bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relative Validity and Reliability of Isometric Lower Extremity Strength Assessment in Older Adults by Using a Handheld Dynamometer
Authors: Grootswagers Pol , Vaes Anouk M. M. , Hangelbroek Roland , Tieland Michael , van Loon Luc J. C. , de Groot Lisette C. P. G. M. 
Published: February 2022

Background: Handheld dynamometry (HHD) is a practical alternative to traditional testing of lower extremity strength. However, its reliability and validity across different populations and settings are not clear. Hypothesis: We hypothesize that HHD is a valid and reliable device to assess lower extremity strength in a population of older adults. Study Design: Cross-sectional/cohort. Level of Evidence: Level 3. Methods: This study included 258 older adults (≥65 years). Isometric knee extension and flexion force were measured by 1 examiner, using an HHD (n = 222), including 3 repetitions to calculate within-day intrarater reliability. These measurements were repeated by the examiner in a subgroup (n = 23) to analyze intrarater reliability over a test-retest period of on average 8 weeks. In addition, HHD force measures were performed by a second examiner (n = 29) to analyze interrater reliability. In another subgroup (n = 77), isometric knee extension and flexion torque were measured by 1 examiner using both the HHD and Biodex System 4 to assess relative validity. Results: HHD and Biodex measurements were highly correlated and showed excellent concurrent validity. HHD systematically overestimated torque as compared with Biodex by 8 N·m on average. Same-day intrarater intraclass correlation coefficients (ICCs) ranged from 0.97 to 0.98. Interrater reliability ICCs ranged from 0.83 to 0.95. Conclusion: HHD represents a reliable and valid alternative to Biodex to rank individuals on leg strength, or to assess within-person changes in leg strength over time, because of the high validity and reliability. The HHD is less suited for absolute strength assessment because of significant systematic overestimations. Clinical Relevance: Clinicians are encouraged to use HHD to rank older adults on leg strength, or to assess within-person changes in leg strength over time, but not to compare readings with cut-offs or normative values.
Quantitative Assessment of Balance for Accurate Prediction of Return to Sport From Sport-Related Concussion
Authors: Kerr Hamish A. , Ledet Eric H. , Hahn Juergen , Hollowood-Jones Kathryn 
Published: February 2022

Background: Determining when athletes are able to return to sport after sports-related concussion (SRC) can be difficult. Hypothesis: A multimodal algorithm using cognitive testing, postural stability, and clinical assessment can predict return to sports after SRC. Study Design: Prospective cohort. Level of Evidence: Level 2b. Methods: Athletes were evaluated within 2 to 3 weeks of SRC. Clinical assessment, Immediate Post Concussion and Cognitive Testing (ImPACT), and postural stability (Equilibrate) were conducted. Resulting data and machine learning techniques were used to optimize an algorithm discriminating between patients ready to return to sports versus those who are not yet recovered. A Fisher discriminant analysis with leave-one-out cross-validation assessed every combination of 2 to 5 factors to optimize the algorithm with lowest combination of type I and type II errors. Results: A total of 193 athletes returned to contact sports after SRC at a mean 84.6 days (±88.8). Twelve subjects (6.2%) sustained repeat SRC within 12 months after return to sport. The combination of (1) days since injury, (2) total symptom score, and (3) nondominant foot tandem eyes closed postural stability score created the best algorithm for discriminating those ready to return to sports after SRC with lowest type I error (13.85%) and type II error (11.25%). The model was able to discriminate between patients who were ready to successfully return to sports versus those who were not with area under the receiver operating characteristic (ROC) curve of 0.82. Conclusion: The algorithm predicts successful return to sports with an acceptable sensitivity and specificity. Tandem balance with eyes closed measured with a video-force plate discriminated athletes ready to return to sports from SRC when combined in multivariate analysis with symptom score and time since injury. The combination of these factors may pose advantages over computerized neuropsychological testing when evaluating young athletes with SRC for return to contact sports. Clinical Relevance: When assessing young athletes sustaining an SRC in a concussion clinic, measuring postural stability in tandem stance with eyes closed combined with clinical assessment and cognitive recovery is effective to determine who is ready to successfully return to sports.
Stable patients with suspected myocardial ischemia: comparison of machine-learning computed tomography-based fractional flow reserve and stress perfusion cardiovascular magnetic resonance imaging to detect myocardial ischemia
Authors: Lossnitzer Dirk , Klenantz Selina , Andre Florian , Goerich Johannes , Schoepf U. Joseph , Pazzo Kyle L. , Sommer Andre , Brado Matthias , Gückel Friedemann , Sokiranski Roman , Becher Tobias , Akin Ibrahim , Buss Sebastian J. , Baumann Stefan 
Published: February 2022

Abstract
Background
Machine-Learning Computed Tomography-Based Fractional Flow Reserve (CT-FFRML) is a novel tool for the assessment of hemodynamic relevance of coronary artery stenoses. We examined the diagnostic performance of CT-FFRML compared to stress perfusion cardiovascular magnetic resonance (CMR) and tested if there is an additional value of CT-FFRML over coronary computed tomography angiography (cCTA).

Methods
Our retrospective analysis included 269 vessels in 141 patients (mean age 67 ± 9 years, 78% males) who underwent clinically indicated cCTA and subsequent stress perfusion CMR within a period of 2 months. CT-FFRML values were calculated from standard cCTA.

Results
CT-FFRML revealed no hemodynamic significance in 79% of the patients having ≥ 50% stenosis in cCTA. Chi2 values for the statistical relationship between CT-FFRML and stress perfusion CMR was significant (p < 0.0001). CT-FFRML and cCTA (≥ 70% stenosis) provided a per patient sensitivity of 88% (95%CI 64–99%) and 59% (95%CI 33–82%); specificity of 90% (95%CI 84–95%) and 85% (95%CI 78–91%); positive predictive value of 56% (95%CI 42–69%) and 36% (95%CI 24–50%); negative predictive value of 98% (95%CI 94–100%) and 94% (95%CI 90–96%); accuracy of 90% (95%CI 84–94%) and 82% (95%CI 75–88%) when compared to stress perfusion CMR. The accuracy of cCTA (≥ 50% stenosis) was 19% (95%CI 13–27%). The AUCs were 0.89 for CT-FFRML and 0.74 for cCTA (≥ 70% stenosis) and therefore significantly different (p < 0.05).

Conclusion
CT-FFRML compared to stress perfusion CMR as the reference standard shows high diagnostic power in the identification of patients with hemodynamically significant coronary artery stenosis. This could support the role of cCTA as gatekeeper for further downstream testing and may reduce the number of patients undergoing unnecessary invasive workup.
A baseline profile of the Queensland Cardiac Record Linkage Cohort (QCard) study
Authors: Nghiem Son , Afoakwah Clifford , Scuffham Paul , Byrnes Joshua 
Published: February 2022

Abstract
Background
Cardiovascular disease (CVD) is one of the leading causes of death in Australia. Longitudinal record linkage studies have the potency to influence clinical decision making to improve cardiac health. This paper describes the baseline characteristics of the Queensland Cardiac Record Linkage Cohort study (QCard).

Methods
International Classification of Disease, 10th Revision Australian Modification (ICD-10-AM) diagnosis codes were used to identify CVD and comorbidities. Cost and adverse health outcomes (e.g., comorbidities, hospital-acquired complications) were compared between first-time and recurrent admissions. Descriptive statistics and standard tests were used to analyse the baseline data.

Results
There were 132,343 patients with hospitalisations in 2010, of which 47% were recurrent admissions, and 53% were males. There were systematic differences between characteristics of recurrent and first-time hospitalisations. Patients with recurrent episodes were nine years older (70 vs. 61; p < 0.001) and experienced a twice higher risk of multiple comorbidities (3.17 vs. 1.59; p < 0.001). CVD index hospitalisations were concentrated in large metropolitan hospitals.

Conclusions
Our study demonstrates that linked administrative health data provide an effective tool to investigate factors determining the progress of heart disease. Our main finding suggests that recurrent admissions were associated with higher hospital costs and a higher risk of having adverse outcomes.
The usefulness of proximal anchor balloon technique during implantation of a cardiac resynchronization therapy device in a patient with complex coronary venous anatomy: a case report
Authors: Bhardwaj Ravindra , Chaurasia Amit , Mahajan Nipun , Dod Harvinder , Arora Kuldeep 
Published: February 2022

Abstract
Background
Cardiac resynchronization therapy (CRT) is an accepted device treatment in stable heart failure (HF) patients. In recent years increased awareness of coronary anatomy and implantation techniques have significantly impacted this evolving therapy.

Case presentation
In this article, we present a case describing the usefulness of the proximal balloon anchoring technique to enable initial coronary sinus (CS) cannulization and left ventricular (LV) lead placement in the tortuous coronary sinus during CRT implantation.

Conclusions
The proximal anchor balloon technique can easily enable coronary sinus cannulization and left ventricular lead placement in patients with complex venous anatomy.
Weighted composite time to event endpoints with recurrent events: comparison of three analytical approaches
Authors: Ozga Ann-Kathrin , Rauch Geraldine 
Published: February 2022

AbstractBackgroundIn clinical trials the study interest often lies in the comparison of a treatment to a control regarding a time to event endpoint. A composite endpoint allows to consider several time to event endpoints at once. Usually, only the time to the first occurring event for a patient is thereby analyzed. However, an individual may experience more than one non-fatal event. Including all observed events in the analysis can increase the power and provides a more complete picture of the disease. Thus, analytical methods for recurrent events are required. A challenge is that the different event types belonging to the composite often are of different clinical relevance. In this case, weighting the event types according to their clinical relevance is an option. Different weight-based methods for composite time to event endpoints were proposed. So far, there exists no systematic comparison of these methods.MethodsWithin this work we provide a systematic comparison of three methods proposed for weighted composite endpoints in a recurrent event setting combining non-fatal and fatal events of different clinical relevance. We consider an extension of an approach proposed by Wei and Lachin, an approach by Rauch et al., and an approach by Bakal et al.. Comparison is done based on a simulation study and based on a clinical study example.ResultsFor all three approaches closed formula test statistics are available. The Wei-Lachin approach and the approach by Rauch et al. show similar results in mean squared error. For the approach by Wei and Lachin confidence intervals are provided. The approach by Bakal et al. is not related to a quantifiable estimand. The relevance weights of the different approaches work on different level, i.e. either on cause-specific hazard ratios or on event count.ConclusionThe provided comparison and simulations can help to guide applied researchers to choose an adequate method for the analysis of composite endpoints combining (recurrent) events of different clinical relevance. The approach by Wei and Lachin and Rauch et al. can be recommended in scenarios where the composite effect is time-independent. The approach by Bakal et al. should be applied carefully.
Identification of SCN7A as the key gene associated with tumor mutation burden in gastric cancer
Authors: Li Wenjie , Zhou Kezhi , Li Mengting , Hu Qian , Wei Wanhui , Liu Lan , Zhao Qiu 
Published: February 2022

Abstract
Objective
Previous studies have shown that tumor mutation burden (TMB) in cancer is associated with prognosis. The purpose of this study is to identify TMB related genes in gastric cancer (GC) and to explore their prognostic value.

Methods
In our research, weighted gene coexpression network analysis (WGCNA) algorithm was used to cluster the most relevant TMB modules in the Cancer Genome Atlas (TCGA) database. Limma package was used to screen the differentially expressed genes, and the intersection was identified as hub genes. We used gene expression profiling interactive analysis (GEPIA) and survival algorithm to analyze the clinical characteristics and prognosis of hub genes in tumor and normal tissue samples of TCGA and Gene Expression Omnibus cohort respectively. We also used CIBERSORT algorithm to calculate the proportion of 22 tumor immune cells in the high and low expression subgroups of hub genes. In addition, we used gene set enrichment analysis (GSEA) to predict the biological function of hub genes. P < 0.05 was considered statistically significant.

Results
In the TCGA cohort, TMB was significantly correlated with the clinical features of GC (P < 0.05). Through WGCNA and differential gene analysis, we identified SCN7A as the hub gene (P < 0.05, |log2fc|> 1, and mm > 0.8). We found that the expression of SCN7A in tumor tissues was lower than that in normal tissues, and its expression level was also related to overall survival rate and tumor stage. GSEA analysis showed that SCN7A low expression group was enriched with "DNA replication", "base extension repair" and "proteasome" gene sets in GC. In addition, we found that there were significant differences in the infiltration degree of 7 kinds of immune cells between the two groups.

Conclusion
TMB can indicate the prognosis of gastric cancer. SCN7A is a hub gene associated with TMB, and its low expression is associated with better prognosis.
Seroepidemiology study of Cytomegalovirus and Rubella in pregnant women in Luanda, Angola: geospatial distribution and its association with socio-demographic and clinical-obstetric determinants
Authors: Vueba Amélia , Faria Clarissa , Almendra Ricardo , Santana Paula , Sousa Maria do Céu 
Published: February 2022

Abstract
Background
Both CMV and Rubella virus infections are associated with the risk of vertical transmission, fetal death or congenital malformations. In Angola, there are no reports of CMV and Rubella studies. Therefore, our objectives were to study the seroprevalence of anti-CMV and anti-Rubella antibodies in pregnant women of Luanda (Angola), identify the risk of primary infection during pregnancy and evaluate the socio-demographic risk factors associated with both infections.

Methods
A prospective cross-sectional study was conducted from August 2016 to May 2017. Specific anti-CMV and anti-Rubella antibodies were quantified by electrochemiluminescence and demographic and clinical data were collected using standardized questionnaire. Bivariate and multivariate logistic regression analysis were used to quantify the effect of clinical and obstetric risk factors on virus seroprevalence.

Results
We recruited 396 pregnant women aged from 15 to 47. Among them, 335 (84.6%) were immune to both CMV and Rubella virus infections, while 8 (2.0%) had active CMV infection and 4 (1.0%) active RV infection but none had an active dual infection. Five women (1.2%) were susceptible to only CMV infection, 43 (10.9%) to only RV infection, and 1 (0.3) to both infections. Multivariate analysis showed a significant association between Rubella virus infection and number of previous births and suffering spontaneous abortion.

Conclusions
Overall, this study showed that there is a high prevalence of anti-CMV and anti-Rubella antibodies in pregnant women in Luanda. It also showed that a small but important proportion of pregnant women, about 11%, are at risk of primary infection with rubella during pregnancy. This emphasizes the need for vaccination.
Depression, anxiety and posttraumatic stress disorder six months following preeclampsia and normotensive pregnancy: a P4 study
Authors: Roberts Lynne , Henry Amanda , Harvey Samuel B. , Homer Caroline S. E. , Davis Gregory K. 
Published: February 2022

Abstract
Background
Mental health is an integral part of overall health. Mental health disorders following childbirth are common and poor maternal mental health has consequences for both the mother and her infant. Preeclampsia is also relatively common in pregnancy but there is little known about the intersection between these two important conditions. Gaining a better understanding of the psychological consequences following preeclampsia is important, especially the link with depression, anxiety and posttraumatic stress disorder. If women who experience preeclampsia are recognised as being at increased risk of poor mental health, targeted screening in the postpartum period should be implemented.

Aims
To describe the prevalence and symptom severity of depression, anxiety and posttraumatic stress disorder at six months postpartum in women, who had a diagnosis of preeclampsia, compared to those who had normal blood pressure in pregnancy.

Methods
The mental health component of the prospective cohort study, the Postpartum, Physiology, Psychology and Paediatric follow-up study (P4 Study) was used. Women diagnosed with preeclampsia (n = 90) and those who were normotensive during pregnancy (n = 302) completed the Edinburgh Postnatal Depression Scale, General Anxiety Disorder Scale, and the Posttraumatic Stress Diagnostic Scale or Posttraumatic Stress Diagnostic Sclae-5 at six months postpartum.

Results
At six months postpartum, depressive scores were similar in both groups but a higher proportion of women from the preeclampsia group scored above the threshold for depression (2% v 7% p = 0.04). There were no differences between the groups in the prevalence or severity of anxiety or PTSD. However, more women in the preeclampsia group reported their birth experience as a traumatic event (1% vs 7%, p = 0.01). On correlation testing and modelling, booking Edinburgh Postnatal Depression Scale score, any mental health history, experiencing birth as traumatic and the General Anxiety Disorder Scale score were independent predictors of postpartum Edinburgh Postnatal Depression Scale scores.

Conclusion
The postpartum clinical care of women with preeclampsia often focusses on the immediate physical health issues, but these women may also benefit from mental health screening. Targeted screening of preeclamptic women in the postpartum period may lead to more timely referral and initiation of treatment.

Trial registration
Retrospectively registered on 18/11/2013 with the Australian and New Zealand Clinical Trials Registry. Registration Number: ACTRN12613001260718.
The ISCON-trial protocol: laparoscopic ischemic conditioning prior to esophagectomy in patients with esophageal cancer and arterial calcifications
Authors: Veen A. van der , Schiffmann L. M. , de Groot E. M. , Bartella I. , de Jong P. A. , Borggreve A. S. , Brosens L. A. A. , Santos D. Pinto Dos , Fuchs H. , Ruurda J. P. , Bruns C. J. , van Hillegersberg R. , Schröder W. 
Published: February 2022

Abstract
Background
Anastomotic leakage is the most important surgical complication following esophagectomy. A major cause of leakage is ischemia of the gastric tube that is used for reconstruction of the gastrointestinal tract. Generalized cardiovascular disease, expressed by calcifications of the aorta and celiac axis stenosis on a pre-operative CT scan, is associated with an increased risk of anastomotic leakage. Laparoscopic ischemic conditioning (ISCON) aims to redistribute blood flow and increase perfusion at the anastomotic site by occluding the left gastric, left gastroepiploic and short gastric arteries prior to esophagectomy. This study aims to assess the safety and feasibility of laparoscopic ISCON in selected patients with esophageal cancer and concomitant arterial calcifications.

Methods
In this prospective single-arm safety and feasibility trial based upon the IDEAL recommendations for surgical innovation, a total of 20 patients will be included recruited in 2 European high-volume centers for esophageal cancer surgery. Patients with resectable esophageal carcinoma (cT1-4a, N0–3, M0) with “major calcifications” of the thoracic aorta accordingly to the Uniform Calcification Score (UCS) or a stenosis of the celiac axis accordingly to the modified North American Symptomatic Carotid Endarterectomy Trial (NASCET) score on preoperative CT scan, who are planned to undergo esophagectomy are eligible for inclusion. The primary outcome variables are complications grade 2 and higher (Clavien-Dindo classification) occurring during or after laparoscopic ISCON and before esophagectomy. Secondary outcomes include intra- and postoperative complications of esophagectomy and the induction of angiogenesis by biomarkers of microcirculation and redistribution of blood flow by measurement of indocyanine green (ICG) fluorescence angiography.

Discussion
We hypothesize that in selected patients with impaired vascularization of the gastric tube, laparoscopic ISCON is feasible and can be safely performed 12–18 days prior to esophagectomy. Depending on the results, a randomized controlled trial will be needed to investigate whether ISCON leads to a lower percentage and less severe course of anastomotic leakage in selected patients.

Trial registration
Clinicaltrials.gov, NCT03896399. Registered 4 January 2019.
Outcomes of four-point suture fixated and two-point sutureless posterior chamber IOLs combined with pars plana vitrectomy
Authors: Zyablitskaya Mariya , Hong Estee , Chen Royce W. S. , Chang Stanley , Suh Leejee H. 
Published: February 2022

Abstract
Background
While each scleral fixation method has its own advantages, there is a lack of strong evidence to suggest a superior technique. Advances in cataract surgery expand patient eligibility for successful cataract extraction, benefitting a growing population of pseudophakic patients. However, implantation of secondary intraocular lens (IOL) with compromised anterior or posterior capsule is a more challenging task. Each method of scleral fixation has its own advantages and none of them has strong evidence to be superior. This paper describes postsurgical outcomes of two scleral intraocular(IOL) fixation techniques combined with pars plana vitrectomy(PPV) from a single tertiary referral eye center.

Methods
Patients underwent PPV and IOL implantation with either four-point sutured scleral fixation (Akreos AO60(AK); n = 24) or two-point sutureless flanged intrascleral fixation (CT Lucia(CTL); n = 7). Reports include IOL and sclerotomy placement, fixation techniques, and IOL model.

Results
Thirty-one eyes of thirty patients were analyzed. Average change in vision from baseline measurement was LogMAR − 0.68 ± 0.66 and − 0.90 ± 0.63 for AK and CTL groups, respectively. Average postoperative refractive error was − 0.3 ± 1.03 D (AK) and 0.4 ± 0.60 D (CTL). No opacification cases of Akreos lens were found in this study with the longest follow up of 53 months.

Conclusions
Both methods of implantation (sutured and sutureless) could provide good visual and refractive outcomes. Minimal complication rates were reported despite including patients with multiple comorbidities, making both techniques an attractive choice for secondary IOL implantation.