Necking of Q&P Steel during Uniaxial Tensile Test with the Aid of DIC Technique

A lot of research has been focused on the necking process during the plastic deformation of sheet metals, but the localized necking is rarely distinguished form diffused necking by experiments, due to the limit of measurement equipment and method. Quenching and Partitioning (Q&P) steel is a 3rd generation advanced high strength steel (AHSS). Its good combination of high strength and ductility ensures potential application in automobile industry. Uniaxial tensile tests of QP980 steel sheet at five strain rates are performed to investigate the necking process and the effect of strain rate on necking behavior of Q&P steel. Digital image correlation (DIC) method is applied during tensile tests, and evolutions of major strain, minor strain and normal strain distributions along gauge section of the tensile specimens are obtained. The diffused and localized necking strains are determined according to SWIFT necking theory and HILL necking theory respectively. The test results indicate that with the increasing of strain rate in the investigated range, the diffused necking strain decreases from 0.152 to 0.120 and localized necking strain decreases from 0.245 to 0.137. Meanwhile, the difference of the two strains decreases form 0.096 to 0.017. Thus it can be concluded that strain rate has an influence on both necking strains during the deformation of QP980 steel sheet. Diffused and localized necking strains are determined by uniaxial tensile tests with the aid of DIC technique and the effect of strain rate on necking strains is evaluated.

MECHANISMS OF LOCALIZED NECKING DEFORMATION OF SHEET METALS

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Numerical simulation of spinning deformation of thin-walled tube in necking process

The spinning deformation of thin walled tube in necking process is simulated with a dynamic explicit FEM program,LS DYNA3D and the distributions of Cauchy strains and thickness are analyzed through time history to achieve a good understanding of the deformation in necking process by spinning and the numerical simulation results are in good agreement with the test results.

Mechanism of necking defect of 6082 aluminium alloy rolled by cross-wedge rolling method based on material thermal properties

Necking defects have long troubled the application of cross-wedge rolling technology in aluminium alloy shaft parts.To accurately predict necking defects,new judgement conditions are established based on the thermal performance of 6082 aluminium alloy.The limit-sectional shrinkage without necking defects is achieved by combining theoretical calculation and finite-element model analysis,which couples heat transfer and deformation.In this paper,a 6082 aluminium alloy extruded rod with a 40 mm diameter rolled at a preheated temperature of 500℃and a rolling angular velocity of 1 rad/s is taken as an example.The simulation and experimental results show that necking defects do not occur on the rolled pieces if the sectional shrinkage is below the limit-sectional shrinkage but will occur when the sectional shrinkage is above it.The results prove that the prediction model of necking defects in cross-wedge rolling of 6082 aluminum alloy is feasible,and this research provides a theoretical basis for the qualified aluminum alloy shafts produced by the cross-wedge rolling.

Necking Point in PET High-speed Fiber Spinning

Cross-over method is established to predict necking point for PET high- speed fiber spinning. Even slowly crystallizing polymers such as PET can crystallize on the spinline at sufficiently high spinning speed. The development of rtmning velocity, temperature, crystallinity and theological force is investigated for the take-up velocity over a range of 6 000 - 10 000 m/min. The position of necking point, temperature rise and abrupt increase of crystallinity move closer to the spinneret with the increase of take-up velocity,

Complication rates after direct anterior vs posterior approach for hip hemiarthroplasty in elderly individuals with femoral neck fractures

BACKGROUND Dislocation rates after hemiarthroplasty reportedly vary from 1%to 17%.This serious complication is associated with increased morbidity and mortality rates.Approaches to this surgery are still debated,with no consensus regarding the superiority of any single approach.AIM To compare early postoperative complications after implementing the direct anterior and posterior approaches(PL)for hip hemiarthroplasty after femoral neck fractures.METHODS This is a comparative,retrospective,single-center cohort study conducted at a university hospital.Between March 2008 and December 2018,273 patients(a total of 280 hips)underwent bipolar hemiarthroplasties(n=280)for displaced femoral neck fractures using either the PL(n=171)or the minimally invasive direct anterior approach(DAA)(n=109).The choice of approach was related to the surgeons’practices;the implant types were similar and unrelated to the approach.Dislocation rates and other complications were reviewed after a minimum followup of 6 mo.RESULTS Both treatment groups had similarly aged patients(mean age:82 years),sex ratios,patient body mass indexes,and patient comorbidities.Surgical data(surgery delay time,operative time,and blood loss volume)did not differ significantly between the groups.The 30 d mortality rate was higher in the PL group(9.9%)than in the DAA group(3.7%),but the difference was not statistically significant(P=0.052).Among the one-month survivors,a significantly higher rate of dislocation was observed in the PL group(14/154;9.1%)than in the DAA group(0/105;0%)(P=0.002).Of the 14 patients with dislocation,8 underwent revision surgery for recurrent instability(posterior group),and one of them had 2 additional procedures due to a deep infection.The rate of other complications(e.g.,perioperative and early postoperative periprosthetic fractures and infection-related complications)did not differ significantly between the groups.CONCLUSION These findings suggest that the DAA to bipolar hemiarthroplasty for patients with femoral neck fractures is associated with a lower dislocation rate(<1%)than the PL.

Theoretical and Numerical Comparison of Limit Point Bifurcation and Maximum Force Criteria. Application to the Prediction of Diffuse Necking

A large number of criteria has been developed to predict material instabilities, but their choice is limited by the lack of existing comparison of their theoretical basis and application domains. To overcome this limitation, a theoretical and numerical comparison of two major models used to predict diffuse necking is present in this paper. Limit Point Bifurcation criterion is first introduced. An original formulation of the Maximum Force Criterion (MFC), taking into account the effects of damage and isotropic and kinematic hardenings, is then proposed. Strong connections are shown between them by comparing their theoretical basis. Numerical Forming Limit Diagrams at diffuse necking obtained with these criteria for different metallic materials are given. They illustrate the theoretical link and similar predictions are shown for both models.

Summarizing the evidence for robotic-assisted bladder neck reconstruction: Systematic review of patency and incontinence outcomes

Objective:Bladder neck contracture and vesicourethral anastomotic stenosis are difficult to manage endoscopically,and open repair is associated with high rates of incontinence.In recent years,there have been increasing reports of robotic-assisted bladder neck reconstruction in the literature.However,existing studies are small,heterogeneous case series.The objective of this study was to perform a systematic review of robotic-assisted bladder neck reconstruction to better evaluate patency and incontinence outcomes.Methods:We performed a systematic review of PubMed from first available date to May 2023 for all studies evaluating robotic-assisted reconstructive surgery of the bladder neck in adult men.Articles in non-English,author replies,editorials,pediatric-based studies,and reviews were excluded.Outcomes of interest were patency and incontinence rates,which were pooled when appropriate.Results:After identifying 158 articles on initial search,we included only ten studies that fit all aforementioned criteria for robotic-assisted bladder neck reconstruction.All were case series published from March 2018 to March 2022 ranging from six to 32 men,with the median follow-up of 5e23 months.A total of 119 patients were included in our analysis.A variety of etiologies and surgical techniques were described.Patency rates ranged from 50%to 100%,and pooled patency was 80%(95/119).De novo incontinence rates ranged from 0%to 33%,and pooled incontinence was 17%(8/47).Our findings were limited by small sample sizes,relatively short follow-ups,and heterogeneity between studies.

Engineering The Neck Hinge Reshapes The Processive Movement of Kinesin-3

Objective In kinesin-3,the neck coil correlates with the following segments to form an extended neck that contains a characteristic hinge diverse from a proline in KIF13B to a long flexible linker in KIF1A.The function of this neck hinge for controlling processive movement,however,remains unclear.Methods We made a series of modifications to the neck hinges of KIF13B and KIF1A and tested their movement using a single-molecule motility assay.Results In KIF13B,the insertion of flexible residues before or after the proline differentially impacts the processivity or velocity,while the removal of this proline increases the both.In KIF1A,the deletion of entire flexible neck hinge merely enhances the processivity.The engineering of these hinge-truncated necks of kinesin-3 into kinesin-1 similarly boosts the processive movement of kinesin-1.Conclusion The neck hinge in kinesin-3 controls its processive movement and proper modifications tune the motor motility,which provides a novel strategy to reshape the processive movement of kinesin motors.

Consolidation of a Femoral Neck Fracture in Sickle Cell Disease Patient after Surgical Abstention: A Beneficial and Favorable Outcome

Femoral neck fracture is classically a traumatic pathology in the elderly but it can also occur in young people during a road traffic accident or occasionally when the femoral neck has been weakened by a pathological process. In sickle cell patients, the hip is often subjected to aseptic necrosis. The authors report the case of the child NL, aged 5 years and 4 months in whom a fracture of the femoral neck classified Delbet 3 was found as well as his sickle cell status discovered and in whom treatment by surgical abstention was carried out with a favorable evolution. This association of factors of the femoral head necrosis or nonunion is unusual and confirms the osteogenetic potential of a child. However, monitoring is necessary because other anomalies may reveal themselves.

Deep neck infections mortal complications:Intrathoracic complications and necrotising fasciitis

BACKGROUND We planned this study considering that complications of deep neck infections can be seriously life threatening.AIM To raise awareness that introthoracic complications and necrotizing fasciitis are causes of serious mortality and morbidity.METHODS This study was carried out with the participation of 188 patients who were treated at Mersin University Department of Otorhinolaryngology and Head and Neck Surgery at January 1,2024.When the patient files were retrospectively examined,16 of 188 patients(8.5%)were included in the study because they were observed to have necrotizing fasciitis and/or intrathoracic complications.RESULTS There were a total of 16 patients in this study,9 males(56.25%)and 7 females(43.75%).All patients were adults(>18 years)and the mean age was 50.37 years±15.37 years.Female patients had a mean age of 40.42 years±13.38 years,whereas for male patients was 58.11 years±12.44 years.CONCLUSION Patients with necrotizing fasciitis and/or intrathoracic complications require more complicated and serious surgeries,intensive care unit monitoring,and mechanical ventilator support.Higher rates of morbidity and mortality should be expected in Bal KK et al.Deep neck infections mortal complications WJCC https://www.wjgnet.com 6384 October 26,2024 Volume 12 Issue 30 these patients who are hospitalized for longer periods of time.

Lateral femoral neck stress fractures: A case report

BACKGROUND Sport-induced injuries particularly affect young,healthy,and active individuals.Running,a popular and accessible sport,can cause a wide range of injuries,including stress fractures.Stress fractures can occur during high-intensity training or competitions,especially among well-trained amateurs and professional athletes.Adequate diagnosis can be complicated by the typically young age,unremarkable medical history,and vital condition of the patient.Stress fractures present insidiously,and this is specifically the case with stress fractures of the femoral neck.Timely intervention is crucial to prevent progressive displacement,as this can damage the blood supply to the femoral head.CASE SUMMARY A 30-year-old male runner presented to our outpatient clinic with persistent pain 3 weeks after running a marathon.X-ray showed a complete lateral fracture of the left femoral neck,which was treated surgically with a dynamic hip screw.CONCLUSION It is essential for healthcare providers to be vigilant for the subtle symptoms of stress fractures to ensure timely treatment.Early recognition prevents com-plication and leads to a better prognosis.

New perspectives on biology,disease progression,and therapy response of head and neck cancer gained from single cell RNA sequencing and spatial transcriptomics

Head and neck squamous cell carcinoma(HNSCC)is one of the most frequent cancers worldwide.The main risk factors are consumption of tobacco products and alcohol,as well as infection with human papilloma virus.Approved therapeutic options comprise surgery,radiation,chemotherapy,targeted therapy through epidermal growth factor receptor inhibition,and immunotherapy,but outcome has remained unsatisfactory due to recurrence rates of~50%and the frequent occurrence of second primaries.The availability of the human genome sequence at the beginning of the millennium heralded the omics era,in which rapid technological progress has advanced our knowledge of the molecular biology of malignant diseases,including HNSCC,at an unprecedented pace.Initially,microarray-based methods,followed by approaches based on next-generation sequencing,were applied to study the genetics,epigenetics,and gene expression patterns of bulk tumors.More recently,the advent of single-cell RNA sequencing(scRNAseq)and spatial transcriptomics methods has facilitated the investigation of the heterogeneity between and within different cell populations in the tumor microenvironment(e.g.,cancer cells,fibroblasts,immune cells,endothelial cells),led to the discovery of novel cell types,and advanced the discovery of cell-cell communication within tumors.This review provides an overview of scRNAseq,spatial transcriptomics,and the associated bioinformatics methods,and summarizes how their application has promoted our understanding of the emergence,composition,progression,and therapy responsiveness of,and intercellular signaling within,HNSCC.

Fibroblast activation protein (FAP) as a prognostic biomarker in multiple tumors and its therapeutic potential in head and neck squamous cell carcinoma

Background:Fibroblast activation protein(FAP),a cell surface serine protease,plays roles in tumor invasion and immune regulation.However,there is currently no pan-cancer analysis of FAP.Objective:We aimed to assess the pan-cancer expression profile of FAP,its molecular function,and its potential role in head and neck squamous cell carcinoma(HNSC).Methods:We analyzed gene expression,survival status,immune infiltration,and molecular functional pathways of FAP in The Cancer Genome Atlas(TCGA)and Genotype Tissue Expression(GTEx)tumors.Furthermore,to elucidate the role of FAP in HNSC,we performed proliferation,migration,and invasion assays post-FAP overexpression or knock-down.Results:FAP expression was elevated in nine tumor types and was associated with poor survival in eight of them.In the context of immune infiltration,FAP expression negatively correlated with CD8+T-cell infiltration infive tumor types and positively with regulatory T-cell infiltration in four tumor types.Our enrichment analysis highlighted FAP’s involvement in the PI3K-Akt signaling pathway.In HNSC cells,FAP overexpression activated the PI3K-Akt pathway,promoting tumor proliferation,migration,and invasion.Conversely,FAP knockdown showed inhibitory effects.Conclusion:Our study unveils the association of FAP with poor tumor prognosis across multiple cancers and highlights its potential as a therapeutic target in HNSC.

PPP1R14A is Associated with Immunotherapy Resistance in Head and Neck Squamous Cell Carcinoma Identified by Single-Cell and Bulk RNA-Sequencing

Objective To identify nivolumab resistance-related genes in patients with head and neck squamous cell carcinoma(HNSCC)using single-cell and bulk RNA-sequencing data.Methods The single-cell and bulk RNA-sequencing data downloaded from the Gene Expression Omnibus database were analyzed to screen out differentially expressed genes(DEGs)between nivolumab resistant and nivolumab sensitive patients using R software.The Least Absolute Shrinkage Selection Operator(LASSO)regression and Recursive Feature Elimination(RFE)algorithm were performed to identify key genes associated with nivolumab resistance.Functional enrichment of DEGs was analyzed with Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses.The relationships of key genes with immune cell infiltration,differentation trajectory,dynamic gene expression profiles,and ligand-receptor interaction were explored.Results We found 83 DEGs.They were mainly enriched in T-cell differentiation,PD-1 and PD-L1 checkpoint,and T-cell receptor pathways.Among six key genes identified using machine learning algorithms,only PPP1R14A gene was differentially expressed between the nivolumab resistant and nivolumab sensitive groups both before and after immunotherapy(P<0.05).The high PPP1R14A gene expression group had lower immune score(P<0.01),higher expression of immunosuppressive factors(such as PDCD1,CTLA4,and PDCD1LG2)(r>0,P<0.05),lower differentiation of infiltrated immune cells(P<0.05),and a higher degree of interaction between HLA and CD4(P<0.05).Conclusions PPP1R14A gene is closely associated with resistance to nivolumab in HNSCC patients.Therefore,PPP1R14A may be a target to ameliorate nivolumab resistance of HNSCC patients.

Bipolar hip arthroplasty using conjoined tendon preserving posterior lateral approach in treatment of displaced femoral neck fractures

BACKGROUND Hip fractures account for 23.8%of all fractures in patients over the age of 75 years.More than half of these patients are older than 80 years.Bipolar hemiarthroplasty(BHA)was established as an effective management option for these patients.Various approaches can be used for the BHA procedure.However,there is a high risk of postoperative dislocation.The conjoined tendon-preserving posterior(CPP)lateral approach was introduced to reduce postoperative dislocation rates.AIM To evaluate the effectiveness and safety of the CPP lateral approach for BHA in elderly patients.METHODS We retrospectively analyzed medical data from 80 patients with displaced femoral neck fractures who underwent BHA.The patients were followed up for at least 1 year.Among the 80 patients,57(71.3%)were female.The time to operation averaged 2.3 d(range:1-5 d).The mean age was 80.5 years(range:67-90 years),and the mean body mass index was 24.9 kg/m^(2)(range:17-36 kg/m^(2)).According to the Garden classification,42.5%of patients were typeⅢand 57.5%of patients were typeⅣ.Uncemented bipolar hip prostheses were used for all patients.Torn conjoined tendons,dislocations,and adverse complications during and after surgery were recorded.RESULTS The mean postoperative follow-up time was 15.3 months(range:12-18 months).The average surgery time was 52 min(range:40-70 min)with an average blood loss of 120 mL(range:80-320 mL).The transfusion rate was 10%(8 of 80 patients).The gemellus inferior was torn in 4 patients(5%),while it was difficult to identify in 2 patients(2.5%)during surgery.The posterior capsule was punctured by the fractured femoral neck in 3 patients,but the conjoined tendon and the piriformis tendon remained intact.No patients had stem varus greater than 3 degrees or femoral fracture.There were no patients with stem subsidence more than 5 mm at the last follow-up.No postoperative dislocations were observed throughout the follow-up period.No significance was found between preoperative and postoperative mean Health Service System scores(87.30±2.98 vs 86.10±6.10,t=1.89,P=0.063).CONCLUSION The CPP lateral approach can effectively reduce the incidence of postoperative dislocation without increasing perioperative complications.For surgeons familiar with the posterior lateral approach,there is no need for additional surgical instruments,and it does not increase surgical difficulty.

Effect of Mouth Opening Training Stick Combined with Oral Massage on Mouth Opening Difficulty in Head and Neck Cancer Patients after Treatment

Objective: To study the application effect of mouth-opening training sticks combined with oral massage on patients with mouth-opening difficulty after treatment for head and neck cancer. Methods: Using convenient sampling, 60 patients with mouth-opening difficulty after treatment for head and neck cancer admitted to the Oncology Department from February 2022 to October 2023 were selected for a 2-week exercise and nursing program. The patients were divided into a control group (February 1, 2022 to November 30, 2022) and an observation group (December 1, 2022 to October 31, 2023), with 30 patients in each group. The control group underwent routine mouth-opening functional exercises combined with cork for oral support training, while the observation group underwent routine mouth-opening functional exercises combined with oral massage and mouth-opening training sticks for oral support training. The mouth-opening degree, mouth-opening difficulty level, comfort level, compliance, and quality of life were observed in both groups. Results: Before the intervention, there were no statistically significant differences in mouth-opening degree and mouth-opening difficulty level between the two groups (P > 0.05). After the intervention, the mouth-opening degree, mouth-opening difficulty level, oral comfort level, compliance, and QLICP-HN scores in the observation group were all better than those in the control group, with statistically significant differences (P < 0.05). Conclusion: The combination of mouth-opening training sticks and oral massage with mouth-opening functional exercises can effectively improve the degree of mouth-opening difficulty, enhance oral comfort, increase compliance with mouth-opening exercises, and improve quality of life.

Relationship between preoperative psychological stress and shortterm prognosis in elderly patients with femoral neck fracture

BACKGROUND Older adults are at high risk of femoral neck fractures(FNFs).Elderly patients face and adapt to significant psychological burdens,resulting in different degrees of psychological stress response.Total hip replacement is the preferred treatment for FNF in elderly patients;however,some patients have poor postoperative prognoses,and the underlying mechanism is unknown.We speculated that the postoperative prognosis of elderly patients with FNF may be related to preoperative psychological stress.AIM To explore the relationship between preoperative psychological stress and the short-term prognosis of elderly patients with FNF.METHODS In this retrospective analysis,the baseline data,preoperative 90-item Symptom Checklist score,and Harris score within 6 months of surgery of 120 elderly patients with FNF who underwent total hip arthroplasty were collected.We analyzed the indicators of poor short-term postoperative prognosis and the ability of the indicators to predict poor prognosis and compared the correlation between the indicators and the Harris score.RESULTS Anxiety,depression,garden classification of FNF,cause of fracture,FNF reduction quality,and length of hospital stay were independent influencing factors for poor short-term postoperative prognoses in elderly patients with FNF(P<0.05).The areas under the curve for anxiety,depression,and length of hospital stay were 0.742,0.854,and 0.749,respectively.The sensitivities of anxiety,depression,garden classification of FNF,and prediction of the cause of fracture were 0.857,0.786,0.821,and 0.821,respectively.The specificities of depression,FNF quality reduction,and length of hospital stay were the highest at 0.880,0.783,and 0.761,respectively.Anxiety,depression,and somatization scores correlated moderately with Harris scores(r=-0.523,-0.625,and-0.554;all P<0.001).CONCLUSION Preoperative anxiety,depression,and somatization are correlated with poor short-term prognosis in elderly patients with FNF and warrant consideration.

Direct anterior compared to posterior approach for hip hemiarthroplasty following femoral neck fractures

The differences in complication rates between the direct anterior and posterior approaches for hemiarthroplasty in elderly patients with femoral neck fractures are not yet fully understood.Dislocation,a severe complication associated with increased mortality and often requiring additional surgery,may occur less frequently with the direct anterior approach compared to the posterior approach.Careful consideration of patient demographics is essential when planning the surgical approach.Future research in this area should focus on robust randomized controlled trials involving elderly patients recovering from femoral neck fractures.

Paclitaxel for second-line treatment of squamous cell carcinoma of the head and neck:A multicenter retrospective Italian study

BACKGROUND Squamous cell carcinoma of the head and neck(SCCHN)accounts for 3%of all malignant tumors in Italy.Immune checkpoint inhibitors combined with chemotherapy is first-line treatment for SCCHN;however,second-line treatment options are limited.Taxanes are widely used for combination therapy of SCCHN,as clinical trials have shown their efficacy in patients with this disease,partic ularly in patients with prior therapy.AIM To perform a multicenter retrospective study on the efficacy and safety of weekly paclitaxel for SCCHN.METHODS All patients were previously treated with at least one systemic therapy regimen,which included platinum-based therapy in the vast majority.No patient received prior immunotherapy.RESULTS Median progression-free survival(mPFS)was 3.4 months and median overall survival(mOS)was 6.5 months.Subgroup analysis was performed according to three principal prognostic factors:Smoking,alcohol consumption,and body mass index.Analysis demonstrated reduced survival,both mOS and mPFS,in the unfavorable prognostic groups,with the biggest deltas observed in mOS.CONCLUSION Weekly paclitaxel provided favorable survival and disease control rates,with low severe adverse events.Paclitaxel is a safe and valid therapeutic option for patients with SCCHN who received prior therapy.