridian moxibustion on lumbar intervertebral disc protrusion.Methods:Randomized controlled trials on treatment of lumbar intervertebral disc protrusion with governor meridian moxibustion and combined governor meridian moxibustion were retrieved from CNKI,VIP,Wan Fang Data,CBM,Web of ScienceTM Core Collection,EBSCO Medline,PubMed,OVID,the Cochrane Library,and other databases.The time was from the inception of the database until October 2021.The studies were screened according to the inclusion and exclusion criteria,extracted,and evaluated for quality assessment.The data were analyzed with Review Manager 5.3 software.Results:A total of 24 randomized controlled trials(2379 cases in total)were included.Meta-analysis results showed that compared with control groups such as acupuncture,electroacupuncture,and massage,the governor meridian treatment improved the clinical efficacy[RR=1.17,95%CI(1.13,1.20),P<0.001],relieved patients'pain[MD=-1.56,95%CI(-1.89,-1.22),P<0.001],and improved patients’dysfunction to a certain extent[MD=4.84,95%CI(3.87,5.82),P<0.001].Funnel plot analysis showed that the included literature may be potentially biased in publication.Conclusion:Governor meridian moxibustion has a significant effect on the treatment of lumbar disc protrusion and is worthy of widespread use.However,given the small number of high-quality literature included in the study,the small sample size,and the short follow-up time,high-quality randomized controlled trials are needed to further study the long-term therapeutic effect of governor meridian moxibustion.展开更多
<strong>Objective:</strong> This study aimed to systematically review current relevant literature on the prevalence of bimaxillary protrusion. <strong>Materials and Methods:</strong> The electr...<strong>Objective:</strong> This study aimed to systematically review current relevant literature on the prevalence of bimaxillary protrusion. <strong>Materials and Methods:</strong> The electronic databases PubMed, Medline, Scopus, Google Scholar and the Cochrane Library were searched using specific inclusion criteria to obtain applicable articles. References from included studies were also examined. <strong>Results:</strong> Three articles were identified that met the inclusion criteria. Prevalence of bimaxillary protrusion ranged from 3.7% to 68.8% in different populations reported in the literature examined. GRADE assessed overall confidence was deemed to be very low. <strong>Conclusion:</strong> These results show that the prevalence of bimaxillary protrusion varies greatly between races and geographic regions. The Trinidad and Tobago population has a high prevalence of bimaxillary protrusion.展开更多
Objective:To compare the differences in pain mediators and inflammatory factors after percutaneous transforaminal endoscopic discectomy and traditional fenestration operation treatment of protrusion of lumbar interver...Objective:To compare the differences in pain mediators and inflammatory factors after percutaneous transforaminal endoscopic discectomy and traditional fenestration operation treatment of protrusion of lumbar intervertebral disc. Methods:80 patients with protrusion of lumbar intervertebral disc treated in our hospital between March 2013 and December 2015 were collected and divided into observation group and control group (n=40) according to randomized parallel contrast. Control group received traditional fenestration operation and observation group received percutaneous transforaminal endoscopic discectomy. Before operation and 1 week after operation, fluorescence spectrophotometry was used to determine serum pain medium levels;ELISA was used to determine pro-inflammatory factor and anti-inflammatory factor levels. Results:Before operation, differences in serum pain medium and inflammatory factor levels were not statistically significant between two groups (P>0.05). 1 week after operation, serum pain media norepinephrine (NE), dopamine (DA), 5-hydroxytryptamine (5-HT), prostaglandin E2 (PGE2) and substance P (SP) levels as well as pro-inflammatory factors interleukin-1β(IL-1β), interleukin-6 (IL-6), interleukin-18 (IL-18) and tumor necrosis factor alpha (TNF-α) levels of observation group were lower than those of control group (P<0.05) while serum anti-inflammatory factors interleukin-4 (IL-4), interleukin 10 (IL-10), soluble tumor necrosis factor receptor I (sTNF-RI) levels were higher than those of control group (P<0.05). Conclusions:Percutaneous transforaminal endoscopic discectomy can effectively treat protrusion of lumbar intervertebral disc and is more advantageous in alleviating patients’ perception of pain and reducing inflammation.展开更多
OBJECTIVE: To investigate the diagnostic significance of lingual flange protrusion for liver metastasis of patients with malignant neoplasia.METHODS: The data of 191 patients with malignant neoplasia were analyzed. Al...OBJECTIVE: To investigate the diagnostic significance of lingual flange protrusion for liver metastasis of patients with malignant neoplasia.METHODS: The data of 191 patients with malignant neoplasia were analyzed. All photos of patients' tongue image were recorded and lingual flange protrusion was the positive standard. χ~2 test for paired data and Kappa test were used to determine the diagnostic value of lingual flange protrusion for metastatic liver cancer. Mann-Whitney U test was used to compare the levels of liver serolog-ical markers. The area under receiver operating characteristic curve(ROC) and logistic regression model were used to analyze the predictive values of lingual flange protrusion, alkaline phosphatase(ALP), and lactate dehydrogenase(LDH) levels.RESULTS: Patients with lingual flange protrusion had a higher risk of liver metastasis than those without it(P < 0.001). There was no significant difference in diagnosis of liver metastasis between lingual flange protrusion and traditional diagnostic criteria(P = 0.541). Kappa was 0.738(P < 0.001). Lingual flange protrusion was significantly correlated with increased serum ALP and LDH levels(P < 0.01).Comparison of ROC curves showed that the diagnostic value of lingual flange protrusion is better than ALP, LDH and the combination of ALP and LDH(P < 0.01). Furthermore, the combined diagnostic values of lingual flange protrusion and ALP,lingual flange protrusion and LDH, and lingual flange protrusion, ALP and LDH are not better than lingual flange protrusion alone(P > 0.05).CONCLUSION: Lingual flange protrusion is a potential diagnostic marker for liver metastasis of patients with malignant neoplasia.展开更多
Through electroacupuncture(EA) treatment of 51 cases of protrusion of lumbar interver-tebral disc, it was further demonstrated that the specific action and characteristics of Siyao and Wuyao acupoints were significant...Through electroacupuncture(EA) treatment of 51 cases of protrusion of lumbar interver-tebral disc, it was further demonstrated that the specific action and characteristics of Siyao and Wuyao acupoints were significant and elucidated by using some objective indexes and obvious therapeutic ef-fect, which lays a foundation for the development, research, popularization and application of shu-point and provides an effective and practicable way for treatment of lumbar intervertebral disc.展开更多
Stabilizing the interface wave of the molten aluminum(metal)-electrolyte(bath)is beneficial to shorten the anode-cathode distance(ACD)which is critical to the energy saving.A coupled mathematical model was developed t...Stabilizing the interface wave of the molten aluminum(metal)-electrolyte(bath)is beneficial to shorten the anode-cathode distance(ACD)which is critical to the energy saving.A coupled mathematical model was developed to study the impact of the novel cathode protrusion on the molten fluid motion as well as the metal-bath interface deformation.The molten fluid motion in the aluminum reduction ceils is under the combined effect of the electro-magnetic forces(EMFs)and the gas bubbles generated at the anode.A transient inhomogeneous three-phase model(metal-bath-gas bubble)was established in order to calculate more accurate.The results indicate that the metal-bath interface deformation can be reduced significantly by the novel cathode protrusion which is beneficial to the electric energy saving.Besides,The EMFs decreases as a result of the optimizing of the magnetic field due to the novel cathode convex which is an important driving force for the deformation of the interface.In addition,large vortex in the metal flow field is break up into the small vortex by the cathode protrusion and then dissipated due to the viscous force and the hindering effect of the cathode protrusion.The quantity of the vortex as well as the strength of the vortex reduces significantly in the reduction cell with novel cathode protrusion.展开更多
基金the National Natural Science Foundation of China(No. 52176032)the Natural Science Foundation of Tianjin Municipal Science and Technology Commission, China(No. 22JCQNJC00050)the National Science and Technology Major Project, China(No.2017-Ⅱ-0005-0016)
文摘Analysing the influence mechanism of the riblet protrusion height on turbulent drag components is more beneficial in organising the vortical structure over the riblet surface.Therefore, the Large Eddy Simulation(LES) is used to investigate the vortex structure over the riblet surface with different protrusion heights. Then, the variations of Reynolds stress and viscous shear stress in a turbulent channel are analysed. As a result, the drag reduction rate increases from3.4% when the riblets are completely submerged in the turbulent boundary layer to 7.9% when the protrusion height is 11.2. Further analysis shows that the protrusion height affects the streamwise vortices and the normal diffusivity of spanwise and normal vortices, thus driving the variation of Reynolds stress. Compared with the smooth surface, the vorticity strength and the number of streamwise vortices are weakened near the wall but increase in the logarithmic layer with increased protrusion height. Meanwhile, the normal diffusivity of spanwise vorticity decreases with the increase of protrusion height, and the normal diffusivity of normal vorticity is the smallest when the protrusion height is 11.2. Moreover, the protrusion height affects the velocity gradient of the riblet tip and riblet valley, thus driving the variation of viscous shear stress. With the increase of protrusion height, the velocity gradient of the riblet tip increases dramatically but decreases in the riblet valley.
文摘Objective To observe the influence of acupuncture on the post-operative rehabilitation in patients undergoing vertebral pulp extraction due to lumbar intervertebral disc protrusion （LIDP） so as to evaluate its efficacy in the treatment of lumbago induced by LIDP. Methods A total of 69 patients undergoing vertebral pulp extraction were randomized into acupuncture group （ n = 35） and control group （ n = 34）. Patients of acupuncture group were treated with routine rehabilitation method and electroacupuncture （EA） stimulation on Zhìbiān （秩边 BL54） and Wěizhōng （委中 BL40）, acupuncture on Shènshū （ 肾俞 BL23）, Dàchángshū （大肠俞 BL25）, BL54, BL40, Jiájǐ （夹脊 EX-B 2）, Shàngliáo （上髎 BL31）, etc., and cupping on BL40, with 15 days being a therapeutic course and for average 7. 36 courses. Patients of control group were treated with simple rehabilitation method. Functional recovery state was judged before and after surgery by using the standards of Japanese Orthopedic Association （JOA）. Results The average recovery rates of 3 months, 6 months and one year after surgery were 49.93% ,90.31% and 95.08% separately in acupuncture group, and 26.24% ,63.42% and 71.36% successively in control group. The recovery rates of acupuncture group were significantly higher than those of control group at the same time-points （P〈0. 05）. Conclusion Acupuncture has a definite effect on promoting post-operative functional recovery in LIDP patients undergoing vertebral pulp extraction and spinal fusion.
文摘Objective To observe the therapeutic effect of acupuncture combined with atomized herbal medicine in the treatment of protrusion of lumbar intervertebral disc. Methods A total of 211 patients with lumbar intervertebral disc protrusion were randomized into two groups, with 106 cases being in trealment group and 105 in control group. The treatment was given once everyday, 12 days as one course of treatment. After two courses of treatment, the results were analyzed. Results The curative rate was 97.1% in the treatment group and 81.0% in the control group. Conclusion Acupuncture together with herbal medicine for the protrusion of lumbar intervetebral disc was better in effect than acupuncture only.
文摘This paper presents an experimental investigation on the effect of protrusion radial position and height on the sealing performance and flow structure in the rotor-stator cavity. The rotormounted protrusions are assembled at three radial positions and are set to three heights. The cavity is equipped with three rim seals: a radial seal, an axial seal and a seal with double fins on the stator.The annulus Reynolds number is set at 4:39 ×10;and the rotational Reynolds number ranges from 7:51×10;to 1:20×10;. Heat and mass transfer analogy is applied. Pressure and CO;concentration are measured. The experimental results show that in cavities with different rim seals, radial distributions of the sealing efficiency, pressure and swirl ratio are basically the same. The sealing performance is improved by protrusions compared with the cavity without protrusion and improves with the increase of protrusion radial position and height. The effect of protrusion increases with the increase of the rotational Reynolds number. The windage loss and the flow resistance introduced by protrusions are investigated. It is found that induced windage loss and flow resistance decrease with the increase of protrusion radial position but increase with the protrusion height.
文摘In this paper, the effect of different amount of protrusion on various parameters in rotor–stator system was experimentally studied by measuring CO_2 concentration and pressure, in order to obtain the optimal protrusion amount.The parameters of different dimensionless sealing flow were measured under the condition that the annulus Reynolds number was 4.39 × 10~5 and the rotating Reynolds number was 1.05 × 10~6.The results show that the change of the amount of protrusions has little effect on the static pressure in the cavity, and the static pressure change near the sealing ring is almost negligible.But the total pressure and sealing efficiency increase first and then decrease with the increase of the amount of protrusion.The variation of power consumption is the same.A complex vortex structure will appear at the high radius region when the protrusion is installed.On the other hand, the protrusion can effectively reduce the minimum sealing flow of the rotor–stator cavity.Furthermore, considering the sealing efficiency and power consumption,the best range of the protrusion amount is about 36.The ratio near this range can optimally balance the alleviation of the gas ingestion and the reduction of the power consumption.
基金the National Natural Science Foundation of China (Grants 11672268, 11621062, and 91748209)the Zhejiang Provincial Natural Science Foundation of China (Grant LR16A020001)the Fundamental Research Funds for Central Universities of China (Grant 2017FZA4029).
文摘The mechanical behaviors of filamentous actin (F-actin) bundles play an essential role in filopodial protrusions at the leading edge of crawling cells. These bundles consist of parallel actin filaments that are hexagonally packed and interconnected via cross-linking proteins including α-actinin, filamin, and fascin. As pushing against the plasma membrane and/or external barriers, the actin bundles in filopodial protrusion inevitably encounter a compressive load. The bending stiffness and buckling stability of actin bundles are therefore important in determining the filopodia architecture and subsequent cell morphology. In this work, we employ a coarse-grained molecular dynamics model to investigate the buckling behaviors of cross-linked actin bundles under compression, which explicitly accounts for the properties of constituent filaments and the mechanical descriptions of cross-linkers. The bending stiffness of actin bundles exhibits a generic size effect depending on the number of filaments in the bundles, explicitly depending on the degree of inter-filament coupling. The distinct buckling modes are analyzed for bundles with different coupling states and strengths of cross-linkers. This study could clarify the stability and buckling mechanisms of parallelly packed actin bundles and the structure-function relations of mechanical components in filopodial protrusion.
文摘Intravesical prostatic protrusion(IPP)has emerged as a new prostatic morphometric parameter of significance to aid the clinicians in various aspects of managing the patients with some diseases of the lower urinary tract and the prostate.These include but may not be limited to its role in such conditions as:bladder outlet obstruction,trial without catheter,medical treatment effect,progression of lower urinary tract symptoms related to benign prostatic hypertrophy(LUTS/BPH),risk factor for bladder stone in BPH,overactive bladder,prostate carcinoma,and early urinary continence recovery after laparoscopic radical prostatectomy.In this review,I will try to summarize the different researchers’efforts on the potential practical application of this clinical tool.Technology is ever evolving to help us in the diagnosis and management of our patients.However,we as clinicians should contemplate their cost and possible suffering for the patient by wise and judicious utilization based on our clinical experience and tools.IPP seems to be one such promising clinical tool.
文摘The windage loss caused by protrusion in a rotor–stator cavity has been studied in detail,and there are abundant fitting formulas that have been summarized to calculate the moment coefficients.Some other theorists have emphasized its effect on the sealing efficiency,proposing that installation of protrusion could alleviate gas ingestion.However,the protrusion shape which is an influential factor on the sealing efficiency has not been focused in previous research.Using the experimental method of measuring CO2 volume fraction,cavity pressure,and power consumption,we investigated the effects of several typical protrusion shapes on various parameters for two sealing structures,in order to obtain the optimal shape.Results showed that a variation of the protrusion shape had little impact on the static pressure,but the total pressure and the sealing efficiency increased in different degrees.Furthermore,even though the hexagon shape resulted in the highest sealing efficiency,we observed that the drop shape had the best overall performance in all of the eight models,which could result in higher efficiency of the turbine cavity.The combination of a radial seal structure and protrusion could improve sealing efficiency better.
基金supported by National Natural Science Foundation of China(Nos.11735004 and 12005010)。
文摘The attachment of the DC arc on the anode is usually affected by surface morphology such as protrusions due to ablation or melting deformation.A three-dimensional thermodynamic and chemical non-equilibrium model is used to numerically simulate the effect of artificially assumed surface protrusions on the arc anode attachment.The numerical simulation results show that the arc deflects toward the protrusions on the anode and attaches to them in a constricted mode,resulting in an increase in the temperature of the arc attachment region.The analysis shows that the presence of protrusion on the anode surface changes the electric field distribution,intensifies the degree of thermodynamic and chemical non-equilibrium in its vicinity,further influences the chemical kinetic process of the plasma around it,which is the main reason for the deflection of the arc toward the protrusions and the arc anode attachment in a constricted mode.In order to verify the numerical simulation results,verification experiments are also performed using similar size scale anode protrusion,and the results showed that the presence of protrusion can indeed cause the deflection of the arc and even cause the ablation of the protrusion.
基金We would like to thank the National Medical Council,the Goh Foundation and the Lee Foundation for their support in our BPH research,and Dr Hong Hong Huang and Ms Mei Ying Ng for their statistical and editorial support。
文摘Abstract Objective:Despite high-grade intravesical prostatic protrusion(IPP)being closely related to bladder outlet obstruction(BOO),up to 21%of patients with low IPP remain obstructed.This study evaluates the characteristics and urodynamic findings of men with small prostates and low IPP.Methods:One hundred and fourteen men aged>50 years old with lower urinary tract symptoms(LUTS)were assessed with symptoms,uroflowmetry,serum prostate-specific antigen(PSA),transabdominal ultrasound measurement of prostate volume(PV),IPP and post-void residual urine(PVRU).All patients underwent pressure flow studies.Patients with PV<30 mL and IPP10 mm were examined for parameters correlating with BOO or impaired detrusor contractility.Results:Thirty-six patients had PV<30 mL and IPP<10 mm.Nine patients(25.0%)had urodynamic BOO,all with normal bladder contractility.Fourteen patients(38.9%)had poor detrusor contractility and all had no BOO.PV,PVRU and IPP were significantly associated with BOO,with IPP showing greatest positive correlation.Both Qmax and IPP were significantly associated with detrusor contractility.At 5-year follow-up,most patients responded to medical therapy.Only three out of nine patients(33.3%)with BOO eventually underwent surgery,and all had a high bladder neck seen on the resectoscope.Only one patient(7.1%)with poor detrusor contractility eventually required surgery after repeat pressure flow study revealed BOO.Conclusion:In men with small prostates and low IPP,the presence of BOO is associated with higher PV,PVRU and IPP,and most respond well to medical management.BOO can possibly be explained by elevation of the bladder neck by a small subcervical adenoma.
基金National Natural Science Foundation of China,No.81970906and Sichuan Science and Technology Program,No.2019YJ0689.
文摘BACKGROUND Bimaxillary protrusion is a clinically common dentofacial deformity,particularly among Chinese patients.This kind of malformation can severely affect facial esthetics and,even in mild cases,is difficult to correct without surgery.Unfortunately,many patients abandon treatment because of fear of surgery.Here,we describe a case of severe skeletal bimaxillary protrusion treated with nonsurgical orthodontic treatments,highlighting an alternative treatment option.CASE SUMMARY A 31-year-old woman wished to address a severe protrusion profile(approximately 8 mm overbite)and gummy smile.Cephalometric analysis and superimposition showed a severe skeletal class II pattern with a mandibular retrusion,and proclined and protrusive mandibular incisors.Panoramic radiograph showed a missing mandibular right third molar.A diagnosis of severe bimaxillary dentoalveolar protrusion was made.Taking into account the patient’s fear of orthognathic surgery,she accepted the proposed alternative treatment using micro-implants and a self-made four-curvature torquing auxiliary.The treatment allowed for maximal en masse anterior tooth retraction,proper relocation of incisors,and alleviation of the skeletal class II pattern.Esthetically,the patient’s lip protrusion was significantly decreased as was the overjet(from 10.5 mm to 1.8 mm),and the results remained stable throughout the 2-year followup.CONCLUSION Nonsurgical treatment using micro-implants and a four-curvature torquing auxiliary may benefit severe cases of skeletal bimaxillary protrusion in adults.
文摘<strong>Background:</strong> Ultrasound is the main method of exploring the prostate. In benign prostatic hyperplasia (BPH), it provides important morphological information and assesses its impact, helping to guide the treatment. <strong>Objective:</strong> To compare intravesical prostatic protrusion (IPP) and middle lobe volume by ultrasound in BPH. <strong>Method:</strong> This was a single center prospective, descriptive and analytical study, over a period of 6 months, including 95 patients, undergoing prostatic trans-abdominal ultrasound. Patients were selected by a single urologist for clinical suspicion of benign prostatic hypertrophy. The ultrasound examination was done by a single senior radiologist. <strong>Results:</strong> The mean age of the patients was 66.63 ± 11.55 years with ranges from 38 to 98 years. The prevalence of BPH was 76.84%. The rate of patient with middle lobe protrusion was 48.42%. The mean middle lobe volume was 11.29 ± 12.90 ml. More than half of the patients (50.91%) had an IPP stage 3 of. The mean bladder wall thickness was 6.08 ± 2.58 mm, with 50.53% being pathological. The post-voiding residue (PVR) was significant in 38.75% of patients. Renal repercussions were present in 17.89%. The correlation analysis did not note a statistical link between prostate volume and quality of life score (<em>p</em> > 0.05). There was a statistically significant correlation between IPP values and quality of life score (<em>p</em> = 00461), IPSS score (<em>p</em> = 0.0424) and PVR (<em>p</em> = 0.0395). For middle lobe volume, there was a correlation with PVR (<em>p</em> = 0.0018). There was no correlation with clinical impact (quality of life score and IPSS score). <strong>Conclusion:</strong> The IPP appears to be an easy element to measure and better than the volume of the prostate and the middle lobe in assessing the impact of BPH.
文摘Objective： To investigate epidural fat distribution patterns in patients with lumbar intervertebral disc protrusion. Methods： Medical records were selected randomly from 30 patients whose diagnoses were consistent with the inclusion criteria of the study. Thickness of bilateral fat, the longest length of posterior fat, thickness of bilateral yellow ligament and the hernial distance of lumbar discs were measured by MRI at L3/L4, L4/L5 and L5/S 1 levels. According to clinical symptoms of lumbar intervertebral disc protrusion, the patients were divided into two groups at all space levels. All data were analyzed by statistical software. Results： The longest length of posterior epidural fat at the symptomatic levels was shorter than that at the non-symptomatic levels in each disc space. The symptomatic levels had no effect on the whole thickness of the lateral fat and lateral yellow ligaments. Conclusion： Epidural fat distribution in patients with lumbar intcrvertebral disc protrusion is different from that in normal adults. It is affected by the hernial distance of lumbar discs. The diagnostic criteria for spinal epidural lipomatosis in normal adults may therefore prove to be inappropriate for patients with lumbar intervertebral disc protrusion.
基金It was supported by the National Natural Science Fundation of C hina(No.81774340,81973875)Funds from Clinical Medicine Research Center of Chronic Muscle and Bone Diseases of Shanghai City(No.20MC1920600)+2 种基金Cons truction Project of High-level Universities and Colleges in Shanghai City(Guide Strategy for TCM Standardization),Key Clinical Specialty“Orthopedics of Chinese Medicine”(No.shslczdzk03901)Pilot Construction Project of Innovation Model for TCM Diagnosis and Treatment in Shanghai City[No.ZY(2018-2020)-FWTX-6033]Clinical Science and Technology Innovation Project of Development Center of Shanghai Shenkang Hospital(No.SHDC2020CR1051B)。
文摘Objective:To explore the clinical effect of governor meridian moxibustion on lumbar intervertebral disc protrusion.Methods:Randomized controlled trials on treatment of lumbar intervertebral disc protrusion with governor meridian moxibustion and combined governor meridian moxibustion were retrieved from CNKI,VIP,Wan Fang Data,CBM,Web of ScienceTM Core Collection,EBSCO Medline,PubMed,OVID,the Cochrane Library,and other databases.The time was from the inception of the database until October 2021.The studies were screened according to the inclusion and exclusion criteria,extracted,and evaluated for quality assessment.The data were analyzed with Review Manager 5.3 software.Results:A total of 24 randomized controlled trials(2379 cases in total)were included.Meta-analysis results showed that compared with control groups such as acupuncture,electroacupuncture,and massage,the governor meridian treatment improved the clinical efficacy[RR=1.17,95%CI(1.13,1.20),P<0.001],relieved patients'pain[MD=-1.56,95%CI(-1.89,-1.22),P<0.001],and improved patients’dysfunction to a certain extent[MD=4.84,95%CI(3.87,5.82),P<0.001].Funnel plot analysis showed that the included literature may be potentially biased in publication.Conclusion:Governor meridian moxibustion has a significant effect on the treatment of lumbar disc protrusion and is worthy of widespread use.However,given the small number of high-quality literature included in the study,the small sample size,and the short follow-up time,high-quality randomized controlled trials are needed to further study the long-term therapeutic effect of governor meridian moxibustion.
文摘<strong>Objective:</strong> This study aimed to systematically review current relevant literature on the prevalence of bimaxillary protrusion. <strong>Materials and Methods:</strong> The electronic databases PubMed, Medline, Scopus, Google Scholar and the Cochrane Library were searched using specific inclusion criteria to obtain applicable articles. References from included studies were also examined. <strong>Results:</strong> Three articles were identified that met the inclusion criteria. Prevalence of bimaxillary protrusion ranged from 3.7% to 68.8% in different populations reported in the literature examined. GRADE assessed overall confidence was deemed to be very low. <strong>Conclusion:</strong> These results show that the prevalence of bimaxillary protrusion varies greatly between races and geographic regions. The Trinidad and Tobago population has a high prevalence of bimaxillary protrusion.
基金Research Project of Sichuan Provincial Health Department(No:130914).
文摘Objective:To compare the differences in pain mediators and inflammatory factors after percutaneous transforaminal endoscopic discectomy and traditional fenestration operation treatment of protrusion of lumbar intervertebral disc. Methods:80 patients with protrusion of lumbar intervertebral disc treated in our hospital between March 2013 and December 2015 were collected and divided into observation group and control group (n=40) according to randomized parallel contrast. Control group received traditional fenestration operation and observation group received percutaneous transforaminal endoscopic discectomy. Before operation and 1 week after operation, fluorescence spectrophotometry was used to determine serum pain medium levels;ELISA was used to determine pro-inflammatory factor and anti-inflammatory factor levels. Results:Before operation, differences in serum pain medium and inflammatory factor levels were not statistically significant between two groups (P>0.05). 1 week after operation, serum pain media norepinephrine (NE), dopamine (DA), 5-hydroxytryptamine (5-HT), prostaglandin E2 (PGE2) and substance P (SP) levels as well as pro-inflammatory factors interleukin-1β(IL-1β), interleukin-6 (IL-6), interleukin-18 (IL-18) and tumor necrosis factor alpha (TNF-α) levels of observation group were lower than those of control group (P<0.05) while serum anti-inflammatory factors interleukin-4 (IL-4), interleukin 10 (IL-10), soluble tumor necrosis factor receptor I (sTNF-RI) levels were higher than those of control group (P<0.05). Conclusions:Percutaneous transforaminal endoscopic discectomy can effectively treat protrusion of lumbar intervertebral disc and is more advantageous in alleviating patients’ perception of pain and reducing inflammation.
基金Supported by National Natural Science Foundation of China(Biomechanics Mechanism of the Anti-Tumor Effects of Softing and Resolving Hard Mass Drugs,No.81473441)
文摘OBJECTIVE: To investigate the diagnostic significance of lingual flange protrusion for liver metastasis of patients with malignant neoplasia.METHODS: The data of 191 patients with malignant neoplasia were analyzed. All photos of patients' tongue image were recorded and lingual flange protrusion was the positive standard. χ~2 test for paired data and Kappa test were used to determine the diagnostic value of lingual flange protrusion for metastatic liver cancer. Mann-Whitney U test was used to compare the levels of liver serolog-ical markers. The area under receiver operating characteristic curve(ROC) and logistic regression model were used to analyze the predictive values of lingual flange protrusion, alkaline phosphatase(ALP), and lactate dehydrogenase(LDH) levels.RESULTS: Patients with lingual flange protrusion had a higher risk of liver metastasis than those without it(P < 0.001). There was no significant difference in diagnosis of liver metastasis between lingual flange protrusion and traditional diagnostic criteria(P = 0.541). Kappa was 0.738(P < 0.001). Lingual flange protrusion was significantly correlated with increased serum ALP and LDH levels(P < 0.01).Comparison of ROC curves showed that the diagnostic value of lingual flange protrusion is better than ALP, LDH and the combination of ALP and LDH(P < 0.01). Furthermore, the combined diagnostic values of lingual flange protrusion and ALP,lingual flange protrusion and LDH, and lingual flange protrusion, ALP and LDH are not better than lingual flange protrusion alone(P > 0.05).CONCLUSION: Lingual flange protrusion is a potential diagnostic marker for liver metastasis of patients with malignant neoplasia.
文摘Through electroacupuncture(EA) treatment of 51 cases of protrusion of lumbar interver-tebral disc, it was further demonstrated that the specific action and characteristics of Siyao and Wuyao acupoints were significant and elucidated by using some objective indexes and obvious therapeutic ef-fect, which lays a foundation for the development, research, popularization and application of shu-point and provides an effective and practicable way for treatment of lumbar intervertebral disc.
基金Item Sponsored by the National Natural Science Foundation of China[NO.50934005 and NO.50904014]
文摘Stabilizing the interface wave of the molten aluminum(metal)-electrolyte(bath)is beneficial to shorten the anode-cathode distance(ACD)which is critical to the energy saving.A coupled mathematical model was developed to study the impact of the novel cathode protrusion on the molten fluid motion as well as the metal-bath interface deformation.The molten fluid motion in the aluminum reduction ceils is under the combined effect of the electro-magnetic forces(EMFs)and the gas bubbles generated at the anode.A transient inhomogeneous three-phase model(metal-bath-gas bubble)was established in order to calculate more accurate.The results indicate that the metal-bath interface deformation can be reduced significantly by the novel cathode protrusion which is beneficial to the electric energy saving.Besides,The EMFs decreases as a result of the optimizing of the magnetic field due to the novel cathode convex which is an important driving force for the deformation of the interface.In addition,large vortex in the metal flow field is break up into the small vortex by the cathode protrusion and then dissipated due to the viscous force and the hindering effect of the cathode protrusion.The quantity of the vortex as well as the strength of the vortex reduces significantly in the reduction cell with novel cathode protrusion.
