Seismic bearing capacity of strip footings on rock masses using the Hoeke Brown failure criterion

In this paper,the bearing capacity of strip footings on rock masses has been studied in the seismic case.The stress characteristics or slip line method was used for analysis.The problem was analyzed in the plane strain condition using the Hoeke Brown failure criterion.First,the equilibrium equations along the stress characteristics were obtained and the rock failure criterion was applied.Then,the equations were solved using the finite difference method.A computer code has been provided for analysis.Given the footing and rock parameters,the code can calculate the stress characteristics network and obtain the stress distribution under the footing.The seismic effects have been applied as the horizontal and vertical pseudo-static coefficients.The results of this paper are very close to those of the other studies.The seismic bearing capacity of weightless rock masses can be obtained using the proposed equations and graphs without calculating the whole stress characteristics network.

Settlement predictions of footings on sands using probabilisticanalysis

The design of footings on sands is often controlled by settlement rather than bearing capacity.Therefore,settlement predictions are essential in the design of shallow foundations.However,predicted settlements of footings are highly dependent on the chosen elastic modulus and the used method.This paper presents the use of probabilistic analysis to evaluate the variability of predicted settlements of footings on sands,focusing on the load curve(predicted settlements)characterization.Three methodologies,the first-and second-order second-moment(FOSM and SOSM),and Monte Carlo simulation(MCS),for calculating the mean and variance of the estimated settlements through Schmertmann(1970)’s equation,are presented and discussed.The soil beneath the footing is treated as an uncorrelated layered material,so the total settlement and variance are found by adding up the increments of the layers.The deformability modulus(ESi)is considered as the only independent random variable.As an example of application,a hypothetical case of a typical subsoil in the state of Espirito Santo,southeast of Brazil,is evaluated.The results indicate that there is a significant similarity between the SOSM and MCS methods,while the FOSM method underestimates the results due to the non-consideration of the high-order terms in Taylor’s series.The contribution of the knowledge of the uncertainties in settlement prediction can provide a safer design.

Effect of Overlap Stress as Well as Tie Beam Length and Width on Settlement of Isolated Footings Using Finite Element

Effects of tie beam length, width and overlap stress on settlement of foundations have been investigated. In this investigation square concrete footings have been used with dimensions (B × B × d) where (d) is footing depth and (B) is footing width (1, 1.5,2 m). Width of tie beam (b) has been taken equal to 0.25, 0.30, 0.40, 0.50 and 0.75 (m). Tie beam length (L) has been taken varying from B till 3B with same footing depth = 0.50 m. Effect of overlap stress on settlement as well as effect of tie beam width and length on settlement has been determined. Also, the efficiency of tie beam length and width has been obtained. An equation is presented to compute the overlap stress zone in case of existing tie beam. It is found that the settlement increases with increasing the length of tie beam which is clear after the effect of the overlap stresses zone. The width of overlap stress zone case of existing tie beam has been found to be equal to (1.6 -1.75) B. The settlement of footings decreases with increasing tie beam width. It is found that the settlement after the effect of the overlap stress zone increases with increasing the length of tie beam.

Assessment of bearing capacity of interfering strip footings located near sloping surface considering artificial neural network technique

The bearing capacity of interfering footings located near the slope face suffers from reduced bearing capacity due to the formation of the curtailed passive zone. Depending upon the position of the footing, their spacing and steepness of the slope different extents of bearing capacity reduction can be exhibited. A series of finite element investigation has been done with the aid of Plaxis 3 D v AE.01 to elucidate the influence of various geotechnical and geometrical parameters on the ultimate bearing capacity of interfering surface strip footings located at the crest of the natural soil slope. Based on the large database obtained from the numerical simulation, a6-8-1 Artificial Neural Network architecture has been considered for the assessment of the ultimate bearing capacity of interfering strip footings placed on the crest of natural soil slope. Sensitivity analyses have been conducted to establish the relative significance of the contributory parameters, which exhibited that for the stated problem, apart from shear strength parameters, the setback ratio and spacing of footing are the prime contributory parameters.

Load eccentricity effects on behavior of circular footings reinforced with geogrid sheets

In this paper, an experimental study for an eccentrically loaded circular footing, resting on a geogridreinforced sand bed, is performed. To achieve this aim, the steel model footing of 120 mm in diameterand sand in relative density of 60% are used. Also, the effects of depth of first and second geogrid layersand number of reinforcement layers （1e4） on the settlement-load response and tilt of footing undervarious load eccentricities （0 cm, 0.75 cm, 1.5 cm, 2.25 cm and 3 cm） are investigated. Test results indicatethat ultimate bearing capacity increases in comparison with unreinforced condition. It is observed thatwhen the reinforcements are placed in the optimum embedment depth （u/D ？0.42 and h/D ？0.42）, thebearing capacity ratio （BCR） increases with increasing load eccentricity to the core boundary of footing,and that with further increase of load eccentricity, the BCR decreases. Besides, the tilt of footing increaseslinearly with increasing settlement. Finally, by reinforcing the sand bed, the tilt of footing decreases at 2layers of reinforcement and then increases by increasing the number of reinforcement layers.

The use of the node-based smoothed finite element method to estimate static and seismic bearing capacities of shallow strip footings

The node-based smoothed finite element method(NS-FEM)is shortly presented for calculations of the static and seismic bearing capacities of shallow strip footings.A series of computations has been performed to assess variations in seismic bearing capacity factors with both horizontal and vertical seismic accelerations.Numerical results obtained agree very well with those using the slip-line method,revealing that the magnitude of the seismic bearing capacity is highly dependent upon the combinations of various directions of both components of the seismic acceleration.An upward vertical seismic acceleration reduces the seismic bearing capacity compared to the downward vertical seismic acceleration in calculations.In addition,particular emphasis is placed on a separate estimation of the effects of soil and superstructure inertia on each seismic bearing capacity component.While the effect of inertia forces arising in the soil on the seismic bearing capacity is non-trivial,and the superstructure inertia is the major contributor to reductions in the seismic bearing capacity.Both tables and charts are given for practical application to the seismic design of the foundations.

Prevalence of Anemia in Patients with Diabetes Mellitus:A Systematic Review and Meta-Analysis

Objective Anemia is a common public health concern in patients with type 2 diabetes worldwide.This study aimed to identify the prevalence of anemia among patients with diabetes.Methods Electronic databases,including PubMed,Scopus,Web of Sciences,and Google Scholar,were searched systematically for studies published between 2010 and 2021.After removing duplicates and inappropriate reports,the remaining manuscripts were reviewed and appraised using theNewcastleOttawa Scale(NOS)tool.A random-effects model was used to calculate the pooled estimates of the extracted data using Stata version 17.Heterogeneity of the studies was assessed using the Q statistic.Results A total of 51 articles containing information on 26,485 patients with diabetes were included in this study.The articles were mainly from Asia(58.82%)and Africa(35.29%).The overall prevalence of anemia was 35.45%(95%CI:30.30–40.76),with no evidence of heterogeneity by sex.Among the two continents with the highest number of studies,the prevalence of anemia in patients with diabetes was significantly higher in Asia[40.02;95%CI:32.72–47.54]compared to Africa[28.46;95%CI:21.90–35.50](P for heterogeneity=0.029).Moreover,there has been an increasing trend in the prevalence of anemia in patients with diabetes over time,from[15.28;95%CI:9.83–22.21]in 2012 to[40.70;95%CI:10.21–75.93]in 2022.Conclusion Globally,approximately 4 in 10 patients with diabetes suffer from anemia.Therefore,routine anemia screening and control programs every 3 months might be useful in improving the quality of life of these patients.

Acute effect of foot strike patterns on in vivo tibiotalar and subtalar joint kinematics during barefoot running

Background:Foot kinematics,such as excessive eversion and malalignment of the hindfoot,are believed to be associated with running-related injuries.The maj ority of studies to date show that different foot strike patterns influence these specific foot and ankle kinematics.However,technical deficiencies in traditional motion capture approaches limit knowledge of in vivo joint kinematics with respect to rearfoot and forefoot strike patterns(RFS and FFS,respectively).This study uses a high-speed dual fluoroscopic imaging system(DFIS)to determine the effects of different foot strike patterns on 3D in vivo tibiotalar and subtalar joints kinematics.Methods:Fifteen healthy male recreational runners underwent foot computed tomography scanning for the construction of 3-dimensional models.A high-speed DFIS(100 Hz)was used to collect 6 degrees of freedom kinematics for participants’tibiotalar and subtalar joints when they adopted RFS and FFS in barefoot condition.Results:Compared with RFS,FFS exhibited greater internal rotation at 0%-20%of the stance phase in the tibiotalar joint.The peak internal rotation angle of the tibiotalar joint under FFS was greater than under RFS(p<0.001,Cohen’s d=0.92).RFS showed more dorsiflexion at 0%-20%of the stance phase in the tibiotalar joint than FFS.RFS also presented a larger anterior translation(p<0.001,Cohen’s d=1.28)in the subtalar joint at i nitial contact than FFS.Conclusion:Running with acute barefoot FFS increases the internal rotation of the tibiotalar joint in the early stance.The use of high-speed DFIS to quantify the movement of the tibiotalar and subtalar joint was critical to revealing the effects of RF S and FFS during running.

The deterministic condition for the ground reaction force acting point on the combined knee valgus and tibial internal rotation moments in early phase of cutting maneuvers in female athletes

Background:Combined knee valgus and tibial internal rotation(VL+IR)moments have been shown to stress the anterior cruciate ligament(ACL)in several in vitro cadaveric studies.To utilize this knowledge for non-contact ACL injury prevention in sports,it is necessary to elucidate how the ground reaction force(GRF)acting point(center of pressure(CoP))in the stance foot produces combined knee VL+IR moments in risky maneuvers,such as cuttings.However,the effects of the GRF acting point on the development of the combined knee VL+IR moment in cutting are still unknown.Methods:We first established the deterministic mechanical condition that the CoP position relative to the tibial rotational axis differentiates the GRF vector’s directional probability for developing the combined knee VL+IR moment,and theoretically predicted that when the CoP is posterior to the tibial rotational axis,the GRF vector is more likely to produce the combined knee VL+IR moment than when the CoP is anterior to the tibial rotational axis.Then,we tested a stochastic aspect of our theory in a lab-controlled in vivo experiment.Fourteen females performed 60˚cutting under forefoot/rearfoot strike conditions(10 trials each).The positions of lower limb markers and GRF data were measured,and the knee moment due to GRF vector was calculated.The trials were divided into anterior-and posterior-CoP groups depending on the CoP position relative to the tibial rotational axis at each 10 ms interval from 0 to 100 ms after foot strike,and the occurrence rate of the combined knee VL+IR moment was compared between trial groups.Results:The posterior-CoP group showed significantly higher occurrence rates of the combined knee VL+IR moment(maximum of 82.8%)at every time point than those of the anterior-CoP trials,as theoretically predicted by the deterministic mechanical condition.Conclusion:The rearfoot strikes inducing the posterior CoP should be avoided to reduce the risk of non-contact ACL injury associated with the combined knee VL+IR stress.

Research progress and challenges in stem cell therapy for diabetic foot: Bibliometric analysis and perspectives

BACKGROUND Stem cell therapy has shown great potential for treating diabetic foot(DF).AIM To conduct a bibliometric analysis of studies on the use of stem cell therapy for DF over the past two decades,with the aim of depicting the current global research landscape,identifying the most influential research hotspots,and providing insights for future research directions.METHODS We searched the Web of Science Core Collection database for all relevant studies on the use of stem cell therapy in DF.Bibliometric analysis was carried out using CiteSpace,VOSviewer,and R(4.3.1)to identify the most notable studies.RESULTS A search was conducted to identify publications related to the use of stem cells for DF treatment.A total of 542 articles published from 2000 to 2023 were identified.The United States had published the most papers on this subject.In this field,Iran’s Shahid Beheshti University Medical Sciences demonstrated the highest productivity.Furthermore,Dr.Bayat from the same university has been an outstanding researcher in this field.Stem Cell Research&Therapy is the journal with the highest number of publications in this field.The main keywords were“diabetic foot ulcers,”“wound healing,”and“angiogenesis.”CONCLUSION This study systematically illustrated the advances in the use of stem cell therapy to treat DF over the past 23 years.Current research findings suggested that the hotspots in this field include stem cell dressings,exosomes,wound healing,and adipose-derived stem cells.Future research should also focus on the clinical translation of stem cell therapies for DF.

Impact of tibial transverse transport in tissue regeneration and wound healing with perspective on diabetic foot ulcers

In this editorial,we comment on an article by Liao et al published in the current issue of the World Journal of Diabetes.We focus on the clinical significance of tibial transverse transport(TTT)as an effective treatment for patients with diabetic foot ulcers(DFU).TTT has been associated with tissue regeneration,improved blood circulation,reduced amputation rates,and increased expression of early angiogenic factors.Mechanistically,TTT can influence macrophage polarization and growth factor upregulation.Despite this potential,the limitations and conflicting results of existing studies justify the need for further research into its optimal application and development.These clinical implications highlight the efficacy of TTT in recalcitrant DFU and provide lasting stimuli for tissue re-generation,and blood vessel and bone marrow improvement.Immunomodu-lation via systemic responses contributes to its therapeutic potential.Future studies should investigate the underlying molecular mechanisms to enhance our understanding and the efficacy of TTT.This manuscript emphasizes the potential of TTT in limb preservation and diabetic wound healing and suggests avenues for preventive measures against limb amputation in diabetes and peripheral artery disease.Here,we highlight the clinical significance of the TTT and its importance in healing DFU to promote the use of this technique in tissue regeneration.

Surgical management of the diabetic foot:The current evidence

The prevalence of diabetes mellitus and its associated complications,particularly diabetic foot pathologies,poses significant healthcare challenges and economic burdens globally.This review synthesises current evidence on the surgical management of the diabetic foot,focusing on the interplay between neuropathy,ischemia,and infection that commonly culminates in ulcers,infections,and,in severe cases,amputations.The escalating incidence of diabetes mellitus underscores the urgency for effective management strategies,as diabetic foot complications are a leading cause of hospital admissions among diabetic patients,significantly impacting morbidity and mortality rates.This review explores the pathophysiological mechanisms underlying diabetic foot complications and further examines diabetic foot ulcers,infections,and skeletal pathologies such as Charcot arthropathy,emphasising the critical role of early diagnosis,comprehensive management strategies,and interdisciplinary care in mitigating adverse outcomes.In addressing surgical interventions,this review evaluates conservative surgeries,amputations,and reconstructive procedures,highlighting the importance of tailored approaches based on individual patient profiles and the specific characteristics of foot pathologies.The integration of advanced diagnostic tools,novel surgical techniques,and postoperative care,including offloading and infection control,are discussed in the context of optimising healing and preserving limb function.

Prevalence and risk factors of wound complications after transtibial amputation in patients with diabetic foot

BACKGROUND Diabetic foot(DMF)complications are common and are increasing in incidence.Risk factors related to wound complications are yet to be established after transtibial amputation under the diagnosis of DMF infection.AIM To analyze the prognosis and risk factors related to wound complications after transtibial amputation in patients with diabetes.METHODS This retrospective cohort study included seventy-two patients with DMF complications who underwent transtibial amputation between April 2014 and March 2023.The groups were categorized based on the occurrence of wound complications,and we compared demographic data between the complication group and the non-complication group to analyze risk factors.Moreover,a multivariate logistic regression analysis was performed to identify risk factors.RESULTS The average follow-up period was 36.2 months.Among the 72 cases,31(43.1%)had wound complications.Of these,12 cases(16.7%)received further treatment,such as debridement,soft tissue stump revision,and re-amputation at the proximal level.In a group that required further management due to wound complications after transtibial amputation,the hemoglobin A1c(HbA1c)level was 9.32,while the other group that did not require any treatment had a 7.54 HbA1c level.The prevalence of a history of kidney transplantation with wound complications after transtibial amputation surgery in DMF patients was significantly greater than in cases without wound complications(P=0.02).Other factors did not show significant differences.CONCLUSION Approximately 43.1%of the patients with transtibial amputation surgery experienced wound complications,and 16.7%required additional surgical treatment.High HbA1c levels and kidney transplant history are risk factors for postoperative wound complications.

Foot and ankle surgery:Tourniquet placement site to cause as little postoperative pain as possible

There is controversy in the literature on where to place the tourniquet(thigh,calf,ankle)for foot and ankle surgery.While some authors prefer the ankle tourniquet to the calf tourniquet,others state that the surgeon can decide between using the thigh tourniquet or the ankle tourniquet,since there was no difference in postoperative pain between them.Where to place the tourniquet during foot and ankle surgery to cause the least possible postoperative pain to the patient as a result of the tourniquet is a common question in clinical practice.The reality is that,unfortunately,there is no consensus on this issue.Perhaps the only possible way to answer this question would be to conduct a comparative study with sufficient statistical power to reach scientifically sound conclusions.It does not seem easy to carry out such a study,but it would be important to be able to answer the question posed in the title of this Editorial once and for all.

Adipose-derived stem cells in diabetic foot care:Bridging clinical trials and practical application

Diabetic foot ulcers(DFUs)pose a critical medical challenge,significantly impairing the quality of life of patients.Adipose-derived stem cells(ADSCs)have been identified as a promising therapeutic approach for improving wound healing in DFUs.Despite extensive exploration of the mechanical aspects of ADSC therapy against DFU,its clinical applications remain elusive.In this review,we aimed to bridge this gap by evaluating the use and advancements of ADSCs in the clinical management of DFUs.The review begins with a discussion of the classification and clinical management of diabetic foot conditions.It then discusses the current landscape of clinical trials,focusing on their geographic distribution,reported efficacy,safety profiles,treatment timing,administration techniques,and dosing considerations.Finally,the review discusses the preclinical strategies to enhance ADSC efficacy.This review shows that many trials exhibit biases in study design,unclear inclusion criteria,and intervention protocols.In conclusion,this review underscores the potential of ADSCs in DFU treatment and emphasizes the critical need for further research and refinement of therapeutic approaches,with a focus on improving the quality of future clinical trials to enhance treatment outcomes and advance the field of diabetic wound care.

Home-based Detection and Prediction of Diabetic Foot Ulcers at Early Stage Using Sensor Technology and Supervised Learning

For years,foot ulcers linked with diabetes mellitus and neuropathy have significantly impacted diabetic patients’ health-related quality of life(HRQoL). Diabetes foot ulcers impact15% of all diabetic patients at some point in their lives. The facilities and resources used for DFU detection and treatment are only available at hospitals and clinics,which results in the unavailability of feasible and timely detection at an early stage. This necessitates the development of an at-home DFU detection system that enables timely predictions and seamless communication with users,thereby preventing amputations due to neglect and severity. This paper proposes a feasible system consisting of three major modules:an IoT device that works to sense foot nodes to send vibrations onto a foot sole,a machine learning model based on supervised learning which predicts the level of severity of the DFU using four different classification techniques including XGBoost,K-SVM,Random Forest,and Decision tree,and a mobile application that acts as an interface between the sensors and the patient. Based on the severity levels,necessary steps for prevention,treatment,and medications are recommended via the application.

Effect of foot reflexology on an infant with sensorineural hearing loss:A case report

BACKGROUND Our study contributes to the further understanding of the mechanism of foot reflexology.Foot reflexology has been reported to affect hearing recovery,but no physiological evidence has been provided.This lack of evidence hampers the acceptance of the technique in clinical practice.CASE SUMMARY A girl was taken to North Sichuan Medical University Affiliated Hospital for a hearing screen by her parents.Her parents reported that her hearing level was the same as when she was born.The girl was diagnosed with sensorineural hearing loss(SNHL)by a doctor in the otolaryngology department.After we introduced the foot reflexology project,the parents agreed to participate in the experiment.After 6 months of foot reflexology treatment,the hearing threshold of the girl recovered to a normal level,below 30 dB.CONCLUSION Foot reflexology should be encouraged in clinical practice and for families of infants with SNHL.

Clinical comprehensive treatment protocol for managing diabetic foot ulcers:A retrospective cohort study

BACKGROUND Diabetic foot ulcers(DFUs)are a common complication of diabetes,often leading to severe infections,amputations,and reduced quality of life.The current standard treatment protocols for DFUs have limitations in promoting efficient wound healing and preventing complications.A comprehensive treatment approach targeting multiple aspects of wound care may offer improved outcomes for patients with DFUs.The hypothesis of this study is that a comprehensive treatment protocol for DFUs will result in faster wound healing,reduced amputation rates,and improved overall patient outcomes compared to standard treatment protocols.AIM To compare the efficacy and safety of a comprehensive treatment protocol for DFUs with those of the standard treatment protocol.METHODS This retrospective study included 62 patients with DFUs,enrolled between January 2022 and January 2024,randomly assigned to the experimental(n=32)or control(n=30)group.The experimental group received a comprehensive treatment comprising blood circulation improvement,debridement,vacuum sealing drainage,recombinant human epidermal growth factor and anti-inflammatory dressing,and skin grafting.The control group received standard treatment,which included wound cleaning and dressing,antibiotics administration,and surgical debridement or amputation,if necessary.Time taken to reduce the white blood cell count,number of dressing changes,wound healing rate and time,and amputation rate were assessed.RESULTS The experimental group exhibited significantly better outcomes than those of the control group in terms of the wound healing rate,wound healing time,and amputation rate.Additionally,the comprehensive treatment protocol was safe and well tolerated by the patients.CONCLUSION Comprehensive treatment for DFUs is more effective than standard treatment,promoting granulation tissue growth,shortening hospitalization time,reducing pain and amputation rate,improving wound healing,and enhancing quality of life.

Efficacy of Huangma Ding or autologous platelet-rich gel for the diabetic lower extremity arterial disease patients with foot ulcers

BACKGROUND Diabetes foot is one of the most serious complications of diabetes and an important cause of death and disability,traditional treatment has poor efficacy and there is an urgent need to develop a practical treatment method.AIM To investigate whether Huangma Ding or autologous platelet-rich gel(APG)treatment would benefit diabetic lower extremity arterial disease(LEAD)patients with foot ulcers.METHODS A total of 155 diabetic LEAD patients with foot ulcers were enrolled and divided into three groups:Group A(62 patients;basal treatment),Group B(38 patients;basal treatment and APG),and Group C(55 patients;basal treatment and Huangma Ding).All patients underwent routine follow-up visits for six months.After follow-up,we calculated the changes in all variables from baseline and determined the differences between groups and the relationships between parameters.RESULTS The infection status of the three groups before treatment was the same.Procalcitonin(PCT)improved after APG and Huangma Ding treatment more than after traditional treatment and was significantly greater in Group C than in Group B.Logistic regression analysis revealed that PCT was positively correlated with total amputation,primary amputation,and minor amputation rates.The ankle-brachial pressure and the transcutaneous oxygen pressure in Groups B and C were greater than those in Group A.The major amputation rate,minor amputation rate,and total amputation times in Groups B and C were lower than those in Group A.CONCLUSION Our research indicated that diabetic foot ulcers(DFUs)lead to major amputation,minor amputation,and total amputation through local infection and poor microcirculation and macrocirculation.Huangma Ding and APG were effective attreating DFUs.The clinical efficacy of Huangma Ding was better than that of autologous platelet gel,which may be related to the better control of local infection by Huangma Ding.This finding suggested that in patients with DFUs combined with coinfection,controlling infection is as important as improving circulation.

Academic productivity correlates with industry earnings in foot and ankle fellowship programs in the United States:A retrospective analysis

BACKGROUND The study investigates the connection between academic productivity and industry earnings in foot and ankle orthopedic surgery fellowships.Utilizing metrics like the H-index and Open Payments Database(OPD)data,it addresses a gap in understanding the relationship between scholarly achievements and financial outcomes,providing a basis for further exploration in this specialized medical field.AIM To elucidate the trends between academic productivity and industry earnings across foot and ankle orthopedic surgery fellowship programs in the United States.METHODS This study is a retrospective analysis of the relationship between academic productivity and industry earnings of foot and ankle orthopedic surgery fellowships at an individual faculty and fellowship level.Academic productivity was defined via H-index and recorded from the Scopus website.Industry earnings were recorded from the OPD.RESULTS Forty-eight foot and ankle orthopedic surgery fellowships(100%of fellowships)in the United States with a combined total of 165 physicians(95.9%of physicians)were included.Mean individual physician(n=165)total life-time earnings reported on the OPD website was United States Dollar(USD)451430.30±1851084.89(range:USD 25.16-21269249.85;median:USD 27839.80).Mean physician(n=165)H-index as reported on Scopus is 14.24±12.39(range:0-63;median:11).There was a significant but weak correlation between individual physician H-index and individual physician total life-time earnings(P<0.001;Spearman’s rho=0.334)and a significant and moderate positive correlation between combined fellowship H-index and total life-time earnings per fellowship(P=0.004,Spearman’s rho=0.409).CONCLUSION There is a significant and positive correlation between academic productivity and industry earnings at foot and ankle orthopedic surgery fellowships in the United States.This observation is true on an individual physician level as well as on a fellowship level.