Extended Length Research Articles

Tying the knot: Unraveling the intricacies of the coronavirus frameshift pseudoknot.

Understanding and targeting functional RNA structures towards treatment of coronavirus infection can help us to prepare for novel variants of SARS-CoV-2 (the virus causing COVID-19), and any other coronaviruses that could emerge via human-to-human transmission or potential zoonotic (inter-species) events. Leveraging the fact that all coronaviruses use a mechanism known as -1 programmed ribosomal frameshifting (-1 PRF) to replicate, we apply algorithms to predict the most energetically favourable secondary structures (each nucleotide involved in at most one pairing) that may be involved in regulating the -1 PRF event in coronaviruses, especially SARS-CoV-2. We compute previously unknown most stable structure predictions for the frameshift site of coronaviruses via hierarchical folding, a biologically motivated framework where initial non-crossing structure folds first, followed by subsequent, possibly crossing (pseudoknotted), structures. Using mutual information from 181 coronavirus sequences, in conjunction with the algorithm KnotAli, we compute secondary structure predictions for the frameshift site of different coronaviruses. We then utilize the Shapify algorithm to obtain most stable SARS-CoV-2 secondary structure predictions guided by frameshift sequence-specific and genome-wide experimental data. We build on our previous secondary structure investigation of the singular SARS-CoV-2 68 nt frameshift element sequence, by using Shapify to obtain predictions for 132 extended sequences and including covariation information. Previous investigations have not applied hierarchical folding to extended length SARS-CoV-2 frameshift sequences. By doing so, we simulate the effects of ribosome interaction with the frameshift site, providing insight to biological function. We contribute in-depth discussion to contextualize secondary structure dual-graph motifs for SARS-CoV-2, highlighting the energetic stability of the previously identified 3_8 motif alongside the known dominant 3_3 and 3_6 (native-type) -1 PRF structures. Using a combination of thermodynamic methods and sequence covariation, our novel predictions suggest function of the attenuator hairpin via previously unknown pseudoknotted base pairing. While certain initial RNA folding is consistent, other pseudoknotted base pairs form which indicate potential conformational switching between the two structures.

Utilizing a comprehensive machine learning approach to identify patients at high risk for extended length of stay following spinal deformity surgery in pediatric patients with early onset scoliosis.

Early onset scoliosis (EOS) patient diversity makes outcome prediction challenging. Machine learning offers an innovative approach to analyze patient data and predict results, including LOS in pediatric spinal deformity surgery. Children under 10 with EOS were chosen from the American College of Surgeon's NSQIP database. Extended LOS, defined as over 5days, was predicted using feature selection and machine learning in Python. The best model, determined by the area under the curve (AUC), was optimized and used to create a risk calculator for prolonged LOS. The study included 1587 patients, mostly young (average age: 6.94 ± 2.58years), with 33.1% experiencing prolonged LOS (n = 526). Most patients were female (59.2%, n = 940), with an average BMI of 17.0 ± 8.7. Factors influencing LOS were operative time, age, BMI, ASA class, levels operated on, etiology, nutritional support, pulmonary and neurologic comorbidities. The gradient boosting model performed best with a test accuracy of 0.723, AUC of 0.630, and a Brier score of 0.189, leading to a patient-specific risk calculator for prolonged LOS. Machine learning algorithms accurately predict extended LOS across a national patient cohort and characterize key preoperative drivers of increased LOS after PSIF in pediatric patients with EOS.

Predictors of extended length of stay following outpatient reduction mammaplasty

PurposeReduction mammaplasty has transitioned into a largely outpatient procedure in the United States. Following planned outpatient procedures, patients may still be admitted for additional inpatient care, incurring clinical and economic burden. Prior literature has not explored the preoperative and perioperative determinants of extended lengths of stay (LOS) after breast reduction surgery. MethodsPatients who underwent scheduled outpatient reduction mammaplasty were identified via current procedural terminology code from the 2013 to 2021 National Surgical Quality Improvement Program databases. The primary outcome was extended LOS, defined as an LOS greater than 1 day. The most significant predictor variables were identified through bivariate association, and a binary logistic regression model was used to characterize predictive associations (p < 0.05). ResultsIn this study, 33,924 patients were included in the final cohort of planned outpatient reduction mammaplasty cases. Among them 325 (1.0%) patients had extended LOS. Concurrent liposuction, body contouring, and increased operative time were the most significant predictors of extended LOS (p < 0.001), followed by older age, higher body mass index, bleeding disorder, history of diabetes, higher American Society of Anesthesiologists class, and White race (p < 0.05). When adjusted for other confounding variables, extended LOS was also a significant predictor of increased risk of postoperative complications after discharge (OR: 1.85, 95% confidence intervals: 1.27–2.69, p = 0.0012). ConclusionExtended LOS after planned outpatient reduction mammaplasty is associated with specific comorbidities, and is a significant predictor of postoperative complications following hospital discharge. Data availability statementThe data that support the findings of this study are publicly available.

An analysis of order utilization and overall costs secondary to an extended length of stay in hospitalized patients pending discharge to long term care facilities during the peak of Omicron

During the covid pandemic there was an influx of patients admitted to hospitals worldwide. This resulted in a presumptive overuse of resources, increased utilization costs, and decrease in hospital bed availability. This study focuses on patients admitted with a positive covid test, who required transfer to a long-term health facility after the acuity of their symptoms no longer required hospitalization but necessitated an extended length of stay due to acceptance into these facilities. Such facilities included: alternative living facility, skilled nursing facility, psychiatric institutions, or hospice. Wherein these facilities required a negative Covid PCR test or required a certain time frame to have elapsed after a positive test prior to accepting or recovering a patient. This study utilized patient records from Keralty Hospital, with admission during the 2022 peak of Omicron (January 31, 2022- February 13, 2022). Patient inclusion criteria was if they had a positive covid test on admission and experienced an extended length of stay over 2 days pending discharge to a long-term care facility. A quantitative/qualitative analysis was conducted of all orders placed subsequent to the first discharge order, and the number of additional days spent at the hospital. Correlations regarding total bed cost, and total overall, were then calculated using single tailed p values utilizing Prism 9 GraphPad software. Our research findings indicate there was a significant correlation between the number of extended hospitalization days and total bed costs but no correlation in the total overall costs or initial length of stay for each patient.

Unveiling the Variances: Myelodysplastic Syndrome (MDS) Patient Admissions in Teaching vs Nonteaching Hospitals

Background We have carried out an analysis to evaluate the influence of hospital teaching status on the outcomes of individuals hospitalized with MDS. Methods The National Inpatient Sample (NIS) dataset for the years 2019-2020 was employed to identify individuals who were hospitalized with a primary diagnosis of MDS. These patients were then categorized into two groups: those who were hospitalized in teaching hospitals and those who were hospitalized in non-teaching hospitals. Multivariate regression analysis was performed to calculate the primary and secondary outcomes. Results In the years 2019 and 2020, a total of 17,000 patients were hospitalized with myelodysplastic syndromes (MDS). Among these, 24.05% (4,080) were admitted to non-teaching hospitals, while 75.94% (12,920) were admitted to teaching hospitals. Patients admitted to teaching hospitals had a higher likelihood of mortality (OR 1.84, 95% CI 1.03-3.27, P=0.037), as well as increased lengths of stay (+3.58 Days, 95% CI 2.82-4.34, P&lt;0.001)and total hospitalization costs (+USD 66818, 95% CI 50528-83108, P&lt;0.001). Additionally, patients in teaching hospitals had a higher incidence of acute respiratory failure (6.81% vs 4.4%), acute kidney injury (23.89% vs 17.72%), hematopoietic stem cell transplantation (14.36% vs 0.61%), and febrile neutropenia (11.03% vs 5.86%). However, patients in teaching hospitals had a lower incidence of anemia (41.86% vs 48.53%) and blood transfusions (38.8% vs 55.37%). Conclusion Individuals who were admitted to teaching hospitals with Myelodysplastic Syndromes (MDS) exhibited a notably higher mortality rate, as well as an extended length of stay and a corresponding increase in the total cost of hospitalization. Patients in teaching hospitals were also at risk for acute kidney injury, acute respiratory failure and febrile neutropenia.

Design of short Venturi flow meters for incompressible and isothermal flow applications

The Venturi flow meter offers a range of measurement options for liquids, gas, steam, and slurries in piped systems. The main criteria for assessing Venturi performance include permanent pressure loss, discharge coefficient, relative pressure loss coefficient, and measurement accuracy. However, the extended length of Venturis, relative to other flow rate measuring instruments, can present limitations in some applications. Furthermore, the manufacturing of shorter Venturis requires less material and energy. This study addresses the challenge by developing shorter Venturi meters that adhere to established performance standards. Previous studies show that cone angles, the ratio of throat diameter to inlet diameter (β-ratio), and the throat length impact the performance of a Venturi. The scope of this research considers single-phase, incompressible and isothermal flows. The investigation focuses on the effect of cone angles for flows with Reynolds numbers ranging from 5000 to 10,000,000. Two axisymmetric Venturis, with a β-ratio of 0.7, were designed and evaluated against an ISO-5167 classical Venturi with the same β-ratio. Despite the ISO-5167 Venturi outperforming the others across the key criteria, a Venturi designed with a 40-degree convergent cone angle and a 10-degree divergent cone angle was 24.9 % shorter than the classical design and demonstrated similar performance to the ISO-5167 Venturi across Reynolds numbers from 100,000 to 10,000,000.

Existing Psychiatric Diagnoses Among Breast Cancer Patients Interact with Outcomes After Autologous and Implant-Based Bilateral Breast Reconstruction: A Propensity Score Matched Analysis

BackgroundBreast reconstruction is an integral postoncologic procedure that has been associated with improved mental health and psychological outcomes. The possible interaction between existing psychiatric diagnoses hospital courses and postoperative complications warrants further exploration. MethodsBilateral breast reconstruction patients were identified from the 2016 to 2018 Healthcare Cost and Utilization Project-National Inpatient Sample (HCUP - NIS). Number and type of psychiatric diagnoses within the cohort were then evaluated using a host of ICD-10 codes. A propensity score analysis was applied to control for confounding variables such as demographics, existing comorbidities, and hospital characteristics. A binary logistic regression model was then used to identify the prediction value of psychiatric diagnosis and its interaction with modality of reconstruction for objective outcomes like length of hospital stay, treatment charge, and postoperative complications. ResultsA total of 10,114 patients were identified as the final cohort of breast reconstruction patients. 2621 (25.9%) patients possessed an average of 1.4 ± 0.6 existing psychiatric diagnoses. Presence of at least 1 psychiatric diagnosis was a strong predictor alone for extended length of stay (OR: 1.34, 95% CI: 1.28-1.41, P < .001) and occurrence of postoperative complications (OR: 1.31, 95% CI: 1.21-1.41, P < .001). Psychiatric diagnosis displayed a significant interaction with modality of breast reconstruction and conferred a lower increase in risk of extended length of stay in autologous reconstruction when compared to implant-based reconstruction (OR: 0.80, 95% CI: 0.72-0.89, P < .001). ConclusionExisting psychiatric diagnoses were shown to strongly predict and modulate risk of adverse postoperative outcomes depending on modality of reconstruction.

Large eddy simulation of non-premixed flame behavior and NOx emission characteristics in a staged combustor with multi-swirling flows

This study utilizes Large Eddy Simulation (LES) to investigate flame characteristics and NOx emission generation in a concentric staged combustor with three distinct pilot swirler arrangements. We examine the effects of multi-swirling flow on the instantaneous flow field and flame characteristics using the Proper Orthogonal Decomposition (POD) method, and assess how variations in swirler structures influence thermoacoustic instability. Furthermore, a comparison of NOx emissions between two pilot swirler configurations, with similar mean flow field and flame characteristics, highlights the precessing vortex core's role in NOx emissions. Compared to a single-swirler setup, a double-swirler configuration produces a more distinct single precessing vortex core, thereby amplifying thermoacoustic instability. The extended venturi structure in the double-swirler setup mitigates the development of the swirl-induced vortex core, reducing thermoacoustic instability. However, the expansion section in this setup impedes initial fuel and air mixing, leading to an extended flame length, which in turn results in higher NOx emissions due to a more concentrated temperature distribution. With similar mean flow field and flame structure, the double-swirler combustor proves more effective in reducing NO emissions than the triple-swirler combustor.

Pediatric kidney transplantation: is it safe to perform during night-time or day-off?

PurposeTo investigate the impact of after-hours surgery on the outcomes of pediatric kidney transplantation (KT).MethodsMedical records of pediatric KTs performed at a single institution between 2013 and 2021 were retrospectively reviewed. The population was split into three groups according to the incision time and calendar: ordinary day (8.00 AM – 6.30 PM), day-off, and night-time (6.30 PM – 8.00 AM). The following endpoints were compared: ischemia times, length of surgery, complications, delayed graft function (DGF), primary graft non-function (PGNF), and eGFR at three-month follow-up.ResultsNinety-six non-living donor KTs were performed, median age 11 (IQR 4.3–14) years and median body weight 26 (IQR 13–50) kg. Forty-one (43%) were performed during night-time and 28 (29%) during day-off. Ischemia times were similar (p = 0.769, p = 0.536). Day-off KTs presented an extended length of surgery (p = 0.011). Thirty-two complications were reported in 31 KTs. No difference in the overall rate of complications, DGF, PNGF, and three-month eGFR was found (p = 0.669, p = 0.383, p = 0.949, p = 0.093). Post-operative bleedings were more common in days-off (p = 0.003).ConclusionThe number of pediatric KTs performed during after-hours was considerable. Even though similar outcomes were reported, more caution should be focused on the KTs performed in days-off to avoid severe complications.

Walking performance in individuals with lumbar spinal stenosis—possible outcome measures and assessment of known-group validity

BACKGROUND CONTEXTOne of the primary goals of treatments received by individuals with lumbar spinal stenosis with neurogenic claudication is to improve walking ability. Thus, a thorough and valid assessment of walking ability in patients with lumbar spinal stenosis is needed. Duration of continuous walking and steps per day could be relevant when evaluating walking ability in daily living. PURPOSETo describe and evaluate a method for estimating continuous walking periods in daily living and to evaluate the known-group validity of steps per day in individuals with lumbar spinal stenosis. STUDY DESIGNThis is a cross-sectional observational study. PATIENT SAMPLEThe study contains three study groups: individuals with lumbar spinal stenosis, individuals with low back pain, and a background population from the Lolland-Falster Health Study (LOFUS). OUTCOME MEASURESParticipants in all three study groups wore an accelerometer on the thigh for seven days. METHODSAccelerometer data were processed to summarize the continuous walking periods according to their length: the number of short (4–9 seconds), moderate (10–89 seconds), and extended (≥90 seconds) continuous walking periods per day, and the number of steps per day. Results from the three groups were compared using negative binomial regression with lumbar spinal stenosis as the reference level. RESULTSContinuous walking periods of moderate length were observed 1.48 (95% CI 1.27, 1.72) times more often in individuals from the background population than in individuals with LSS. Continuous walking periods of extended length were observed 1.53 (95% CI 1.13, 2.06) times more often by individuals with low back pain and 1.60 (95% CI 1.29, 1.99) times more often by individuals from the background population. The number of steps per day was 1.22 (95% CI 1.03, 1.46) times larger in individuals with LBP and 1.35 (95% CI 1.20, 1.53) times larger in individuals from background population. CONCLUSIONSThe impact of neurogenic claudication on walking ability in daily living seems possible to describe by continuous walking periods along with steps per day. The results support known-group validity of steps per day. This is the next step toward a clinically relevant and comprehensive assessment of walking in daily living in individuals with lumbar spinal stenosis.

The pattern of eye disease in a provincial ophthalmic hospital of Viet Nam

: To describe the pattern of eye disease in a provincial ophthalmic hospital in Viet Nam.: We retrospectively analyzed records of 1735 patients with disorders of the eye and adnexa admitted to the Nghe an Eye Hospital, Nghe an province, Vietnam between January 2022 and May 2023. : The mean age of patients was 60.4± 16.6 years old and 54.7% were females. The most common cause of hospitalizations were disorders of sclera, cornea, iris, and ciliary body (55.0% of cases) followed by glaucoma (29.2%) and disorders of the eyelid, lacrimal system, and orbit (15.8%). Keratitis was the most common ocular morbidity (40.1%), followed by glaucoma (29.20%), and iridocyclitis (13.5%). The average highest age was in patients with disorders of the eyelid, lacrimal system, and orbit (67.3 ± 13.4 years) followed by those with glaucoma (62.2 ± 13.8 years) and lesions on the sclera, cornea, iris, and ciliary body (57.5 ± 17.9 years). The female/male rate among those with disorders of eyelid, lacrimal system and orbit was higher than among cases with the other disorders (1.6/1 vs 1.1/1, p = 0.008). The mean length of hospital stay was 8.6 days and patients with disorders of sclera and cornea had the most extended average length of hospital stay (more than 10 days). Keratitis, glaucoma, and iridocyclitis were the major ocular conditions seen in this study. Prevention of keratitis should decrease both morbidity and health expenditure for eye disease.

Immediate rehabilitation of severely atrophic maxillae using conventional and extended length subcrestal angulated (ELSA) implants: A retrospective analysis of 187 implants in 33 patients with up to three years of function.

The purpose of this study was to evaluate and determine clinical outcomes and survival rates of straight and extended length subcrestal angulated (ELSA) implants (20-24mm lengths) placed for immediate (up to 72h post-operative) or delayed rehabilitation (4 months post-operative) of severely atrophic maxillae. Prosthetic treatment consisted of interim and definitive implant-supported fixed implant-supported prostheses with up to 3 years of function. A retrospective analysis was conducted of 38 patients (five dropped out; final total was 33), treated between 2017 and 2019 in a private practice. Extended length subcrestal angulated (ELSA) implants and conventional endosseous straight implants (Southern Implants, Irene, South Africa) with (fixed) full arch prostheses were used to restore patients with edentulous maxillae immediately (within 72hs) or delayed (4 months). ELSA implants have subcrestal angulations of 24° and 36° of the restorative platforms, external hexagon crestal anti-rotation abutment connections, and lengths between 18 and 26mm. Implant loading was determined by implant insertion torque values (as determined on the surgical units); 120Ncm was the threshold level for immediate loading. Clinical and radiographic examinations were done that recorded the clinical outcomes of implants and prostheses. SPSS was used to process the data. Thirty-three patients and 187 implants were included with follow-up periods of at least 12 months (range 12-36 months). The mean age of the study population was 62.6 ± 8.4 years old (at the time of implant placement). Thirty-three patients (86.8%) were followed for 12 months; 13 patients (39.4%) were followed for 24-35 months; 9 patients (27.3%) were followed for 36 months. In total, 13 implants in six patients failed secondary to sinus infections. Mean bone levels (MBLs) were respectively: 0.88±2.12mm at loading, -1.53±2.03mm at 12 months, -2.26±1.45mm at 24 months, and -2.54±1.46mm at 36 months. The ELSA implants showed significantly lower (p = 0.014) MBL at 36 months than did the conventional implants. One hundred thirty-seven implants were placed and loaded within 72h; 50 implants were placed and loaded 4 months post placement. The combined implant survival rates were 93.0% at 12 months, 91.1% at 24 months, and 100% at 36 months. The ELSA implants showed significantly lower (p = 0.014) MBLs at 36 months when compared to the conventional implants. The results of this retrospective clinical chart review indicated that the use of ELSA implants placed into anterior maxillae and nasal crests with accentuated distal tilts (>30°) and simultaneous sinus augmentation provided favorable outcomes for prosthetic rehabilitation in patients with severe atrophic maxillae. ELSA implants placed with simultaneous sinus augmentation are an alternative option to zygomatic implants (ZI) when immediate loading is prescribed. Sinus infections were thought to be the proximate causes of all implant failures. Further long-term clinical studies are warranted with larger patient populations.

Unlocking the Mysteries of Technical Catalyst Deactivation: A View from Space

AbstractModern analytical techniques enable researchers to study heterogeneous catalytic systems at extended length scales and with local probing methods which were previously impractical. Such spatially–resolved analyses are ideal for exploring the complex dynamics governing catalytic activity, and more specifically, deactivation. Here we highlight significant experimental concepts and milestones in the spatially–resolved analysis of technical catalysts, where it is now possible to study catalyst behavior even up to industrially relevant scale. At such extended length scales and in contrast to many model systems, spatial heterogeneities in solid catalyst bodies may play a crucial role in controlling catalytic properties and may be closely linked to catalyst deactivation. Spatially–resolved studies can therefore provide a unique source of information about such local phenomena. Researchers can gain a deeper insight into the operational life of a catalyst by understanding deactivation patterns, which are one of many factors influencing the dynamics of catalytic reactions. In turn, this information promotes the design of more robust and sustainable catalytic systems. We therefore outline the current state of spatially–resolved characterization, together with its role in deconvoluting the complexity of technical catalysts and their deactivation.

Impact of Sociodemographic and Hospital Factors on Inpatient Bilateral Reduction Mammaplasty: A National Inpatient Sample Analysis

Background: Although reduction mammaplasty remains a common procedure in plastic surgery, its interaction with sociodemographic and economic disparities has remained relatively uncharacterized on a nationwide scale. Methods: Patients who underwent reduction mammaplasty were identified within the 2016–2018 National Inpatient Sample databases. In addition to clinical comorbidities, sociodemographic characteristics, hospital-level variables, and postoperative outcomes of each patient were collected for analysis. Statistical analyses, including univariate comparison and multivariate logistic regression, were applied to the cohort to determine significant predictors of adverse outcomes, described as extended length of stay, higher financial cost, and postoperative complications. Results: The final patient cohort included 414 patients who underwent inpatient reduction mammaplasty. The average age was 45.2 ± 14.5 years. The average length of stay was 1.6 ± 1.5 days, and the average hospital charge was $53,873.81 ± $36,014.50. Sixty (14.5%) patients experienced at least one postoperative complication. Black race and treatment within a nonmetropolitan or rural county predicted postoperative complications (P &lt; 0.01). Black race, lower relative income, and concurrent abdominal contouring procedures also predicted occurrence of extended length of stay (P &lt; 0.01). Hospital factors, including larger bed capacity and for-profit ownership, predicted high hospital charges (P &lt; 0.05). Severity of comorbidities, measured by a clinical index, also predicted all three outcomes (P &lt; 0.001). Conclusion: In addition to well-described clinical variables, multiple sociodemographic and economic disparities affect outcomes in inpatient reduction mammaplasty.

Application of machine learning constructs to predict post-operative complications and adverse events following shoulder hemiarthroplasty

Background: Artificial intelligence (AI) constructs and machine learning (ML) algorithms have demonstrated utility in predicting various clinical, surgical, and financial outcomes. In this study, we applied AI to shoulder hemiarthroplasty (HA) to predict various post-operative complications. Methods: The sample was queried from the American college of surgeons-national surgical quality improvement program (ACS-NSQIP) database for all shoulder HA cases from 2008-2018. Six ML algorithms-random forest classifier, gradient boosting classifier, decision tree classifier, SVM classifier-tuned model, Gaussian Naïve Bayes classifier, multi-layer perception-analyzed the sample dataset. Postoperative complications included extended length of stay, non-home discharge destination, transfusion, and any adverse event. Each ML model was compared to logistic regression (LR), and model strength was evaluated. Results: We identified a total of 1585 shoulder HA cases. Mean age, BMI, operative time, and length of stay were 66±12 years, 31±8 kg/m2, 114±61 minutes, and 2.93±6.61 days. Preop hematocrit, longer operative time, and older age were most predictive of extended length of stay. Preop hematocrit, operative time, and ASA class had the highest importance in any adverse events (AAE) prediction. ML models outperformed traditional comorbidity indices, LR, for predicting extended length of stay (79% vs. 66%), non-home discharge destination (79% vs. 65%), any adverse event (78% vs. 66%), and transfusion requirement (82% vs. 63%). Conclusions: ML algorithms predicted post-surgical outcomes of interest following shoulder HA at a higher rate to conventional LR and can assist orthopedic surgeons in decision making.

The effect of groyne field on trapping macroplastic. Preliminary results from laboratory experiments

Macroplastic, a precursor of microplastic pollution, has become a new scope of research interest. However, the physical processes of macroplastic transport and deposition in rivers are poorly understood, which makes the decisions of where to locate macroplastic trapping infrastructure difficult. In this research, we conducted a series of experiments in a laboratory channel, exploring the impact of groynes and flexible artificial vegetation on the floating macroplastic litter. The goal was to investigate the litter paths with different obstruction arrangements, which was done by implementing a particle tracking technique on video recordings from each experimental run. We found that increasing discharge correlated with the number of plastic litter floating into the recirculation zone within the groyne fields, especially if the upstream groyne had an extended length. This produced a strong mixing interface between the main flow and the groyne field, while a vegetation patch added in the same groyne field changed the paths of plastic litter by deflecting the flow. We noticed that during a moderate discharge rate, the litter pieces flowing into the groyne field with the vegetation circulated there for the longest period, and some of them got entangled between floating stems when discharge was at its lowest. This phenomenon points to the conclusion that low flow velocity paired with the presence of vegetation can be a primer for plastic deposition and consequently, its degradation. The insights from the experiment allowed us to recommend a place downstream of an extended groyne as the desirable (efficient) area for installing a plastic trapping infrastructure or conducting plastic cleaning actions.

Extending the propagation length of graphene plasmons via nonlinear frequency conversion

Graphene plasmons (GPs) are broadband and electrically tunable mid-infrared (MIR)/terahertz (THz) excitations, exhibiting high confinement factors exceeding two orders of magnitude. Such highly confined modes are extremely attractive for nonlinear frequency conversion owing to the large inherent field enhancement. However, this high confinement is also accompanied by losses, and together with the centrosymmetric nature of graphene practical usage of its properties in second-order nonlinear processes remains hindered. In this paper, we introduce an approach for realizing quasi-phase-matching (QPM) of propagating GPs, by placing the graphene on an orientationally patterned GaAs substrate—a transparent material in the MIR/THz range with a large second-order nonlinear coefficient. We analyze the complete frequency/Fermi-level space for QPMed second-harmonic generation of GPs in the MIR and THz and demonstrate GP amplification and loss compensation. We find that our approach provides extended GP propagation lengths that are more than twice larger than the state-of-the-art cryogenic temperature propagation lengths. The approach is general to all second-order nonlinear processes, such as sum and difference frequency generation, thus opening a path for efficient and electrically tunable QPM nonlinear processes at the atomic scale.

Factors affecting length of stay according to bronchopulmonary dysplasia severity: a nationwide cohort study in Korea

BackgroundLonger hospitalizations for preterm infants with bronchopulmonary dysplasia (BPD) delay developmental outcomes, increase the risk for hospital-acquired complications, and exert a substantial socioeconomic burden. This study aimed to identify factors associated with an extended length of stay (LOS) at different levels of severity of BPD.MethodsA cohort study was conducted using the Korean Neonatal Network registry of very low birth weight infants with BPD between 2013 and 2017 through retrospective analysis.ResultsA total of 4263 infants were diagnosed with BPD. For mild BPD, infants requiring surgical treatment for patent ductus arteriosus needed a longer LOS [eadjusted β coefficients (adj β) 1.041; 95% confidence interval (CI): 0.01–0.08] and hydrocephalus (eadj β 1.094; 95% CI 0.01–0.17). In moderate BPD, infants administered steroids or with intraventricular hemorrhage required a longer LOS (eadj β 1.041; 95% CI 0.00–0.07 and eadj β 1.271; 95% CI 0.11–0.38, respectively). In severe BPD, infants with comorbidities required a longer LOS: pulmonary hypertension (eadj β 1.174; 95% CI 0.09–0.23), administrated steroid for BPD (eadj β 1.116; 95% CI 0.07–0.14), sepsis (eadj β 1.062; 95% CI 0.01–0.11), patent ductus arteriosus requiring surgical ligation (eadj β 1.041; 95% CI 0.00–0.08), and intraventricular hemorrhage (eadj β 1.016; 95% CI 0.05–0.26). Additionally, the higher the clinical risk index score, the longer the LOS needed for infants in all groups.ConclusionsThe factors affecting LOS differed according to the severity of BPD. Individualized approaches to reducing LOS may be devised using knowledge of the various risk factors affecting LOS by BPD severity.Graphical

Incidence and risk factors of venous thromboembolism in neurosurgical patients after implementing a screening protocol; a retrospective cohort study of a tertiary center

Introduction: Venous thromboembolism (VTE) is a common complication in neurosurgical procedures both before and after surgery. Objective: To examine the incidence of venous thromboembolism (VTE) in neurosurgical patients before surgery and in the postoperative period after implementing a VTE prophylaxis protocol. We also aimed to determine VTE risk factors. Methods: We conducted a retrospective cohort study examining 200 patients admitted to the hospital for cranial and spine neurosurgical procedures between January 2020 and October 2021. All patients were screened for VTE using a protocol combining measurement of D-dimer level and venous duplex ultrasonography. Patients who screened negative for VTE were evaluated for VTE risk using the Caprini risk assessment model; those with Caprini score ≥3 (indicating moderate-to-high risk) received VTE prophylaxis using intermittent pneumatic compression devices. Results: Preoperative screening demonstrated DVT in seven of 200 patients (3.5%). All DVTs were asymptomatic and proximal in location. Univariate logistic regression showed that stroke, neurodegenerative disease, and confinement to bed for more than 72 hours were significant predictors of preoperative DVT. Among the patients without DVT on preoperative screening, 179 (93%) had a Caprini score ≥3; intermittent pneumatic compression was used for prophylaxis in 173 of these (96.6%). Incidence of postoperative VTE was 2.6% (5/193). Extended length of hospital stay, postoperative hydrocephalus, and infection were significant risk factors for VTE. Conclusion: Preoperative VTE screening using D-dimer level and V-DUS and implementation of VTE prophylaxis using IPC can reduce the incidence of VTE and VTE-related mortality in neurosurgical patients.

Perioperative quality indicators among neurosurgery patients: A retrospective cohort study of 1142 cases at a tertiary center.

The purpose of this study was to present the first comprehensive analysis of perioperative quality indicators; length of hospital stay; readmission; reoperation; pre-, intra, and postoperative events; and mortality in a diverse neurosurgical patient cohort in Europe. Electronic medical records of all patients who were admitted to our institution between January 1 and December 31 of 2020, and underwent an index neurosurgical operation (n = 1142) were retrospectively reviewed. The median length of hospital stay at the index admission and readmission was 8 days (range: 1-242 days) and 5 days (range: 0-94 days), respectively. Of the 1142 patients, 22.9% (n = 262) had an extended length of hospital stay of ≥14 days. The all-cause 7-, 15-, 30-, 60-, and 90-day readmission rates were 3.9% (n = 44), 5.7% (n = 65), 8.8% (n = 100), 12.3% (n = 141), and 16.5% (n = 188), respectively. The main reason for unplanned readmission was deterioration of medical and/or neurological condition. The all-cause 7-, 15-, 30-, 60-, and 90-day reoperation rates were 11.1% (n = 127), 13.8% (n = 158), 16.5% (n = 189), 18.7% (n = 213), and 19.4% (n = 221), respectively. Unplanned reoperations were due primarily to hydrocephalus. The rate of preoperative events was 1.1% (n = 13), one-third of which were associated with infection. The rate of intraoperative events was 11.0% (n = 126), of which 98 (64.47%) were surgical, 37 (24.34%) were anesthesiologic, and 17 (11.18%) were associated with technical equipment. The rate of postoperative events was 9.5% (n = 109). The most common postoperative event was malfunction, disconnection, or dislocation of an implanted device (n = 24, 17.91%). The mortality rates within 7, 15, 30, 60, and 90 days after the index operation were 0.9% (n = 10), 1.8% (n = 21), 2.5% (n = 29), 3.4% (n = 39), and 4.7% (n = 54), respectively. Several patient characteristics and perioperative factors were significantly associated with outcome parameters. This study provides an in-depth analysis of quality indicators in neurosurgery, highlighting a variety of inherent and modifiable factors influencing patient outcomes.