Simple Parameters Research Articles

Møller-Plesset and Density-Fixed Adiabatic Connections for a Model Diatomic System at Different Correlation Regimes.

In recent years, adiabatic connection (AC) interpolations developed within density functional theory (DFT) have been found to provide good performances in the calculation of interaction energies when used with Hartree-Fock (HF) ingredients. The physical and mathematical reasons for such unanticipated performance have been clarified, to some extent, by studying the strong-interaction limit of the Møller-Plesset (MP) AC. In this work, we calculate both the MP and the DFT AC integrand for the asymmetric Hubbard dimer, which allows for a systematic investigation of different correlation regimes by varying two simple parameters in the Hamiltonian: the external potential, Δv, and the interaction strength, U. Notably, we find that, while the DFT AC integrand appears to be convex in the full parameter space, the MP integrand may change curvature twice. Furthermore, we discuss different aspects of the second-order expansion of the correlation energy in each AC, and we demonstrate why the derivative of the λ-dependent density in the MP AC at λ = 0 (i.e., at the HF density) is zero in the model. Concerning the strong-interaction limit of both ACs in the Hubbard dimer setting, we show that the asymptotic value of the MP AC, W∞HF, is lower than (or equal to) its DFT analogue, W∞KS, if the two are compared at a given density, just like in real space. However, we also show that this is not always the case if the two quantities are compared at a given external potential.

Automatically Finding the Right Probabilities in Bayesian Networks

This paper presents alternative techniques for inference on classical Bayesian networks in which all probabilities are fixed, and for synthesis problems when conditional probability tables (CPTs) in such networks contain symbolic parameters rather than concrete probabilities. The key idea is to exploit probabilistic model checking as well as its recent extension to parameter synthesis techniques for parametric Markov chains. To enable this, the Bayesian networks are transformed into Markov chains and their objectives are mapped onto probabilistic temporal logic formulas. For exact inference, we compare probabilistic model checking to weighted model counting on various Bayesian network benchmarks. We contrast symbolic model checking using multi-terminal binary (aka: algebraic) decision diagrams to symbolic inference using proba- bilistic sentential decision diagrams, symbolic data structures that are tailored to Bayesian networks. For the parametric setting, we describe how our techniques can be used for various synthesis problems such as computing sensitivity functions (and values), simple and difference parameter tuning and ratio parameter tuning. Our parameter synthesis techniques are applicable to arbitrarily many, possibly dependent, parameters that may occur in multiple CPTs. This lifts restrictions, e.g., on the number of parametrized CPTs, or on parameter dependencies between several CPTs, that exist in the literature. Experiments on several benchmarks show that our parameter synthesis techniques can treat parameter synthesis for Bayesian networks (with hundreds of unknown parameters) that are out of reach for existing techniques.

Predictors of rapidly progressive interstitial lung disease and prognosis in Chinese patients with anti-melanoma differentiation-associated gene 5-positive dermatomyositis.

Rapidly progressive interstitial lung disease (RP-ILD) is the most serious complication of anti-melanoma differentiation-associated gene 5-positive dermatomyositis (anti-MDA5+ DM). This study was performed to assess the prognostic factors of patients with anti-MDA5+ DM and the clinical characteristics and predictors of anti-MDA5+ DM in combination with RP-ILD. In total, 73 MDA5+ DM patients were enrolled in this study from March 2017 to December 2021. They were divided into survival and non-survival subgroups and non-RP-ILD and RP-ILD subgroups. The lactate dehydrogenase (LDH) concentration and prognostic nutritional index (PNI) were independent prognostic factors in patients with anti-MDA5+ DM: the elevated LDH was associated with increased mortality (p = 0.01), whereas the elevated PNI was associated with reduced mortality (p < 0.001). The elevated LDH was independent risk prognostic factor for patients with anti-MDA5+ DM (HR 2.42, 95% CI: 1.02-4.83, p = 0.039), and the elevated PNI was independent protective prognostic factor (HR, 0.27; 95% CI, 0.08 - 0.94; p = 0.039). Patients who had anti-MDA5+ DM with RP-ILD had a significantly higher white blood cell count and LDH concentration than those without RP-ILD (p = 0.007 and p = 0.019, respectively). In contrast, PNI was significantly lower in patients with RP-ILD than those without RP-ILD (p < 0.001). The white blood cell count and elevated LDH were independent and significant risk factors for RP-ILD (OR 1.54, 95% CI: 1.12 - 2.13, p = 0.009 and OR 8.68, 95% CI: 1.28 - 58.83, p = 0.027, respectively), whereas the lymphocyte was an independent protective factor (OR, 0.11; 95% CI, 0.01 - 0.81; p = 0.03). The elevated LDH and elevated PNI were independent prognostic factors for patients with anti-MDA5+ DM. The elevated LDH was independent risk factor for RP-ILD. Patients with anti-MDA5+ DM could benefit from the measurement of LDH and PNI, which are inexpensive and simple parameters that could be used for diagnosis as well as prediction of the extent of lung involvement and prognosis.

Quantifying Ozone-Dependent Emissions of Volatile Organic Compounds from the Human Body.

Ozone reactions on human body surfaces produce volatile organic compounds (VOCs) that influence indoor air quality. However, the dependence of VOC emissions on the ozone concentration has received limited attention. In this study, we conducted 36 sets of single-person chamber experiments with three volunteers exposed to ozone concentrations ranging from 0 to 32 ppb. Emission fluxes from human body surfaces were measured for 11 targeted skin-oil oxidation products. For the majority of these products, the emission fluxes linearly correlated with ozone concentration, indicating a constant surface yield (moles of VOC emitted per mole of ozone deposited). However, for the second-generation oxidation product 4-oxopentanal, a higher surface yield was observed at higher ozone concentrations. Furthermore, many VOCs have substantial emissions in the absence of ozone. Overall, these results suggest that the complex surface reactions and mass transfer processes involved in ozone-dependent VOC emissions from the human body can be represented using a simplified parametrization based on surface yield and baseline emission flux. Values of these two parameters were quantified for targeted products and estimated for other semiquantified VOC signals, facilitating the inclusion of ozone/skin oil chemistry in indoor air quality models and providing new insights on skin oil chemistry.

Friction and neuroimaging of active and passive tactile touch

Two types of exploratory touch including active sliding and passive sliding are usually encountered in the daily life. The friction behavior of the human finger against the surface of objects is important in tactile perception. The neural mechanisms correlating to tribological behavior are not fully understood. This study investigated the tactile response of active and passive finger friction characterized with functional near-infrared spectroscopy (fNIRS). The friction test and fNIRS test were performed simultaneously using the tactile stimulus of polytetrafluoroethylene (PTFE) specimens. Results showed that the sliding modes did not obviously influence the friction property of skin. While three cortex regions were activated in the prefrontal cortex (PFC), showing a higher activation level of passive sliding. This revealed that the tribological performance was not a simple parameter to affect tactile perception, and the difference in cortical hemodynamic activity of active and passive touch was also recognised. The movement-related blood flow changes revealed the role of PFC in integrating tactile sensation although there was no estimation task on roughness perception.

Position-Induced Controllable Growth of Vertically Oriented Graphene Using Plasma-Enhanced Chemical Vapor Deposition.

Because the morphology of vertically oriented graphene (VG) synthesized by the plasma-enhanced chemical vapor deposition process determines the application performance of VG, morphology control is always an important part of the research. A concise correspondence between plasma and the morphology of VG is the key to investigating the morphology control of VG, which is still under research. In this study, a simple but effective parameter, position, is used to grow VG, by which the continuous morphology evolution of VG is realized. As a result, the morphology of VGs varies from a porous structure to a "wall-like" structure, thus leading to a continuous change in its hydrophobicity and thermal emissivity. An ultrahigh emissivity of 0.999 with superhydrophobicity is obtained among these VGs, showing great potential in the area of the black body and infrared thermometer. Finally, the states of active particles in plasma depending on the positions are diagnosed to investigate their relations with the morphology of VGs.

Development, validation, and prognostic evaluation of a risk score for long-term liver-related outcomes in the general population: a multicohort study

Liver cirrhosis is a major cause of death worldwide. Cirrhosis develops after a long asymptomatic period of fibrosis progression, with the diagnosis frequently occurring late, when major complications or cancer develop. Few reliable tools exist for timely identification of individuals at risk of cirrhosis to allow for early intervention. We aimed to develop a novel score to identify individuals at risk for future liver-related outcomes. We derived the LiverRisk score from an international prospective cohort of individuals from six countries without known liver disease from the general population, who underwent liver fibrosis assessment by transient elastography. The score included age, sex, and six standard laboratory variables. We created four groups: minimal risk, low risk, medium risk, and high risk according to selected cutoff values of the LiverRisk score (6, 10, and 15). The model's discriminatory accuracy and calibration were externally validated in two prospective cohorts from the general population. Moreover, we ascertained the prognostic value of the score in the prediction of liver-related outcomes in participants without known liver disease with median follow-up of 12 years (UK Biobank cohort). We included 14 726 participants: 6357 (43·2%) in the derivation cohort, 4370 (29·7%) in the first external validation cohort, and 3999 (27·2%) in the second external validation cohort. The score accurately predicted liver stiffness in the development and external validation cohorts, and was superior to conventional serum biomarkers of fibrosis, as measured by area under the receiver-operating characteristics curve (AUC; 0·83 [95% CI [0·78-0·89]) versus the fibrosis-4 index (FIB-4; 0·68 [0·61-0·75] at 10 kPa). The score was effective in identifying individuals at risk of liver-related mortality, liver-related hospitalisation, and liver cancer, thereby allowing stratification to different risk groups for liver-related outcomes. The hazard ratio for liver-related mortality in the high-risk group was 471 (95% CI 347-641) compared with the minimal risk group, and the overall AUC of the score in predicting 10-year liver-related mortality was 0·90 (0·88-0·91) versus 0.84 (0·82-0·86) for FIB-4. The LiverRisk score, based on simple parameters, predicted liver fibrosis and future development of liver-related outcomes in the general population. The score might allow for stratification of individuals according to liver risk and thus guide preventive care. European Commission under the H20/20 programme; Fondo de Investigación Sanitaria de Salud; Instituto de Salud Carlos III; Spanish Ministry of Economy, Industry, and Competitiveness; the European Regional Development Fund; and the German Ministry of Education and Research (BMBF).

Physicochemical considerations in the formulation development of silicone elastomer vaginal rings releasing 5-nitroimidazole drugs for the treatment of bacterial vaginosis

Bacterial vaginosis (BV) is a common dysbiosis of the human vaginal microbiota characterized by depletion of hydrogen peroxide and lactic acid-producing Lactobacillus bacteria and an overgrowth of certain facultative anaerobic bacteria. Although short-term cure rates following treatment with frontline antibiotics (most notably oral metronidazole (MNZ), clindamycin vaginal cream, and MNZ vaginal gel) are generally high, longer-term recurrence rates are an issue. The development of vaginal formulations offering continuous/sustained administration of antibiotic drugs over one or more weeks might prove useful in reducing recurrence. Here, we report the manufacture and preclinical testing of matrix-type vaginal rings offering sustained release of four 5-nitroimidazole antimicrobial drugs either being used clinically or having potential in treatment of BV – MNZ, tinidazole (TNZ), secnidazole (SNZ) and ornidazole (ONZ). All four drugs showed good compatibility with a medical-grade addition-cure silicone elastomer based upon thermal analysis experiments, and matrix-type rings containing 250 mg (3.125 %w/w) of each drug were successfully manufactured by reaction injection molding. 28-day in vitro drug release studies demonstrated root-time kinetics, with daily release rates of 25, 22, 9 and 6 mg/day½ for SNZ, ONZ, MNZ and TNZ, respectively. The rank order of drug release from rings correlated with the simple molecular permeability parameter S/V, where S is the measured drug solubility in silicone fluid and V is the drug molecular volume. The relative merits of SNZ and ONZ over MNZ (the current reference treatment) are discussed. The data support development of vaginal rings for sustained release of 5-nitroimidazole compounds for treatment of BV.

Early evaluation of waist-to-height ratio for the prediction of worsening acute pancreatitis.

The purpose of this study was to evaluate the association between the waist-to-height ratio (WHtR) and the aggravation of acute pancreatitis (AP). This prospective study included AP patients treated from May 2019 to December 2019 in the Department of Gastroenterology, the First Affiliated Hospital of Nanchang University. Receiver operating characteristic curves were constructed to determine the optimal threshold values for predicting the aggravation of AP. Risk factor analysis was performed via logistic regression analysis. Of 258 patients included in this study, 77 (29.84%) were diagnosed with mild acute pancreatitis, 120 (46.51%) with moderately severe acute pancreatitis, and 61 (23.64%) with severe acute pancreatitis (SAP). WHtR, waist circumference, weight, and body mass index were all associated with AP severity, and the highest area under the receiver operating characteristic value was observed for WHtR. The optimal threshold WHtR value for predicting SAP was 0.567. Multivariate logistic regression analysis identified WHtR ≥ 0.567 as independent risk factor for SAP. Moreover, the hospital stay was longer and intensive care unit admission rate was higher among AP patients with a WHtR ≥ 0.567. The WHtR was found to be closely related to the severity of AP and an independent risk factor for the aggravation of AP. This simple parameter can aid the early prediction of AP progression, thereby facilitating early intervention and improving patient outcomes.

Undoped junctionless EZ-FET: Model and measurements

The junctionless EZ-FET is a device with simplified architecture and processing. With only two lithography levels and using regular process steps, it enables fast electrical characterization of semiconductor films on insulators (SOI) with undoped source and drain. An electrical model reproducing the peculiar transfer characteristics of a junctionless EZ-FET is presented in this work. Based on this model, a simplified parameter extraction methodology is proposed and used to access the electrical properties of SOI structures (i.e. threshold voltage, mobility).

Touchdown dynamics of a liquid droplet on a patterned substrate: A generalized lumped parameter-based model

Droplet dynamics post-impingement on a solid surface is of immense technological importance due to its applicability in self-cleaning, anti-frosting, anti-biofouling, anti-icing, thermal management, and inkjet printing. While sustained droplet oscillation is desirable in some applications, a fast seizure of oscillations after the surface touchdown of the droplets is necessary for others. The post-impingement dynamics is a complex non-linear interaction of the fluid and solid properties and a common framework to characterize the short-time response of a droplet is provided here. We describe these post-impact droplet dynamics on a patterned surface in terms of lumped simple harmonic oscillator parameters. We delineate the effect of the substrate and fluid properties and attribute the same to one or more terms in the dynamical model of the oscillator, describing an analogy between the terms. Our analogy gives a universal mapping between the fluid–solid parameters and droplet dynamics, making it feasible to predict with accuracy the post-impact behavior. Here for the first time, we developed a simplified universal approach to predict the droplet oscillation dynamics impacting any solid surface for a broad range of fluid and solid properties and impingement conditions.

Predictive value of clinical and laboratory parameters in differentiating hypertensive pulmonary edema and acute pulmonary embolism.

Pulmonary embolism and acute pulmonary edema can often be confused. The aim of this study is to investigate the role of clinical and laboratory parameters in the differentiation of these two pathologies. Between March 2017 and December 2021, a total of 114 patients (51 patients with acute hypertensive pulmonary edema and 63 patients with pulmonary embolism) were included in the study. The medical history, hemodynamic findings, main echocardiographic data, and routine laboratory markers were recorded, retrospectively. Coronary artery disease (CAD), chronic obstructive pulmonary disease (COPD), and recent operation histories were found as more common concomitant disorders in the pulmonary embolism group (p = 0.001, p = 0.011, p = 0.001, respectively). In addition, patients with pulmonary embolism had a higher heart rate (p = 0.001) and systolic pulmonary artery pressure (SPAP) (p = 0.001) compared to those with hypertensive pulmonary edema, while patients with hypertensive pulmonary edema had higher blood pressure (p = 0.001). While significantly low albumin levels (p = 0.001) were found among blood parameters in the pulmonary embolism group, D-Dimer, fibrinogen, troponin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), creatine kinase myocardial band (CK-MB), red blood cell distribution width (RDW), and creatinine values were found to be higher (p < 0.001). The most sensitive (95%) and specific (92%) clinical parameter was the SPAP with a 19.00 mmHg cut-off level. Additionally, the most sensitive (98%) and specific (97%) laboratory parameter was the D-Dimer, with a 260.5 ng/mL cut-off level. Especially simple blood parameters such as D-dimer and echocardiographic evaluation of SPAP seem to be quite effective in distinguishing pulmonary embolism from hypertensive pulmonary edema.

Parameter identification for the non-associated flow rules representing corner effects through the equivalent tangential shear modulus reduction after abrupt strain-path change

Some specific plastic flow rules have been proposed to describe the experimental observations of “corner effects”—the apparent violation of the normality of plastic flow after abrupt strain-path change, and rotation of the plastic strain rate direction toward the strain rate direction. In this paper, a simple parameter identification scheme for these non-associated flow rules representing corner effects is proposed from the perspective of the equivalent tangential shear modulus reduction. The nonlinear tension–torsion loading experiments with abrupt strain-path changes were performed on tube specimens made of the aluminum alloy A6063-T5, and working conditions of different prestrains and different loading path changes were included. The finite element analysis was used to verify the rationality of the determined parameters and compare the performances of different plastic flow rules in predicting the non-normality of the plastic flow. The experimental and simulation results suggest that the non-associated flow rules can well predict the plastic flow when the determined parameters are used, with the rules proposed by Yoshida and Tsuchimoto (2018) and Zhang et al. (2022) yielding the most accurate predictions. At the same time, the equivalent tangential shear modulus is apparently reduced during the transient process of strain-path change without elastic unloading; however, it does not seem to decrease to near zero as reported before.

Characteristics of Anemia in the Elderly: Hospital-Based Study in West Java

Geriatric anemia can cause many problems and is a major health condition worldwide and in Indonesia. It is important to know the characteristics and prevalence of anemia among geriatrics in Indonesia, especially in West Java. By using simple hematology parameters to detect anemia in geriatrics, and then giving adequate treatment, morbidity, and mortality due to anemia may decrease in geriatrics. This study aimed to identify the type of anemia, etiology, age, gender, and prevalence of elderly patients with anemia in West Java. This was a cross-sectional study. Patients above 59 years old attending the geriatric clinic in Hasan Sadikin General Hospital and the geriatric community was included in this study to be evaluated for anemia, the characteristics of anemia (normocytic, microcytic, and macrocytic) based on MCV and MCHC, age group (&lt;=65 and &gt; 65 year old), and gender. Among 247 elderly patients, anemia was found in 33 patients (13.64%) and mostly found in females. Mostly represented as normochromic normocytic anemia (78.8%) and microcytic hypochromic anemia (21.2%), respectively. Individuals older than 65 years old were mostly presented with microcytic hypochromic anemia (66.7%). Meanwhile, normocytic normochromic anemia was more commonly found in individuals below 65 years old (12.1%). Anemia was commonly found in people older than 65 years old. The most common type of anemia in geriatrics in West Java was normocytic normochromic. Females experience anemia more than males.

Research on the dq-Axis Current Reaction Time of an Interior Permanent Magnet Synchronous Motor for Electric Vehicle

An interior permanent magnet synchronous motor (IPMSM) is a kind of drive motor with high power density that is suitable for electric vehicles. In this paper, the dq-axis current reaction time of IPMSM was investigated in order to improve the reaction time of the electric vehicle. Firstly, the mathematical model of the current-loop decoupling of IPMSM was presented. Secondly, the controller design of dq-axis current-loop decoupling of IPMSM was investigated by the methods of proportional integral (PI) and internal model control PI (IMC-PI). Thirdly, based on the methods of PI and IMC-PI, the influence of the inverter switching frequency on the dq-axis current reaction time of IPMSM was analyzed and simulated, and it was found that the inverter switching frequency only had a significant influence on the parameters set of the PI controller. Lastly, compared with the PI method, the results of the simulation and hardware experiment demonstrate that the dq-axis current reaction time of IPMSM was improved by the IMC-PI method, and the IMC-PI method had the advantage of simple parameters setting and was not influenced by the inverter switching frequency.

High‐Accuracy Classification of Radiation Waveforms of Lightning Return Strokes

AbstractA machine‐learning classifier for radiation waveforms of negative return strokes (RSs) is built and tested based on the Random Forest classifier using a large data set consisting of 14,898 negative RSs and 159,277 intracloud (IC) pulses with 3‐D location information. Eleven simple parameters including three parameters related with pulse characteristics and eight parameters related with the relative strength of pulses are defined to build the classifier. Two parameters for the evaluation of the classifier performance are also defined, including the classification accuracy, which is the percentage of true RSs in all classified RSs, and the identification efficiency, which is the percentage of correctly classified RSs in all true RSs. The tradeoff between the accuracy and the efficiency is examined and simple methods to tune the tradeoff are developed. The classifier achieved the best overall performance with an accuracy of 98.84% and an efficiency of 98.81%. With the same technique, the classifier for positive RSs is also built and tested using a data set consisting of 8,700 positive RSs. The classifier has an accuracy of 99.04% and an efficiency of 98.37%. By examining misclassified waveforms, we show evidence that some RSs and IC discharges produce special radiation waveforms that are almost impossible to correctly classify without 3‐D location information, resulting in a fundamental difficulty to achieve very high accuracy and efficiency in the classification of lightning radiation waveforms.

A simplified ANN-based evaluation method for creep sensitive girder bridge identification at preliminary design stage

Excessive deflection which exceeded expectations has been identified as one of the main problems contributing to long-term performance degradation of long-span girder bridges. Although the 3D refined finite element model of the full bridge can improve the prediction accuracy of long-term creep deformation, there is still a lack of efficient creep-sensitive structural judgment methods in the preliminary design stage. This study was thus intended to develop a new evaluation method and model to identify the possibility of excessive deflection will occur by utilizing simple structural design parameters, which contributed to new understandings of the creep deformation of bridge structural level. A finite element model database established by 20 long-span prestressed concrete girder bridges with actual project backgrounds was used for providing training, testing, and validation sample datasets for the artificial neural networks (ANN). The Back Propagation (BP) model was chosen for creating mappings among variables and results and solving complex problems with a fairly accurate prediction even without sufficient information. The indicator of deflection-span ratio difference between creep models was proposed as the key analysis factor. A case study was conducted to validate the effectiveness of the ANN model. The mean absolute error (MAE) between the results of the ANN model and FE analysis was 6.25%, which indicated a high consistency. The analysis of bridge design parameters using the ANN model revealed that it had a high risk of excessive deformation, which was consistent with the conclusion of the actual situation. Multiparameter sensitivity analysis results from the model also suggest that the side-span ratio, the main span, and the deflection caused by the pavement are the most three significant impacts compared to different input variables in this model. Based on the results, it can be concluded that the performance of the ANN-based technique can predict possible excessive creep problems in advance.

A General One-Step Synthesis of Alkanethiyl-Stabilized Gold Nanoparticles with Control over Core Size and Monolayer Functionality.

In spite of widespread interest in the unique size-dependent properties and consequent applications of gold nanoparticles (AuNPs), synthetic protocols that reliably allow for independent tuning of surface chemistry and core size, the two critical determinants of AuNP properties, remain limited. Often, core size is inherently affected by the ligand structure in an unpredictable fashion. Functionalized ligands are commonly introduced using postsynthesis exchange procedures, which can be inefficient and operationally delicate. Here, we report a one-step protocol for preparing monolayer-stabilized AuNPs that is compatible with a wide range of ligand functional groups and also allows for the systematic control of core size. In a single-phase reaction using the mild reducing agent tert-butylamine borane, AuNPs that are compatible with solvents spanning a wide range of polarities from toluene to water can be produced without damaging reactive chemical functionalities within the small-molecule surface-stabilizing ligands. We demonstrate that the rate of reduction, which is easily controlled by adjusting the period over which the reducing agent is added, is a simple parameter that can be used irrespective of the ligand structure to adjust the core size of AuNPs without broadening the size distribution. Core sizes in the range of 2-10 nm can thus be generated. The upper size limit appears to be determined by the nature of each specific ligand/solvent pairing. This protocol produces high quality, functionally sophisticated nanoparticles in a single step. By combining the ability to vary size-related nanoparticle properties with the option to incorporate reactive functional groups at the nanoparticle-solvent interface, it is possible to generate chemically reactive colloidal building blocks from which more complex nanoparticle-based devices and materials may subsequently be constructed.

Evaluation of simple diagnostic parameters in acute kidney injury in hospitalized patients—diagnostic recommendations for non-nephrologists

Acute kidney injury (AKI) is very common in hospitalized patients, affecting patient’s mortality and morbidity. Major causes are prerenal AKI and acute tubular necrosis (ATN). Even though a variety of parameters/indices exist, their reliability and practicability are controversial: in fact, there is a need for a simple diagnostic approach for AKI in in-patients with parameters easily obtained in any hospital. The objective of the study was: (1) to assess reliability of simple laboratory parameters/indices to differentiate pre-/intrarenal AKI; (2) to evaluate the most reliable and feasible parameters/indices; and (3) to identify the possible impact of confounding factors. Retrospectively, in-patients with AKI hospitalized in 2020 in a university nephrology department were included. Spot urine and 24-h collection urine was analyzed with urine sodium (UNa), urine specific gravity (USG), fractional excretion of sodium (FENa), fractional excretion of urea (FEUrea), urine osmolality (UOsm), urine to plasma creatinine ratio (UCr/PCr) and renal failure index (RFI). Overall, 431 patients were included. UNa, UOsm, USG and RFI showed high specificity > 85% for prerenal AKI, UNa and RFI provided good specificity for ATN. Loop diuretics, ACE inhibitors/AT1 blockers or pre-existing chronic kidney disease had no impact. In patients with AKI, UNa, USG and RFI: (1) proved to be very specific for prerenal AKI and showed high sensitivity for ATN; (2) can be easily determined using serum and spot urine; and (3) are not confounded by medication or comorbidities. These parameters/indices are helpful to identify the aetiology of AKI and to guide therapy, thereby improving patients’ safety and outcome.

A new scoring system with simple preoperative parameters as predictors of early recurrence of pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) often recurs early after radical resection, and such early recurrence (ER) is associated with a poor prognosis. Predicting ER is useful for determining the optimal treatment. One hundred fifty-three patients who underwent pancreatectomy for PDAC were divided into an ER group (n = 54) and non-ER group (n = 99). Clinicopathological factors were compared between the groups, and the predictors of ER and prognosis after PDAC resection were examined. The ER group had a higher platelet count, higher platelet-to-lymphocyte ratio (PLR), higher preoperative CA19-9 concentration, higher SPan-1 concentration, larger tumor diameter, and more lymph node metastasis. The receiver operating characteristic (ROC) curve analysis identified cut-off values for PLR, carbohydrate antigen 19-9 (CA19-9), SPan-1, and tumor diameter. In the multivariate analysis, a high PLR, high CA19-9, and tumor diameter of >3.1 cm were independent predictors of ER after resection (all p < 0.05). When the parameter exceeded the cut-off level, 1 point was given, and the total score of the three factors was defined as the ER prediction score. Next, our new ER prediction model using PLR, CA19-9 and tumor diameter (Logit(p) = 1.6 + 1.2 × high PLR + 0.7 × high CA19-9 + 0.5 × tumor diameter > 3.1cm) distinguished ER with an area under the curve of 0.763, a sensitivity of 85.2%, and a specificity of 55.6%. ER after resection of PDAC can be predicted by calculation of a score using the preoperative serum CA19-9 concentration, PLR, and tumor diameter.