Absolute Frequency Research Articles

Wolff-Parkinson-White (WPW) syndrome is a rare cardiac disorder that predispose to supraventricular arrhythmias. Prognosis is usually benign, yet there is an increased lifetime risk of sudden death. While typically sporadic, familial clustering has been reported. This study aimed to assess the risk of WPW, arrhythmias, and mortality among siblings of individuals with WPW. This population-based sibling cohort included 5,338,434 individuals born in Sweden (1932-2018), with 3,172 WPW cases identified from the Swedish National Patient Registers. Familial risks among siblings were assessed using incidence rate ratios (IRRs) and adjusted subdistributional hazard ratios (SHRs). Sensitivity analyses excluded syndromic WPW and cases without electrophysiologic procedural confirmation. Although familial occurrence of WPW was exceedingly rare with only 14 of 3,172 cases (0.4%; ≈0.0003% of the total population), siblings of affected individuals showed a significantly higher rate of WPW diagnosis (0.121 vs. 0.032 per 1,000 person-years; IRR 3.83; 95%CI 2.27-6.46; p<0.001) translating to an almost fourfold higher adjusted risk (SHR 3.79; 95%CI 1.81-7.97; p<0.001). Risks of atrial fibrillation (SHR 1.19; 95%CI 1.05-1.35; p<0.01) and ventricular arrhythmias (SHR 1.84; 95%CI 1.45-2.35; p<0.001) were also higher, whereas all-cause mortality was comparable irrespective of sibling history (HR 1.01; 95% CI 0.92-1.11; p=0.88). WPW features familial aggregation and increased arrhythmic risk among siblings of affected individuals despite its extremely low absolute frequency in the general population. The evidence of a measurable hereditary component within an otherwise sporadic, non-syndromic condition points to a genetic contribution driven by complex inheritance patterns.

With the growing global demand for renewable energy, the pump as turbine (PAT) exhibits significant potential in the micro-hydropower sector. To reveal its internal unsteady flow characteristics and energy loss mechanisms, this study analyzes the internal flow field of an ultra-low specific speed pump as turbine (USSPAT) by employing a combined approach of entropy generation theory and dynamic mode decomposition (DMD). The results indicate that the outlet pressure pulsation characteristics are highly dependent on the flow rate. Under low flow rate conditions, pulsations are dominated by low-frequency vortex bands induced by rotor-stator interaction (RSI), whereas at high flow rates, the blade passing frequency (BPF) becomes the absolute dominant frequency. Energy losses within the PAT are primarily composed of turbulent and wall dissipation, concentrated in the impeller and volute, particularly at the impeller inlet, outlet, and near the volute tongue. DMD reveals that the flow field is governed by a series of stable modes with near-zero growth rates, whose frequencies are the shaft frequency (25 Hz) and its harmonics (50 Hz, 75 Hz, 100 Hz). These low-frequency modes, driven by RSI, contain the majority of the fluctuation energy. Therefore, this study confirms that RSI between the impeller and the volute is the root cause of the dominant pressure pulsations and periodic energy losses. This provides crucial theoretical and data-driven guidance for the design optimization, efficient operation, and stability control of PAT.

Risk communication of study drug side effects: An evaluation of informed consent forms from ClinicalTrials.gov.

ABSTRACT The climacteric period is associated with physical and psychosocial symptoms that may adversely affect functional capacity. This study aimed to assess physical performance and the severity of climacteric symptoms in women undergoing the menopausal transition, and to analyze the relationship between symptom intensity and physical performance. A cross-sectional study was conducted with 184 women presenting climacteric symptoms, aged between 40 and 65 years, in the pre-menopause, perimenopause, and post-menopause stages. Menopausal status was determined using the Stage of Reproductive Aging Workshop, and climacteric symptoms were assessed with the Menopause Rating Scale. Physical performance was assessed using the Short Physical Performance Battery, while cognitive function was evaluated through the Montreal Cognitive Assessment instrument. Absolute and relative frequencies, means, and standard deviations were used. Group comparisons were evaluated using the Kruskal–Wallis test, and correlation between variables were assessed using the Spearman correlation test. A significance level of p < .05 and a 95 percent confidence interval were considered. Postmenopausal women exhibited lower scores in balance (p = 0,025) and sit-to-stand (p = 0,006) compared to premenopausal women. Overall, 70,1 percent of participants reported severe menopausal symptoms. There were weak but significant correlations between greater symptom intensity and worse gait speed performance (rs = 0.18; p = 0.014), as well as between somatovegetative symptoms (rs = 0.20; p = 0.007) reduced balance (rs = −0.18; p = 0.016) and gait performance (r 2= 0.20; p = 0.007). Advanced menopausal stages are associated with poorer physical performance. Symptom severity additionally impacts physical function, reinforcing the importance of preventive strategies.

We present results for novel design and implementation of a high-power, high-resolution continuous-wave optical parametric oscillator (OPO) emitting mid-infrared radiation tunable from 3-4 μm, with output powers in excess of 2.5 W. Our home-built "JILA OPO" design is based on a periodically poled lithium niobate fanout crystal inside a four-mirror ring cavity singly resonant at the signal wavelength (1.4-1.7 μm). The 50 mm-long fanout crystal is pumped by a single-mode, narrow-line width continuous-wave 1064 nm fiber laser, which achieves an oscillation threshold of 2 W. For long-term frequency stabilization and control, we actively lock the OPO to an optical transfer cavity (OTC), which is in turn locked to a polarization-stabilized HeNe laser to achieve root-mean-square noise of ≤2.3(2) MHz within 10 ms and absolute OPO idler frequency drifts of <1 MHz/hour. The high output power and narrow line width of the OPO are demonstrated via saturated absorption spectroscopy on the ν3 P(7) transition of CH4 (40-300 mTorr) in a retroreflecting double-pass cell, for which narrow Lamb dips with a full width at half-maximum (fwhm) of 3.1(1) MHz are readily observed. Technical aspects of our monolithic laser block construction, thermal cooling, optical transfer cavity, electronic servo loop control, mirror selection, and beam size considerations for optimal low pumping threshold, long-term frequency stability, and maximal conversion efficiency are presented, with further details available on request.

While coaching has been widely adopted by organizations as a human resource development strategy, in-session coach interventions remain opaque. This study examined links between specific coach verbal behaviors and independent session ratings from clients and coaches. Forty-eight coach-client pairs contributed recordings and ratings for three sessions (2-4 of a six-session series). Transcripts were coded with a 37-category scheme. For each code we derived two metrics&amp;mdash;absolute frequency (interventions/hour) and within-session percentage of coach talk&amp;mdash;and used median splits to compare high versus low groups on three outcomes: goal alignment, task accomplishment, and perceived bond. Mann-Whitney U tests supported several patterns. Client ratings were higher when empathic, meaning-making behaviors&amp;mdash;reflections of feeling, explorations of emotion and learning, affirming feedback, and judicious humor&amp;mdash;comprised a larger share of coach talk, and lower when advice, disconfirming feedback, ecosystem probing, repeated verification/checking, or tangential thought occurred at higher rates. Coaches reported greater alignment (and, by percentage, task accomplishment) with more minimal encouragers, and higher task accomplishment and bonding with more affirmations, humor, and learning exploration; they reported lower alignment when emotions or values were explored more frequently. Behavioral dysregulation was associated with lower coach-rated task accomplishment. Longer sessions (~45 vs. ~30 minutes) were associated with higher client ratings on all three outcomes and with higher coach-rated task accomplishment. Overall, findings suggest that style composition and dosage matter, and that client and coach perspectives may be complementary rather than interchangeable. Coaching practice may benefit from prioritizing empathic reflections and focused explorations while limiting high-dosage influence moves.

We report on a 88 Sr + single-ion optical clock with an estimated fractional systematic uncertainty of 7.9× 10 − 19 . The low uncertainty is enabled by small rf losses, a thorough evaluation of the blackbody-radiation temperature, and our recent measurement of the differential polarizability. A detailed uncertainty evaluation is presented. We also report on two absolute frequency measurements: one against a remote cesium fountain clock, and one against International Atomic Time (TAI). The former lasted 12 d and resulted in a frequency value of 444 779 044 095 485.49(15) Hz. The latter spanned 10 months with monthly optical-clock uptimes between 68% and 99%, and yielded a frequency value of 444 779 044 095 485.373(44) Hz. With a fractional uncertainty of 9.8× 10 − 17 , it is, to our knowledge, the most accurate optical frequency measurement reported to date. Both frequency values are in agreement with other recent measurements, providing further evidence that the 2021 CIPM recommended frequency value is too high by 1.6 times its uncertainty.

Disclosure: E.M. Schuck: None. M.O. Dutra: None. T.R. Santiago: None. E.M. Schuck: None. N.D. Rebelo: None. S.F. Ribeiro: None. G. Santi: None. C.D. Abrahim: None. V.F. Diógenes: None. R.F. Villar: None. I.D. Rebelo: None. R.S. Caleffi: None. D.S. Centolanza: None. B.R. Dantas: None. G.G. Rodrigues: None. D.A. Benchimol: None. F.R. Sevilla: None. K.T. D'Almeida: None. H.B. Pimenta: None. K.F. Reis: None. L.P. da Silva: None.Body Mass Index (BMI) is an important indicator of nutritional status and can identify overweight, obesity and underweight. Students, especially in courses such as medicine, may present variations in BMI due to stress and changes in habits. The objective of this study was to analyze the BMI of medical students in Manaus, Amazonas.This is a descriptive, cross-sectional study with a quantitative approach, using data collected through voluntary completion of a questionnaire on Google Forms. The variables analyzed were: color/race, age, sex, monthly income, institution, curricular period, BMI at the beginning of the course, current BMI, previous illnesses, and use of continuous medication. The data collected were tabulated using Excel software, where tables with absolute and relative frequencies were constructed.134 responses were recorded from students from 4 different universities in Manaus, being: 64 (47.8%) Nilton Lins University, 45 (33.6%) Amazonas State University, 19 (14.2%) Fametro University and 6 (4.5%) Federal University of Amazonas. Regarding the curricular period, the sample had the highest record of responses from students in the 5th (18.7%) and 8th (18.7%). The majority of students are white 85 (63.4%) and female 96 (72%), with an average age of 26.1 years. Regarding the students family income: 48 (35.8%) have a monthly income above 11 minimum wages, 32 (23.9%) from 4 to 6 minimum wages, 29 (21.6%) from 7 to 11, 17 (12.7%) from 1 to 3 and 8 (6%) from up to 1. Twelve (8.8%) reported having previous illnesses, among which the most recurrent was obesity (6%). And 40 (30.9%) students use continuous medication, the main ones being: 13 (32.5%) antidepressants, 5 (12.5%) ADHD medications, 2 (5%) anxiolytics. Regarding BMI, of the 134 students, 82 (61.2%) started with normal weight, 31 (23.1%) with overweight, 13 (9.7%) with underweight, 6 (4.5%) with grade I obesity, 1 (0.7%) with grade II obesity and 1 with grade III obesity (0.7%). And during the course, 62 (46.3%) were of normal weight, 49 (36.6%) were overweight, 12 (9%) had grade I obesity, 9 (6.7%) were underweight, 1 (0.7%) had grade II obesity and 1 (0.7%) had grade III obesity. The study found that the majority were female and white with a monthly income above 11 minimum wages and an average age of 26,1. Most students started the course with normal weight, but over time, an increase in overweight and obesity was observed. Approximately 30% of students make continuous use of medications, especially antidepressants and ADHD medications, suggesting the need for attention to the mental and physical health of students during the course.Presentation: Monday, July 14, 2025

Abstract Background and Aims IgA nephropathy (IgAN) is the most common primary glomerulopathy worldwide, with 20%–40% of patients developing chronic kidney disease (CKD) within 10–20 years of diagnosis. There is great variability in the clinical course of IgAN. Proteinuria &amp;gt;1 g/day is the strongest predictor of disease progression. The International IgAN Prediction Tool (IgAN PT) estimates the risk of a 50% decline in the estimated glomerular filtration rate (eGFR) or progression to CKD. While it has been validated in Asian, European, and North American populations, its accuracy in Latin American populations remains unknown. There is insufficient evidence to guide treatment decisions on the basis of the IgAN PT, persistent microscopic hematuria, or Oxford classification. The primary objective of this study is to present an overview of the clinical and histopathological characteristics at the time of diagnosis within a Mexican cohort of patients with IgAN, and to assess the performance of the IgAN PT in this population. Method Observational and retrospective cohort study at a third level center from 1992 to 2024. Records of 46 patients with histopathological diagnoses of IgAN were obtained and 12 were excluded because of a lack of follow-up data. The score of the IgAN PT was calculated and follow-up was performed after 24 months of the biopsy. Clinical and histopathological characteristics are presented as median (interquartile range) or mean (standard deviation), and absolute frequency (percentage) according to the variable type and its distribution. The receiver operating characteristic (ROC) curve was used to assess the diagnostic performance of the IgAN PT in this population. The area under the curve (AUC) values were as follows: AUC ≥ 0.9 excellent; 0.8 ≤ AUC &amp;lt; 0.9 considerable and 0.7 ≤ AUC &amp;lt; 0.8 fair. Results Thirty-three patients were included (Table 1), 54.5% were female, with a median age of 39.2 years and an average body mass index of 26.6 Kg/m². Only 27.2% had a prior infection, and 18.2% had a history of preeclampsia. The most common clinical presentations included rash, edema, and hematuria. Hematuria-proteinuria syndrome was observed in 57.6% of the patients. At the time of biopsy, the mean estimated glomerular filtration rate (eGFR) was 48.2 mL/min/1.73 m², and the proteinuria/creatinuria ratio (PCR) was 1.8 g/g. Notably, 45.4% of patients had antinuclear antibodies titres &amp;gt;1:40, while only 12.1% had decreased C3 levels, with no reduction in C4 levels. Renal biopsy revealed mesangial hypercellularity (M1) in 93.9%, and segmental sclerosis (S1) in 87.9% of the cases. Immunofluorescence analysis showed 3-4+ IgA deposits in 78% of patients, with C3 in 78.7% of cases. At two years of follow-up, 10 patients (30.3%) developed CKD, 5 patients (15.2%) experienced a 50% decline in eGFR, and 4 (12.12%) patients required renal replacement therapy. Regarding proteinuria, 25 patients (80.6%) achieved a 50% reduction in the PCR, and 23 patients (74.2%) reduced their PCR to &amp;lt;0.5 g/g. ROC analysis showed excellent discriminatory abilities with an AUC value of 0.95 for predicting 50% decline in eGFR and considerable discriminatory abilities with an AUC value of 0.870 for predicting CKD (Fig. 1). Conclusion IgAN PT performs well in the Mexican population and clinicians can use it to predict the risk of a 50% decline in eGFR from baseline and use it with discretion for progression to CKD.

Human papillomavirus (HPV) is a DNA virus responsible for one of the most common sexually transmitted infections worldwide. Poor and low knowledge of the vaccine's efficacy, security, and existence is still a barrier to vaccination, especially in low and middle-income countries. This cross-sectional study analyzed knowledge about HPV among 307 adults in quilombola communities in northeast Brazil. The questions were about HPV, transmission, prevention, and relation with genital warts and cervical cancer. Data presentation used absolute and relative frequency. Chi-Square or Fisher's Exact tests were applied to compare categorical variables. All statistical associations were set at a significance level of p ≤ 0.05. The median age of participants was 41.4 years old, with the majority being women. They were individuals with low monthly income and low educational levels, with more than half being illiterate or with only primary education. Knowledge about HPV was greater among young individuals and women were better informed about the HPV association to genital warts and HPV vaccination of their children. Most information about HPV was acquired through traditional media (TV/newspapers/radio). A better knowledge of HPV and its consequences may increase vaccination rates and reduce cancer cases associated with this virus.

Introduction: The predictors of cardiovascular complications of hypertension can be diverse, highlighting older age, precarious social, economic and personal conditions, as well as body conditions, susceptible to modification with comprehensive health interventions. Objective: To predict cardiovascular complications of hypertension in users of a Peruvian public hospital using models. Methodology: The research was analytical, predictive, cross-sectional, with retrospective data collection. 303 patients who attended the Cajamarca Regional Hospital during 2022 were investigated. Sociodemographic data and data on cardiovascular complications of hypertension were obtained from the data stored by the hospital. Descriptive statistics included absolute and relative frequencies, confidence intervals, mean and dispersion measures, and predictive models were performed using binary logistic regression and Cohen's Kappa Index, with a statistical significance of p&lt;0.05. Results: The most frequent cardiovascular complication was heart failure (49.5%). The model for heart failure predicts 70.6% and the years of diagnosis, occupation and marital status are included in the equation, for atrial fibrillation it predicts 82.2% and the equation includes age, sex, years of diagnosis, level of education and marital status and for angina pectoris it predicts 84.8% and the equation includes age, sex and years of diagnosis. Conclusions: The models created for the cardiovascular complications of hypertension have good predictive capacity, therefore, accurate and efficient performance in the predictor variables will allow favorable control of the complications of the disease.

To describe the tooth color of pre-Columbian teeth from two archaeological sites in Costa Rica and to determine the most suitable digital shade guide for postmortem tooth color assessment. A total of 165 anterior teeth were assessed using a VITA EasyShade® V digital spectrophotometer. Color measurements were taken from the middle third of the buccal surface. Two digital shade guides, Vita Classical and Vita 3D-Master, were used to determine tooth shade. Statistical analyses included absolute and relative frequency calculations, along with bivariate analysis. According to the Vita Classical shade guide, 42% of the samples were categorized as color C4, followed by A3.5 and A4. Canines showed the highest percentage for A3.5 (57%) while A4 was equally distributed between canines and lateral incisors (36%). The highest percentage for C4 was observed in central incisors (51%). Using the Vita 3D-Master guide, 47% of the samples were categorized as color 5M3 (central incisors), followed by 4M3 and 3M3 (canines). Postmortem dental color can be effectively assessed using digital methods. Between the two shade guides, the Vita Classical is recommended for its higher precision. Additionally, central incisors in archaeological collections tend to exhibit greater saturation compared to the lateral incisors and canines. The use of digital spectrophotometry may contribute to the standardization of tooth color assessment in anthropological research. Additionally, the incorporation of the Vita Classical shade guide enhances accuracy in both historical and clinical contexts.

The Dutch government has expanded the status and scope of practice of bachelor's degree dental hygienists (DHs) compared to those with a diploma. The aim of this study is to investigate differences in the daily scope of practice of diploma and bachelor's degree DHs. A web-based survey was emailed to all 2972 members of the Dutch Association of Dental Hygienists and distributed via social media platforms. The survey had sections on participants' demographics, educational qualifications, work environment, and scope of practice. Absolute and relative frequencies for each question were reported and statistically compared between groups. In total, 473 DHs completed the survey, 288 in the 'Diploma' and 185 in the 'Bachelor' group. Altogether, Dutch DHs work on average 29 h per week; those with a bachelor's degree work significantly (p < 0.001) more hours. Bachelor DHs work significantly (p < 0.001) more often as paid employees in a general dental practice, a practice dedicated to periodontology, in the educational and research setting. Diploma DHs work significantly (p < 0.001) more often in their own private DH practice. Bachelor DHs are significantly more likely to perform the following activities: administer local anaesthesia, take intra-oral radiographs, and treat primary caries compared to Diploma DHs (p < 0.001). The overall majority in both groups does not treat caries (81.3%) but does administer local anaesthesia (85.1%). Bachelor DHs are more frequently engaged in three tasks in the extended scope of practice and are more likely to work in a team setting.

The inter-night variability of REM sleep without atonia in adult patients with central disorders of hypersomnolence.

PURPOSEThe aim of the present study was to assess the influence of various implant angulations, camera positions and number of implant references on the accuracy of a photogrammetry device for complete arch implant prostheses.MATERIALS AND METHODS2 edentulous models, one with 6 parallel implants (PM) and other with 6 angled implants (AM), underwent digitalization with a coordinate measuring machine (CMM) to establish a reference standard. Both models underwent 20 impressions with 2 different camera positions and 3 different implant references, with a total of 240 impressions. Euclidean linear and angular measurements were obtained on the reference cast and each experimental scan and compared. Absolute (n) and relative frequencies (%) of true and precise measurements at 95% confidence intervals (CI) were calculated. Chi-squared tests were used to assess differences in trueness and precision between these factors.RESULTS3660 distances and 1440 angles were analyzed for trueness. The absolute difference was 54 ± 46 µm and 0.341 ± 0.301°. Precision was 18 ± 23 µm from 68400 measured distances and 0.048 ± 0.074° for the 22800 angulations measured. Statistically significant differences (P < .05) were identified between PM and Am, A1 and A2 and number of references in both distances and angulations for trueness and precision.CONCLUSIONImplant angulations, camera positions and number of implant references used affected the precision and trueness of Precise Implant Capture (PIC) system. However, these differences did not show clinically relevant values.

INTRODUCTION: Pelvic pain affects approximately 30% of sexually active women, and among them, around 50% report experiencing dyspareunia. The goal of treatment is to monitor the progression of pain symptoms of musculoskeletal and myofascial origin, aiming to improve the patients' quality of life. OBJECTIVE: The aim of this study is to describe the effects of fascial manipulation according to the Stecco Method, combined with perineal massage, on pain intensity, sexual function, psychological risk levels for stress, depression, and anxiety, as well as on pain characteristics and pelvic floor muscle strength. METHOD: The sample consisted of seven women participating in a postpartum recovery program, all diagnosed with dyspareunia and undergoing a three-month intervention. The assessment instruments used were the Numeric Pain Rating Scale (NPRS), the McGill Pain Questionnaire, the FSFI-19, the DASS-21 scale, and the Modified Oxford Scale. Participants were evaluated at three distinct time points: M0 (before the intervention – at the time of diagnosis), M1 (one month after the start of the intervention), and M2 (three months after the start of the intervention). A descriptive statistical analysis was conducted using the absolute and relative frequencies of the data collected. To verify the normality of the data, the Shapiro-Wilk test was used. RESULTS: The results reported reductions in pain between time points M0–M1 and M0–M2. In the McGill Pain Questionnaire, a gradual decrease in pain was observed from M0 to M2. In the FSFI-19, the "pain" item showed improvement between M0 and M1, while the "satisfaction" item showed a decrease between M0 and M2. The "total" score of the scale showed a slight increase over the three time points. In the DASS-21 scale, the most notable reduction was in the "stress" item, decreasing from 8.3 at M0 to 5.0 at M2. Finally, in the Modified Oxford Scale, 71.4% of the participants presented low-intensity contractions at M0. At M1 and M2, there was a predominance of more satisfactory contraction intensity, with 42.9% of participants reaching grades 3 and 28.6% grade 4 at M1, and 42.9% reaching grade 3 and another 42.9% grade 4 at M2. CONCLUSION: The combination of fascial manipulation and perineal massage applied in the treatment of dyspareunia resulted in a decrease in pain intensity and characteristics, reduced stress levels, increased pelvic floor muscle strength, and improvements in the "satisfaction" and "pain" items, as well as a reduction in the total scale score.

Objectives: We conducted a systematic review of clinical trials and case reports analyzing the safety of the currently approved BRAF and MEK inhibitors in adults with cutaneous melanoma (CM), and a meta-analysis to estimate the pooled prevalence of treatment-related adverse events (TRAEs). Methods: We systematically searched six databases for studies published since 2009. The TRAE absolute frequencies reported in primary studies were aggregated using the Metaprop command in Stata 17, which calculates 95% confidence intervals (CIs) incorporating the Freeman-Tukey double arcsine transformation of proportions to stabilize variances within random-effect models. Methodological quality was assessed using the RoB 2 tool for randomized controlled trials (RCTs) and the ROBINS-I tool for non-randomized studies. Results: Twelve RCTs, thirteen prospective cohort studies (PCSs), and ten case reports were included. Meta-analysis was feasible for two regimens: vemurafenib 960 mg monotherapy and dabrafenib 150 mg twice daily plus trametinib 1-2 mg daily. The most common TRAEs during vemurafenib treatment were musculoskeletal and connective-tissue disorders (24%, 95% CI: 6-41%, p = 0.01), with arthralgia as the most prevalent (44%, 95% CI: 29-59%, p < 0.001), followed by rash (39%, 95% CI: 22-56%, p < 0.001). The most common TRAEs during dabrafenib plus trametinib were constitutional toxicities (classified in CTCAE as 'General disorders and administration site conditions'; 25%, 95% CI: 14-37%, p < 0.001), with fatigue as the most prevalent (47%, 95% CI: 38-56%, p < 0.001), followed by pyrexia (40%, 95% CI: 26-54%, p < 0.001). Squamous cell carcinoma and keratoacanthoma were among the most frequent grade ≥ 3 cutaneous adverse events observed with vemurafenib therapy. Conclusions: Although additional large-scale studies are needed to corroborate these findings, each treatment has a distinct toxicity profile that should be considered when developing personalized risk-stratified treatment plans and in guiding healthcare resource allocation in melanoma care.

Episiotomy and obstetric anal sphincter injuries (OASIS) are recognized indicators of intrapartum care quality. The aim of this study was to assess episiotomy trends in non-instrumental vaginal deliveries across all Portuguese public maternities over the last decade. Rates of third- and fourth-degree perineal lacerations were also evaluated. A retrospective secondary data analysis was conducted using data from an official national health entity, including all non-instrumental vaginal deliveries in the Portuguese National Health Service between January 1, 2013 and December 31, 2022. Information on episiotomy and third- and fourth-degree perineal lacerations was extracted. Descriptive statistics were presented using absolute and relative frequencies. Linear regression was used to assess trends. Additional national databases were consulted to validate findings, and data quality was assessed using the intraclass correlation coefficient (ICC). A significance level of 5% was considered. Of 689 908 registered deliveries, 490 322 (71%) were vaginal, and 361 887 (52%) were non-instrumental vaginal deliveries. Among the latter, the episiotomy rate was 42.5%. A significant decrease was observed in episiotomy rates, from 63% in 2013 to 21% in 2022, (P < 0.001), accompanied by a significant increase in third-degree perineal lacerations (0.15% to 0.31%, P < 0.001), while fourth-degree perineal lacerations remained stable (0.03% to 0.02%, P = 0.001). A restrictive episiotomy policy was increasingly adopted in Portugal over the last decade. Although rare, third-degree perineal lacerations increased during this period. Further research is needed to determine optimal intrapartum care practices regarding episiotomy use. Standardized data coding and improved access to anonymized national datasets are essential for accurate monitoring and cross-country comparability.

Frequency metrology lies at the heart of precision measurement. Optical frequency combs provide a coherent link uniting the microwave and optical domains in the electromagnetic spectrum, with profound implications in timekeeping, sensing and spectroscopy, fundamental physics tests, exoplanet searches, and light detection and ranging. Here, we extend this frequency link to free electrons by coherent modulation of the electron phase by a continuous-wave laser locked to a fully stabilized optical frequency comb. Microwave frequency standards are transferred to the optical domain via the frequency comb, and are further imprinted in the electron spectrum by optically modulating the electron phase with a photonic chip-based microresonator. As a proof-of-concept demonstration, we apply this frequency link in the calibration of an electron spectrometer and verify its precision by measuring the absolute optical frequency. This approach achieves a 20-fold improvement in the accuracy of electron spectroscopy, relevant for investigating low-energy excitations in quantum materials, two-dimensional materials, nanophotonics, and quantum optics. Our work bridges frequency domains differed by a factor of ~1013 and carried by different physical objects, establishes a spectroscopic connection between electromagnetic waves and free-electron matter waves, and has direct ramifications in ultrahigh-precision electron spectroscopy.

We present a transportable laser-cooled ion microwave clock based on the ground-state hyperfine splitting of 171Yb+. The system achieves a systematic uncertainty of 7.8×10-15 and a short-term frequency stability of 9.5×10-13/τ. Enhancements to the magnetic-field system suppress the decoherence process in the multi-body ion ensemble and reduce the second-order Zeeman frequency shift by a factor of two. The absolute microwave frequency is measured to be 12 642 812 118.468 6(3) Hz, consistent with the previous measurements and demonstrating twice the precision of the current state-of-the-art.