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.

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.

A Study on the Performances of Solar Air Collectors Having a Hemispherical Dimple on the Absorber Plate

In order to increase the efficiency of solar air collectors,a new variant with a protrusion is proposed in this study,and its performances are analyzed from two points of view,namely,in terms of optics and thermodynamics aspects.By comparing and analyzing the light paths of the protrusion and the dimple,it can be concluded that when sunlight shines on the dimple,it is reflected and absorbed multiple times,whereas for the sunlight shining on the protrusion,there is no secondary reflection or absorption of light.When the lighting area and the properties of the surfaces are the same,the absorption rate of the dimple is 10.3 percentage points higher than that of the protrusion.In the range of Reynolds number from 3000 to 11000,numerical simulations about the effects of the relative height(e/Dh=0.033–0.1)and relative spacing(p/e=4.5–8.5)of protrusions on air heat transfer and flow resistance show that,in terms of comprehensive evaluation coefficient(PF),the best relative height is 0.085,when the relative spacing is 5.A correlation of Nu and f with Re,e/Dh and p/e is obtained by linear regression of the results,in order to provide a useful reference for the design and optimization of this kind of solar air collector.

Optimize Multiple Peening Effects on Surface Integrity and Microhardness of Aluminum Alloy Induced by LSP

Laser shock peening is a modernized surface enhancement performed methodically to improve fatigue life, enhance the hardness of the material and make coarse grains flat under the superficial layer. In this current study, the effect of varying optimized multiple laser shock peening (LSP) is studied on the surface integrity, microhardness, and mechanical properties. The results show that the LSP-treated specimens have visible signs of valleys, wavy and varying height distribution as well as dimples. However, the presence of non-uniformity and sharp protrusions was detected from the superficiality of the as-received specimen and this was so because of the SiC abrasive material used to polish the superficial layer of the specimen before the test experiment. Prior to LSP, the surface roughness was 2 μm, however, after LSP the roughness increased to 4 μm, 6 μm and 17 μm for 1, 2, and 4 impacts, respectively. High-density dislocation can also be observed close to the grain boundary because the grain boundary prevents the migration of dislocation which could lead to dislocation walls and dislocation tangles. The increase in impacts decrease the average grain size, nevertheless, the micro-strain increased after multiple impacts. Furthermore, coarse grains after LSP were transformed into finer grains. The increase in the number of impacts increases the micro-strain likewise the full-width half maximum (FWHM). Finally, the increase in microhardness increases as the LSP impacts increase.

Migration of the distal ventriculoperitoneal shunt catheter into the stomach with or without trans-oral extrusion:A systematic literature review and meta-analysis

BACKGROUND Intra-gastric migration of the distal ventriculoperitoneal shunt(VPS)catheter clinically presenting with or without trans-oral extrusion is one of the rare complications of VPS catheter insertion.AIM To identify the demographics,clinical presentation,clinical findings,and results of surgical therapy offered for the treatment of intra-gastric migration of the distal VPS catheter,clinically presented with or without trans-oral extrusion.METHODS An online search was performed for the extraction/retrieval of the published/available literature pertaining to the above-mentioned VPS complication.Manuscripts were searched from PubMed,PMC(PubMed Central),ResearchGate,and Google Scholar databases using various terminology relating to the VPS complications.The first case of migration of a VPS catheter into the stomach was reported in the year 1980,and the data were retrieved from 1980 to December 2022.Cases were categorized into two groups;Group A:Cases who had migration of the distal VPS catheter into the stomach and clinically presented with trans-oral extrusion of the same,and Group B:Cases who had migration of the distal VPS catheter into the stomach,but presented without trans-oral extrusion.RESULTS A total of n=46 cases(n=27;58.69%male,and n=19;41.3%females)were recruited for the systematic review.Group A included n=32,and Group B n=14 cases.Congenital hydrocephalus was the indication for the primary VPS insertion for approximately half of the(n=22)cases.Approximately sixty percent(n=27)of them were children≤5 years of age at the time of the diagnosis of the complication mentioned above.In seventy-two percent(n=33)cases,this complication was detected within 24 mo after the VPS insertion/last shunt revision.Clinical diagnosis was evident for the entire group A cases.Various diagnostic modalities were used to confirm the diagnosis for Group B cases.Various surgical procedures were offered for the management of the complication in n=43 cases of both Groups.In two instances,intra-gastric migration of the distal VPS catheter was detected during the autopsy.This review documented four deaths.CONCLUSION Intra-gastric migration of the peritoneal end of a VPS catheter is one of the rare complications of VPS catheter implantation done for the treatment of hydrocephalus across all age groups.It was more frequently reported in children,although also reported in adults and older people.A very high degree of clinical suspicion is required for the diagnosis of a case of an intra-gastric migration of the distal VPS catheter clinically presenting without transoral extrusion.

EFFECT OF ACUPUNCTURE ON POST-OPERATIVE FUNCTIONAL RECOV-ERY IN PATIENTS WITH LUMBAR INTERVERTEBRAL DISC PROTRUSION

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.

Surface-enhanced fluorescence and application study based on Ag-wheat leaves

Wheat leaves with natural microstructures as substrates were covered by the silver nanoislands by magnetron to prepare a low-cost, environment-friendly and mass production surface-enhanced fluorescence(SEF) substrate(Ag-WL substrate). The best SEF substrate was selected by repeatly certifying the fluorescence intensity of 10^(-5)M Rhodamine B(RB) and 10^(-5)M Rhodamine 6G(R6G) aqueous solutions. The abundant semi-spherical protrusions and flake-like structures on the surface of the Ag-WL substrate produce high-density hot spots, which provides a new and simple idea for the preparation of biomimetic materials. The results of 3D finite-different time-domain(FDTD) simulation show that the nanoisland gap of semi-spherical protrusions and flake-like structures has produced rich hotspots. By adjusting the time of magnetron sputtering, the enhancement factor(EF) was as high as 839 times, relative standard deviation(RSD) reached as low as 10.7%, and the substrate was very stable and repeatable, which shows that Ag-WL substrate is trustworthy.Moreover, semi-spherical protrusions provide stronger surface-enhanced Raman scattering(SERS) effects compared to flake-like structure. What is more surprising is that the detection limit of the substrate for toxic substance crystal violet(CV) is as low as 10^(-10)M.

CLINICAL OBSERVATION ON THE THERAPEUTIC EFFECT OF ACUPUNCTURE PLUS ATOMIZED HERBAL MEDICINE IN THE TREATMENT OF LUMBAR INTERVERTEBRAL DISC PROTRUSION

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.

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.

Non-invasive evaluation of lower urinary tract symptoms(LUTS)in men

Lower urinary tract symptoms(LUTS)are common in males over the age of 40 years old and are likely to increase with an aging population.Currently urodynamic studies are the gold standard to determine the aetiology of voiding dysfunction and LUTS.However,due to its invasive nature,a great number of non-invasive ultrasound based investigations have been developed to assess patients with symptomatic LUTS.The clinical application of noninvasive tests could potentially stratify patients who would require more invasive investigations and allow more precise patient directed treatment.A PubMed literature review was performed and we will discuss the non-invasive investigations that have been developed thus far,focusing on bladder wall and detrusor wall thickness(BWT&DWT),ultrasound estimated bladder weight(UEBW)and intravesical prostatic protrusion(IPP).

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.

Effects of Gas Flow Field on Clogging Phenomenon in Close-Coupled Vortical Loop Slit Gas Atomization

In order to study the basic characteristics of gas flow field in the atomizing chamber near the nozzle outlet of the vortical loop slit atomizer and its influence mechanism on clogging phenomenon,the computational fluid dynamics(CFD)software Fluent is used to conduct a numerical simulation of the gas flow field in the atomizing chamber near the nozzle outlet of this atomizer under different annular slit widths,different atomization gas pressures and different protrusion lengths of the melt delivery tube. The results show that under atomization gas pressure p=4.5 MPa,the greater the annular slit width D,the lower the static temperature near the central hole outlet at the front end of the melt delivery tube,and the smaller the aspirating pressure at the front end of the melt delivery tube. These features can effectively prevent the occurrence of the clogging phenomenon of metallic melt. Under an annular slit width of D=1.2 mm,when the atomization gas pressure satisfies 1 MPa ≤ p ≤ 2 MPa and increases gradually,the aspirating pressure at the front end of the melt delivery tube will decline rapidly. This can prevent the clogging phenomenon of metallic melt. However,when the atomization gas pressure p >2 MPa,the greater the atomization gas pressure,the lower the static temperature near the central hole outlet at the front end of the melt delivery tube,and the greater the aspirating pressure at the front end of the melt delivery tube. Hence,the effect of preventing the solidification-induced clogging phenomenon of metallic melt is restricted. When atomization gas pressure is p =4.5 MPa and annular slit width is D=1.2 mm,the greater the protrusion length H of the melt delivery tube,and the smaller the aspirating pressure at its front end. The static temperature near the central hole that can be observed in its front end is approximate to effectively prevent the occurrence of clogging phenomenon of metallic melt. However,because of the small aspirating pressure,the metallic melt flows into the atomizing chamber from the central hole at the front end of the melt delivery tube at an increasing speed and the gas-melt ratio in the mass flow rate is reduced,which is not conducive to the improvement of atomization performance.

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.

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.

Morphology of cylindrical cell sheets with embedded contractile ring

The behavior of large deformations of cellular tissues is usually affected by the local properties of cells and their interactions,resulting in folding which acts as an important role in the embryonic development,as well as growing and spreading of a tumor,which can rapidly promote the stereo complexity of the architecture of the tissues.In the present study,a cylindrical vertex model is constructed to explore the morphology of the tubular cell sheets subject to an embedded contractile ring.It is found that an inner region of the contractile ring in equilibrium will protrude from the tube wall,and it will suddenly collapse when the contractile strength exceeds a threshold,indicating the occurrence of a bifurcation.These results on the effect of embedded contraction in the tubular shell are quite different from the planar cases,which can reveal the importance of the interaction between the geometric and material non-linearity in cylindrical geometry.The dependence of the large deformation on the bending modulus parameters and contraction strength is also analyzed for the cylindrical cell shell.

Morphological study of floral nectaries in Euonymus and the probable origin of the echinate fruit surface

A conspicuous nectary disk is common but has a distinguishing morphology in the cosmopolitan genus Euonymus. Our study focuses on the morphology of floral nectaries in 21 representatives of Euonymus and Glyptopetalum. Two main types of nectaries were documented: a mix of inter-and extrastaminal nectaries existed between the corolla and the stigma, while the intrastaminal nectaries were distributed between the stigma and the stamen bases. The main route of nectar release in Euonymus is via modified stomata, and different nectarostomata locations were observed: in depressions, slightly raised above the epidermal surface or at the same level as the epidermis. Floral nectaries in E. sect. Echinococcus species developed into the protrusions on the fruit surface at the later stage. The development of nectaries not only explained the mystery of the origin of the echinate fruit surface, but also showed that differences in fruit surface might be inappropriate for use in infrageneric classification. These discoveries inform morphological observations of floral nectaries in Euonymus.

Visualization of pullout behaviour of geogrid in sand with emphasis on size effect of protrusive junctions

Geogrid has been extensively used in geotechnical engineering practice due to its effectiveness and economy. Deep insight into the interaction between the backfill soil and the geogrid is of great importance for proper design and construction of geogrid reinforced earth structures. Based on the calibrated model of sand and geogrid, a series of numerical pullout tests are conducted using PFC^(3D) under special considerations of particle angularity and aperture geometry of the geogrid. In this work, interface characteristics regarding the displacement and contact force developed among particles and the deformation and force distribution along the geogrid are all visualized with PFC^(3D) simulations so that new understanding on how geogrid-soil interaction develops under pullout loads can be obtained. Meanwhile, a new variable named fabric anisotropy coefficient is introduced to evaluate the inherent relationship between macroscopic strength and microscopic fabric anisotropy. A correlation analysis is adopted to compare the accuracy between the newly-proposed coefficient and the most commonly used one. Furthermore, additional pullout tests on geogrid with four different joint protrusion heights have been conducted to investigate what extent and how vertical reinforcement elements may result in reinforcement effects from perspectives of bearing resistance contribution, energy dissipation, as well as volumetric response. Numerical results show that both the magnitude and the directional variation of normal contact forces govern the development of macroscopic strength and the reinforcing effects of joint protrusion height can be attributed to the accelerated energy dissipation across the particle assembly and the intensive mobilization of the geogrid.

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.

Tuina Therapy of Lumbar Intervertebral Disc Protrusion

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Epidural fat distribution patterns in patients with lumbar intervertebral disc protrusion

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.