Buckling of filamentous actin bundles in filopodial protrusion

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.

Clinical value of intravesical prostatic protrusion in the evaluation and management of prostatic and other lower urinary tract diseases

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.

Patients with small prostates and low-grade intravesical prostatic protrusion e A urodynamic evaluation

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 IPP
10 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.

Numerical simulation of the effects of protrusion on DC arc anode attachment

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.

Severe skeletal bimaxillary protrusion treated with micro-implants and a self-made four-curvature torquing auxiliary: A case report

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.

Tuina Therapy of Lumbar Intervertebral Disc Protrusion

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Intravesical Prostate Protrusion (IPP) versus Middle Lobe Volume on Ultrasonography in Assessing the Impact of Benign Prostatic Hyperplasia

Background: 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. Objective: To compare intravesical prostatic protrusion (IPP) and middle lobe volume by ultrasound in BPH. Method: 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. Results: 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 (p > 0.05). There was a statistically significant correlation between IPP values and quality of life score (p = 00461), IPSS score (p = 0.0424) and PVR (p = 0.0395). For middle lobe volume, there was a correlation with PVR (p = 0.0018). There was no correlation with clinical impact (quality of life score and IPSS score). Conclusion: 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.

Comparison of pain media and inflammatory factors after percutaneous transforaminal endoscopic discectomy and traditional fenestration operation treatment of protrusion of lumbar intervertebral disc

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.

CLINICAL OBSERVATION ON ELECTRO-ACUPUNCTURE TREATMENT OF 51 CASES OF PROTRUSION OF LUMBAR INTERVERTEBRAL DISC

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.

Quantitative visualization of Taylor-Couette flow with helical protrusion using optical and ultrasound imaging method

The simplified flow of drilling process in the soil hardening or oil rig site was experimentally investigated. Two flow models were used. One is the concentric cylinders with helical protrusion at the inner cylinder. The other is the concentric plain wall cylinders with axial flow. The radius ratio and aspect ratio of both models are the same with 0. 65 and 48,respectively. The mud is the typical fluid seen in the soil hardening processes. We used the water and the mud for the working fluid. We used the optical PIV for the water flow measurement and echo PIV for the mud flow. In case of the water study,the dominant vortical structures appeared in both the protrusion and plain model with axial flow.In case of mud flow,the vortices shown in the water model disappeared and the push and pull-up motion by the protrusion is dominant. We believe this information can be useful to understand the flow physics of drilling process in the complex fluid flow.

Software development for modeling irregular fine protrusions formed by sputter etching

Irregular fine protrusions formed on the surface of a mechanical part through biomimetic technology can enhance the part’s properties,including tribology,self-cleaning,and light absorption.However,underlying principles for the formation of fine protrusions according to the requirements of their shapes,sizes,and material distributions have not been studied sufficiently.This paper presents the software development for modeling irregular fine protrusions,which is essential for the simulation,experimentation,and analysis of fine protrusions formed by sputter etching.

Clinical effect of governor meridian moxibustion on treatment of lumbar disc protrusion: A meta analysis

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.

Treatment of Skeletal CL II Patient with Maximum Lower Incisor Protrusion and Minimum Overjet with Rahhal Functional Appliance

Treatment of skeletal Cl II includes functional orthopedic treatment, head-gears, extraction of the upper premolars and orthognathic surgery. To treat any patient with functional appliances (bite jumping) an adequate overjet is necessary. In this case an 11 years old female patient has skeletal CLII due to mandibular deficiency with ANB angle 8 degrees, overbite: 3 mm, overjet: 1 mm, extremely convex profile and underdeveloped chin due to the hyper muscle contraction of the lower lip to obtain oral seal. To obtain an adequate overjet lower first premolars were extracted and maximum retraction using mini screws (for maximum anchorage) was applied. Afterwards Rahhal functional appliance was used by the patient 16 hours a day for 6 months and 10 hours a day for another 6 months for retention. After that fixed orthodontic treatment was completed. Lateral cephalometrics were taken, traced and analyzed. In the result Skeletal CLI was obtained (ANB 4 degree), straight facial profile, normal over bite overjet and particular chin development were noticed. As a conclusion, in skeletal CLII malocclusions, lower incisor protrusion will cause a contraindication for functional treatment. Extraction of the lower premolars and retraction of the lower incisors followed by functional orthopedic treatment is an efficient method to treat these cases instead of waiting for orthognathic surgery, also reducing the muscle pressure on the chin will change the development characteristics of it.

Study of the relationship between sphenoid sinus volume and protrusions in the sphenoid sinus

The relationship between the volume of sphenoid sinus (SS) and the prevalence of internal carotid artery (ICA) and optic nerve (ON) protrusions in the SS was studied by using high-resolution CT imaging. The ICA and ON protrusions in SS were observed in randomly selected normal head CT scanning images from 350 adult subjects. Ac-cording to the incidence of ICA protrusion, three groups were divided into no ICA protrusion (70.75%), unilateral protrusion (8.68%) and bi-lateral protrusions (20.57%). The ON protrusion accounted for 16% in 350 subjects and accom-panied absolutely with ICA protrusion, but ICA protrusion appeared without accompanying with ON protrusion. The SS volume depended upon the protrusions in it and showed statistical dif-ferences, without ICA protrusion, the smallest size (11.16 ± 1.60) cm3;the unilateral protrusion, medium size (14.20 ± 1.80) cm3 and the bilateral protrusion, the largest size (25.03 ± 2.21) cm3. By observing 3D reconstructed models of ON and SS, we found ON was adjacent to SS (46%) and to posterior ethmoid sinuses (44%). The current study indicates that SS volume is varied with numbers of the protrusions and that ON location varies with the pneumatization of SS. Our results provide an anatomical basis to the surgeries for SS and its surrounding structures.

Treatment of Protrusion of Lumbar Intervertebral Disc by Massotherapy under Anesthesia—A Report of 64 Cases

Sixty-four cases of protrusion of lumbarintervertebral disc were treated by massotherapy withheavy manipulations plus blocking therapy underanesthesia from August,1997 to July,1998,withsatisfactory therapeutic results as reported in thefollowing.Clinical DataNinety-four cases in the series were randomlydivided into two groups.All the 94 cases satisfied thecriteria for diagnosis of the disorder,and thediagnosis was confirmed by

Prevalence of Bimaxillary Protrusion: A Systematic Review

Objective: This study aimed to systematically review current relevant literature on the prevalence of bimaxillary protrusion. Materials and Methods: 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. Results: 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. Conclusion: 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.

Artificial Water Channel that Couples with Cell Protrusion Formation

In natural systems,water transport across the cellular plasma membranes is mainly mediated by naturally occurring channel protein aquaporins(AQPs),which lead to a series of important physiological functions including cell migration.The construction of artificial analogs of the natural AQPs would generate a new strategy for treating AQP-related diseases.In this report,an artificial water channel has been developed from a unimolecular tubular molecule,which featured structural encapsulation of a single-file water wire composed of oppositely orientated dipolar water molecules.This AQP-like structure endowed the artificial channel in living cells with AQP-like water permeability and selectivity.Interestingly,the artificial channel coupled with cell protrusion formation by mediating water transmembrane transport,leading to cell shape change and migration acceleration.The artificial channel-facilitated cell migration showed application in enhancing in vivo healing of traumatic injury.

Effect of rotor-mounted protrusion on sealing performance and flow structure in rotor-stator cavity

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 ×10~5 and the rotational Reynolds number ranges from 7:51×10~5 to 1:20×10~6. Heat and mass transfer analogy is applied. Pressure and CO_2 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.

Effect of protrusion amount on gas ingestion of radial rim seal

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.

Effect of the protrusion shape on gas ingestion of two sealing structures

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.