bluuebunny/crossref_metadata_2025_split huggingface dataset:
Risk Stratification of Elderly Patients Undergoing Spinal Surgery Using the Modified Frailty Index
Authors: Kweh Barry Ting Sheen , Lee Hui Qing , Tan Terence , Tew Kim Siong , Leong Ronald , Fitzgerald Mark , Matthew Joseph , Kambourakis Anthony , Liew Susan , Hunn Martin , Tee Jin Wee 
Published: March 2021

Study Design: Retrospective cohort. Objectives: To validate the 11-item modified Frailty Index (mFI) as a perioperative risk stratification tool in elderly patients undergoing spine surgery. Methods: All consecutive cases of spine surgery in patients aged 65 years or older between July 2016 and June 2018 at a state-wide trauma center were retrospectively reviewed. The primary outcome was post-operative major complication rate (Clavien-Dindo Classification ≥ III). Secondary outcome measures included the rate of all complications, 6-month mortality and surgical site infection. Results: A total of 348 cases were identified. The major complication rate was significantly lower in patients with an mFI of 0 compared to ≥ 0.45 (18.3% versus 42.5%, P = .049). As the mFI increased from 0 to ≥ 0.45 there was a stepwise increase in risk of major complications ( P < .001). Additionally, 6-month mortality rate was considerably lower when the mFI was 0 rather than ≥ 0.27 (4.2% versus 20.4%, P = .007). Multivariate analysis demonstrated an mFI ≥ 0.27 was significantly associated with an increased incidence of major complication (OR 2.80, 95% CI 1.46-5.35, P = .002), all complication (OR 2.93, 95% CI 1.70-15.11, P < .001), 6-month mortality (OR 7.39, 95% CI 2.55-21.43, P < .001) and surgical site infection (OR 4.43, 95% CI 1.71-11.51, P = .002). The American Society of Anesthesiologists’ (ASA) index did not share a stepwise relationship with any outcome. Conclusion: The mFI is significantly associated in a gradated fashion with increased morbidity and mortality. Patients with an mFI ≥ 0.27 are at greater risk of major complications, all-complications, 6-monthy mortality, and surgical site infection.
Anthropometric study as a predictor of anterior cruciate ligament sizes in Asian Indonesian population
Authors: Pontoh Ludwig AP , Rahyussalim Ahmad Jabir , Widodo Wahyu , Fiolin Jessica , Rhatomy Sholahuddin 
Published: March 2021

Objectives: To evaluate whether anthropometric data can predict anterior cruciate ligament (ACL) sizes on magneti resonance imaging (MRI) in Asian population. Background: Reconstruction of ACL has been performed over a decade ago. Recently, more individualized ACL reconstruction is performed taking account of each patient’s ACL characteristics. However, there has been limited study regarding ACL sizes in Asian Indonesian population. This study aimed to evaluate the role of anthropometric data in ACL sizes using MRI in Asian Indonesian population. Study Design: Retrospective Study. Method: A series of 531 knees from 420 patients with knee pain and intact ACL confirmed by MRI study. Length, width and inclination angle of ACL were measured using a T2-weighted sagittal MRI 3.0 Tesla Magnetom Skyra. Height, weight, body mass index (BMI) and age were recorded. Multiple regression analysis was used to determine relationship between the anthropometric data and size of ACL measurements. Result: ACL length and width were significantly different between male and female, consecutively. Mean ACL length was 35.36 ± 3.63 mm, male was significantly longer (36.59 ± 3.24 mm) compared to female (32.77 ± 2.99 mm), p < 0.0001. Mean ACL width was 10.23 ± 1.84 mm, male was significantly wider (10.85 ± 1.59 mm) compared to female (8.93 ± 1.64 mm), p < 0.0001. The mean ACL inclination angle was 47.75° ± 3.07° (range 40.17°–57.12°). The strongest correlation for ACL length was height and weight (r = 0.437; r = 0.341 consecutively, p < 0.0001). Females had stronger correlation compared to males for ACL length (R2 = 0.489 vs R2 = 0.418). ACL width showed weak correlation with anthropometric data. The following regression analysis equation was obtained for ACL length: ACL length = 60.697 − 0.11*age + 0.461*weight (kg) − 16.522*height (meter) − 1.093*BMI (R2 = 0.539; p < 0.0001). Conclusion: Anthropometric data can be utilized as a predictor of ACL length in Asian Indonesian population. The ACL length in Asian Indonesian population is shorter than that in Western population study.
Effect of Achilles Tendon Rupture on Player Performance and Longevity in Women’s National Basketball Association Players
Authors: Tramer Joseph S. , Khalil Lafi S. , Buckley Patrick , Ziedas Alexander , Kolowich Patricia A. , Okoroha Kelechi R. 
Published: March 2021

Background: Women’s National Basketball Association (WNBA) players have a greater incidence of lower extremity injury compared with male players, yet no data exist on functional outcomes after Achilles tendon rupture (ATR). Purpose: To evaluate the effect of Achilles tendon repair on game utilization, player performance, and career longevity in WNBA athletes. Study Design: Cohort study; Level of evidence, 3. Methods: WNBA players from 1997 to 2019 with a history of ATR (n = 12) were matched 1:2 to a healthy control group. Player characteristics, game utilization, and in-game performance data were collected for each athlete, from which the player efficiency rating (PER) was calculated. Statistical analysis was performed comparing postinjury data to preinjury baseline as well as cumulative career data. Changes at each time point relative to the preinjury baseline were also compared between groups. Results: Of the 12 players with ATR, 10 (83.3%) returned to play at the WNBA level at a mean (±SD) of 12.5 ± 3.3 months. Four players participated in only 1 WNBA season after injury. There were no differences in characteristics between the 10 players who returned to play after injury and the control group. After return to play, the WNBA players demonstrated a significant decrease in game utilization compared with preinjury, playing in 6.0 ± 6.9 fewer games, starting in 12.7 ± 15.4 fewer games, and playing 10.2 ± 9.1 fewer minutes per game ( P < .05 for all). After the index date of injury, the players with Achilles repair played 2.1 ± 1.2 more years in the WNBA, while control players played 5.35 ± 3.2 years ( P < .01) Additionally, the players with Achilles repair had a significant decrease in PER in the year after injury compared with preinjury (7.1 ± 5.3 vs 11.0 ± 4.4; P = .02). The reduction in game utilization and decrease in PER in these players was maintained when compared with the matched controls ( P < .05 for both). Conclusion: The majority of WNBA players who sustained ATR were able to return to sport after their injury; however, their career longevity was shorter than that of healthy controls. There was a significant decrease in game utilization and performance in the year after return to play compared with healthy controls.
Comparison of Modified Mohr–Coulomb Model and Bai–Wierzbicki Model for Constructing 3D Ductile Fracture Envelope of AA6063
Authors: Gao Jianye , He Tao , Huo Yuanming , Song Miao , Yao Tingting , Yang Wanbo 
Published: March 2021

AbstractDuctile fracture of metal often occurs in the plastic forming process of parts. The establishment of ductile fracture criterion can effectively guide the selection of process parameters and avoid ductile fracture of parts during machining. The 3D ductile fracture envelope of AA6063-T6 was developed to predict and prevent its fracture. Smooth round bar tension tests were performed to characterize the flow stress, and a series of experiments were conducted to characterize the ductile fracture firstly, such as notched round bar tension tests, compression tests and torsion tests. These tests cover a wide range of stress triaxiality (ST) and Lode parameter (LP) to calibrate the ductile fracture criterion. Plasticity modeling was performed, and the predicted results were compared with corresponding experimental data to verify the plasticity model after these experiments. Then the relationship between ductile fracture strain and ST with LP was constructed using the modified Mohr–Coulomb (MMC) model and Bai-Wierzbicki (BW) model to develop the 3D ductile fracture envelope. Finally, two ductile damage models were proposed based on the 3D fracture envelope of AA6063. Through the comparison of the two models, it was found that BW model had better fitting effect, and the sum of squares of residual error of BW model was 0.9901. The two models had relatively large errors in predicting the fracture strain of SRB tensile test and torsion test, but both of the predicting error of both two models were within the acceptable range of 15%. In the process of finite element simulation, the evolution process of ductile fracture can be well simulated by the two models. However, BW model can predict the location of fracture more accurately than MMC model.
Associations between trunk-to-peripheral fat ratio and cardiometabolic risk factors in elderly Japanese men: baseline data from the Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) study
Authors: Kouda Katsuyasu , Fujita Yuki , Ohara Kumiko , Tachiki Takahiro , Tamaki Junko , Yura Akiko , Moon Jong-Seong , Kajita Etsuko , Uenishi Kazuhiro , Iki Masayuki 
Published: March 2021

Abstract
Background
Body mass-independent parameters might be more appropriate for assessing cardiometabolic abnormalities than weight-dependent indices in Asians who have relatively high visceral adiposity but low body fat. Dual-energy X-ray absorptiometry (DXA)-measured trunk-to-peripheral fat ratio is one such body mass-independent index. However, there are no reports on relationships between DXA-measured regional fat ratio and cardiometabolic risk factors targeting elderly Asian men.

Methods
We analyzed cross-sectional data of 597 elderly men who participated in the baseline survey of the Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) study, a community-based single-center prospective cohort study conducted in Japan. Whole-body fat and regional fat were measured with a DXA scanner. Trunk-to-appendicular fat ratio (TAR) was calculated as trunk fat divided by appendicular fat (sum of arm and leg fat), and trunk-to-leg fat ratio (TLR) as trunk fat divided by leg fat.

Results
Both TAR and TLR in the group of men who used ≥ 1 medication for hypertension, dyslipidemia, or diabetes (“user group”; N = 347) were significantly larger than those who did not use such medication (“non-user group”; N = 250) (P < 0.05). After adjusting for potential confounding factors including whole-body fat, both TAR and TLR were significantly associated with low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglyceride, fasting serum insulin, and the insulin resistance index in the non-user group and non-overweight men in the non-user group (N = 199).

Conclusion
The trunk-to-peripheral fat ratio was associated with cardiometabolic risk factors independently of whole-body fat mass. Parameters of the fat ratio may be useful for assessing cardiometabolic risk factors, particularly in underweight to normal-weight populations.
Effects of sevoflurane exposure on apoptosis and cell cycle of peripheral blood lymphocytes, and immunologic function
Authors: Ji Zhimin , Wu Wanjun , Zhou Fan , Hu Junfang , Xu Qiuping , Yang Weibin , Peng Xueyong , Wang Xinguo , Zhang Cheng , Li Li 
Published: March 2021

Abstract
Background
Waste anesthetic gases (WAGs) leaked from new-type halogenated inhalational anesthetics such as sevoflurane have been were reported to pose a risk for the health of operating room personnel. The effects of WAGs on peripheral blood lymphocytes, however, remain yet controversial. The present study was undertaken to examine the effects of occupational sevoflurane exposure on the peripheral blood lymphocytes of medical personnel who work in the operating room.

Methods
A cohort of 56 medical residents were divided into exposed group (n = 28) and control group (non-exposed group) (n = 28). Gas chromatography was used to measure the concentration of sevoflurane in the medical resident’s breathing zone during surgeries under inhalation anesthesia in the exposure group. The gas collection lasted an hour. Peripheral blood lymphocytes were isolated from venous blood, and then apoptosis and cell cycle were analyzed by flow cytometry. EDTA-anticoagulated whole blood was harvested to analyze the lymphocyte subsets by flow cytometry. Immunoglobulins (IgA, IgM, IgG) were quantified by immunoturbidimetry.

Results
The average concentration of sevoflurane in the exposed group was 1.03 ppm with a range from 0.03 ppm to 2.24 ppm. No significant effects were found on the apoptosis rates or cell cycles of peripheral blood lymphocytes in the exposed group relative to the control group (P > 0.05). Similarly, there were no significant differences in the lymphocyte subsets or the levels of immunoglobulins (IgA, IgM, IgG) between the two groups (P > 0.05).

Conclusions
Occupational exposure to low-level sevoflurane has no significant effect on the peripheral blood lymphocytes of operating room staff, but this conclusion needs to be confirmed by multicenter and long-term follow-up studies with large samples.

Trial registration number and date of registration
ChiCTR2000040772, December 9, 2020 (Retrospective registration).
Time dependent hazard ratio estimation using instrumental variables without conditioning on an omitted covariate
Authors: MacKenzie Todd A. , Martinez-Camblor Pablo , O’Malley A. James 
Published: March 2021

AbstractBackgroundEstimation that employs instrumental variables (IV) can reduce or eliminate bias due to confounding. In observational studies, instruments result from natural experiments such as the effect of clinician preference or geographic distance on treatment selection. In randomized studies the randomization indicator is typically a valid instrument, especially if the study is blinded, e.g. no placebo effect. Estimation via instruments is a highly developed field for linear models but the use of instruments in time-to-event analysis is far from established. Various IV-based estimators of the hazard ratio (HR) from Cox’s regression models have been proposed.MethodsWe extend IV based estimation of Cox’s model beyond proportionality of hazards, and address estimation of a log-linear time dependent hazard ratio and a piecewise constant HR. We estimate the marginal time-dependent hazard ratio unlike other approaches that estimate the hazard ratio conditional on the omitted covariates. We use estimating equations motivated by Martingale representations that resemble the partial likelihood score statistic. We conducted simulations that include the use of copulas to generate potential times-to-event that have a given marginal structural time dependent hazard ratio but are dependent on omitted covariates. We compare our approach to the partial likelihood estimator, and two other IV based approaches. We apply it to estimation of the time dependent hazard ratio for two vascular interventions.ResultsThe method performs well in simulations of a stepwise time-dependent hazard ratio, but illustrates some bias that increases as the hazard ratio moves away from unity (the value that typically underlies the null hypothesis). It compares well to other approaches when the hazard ratio is stepwise constant. It also performs well for estimation of a log-linear hazard ratio where no other instrumental variable approaches exist.ConclusionThe estimating equations we propose for estimating a time-dependent hazard ratio using an IV perform well in simulations. We encourage the use of our procedure for time-dependent hazard ratio estimation when unmeasured confounding is a concern and a suitable instrumental variable exists.
Bittersweet: infective complications of drug-induced glycosuria in patients with diabetes mellitus on SGLT2-inhibitors: two case reports
Authors: Bartolo Caroline , Hall Victoria , Friedman N. Deborah , Lanyon Chloe , Fuller Andrew , Morrissey C. Orla , Athan Eugene 
Published: March 2021

Abstract
Background
Sodium-glucose co-transporter 2 (SGLT2) inhibitors are novel hypoglycemic agents which reduce reabsorption of glucose at the renal proximal tubule, resulting in significant glycosuria and increased risk of genital mycotic infections (GMI). These infections are typically not severe as reported in large systematic reviews and meta-analyses of the medications. These reviews have also demonstrated significant cardiovascular benefits through other mechanisms of action, making them attractive options for the management of Type 2 diabetes mellitus (T2DM). We present two cases with underlying abnormalities of the urogenital tract in which the GMI were complicated and necessitated cessation of the SGLT2 inhibitor.

Case presentations
Both cases are patients with T2DM on empagliflozin, an SGLT2 inhibitor. The first case is a 64 year old man with Candida albicans balanitis and candidemia who was found to have an obstructing renal calculus and prostatic abscess requiring operative management. The second case describes a 72 year old man with Candida glabrata candidemia who was found to have prostatomegaly, balanitis xerotica obliterans with significant urethral stricture and bladder diverticulae. His treatment was more complex due to fluconazole resistance and concerns about urinary tract penetration of other antifungals. Both patients recovered following prolonged courses of antifungal therapy and in both cases the SGLT2 inhibitor was ceased.

Conclusions
Despite their cardiovascular benefits, SGLT2 inhibitors can be associated with complicated fungal infections including candidemia and patients with anatomical abnormalities of the urogenital tract may be more susceptible to these infections as demonstrated in these cases. Clinicians should be aware of their mechanism of action and associated risk of infection and prior to prescription, assessment of urogenital anatomical abnormalities should be performed to identify patients who may be at risk of complicated infection.
Divergences on expected pneumonia cases during the COVID-19 epidemic in Catalonia: a time-series analysis of primary care electronic health records covering about 6 million people
Authors: Coma Ermengol , Méndez-Boo Leonardo , Mora Núria , Guiriguet Carolina , Benítez Mència , Fina Francesc , Fàbregas Mireia , Balló Elisabet , Ramos Francisa , Medina Manuel , Argimon Josep M. 
Published: March 2021

Abstract
Background
Pneumonia is one of the complications of COVID-19. Primary care electronic health records (EHR) have shown the utility as a surveillance system. We therefore analyse the trends of pneumonia during two waves of COVID-19 pandemic in order to use it as a clinical surveillance system and an early indicator of severity.

Methods
Time series analysis of pneumonia cases, from January 2014 to December 2020. We collected pneumonia diagnoses from primary care EHR, a software system covering > 6 million people in Catalonia (Spain). We compared the trend of pneumonia in the season 2019–2020 with that in the previous years. We estimated the expected pneumonia cases with data from 2014 to 2018 using a time series regression adjusted by seasonality and influenza epidemics.

Results
Between 4 March and 5 May 2020, 11,704 excess pneumonia cases (95% CI: 9909 to 13,498) were identified. Previously, we identified an excess from January to March 2020 in the population older than 15 years of 20%. We observed another excess pneumonia period from 22 october to 15 november of 1377 excess cases (95% CI: 665 to 2089). In contrast, we observed two great periods with reductions of pneumonia cases in children, accounting for 131 days and 3534 less pneumonia cases (95% CI, 1005 to 6064) from March to July; and 54 days and 1960 less pneumonia cases (95% CI 917 to 3002) from October to December.

Conclusions
Diagnoses of pneumonia from the EHR could be used as an early and low cost surveillance system to monitor the spread of COVID-19.
Radiomic model for differentiating parotid pleomorphic adenoma from parotid adenolymphoma based on MRI images
Authors: Song Le-le , Chen Shun-jun , Chen Wang , Shi Zhan , Wang Xiao-dong , Song Li-na , Chen Dian-sen 
Published: March 2021

Abstract
Background
Distinguishing parotid pleomorphic adenoma (PPA) from parotid adenolymphoma (PA) is important for precision treatment, but there is a lack of readily available diagnostic methods. In this study, we aimed to explore the diagnostic value of radiomic signatures based on magnetic resonance imaging (MRI) for PPA and PA.

Methods
The clinical characteristic and imaging data were retrospectively collected from 252 cases (126 cases in the training cohort and 76 patients in the validation cohort) in this study. Radiomic features were extracted from MRI scans, including T1-weighted imaging (T1WI) sequences and T2-weighted imaging (T2WI) sequences. The radiomic features from three sequences (T1WI, T2WI and T1WI combined with T2WI) were selected using univariate analysis, LASSO correlation and Spearman correlation. Then, we built six quantitative radiomic models using the selected features through two machine learning methods (multivariable logistic regression, MLR, and support vector machine, SVM). The performances of the six radiomic models were assessed and the diagnostic efficacies of the ideal T1-2WI radiomic model and the clinical model were compared.

Results
The T1-2WI radiomic model using MLR showed optimal discriminatory ability (accuracy = 0.87 and 0.86, F-1 score = 0.88 and 0.86, sensitivity = 0.90 and 0.88, specificity = 0.82 and 0.80, positive predictive value = 0.86 and 0.84, negative predictive value = 0.86 and 0.84 in the training and validation cohorts, respectively) and its calibration was observed to be good (p > 0.05). The area under the curve (AUC) of the T1-2WI radiomic model was significantly better than that of the clinical model for both the training (0.95 vs. 0.67, p < 0.001) and validation (0.90 vs. 0.68, p = 0.001) cohorts.

Conclusions
The T1-2WI radiomic model in our study is complementary to the current knowledge of differential diagnosis for PPA and PA.