Using Flowable Composite as Gingival Retraction Cord in Prosthodontics Dentistry: Two Case Reports: A Dental Technique

One of the most challenging factors affecting impression quality and good marginal fit is the gingival retraction method, which aims to separate the gingiva from the tooth to expose the finishing line of the prepared tooth. Bleeding and contamination from the crevicular fluid may compete for space with the impression material within the sulcus, leading to indistinct preparations and a lack of detail at the margin. In addition, such procedures might damage the PDL and cause permanent recession. Flowable composite cable, as opposed to traditional retraction cords, offers the proper marginal seal and visibility during the impression record because of its lower viscosity, improved adaptability, and elastic properties. The aim of this report is to present a brand-new, innovative method for controlling gingival hemorrhage in addition to the gingival retraction in restorative and prosthodontic treatment by utilizing a flowable composite during the final impression record procedure. In these case reports, the flowable composite cord technique is used instead of traditional gingival cords to modify and refine the gingival tissue before taking the traditional final impression or digital scan. Two cases were done for patients undergoing fixed prosthodontics and veneer treatment within a 2-year follow-up period. In addition, the flowable composite cord was used as temporary restoration before the final prosthetic cementation or under the provisional crowns. As a result, clean and healthy gingival tissues render cementation of the final prosthesis quicker and easier to perform. The patients in both cases claimed that their prosthodontic treatments, which involved the application of a flowable composite cord to temporarily retraction the gingiva, had produced good outcomes at the yearlong follow-up. In conclusion, the flowable composite cord technique is found to be a useful tool to improve the quality of impressions in fixed prosthodontics by providing excellent access for impression material to record fine details of the finish line of the prepared tooth structure, and to alter the inflamed tissue into a healthy tissue.

Retraction note to:RNA-binding protein CPSF6 regulates IBSP to affect pyroptosis in gastric cancer

The authors have decided to retract the article published on World J Gastrointest Oncol(2023)for further consideration due to data errors and some misunderstandings in communication.

Research misconduct in hospitals is spreading:A bibliometric analysis of retracted papers from Chinese university-affiliated hospitals

Purpose: The number of retracted papers from Chinese university-affiliated hospitals is increasing, which has raised much concern. The aim of this study is to analyze the retracted papers from university-affiliated hospitals in China’s mainland from 2000 to 2021. Design/methodology/approach: Data for 1,031 retracted papers were identified from the Web of Science Core collection database. The information of the hospitals involved was obtained from their official websites. We analyzed the chronological changes, journal distribution, discipline distribution and retraction reasons for the retracted papers. The grade and geographic locations of the hospitals involved were explored as well.Findings: We found a rapid increase in the number of retracted papers, while the retraction time interval is decreasing. The main reasons for retraction are plagiarism/self-plagiarism(n=255), invalid data/images/conclusions(n=212), fake peer review(n=175) and honesty error(n=163). The disciplines are mainly distributed in oncology(n=320), pharmacology & pharmacy(n=198) and research & experimental medicine(n=166). About 43.8% of the retracted papers were from hospitals affiliated with prestigious universities. Research limitations: This study fails to differentiate between retractions due to honest error and retractions due to research misconduct. We believe that there is a fundamental difference between honest error retractions and misconduct retractions. Another limitation is that authors of the retracted papers have not been analyzed in this study.Practical implications: This study provides a reference for addressing research misconduct in Chinese university-affiliated hospitals. It is our recommendation that universities and hospitals should educate all their staff about the basic norms of research integrity, punish authors of scientific misconduct retracted papers, and reform the unreasonable evaluation system.Originality/value: Based on the analysis of retracted papers, this study further analyzes the characteristics of institutions of retracted papers, which may deepen the research on retracted papers and provide a new perspective to understand the retraction phenomenon.

Efficacy of invisible advancement correction for mandibular retraction in adolescents based on Pancherz analysis

BACKGROUND Mandibular retraction is the main etiological mechanism of class II malocclusion in China and the subsequent distal molar relationship can cause functional discomfort in mastication,breathing and the temporomandibular joint.The use of mandibular advancement(MA)devices has recently emerged as an adolescent mandibular retraction treatment;however,current studies regarding the effect thereof are relatively few,and there is lack of sufficient clinical support.AIM To investigate the clinical effect of invisalign MA on the treatment of mandibular retraction in adolescents.METHODS This study included 30 adolescent patients who underwent treatment with the MA appliances from December 2017 to June 2021.The lateral cephalometric data before and after treatment were collected and imported into Dolphin Imaging software.The changes were measured by linear measurement superimposed with lateral cephalometric trajectory based on the Pancherz technology.RESULTS There was no significant difference in the length and position of maxilla before and after the treatment.The position of the mandible moved 3.13 mm,the length increased 4.14 mm,the mandibular ramus length increased 4.09 mm,the body length increased 4.25 mm,and the position of the condyle moved 1.03 mm forward after treatment.Additionally,changes in the incisor sagittal position and labial inclination were observed.The position of the upper incisor point moved back 1.33 mm,without statistical difference,the inclination and tooth angle decreased by 3.44°and 4.06°,respectively;the position of the lower incisor point was moved 2.98 mm,and the inclination and tooth angle increased by 2.62°and 1.23°,respectively.Furthermore,changes in the incisor overjet and molar relationship were seen.Overjet decreased by 4.31 mm,of which 1.78 mm was due to dental factors,accounting for 41.3%of the effect as opposed to 58.7%due to skeletal factors.Molar relationship improved 3.87 mm,with 1.34 mm due to dental factors,and dental and skeletal factors were accounted for 34.6%and 65.4%of the effect,respectively.CONCLUSION For adolescent patients with mandible retraction,invisalign MA can effectively promote the mandible growth,and it was proven to be mainly due to skeletal effects.

Retraction note to:Beneficial effect of probiotics supplements in reflux esophagitis treated with esomeprazole:A randomized controlled trial

We have decided to retract the above article for further consideration due to a data labelling error.

Assessment of retracted papers,and their retraction notices,from a cancer journal associated with“paper mills”

Cancer research is occasionally described as being in a reproducibility crisis.The cancer literature has ample papers retracted due to misconduct,including the use of paper mills,invalid authorship,or fake data.The objective of this paper was to gain an appreciation of the balance of retractions and associated retraction notices of 23 retracted Cancer Biotherapy and Radiopharmaceuticals papers associated with paper mills.By 23 March 2023,these retracted papers had already accumulated 287 citations according to Web of Science Core Collection,253 according to Scopus,and 365 according to Google Scholar,i.e.,metrically speaking,they were highly rewarded.All authors had an affiliation(71%being a hospital)in China.Most(12/21;57%)of corresponding authors had emails with a@163.com suffix.Four of the retraction notices(i.e.,17%)explicitly indicated paper mills as a reason for retraction although,in general,the retraction notices lacked details and background that could assist readers’understanding of the retractions.

Reliability analysis of retractable drill bit with air reverse circulation used for drilling while casing

Casing-while-drilling(CWD)with down the hole(DTH)hammer drilling technology has been widely used in unconsolidated formations,due to its advantages in protecting the borehole wall,excellent rock cuttings capacity,and fast penetration rate in hard rock.As an important component of the CWD system,the structure of the retractable drill bit needs not only to ensure to form stronger reverse circulation,but also to be expandable or retractable as needed,otherwise the drill bit cannot be lift and put down smoothly in the casing,and may lead to drilling accidents.This paper developed a new type of reverse circulation DTH hammer drill bit used for CWD drilling technology.The retractable performance of this type of drill bit is studied using ADAMS software.The results show that it is smoothly expandable and retractable as designed under the conditions of the weight of the bit(WOB)of 0.5–2.0 t and the rotation speed of 30–60 r/min.To investigate the reverse circulation effect of the drill bit,Fluent software was used to simulate the flow characteristic inside it.The simulation results indicated that it can form strong reverse circulation,and the entrainment ratio h can reach 9.5%.

Retractions of One Dimensional Manifold

Our aim in the present article is to introduce and study types of retraction of one dimensional manifold. New types of geodesics in one dimensional manifold are presented. The deformation retracts of one dimensional manifold into itself and onto geodesics is deduced. Also, the isometric and topological folding in each case and the relation between the deformations retracts after and before folding has been obtained. New types of conditional folding are described.

A Geometrical Characterization of Spatially Curved Roberstion-Walker Space and Its Retractions

Our aim in the present article is to introduce and study new types of retractions of closed flat Robertson-Walker W4 model. Types of the deformation retract of closed flat Robertson-Walker W4 model are obtained. The relations between the retraction and the deformation retract of curves in W4 model are deduced. Types of minimal retractions of curves in W4 model are also presented. Also, the isometric and topological folding in each case and the relation between the deformation retracts after and before folding have been obtained. New types of homotopy maps are deduced. New types of conditional folding are presented. Some commutative diagrams are obtained.

幂等元、retract和不动点

用范畴论方法讨论了幂等元、ｒｅｔｒａｃｔ与不动点子空间的性质及其联系．

Long-term effect of triamcinolone acetonide in the treatment of upper lid retraction with thyroid associated ophthalmopathy

AIM： To report the long-term outcomes of a large cohort of upper lid retraction patients treated with subconjunctival triamcinolone acetonide injections.METHODS： This retrospective clinical study was conducted from 2009 to 2016. The documents of 97 patients（126 eyes） were reviewed. The patients were treated with subconjunctival triamcinolone acetonide injections monthly and evaluated pre-and post-treatment by taking measurements of the upper margin reflex distance（MRD1, the distance between the upper-lid margin and the pupil center）, lid aperture, lagophthalmos and proptosis. The patients were divided into the cured group, the improved group and the ineffective group based on the final treatment effectiveness. The improved group and the ineffective group were combined into non-cured group.RESULTS： The follow-up time was 23.45±14.86 mo. Of the patients, 63（64.9%） were assigned to the cured group, 22（22.7%） in the improved group, 12（12.4%） in the ineffective group. Injection times for cured group was 4.66±1.74, and for non-cured group was 5.17±2.08（P≤0.05）. The MRD1 was significantly reduced between baseline and 1 mo after the initiation of treatment in the cured and improved groups（P〈0.001）. The values did not change significantly after 4 mo for the improved group, while they continued to decrease in the cured group. In the ineffective group, the MRD1 did not significantly change after treatment. A statistically significant difference was observed between the baseline and post-treatment values of the mean muscle thickness（2.95±0.99 mm vs 2.04±0.63 mm, P〈0.05） and surface area（27.27±10.5 mm2 vs 18.3±7.04 mm2,P〈0.05） of the levator superioris with magnetic resonance imaging examination. Twelve patients（12.4%） relapsed after treatment and required additional subconjunctival injections. The main side effects included menstrual cycle disturbances（32%） and elevations of intra-ocular pressure（18.6%）. CONCLUSION： A repeated subconjunctival injection of triamcinolone is an effective and relatively safe treatment for upper lid retraction due to thyroid-associated ophthalmopathy. This is related to the anti-inflammation effect of the medicine and the levator thickness can become thinner. Patients must be monitored regularly for recurrences and side effects.

Retraction of lumbar disc herniation achieved by noninvasive techniques: A case report

BACKGROUND Lumbar disc herniation(LDH)has emerged as one of the most common causes of low back pain.The routine treatment approach involves chemonucleolysis therapy,discectomy by percutaneous endoscopy,and percutaneous laser disc decompression.Unfortunately,all of these methods carry inherent risk of causing harm to the patient and,as such,there is an unmet but urgent need for an effective and safe noninvasive treatment for LDH.The purpose of this report is to describe a non-invasive method for re-absorption of LDH.CASE SUMMARY A 34-year-old woman was admitted with a complaint of waist pain that she reported as having become acutely aggravated over the past 3 d and accompanied by discomfort in the right lower limb.Her self-reported medical history included persistent postpartum low back pain from 7 years prior.Physical exam showed positivity for neck flexion test(Lindner sign)and supine abdomen test;the straight leg-raising test showed right 60(+)and left 80(-).Findings from standard imaging(magnetic resonance)and collective physical examinations indicated a L5/S1 herniated lumbar disc.Treatment consisted of three-dimensional(balanced regulating)spinal manipulation and acupuncture,upon which the LDH resolved by retraction.CONCLUSION Following L5/S1 herniated lumbar disc diagnosis,three-dimensional(balanced regulating)spinal manipulation combined with acupuncture therapy is an effective treatment.

Treatment modalities in Duane’s Retraction Syndrome

●AIM:To study the different treatment modalities needed in cases of Duane’s Retraction Syndrome(DRS).●METHODS:This prospective study undergone in more than four years,in Alexandria,included 238 patients of DRS,including type I,162 patients(68%),type II 12 patients(5%)and type III 64 patients(27%).Surgery was indicated in 98(41%)of them,to eliminate abnormal head posture,deviation of the eye in primary position,severe retraction of the globe or cosmetically unacceptable upshoot with attempted adduction.●RESULTS:Type I was the most common and type II was the least.Females were predominant in this study,constituting 125 patients(52.5%),and males 113 patients(47.5%).Left eye was more affected,in 110 patients(46.2%),right eye in 91 patients(38.2%)and bilateral in 37 patients(15.6%).Amblyopia was found in 27 patients(11.3%)and treated in 13 patients under 10 years of age,by patching the normal eye.Ninety-eight patients(41%)were operated,the results were most satisfactory and a nomogram is followed in the surgical plan.●CONCLUSION:The surgical management is needed in less than half of the cases and should be planned for every case individually according to the clinical findings,planned nomogram and modified intraoperatively according to the anatomical findings during surgery.

Retraction pocket excision with cartilage grafting as a preventive surgery for cholesteatoma

Aims: The goal of the present study is to summarize our experience on surgical management of retraction pockets(RP) as a preventive tool against cholesteatomas.Methods:Twenty-five ears have been followed up for a mean period of 6.16 ± 4.35 years(from 1 to 17 years). The sample presented a mean age of 47.56 + 19.11 years(from 16 to 73 years). All patients underwent cartilage graft surgery. Furthermore 10(40%) underwent tympanoplasty(TPL) type Ⅰ, 14(56%) TPL type Ⅱ and 1(4%) TPL type Ⅴ.Results: Eleven ears(44%) showed cholesteatoma: all these cases were stage Ⅲ according to Charachon staging, and stage Ⅳ or Ⅴ according to Gersdorff classification. Twelve patients(48%) showed erosion of the ossicular chain. Of these, five were associated with cholesteatoma and seven only with retraction. The recurrence rate of cholesteatoma was 12%. None of the patients with a stage Ⅱ or Ⅲ RP(according to Gersdorff classification) developed cholesteatoma. The recurrence of RP was 0%.In regards to literature review, seven references were selected. These studies showed a success rate ranging from 79.1% to 88%, while recurrences of RP varied from 6.4% to 13%. Only one study specified a recurrence rate of cholesteatoma of 28%.Conclusions: Surgical treatment of stages Ⅱ and Ⅲ RP is an effective tool to prevent cholesteatoma formation. The presence of keratin accumulation and cholesteatoma at the RP(stages Ⅳ and Ⅴ, according to Gersdorff) are the real predictors of poor prognosis.

Performance Analysis on Retractable Landing Gear and Design of Ground Test System

Landing gears are one of the key components for large or middle unmanned aerial vehicles,and their working performances directly affect flying security and aircraft taking-off and landing performance.Thus,it is meaningful to study the retraction system.Based on CATIA and ADAMS software platforms,a virtual model of landing gear retraction system is built for performance test,and then dynamic simulation is carried out.Afterwards,a test system for landing gear retraction is established,and the test data are compared with the results acquired from dynamics simulation.The main factors which affect the dynamic performance of retractable landing gear are analyzed emphatically.The simulation results show that aerodynamic load has an impact on retraction time,the mass force affects extension process,and the oil hole size of hydraulic actuator has an effect on both retraction time and extension time.

Mechanical performance study of the retractable pier column after stiffening

To solve the problem that the overlapping parts of a retractable pier column are prone to damage,this paper proposed the reinforcing measure of setting a stiffener ring at the bottom of the steel pipe.To study how the stiffener-ring parameters influence the mechanical properties of the pier column.12 scale model specimens(including nine specimens with stiffener-ring widths of 40,50,and 60 mm and three unstiffened comparison specimens)were tested under axial compression.Based on the test results,the specimen load-displacement,load-deflection,and load-strain curves were analyzed,and a finite-element model of a pier column under axial compression was established to determine the optimal stiffener size.The results show that setting a stiffener ring enhances the cooperative working ability between the steel pipe and the internal filling material and restrains the lateral deformation of the pier column,thereby improving the ultimate bearing capacity and overall stability of the pier column.The ultimate bearing capacity of the pier column is related to the width and thickness of the stiffener ring.The optimal size of the stiffener ring of the model pier column is 70 mm in width and 4 mm in thickness.The present research results provide a reference for designing compressible pier columns and column stiffening in mines and have important practical significance.

Dynamic analysis of a deployable/retractable damped cantilever beam

Deployable/retractable damped cantilever beams are a class of time-varying parametric structures which have attracted considerable research interest due to their many potential applications in the intelligent robot field and aerospace.In the present work,the dynamic characteristics of a deployable/retractable damped cantilever beam are investigated experimentally and theoretically.The time-varying damping,as a function of the beam length,is obtained by both the enveloped fitting method and the period decrement method.Furthermore,the governing equation of the deployable/retractable damped cantilever beam is derived by introducing the time-varying damping parameter,and the corresponding closed-form solution and vibration principles are investigated based on the averaged method.The theoretical predictions for transient dynamic responses are in good agreement with the experimental results.The dynamic mechanism analysis on time-varying damping offers flexible technology in mechanical and aerospace fields.

Retraction Statement

As the corresponding author of a paper appearing in J Huazhong Univ Sci Technolog [Med Sci], here I retract the articletitled "Effect of Inhalational Anesthetics on Cytotoxicity and Intracellular Calcium Differently in Rat Pheochromocytoma Cells(PC12)"

Autophagy in degenerating axons following spinal cord injury: evidence for autophagosome biogenesis in retraction bulbs

Macroautophagy （here autophagy） is a catabolic mechanism responsible for the degradation of bulk cytoplasm, long-lived proteins and organeUes. During autophagy, the cargos are engulfed by double-membrane structures named phagophores, which expand to form the autophagosomes. Subsequently, these autophagosomes fuse with lysosomes, in which the cytoplasmic cargos are degraded. Autophagy is a constitutive pro- cess, which plays an important role in cellular homeostasis. In primary neurons autophagosome formation occurs continuously and preferentially at the distal end of axons. On the other hand, autophagy is increased by different stresses, and its dysregulation or excessive induction may lead to detrimental effects. Many neurological disorders have been associated with alterations in the autophagic pathway and an increase in autophagy during axonal degeneration was described.

Experimental and FEM Modal Analysis of a Deployable-Retractable Wing

The aim of this paper is to conduct experimental modal analysis and numerical simulation to verify the structural characteristics of a deployable-retractable wing for aircraft and spacecraft. A modal impact test was conducted in order to determine the free vibration characteristics. Natural frequencies and vibration mode shapes were obtained via measurement in LMS Test. Lab. The frequency response functions were identified and computed by force and acceleration signals, and then mode shapes of this morphing wing structure were subsequently identified by PolyMAX modal parameter estimation method. FEM modal analysis was also implemented and its numerical results convincingly presented the mode shape and natural frequency characteristics were in good agreement with those obtained from experimental modal analysis. Experimental study in this paper focuses on the transverse response of morphing wing as its moveable part is deploying or retreating. Vibration response to different rotation speeds have been collected, managed and analyzed through the use of comparison methodology with each other. Evident phenomena have been discovered including the resonance on which most analysis is focused because of its potential use to generate large amplitude vibration of specific frequency or to avoid such resonant frequencies from a wide spectrum of response. Manufactured deployable-retractable wings are studied in stage of experimental modal analysis, in which some nonlinear vibration resulted should be particularly noted because such wing structure displays a low resonant frequency which is always optimal to be avoided for structural safety and stability.