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Abstract Sepsis-associated encephalopathy (SAE) is a frequent and severe complication in septic patients, characterized by diffuse brain dysfunction resulting from systemic inflammation. Accurate prediction of long-term mortality in these patients is critical for improving clinical outcomes and guiding treatment strategies. We conducted a retrospective cohort study using the MIMIC IV database to identify adult patients diagnosed with SAE. Patients were randomly divided into a training set (70%) and a validation set (30%). Least absolute shrinkage and selection operator regression and multivariate logistic regression were employed to identify significant predictors of 1-year mortality, which were then used to develop a prognostic nomogram. The model’s discrimination, calibration, and clinical utility were assessed using the area under the receiver operating characteristic curve (AUC), calibration plots, and decision curve analysis, respectively. A total of 3,882 SAE patients were included in the analysis. The nomogram demonstrated strong predictive performance with AUCs of 0.881 (95% CI: 0.865, 0.896) in the training set and 0.859 (95% CI: 0.830, 0.888) in the validation set. Calibration plots indicated good agreement between predicted and observed 1-year mortality rates. The decision curve analysis showed that the nomogram provided greater net benefit across a range of threshold probabilities compared to traditional scoring systems such as Glasgow Coma Scale and Sequential Organ Failure Assessment. Our study presents a robust and clinically applicable nomogram for predicting 1-year mortality in SAE patients. This tool offers superior predictive performance compared to existing severity scoring systems and has significant potential to enhance clinical decision-making and patient management in critical care settings.

Using first principles calculations based on the density functional theory and the structural, electronic, and optical properties of the substitution of K elements by Li+, Na+, Mg2+, and Ca2+ in KH2PO4 (KDP) crystals are investigated in depth. This study provides insight into the structural properties of crystals, with particular emphasis on internal chemical bonding effects. It further discusses the impact of H and O defects on the bandgap and optical properties of KDP crystals. Detailed analysis of structural characteristics and comprehensive examination of the effects of chemical bonds contribute to a deeper understanding of the effects of defects on the lattice and electronic structure, revealing potential alterations and their underlying mechanisms. Our investigation focuses on the regulatory role of different defects on the bandgap and optical properties. These comprehensive analyses provide a more thorough understanding of the impact of defects on the properties of KDP crystals, establishing an essential research foundation for further exploration of nonlinear optics crystal potential applications.

Abstract Stroke is a major healthcare problem worldwide, particularly in the elderly population. Despite limited research on the development of prediction models for mortality in elderly individuals with ischemic stroke, our study aimed to address this knowledge gap. By leveraging data from the Medical Information Mart for Intensive Care IV database, we collected comprehensive raw data pertaining to elderly patients diagnosed with ischemic stroke. Through meticulous screening of clinical variables associated with 28-day mortality, we successfully established a robust nomogram. To assess the performance and clinical utility of our nomogram, various statistical analyses were conducted, including the concordance index, integrated discrimination improvement (IDI), net reclassification index (NRI), calibration curves and decision curve analysis (DCA). Our study comprised a total of 1259 individuals, who were further divided into training (n = 894) and validation (n = 365) cohorts. By identifying several common clinical features, we developed a nomogram that exhibited a concordance index of 0.809 in the training dataset. Notably, our findings demonstrated positive improvements in predictive performance through the IDI and NRI analyses in both cohorts. Furthermore, calibration curves indicated favorable agreement between the predicted and actual incidence of mortality (P > 0.05). DCA curves highlighted the substantial net clinical benefit of our nomogram compared to existing scoring systems used in routine clinical practice. In conclusion, our study successfully constructed and validated a prognostic nomogram, which enables accurate short-term mortality prediction in elderly individuals with ischemic stroke.

Background: Limited clinical prediction models exist to assess the likelihood of acute kidney injury (AKI) occurrence in ischemic stroke individuals. In this retrospective study, our aim was to construct a nomogram that utilizes commonly available clinical features to predict the occurrence of AKI during intensive care unit hospitalization among this patient population. Methods: In this study, the MIMIC-IV database was utilized to investigate potential risk factors associated with the incidence of AKI among ischemic stroke individuals. A predictive nomogram was developed based on these identified risk factors. The discriminative performance of the constructed nomogram was assessed. Calibration analysis was utilized to evaluate the calibration performance of the constructed model, assessing the agreement between predicted probabilities and actual outcomes. Furthermore, decision curve analysis (DCA) was employed to assess the clinical net benefit, taking into account the potential risks and benefits associated with different decision thresholds. Results: A total of 2089 ischemic stroke individuals were included and randomly allocated into developing (n = 1452) and verification cohorts (n = 637). Risk factors for AKI incidence in ischemic stroke individuals, determined through LASSO and logistic regression. The constructed nomogram had good performance in predicting the occurrence of AKI among ischemic stroke patients and provided significant improvement compared to existing scoring systems. DCA demonstrated satisfactory clinical net benefit of the constructed nomogram in both the validation and development cohorts. Conclusions: The developed nomogram exhibits robust predictive performance in forecasting AKI occurrence in ischemic stroke individuals.

In this paper, the Laguerre–Gaussian (LG) mode superposition is obtained by using the technology of double-end off-axis pumping Tm:YLF crystal, and the LG mode superposition is achieved by combining the extra-cavity conversion method. The impact of changing the off-axis distance on the order of Hermite–Gaussian (HG) mode and the topological charge of LG mode is studied. The results show that when the off-axis distance of the pump source at both ends is tuned, when the off-axis distance is in the range of 260 μm~845 μm, the single-ended 0~10 order HG mode can be obtained. Subsequently, the mode converter is placed to obtain the LG mode beam, and the double-end simultaneously pumps the crystal to obtain the superimposed LG mode. The tuning off-axis quantity changes the topological charge number. When P = 0, l1=l2, the superimposed LG mode is a single-ring spot, and the vortex beam center’s dark hollow area increases with the topological charge number. When P = 0, l1=−l2, the superimposed LG mode is a petal-like spot. The number of petals differs from the topological charges of two opposite numbers. Finally, in the case of changing the topological charge number of the double-ended LG mode, the output of the vortex array structured beams of the tuning mode order 1.9 μm Tm:YLF is completed in the case of conversion and superposition.

Paint removal is an essential process in the industrial field. Laser technology provides an effective method of paint removal to replace traditional mechanical and chemical methods. This paper establishes a continuous wave (CW) laser thermal paint removal model based on heat conduction theory and Arrhenius’ law. The paint stripping process of epoxy paint film on the surface of 6061 aluminum alloy via CW laser was studied through simulation and experiment. We found that the carbonization of the paint film during the CW laser paint removal process will inhibit the laser paint removal process. Therefore, the paint removal efficiency of the CW laser is limited. The depth of CW laser paint removal increases linearly with the CW laser power density. However, during the CW laser paint removal process, due to the pyrolysis of the paint film and the reflection of the laser by the substrate, the surface temperature of the material first increases and then decreases. In addition, after laser paint removal, the surface roughness of the material after paint removal is reduced due to the melting of the base material. The model established in this article can provide a theoretical reference for studying the CW laser paint removal process.

Laser paint removal is a new cleaning technology that mainly removes paint through thermal ablation and mechanical stripping mechanisms. This paper established a thermal-mechanical coupling laser removal model of paint based on the heat conduction equation, Newton’s second law, and Fabbro’s theory. The removal process of epoxy resin paint film on an aluminum alloy surface via a nanosecond pulsed laser was studied using finite element simulations and experimental measurements. The simulation and experimental results show that the nanosecond pulse laser’s primary paint removal mechanism is the mechanical stripping caused by thermal stress and plasma shock. The laser paint removal threshold is 1.4 J/cm2. In addition, due to the different generation times of plasma shock and thermal stress, the mutual superposition of stress waves occurs in the material. This results in a discrepancy between the actual and thermal stress differences. Moreover, the thermal stress difference causes the maximum actual stress difference to fluctuate. The simulation model established in this paper can provide a reference for studying the thermal-mechanical coupling process of laser paint removal.

BackgroundThis study aimed to establish and validate an easy-to-use nomogram for predicting long-term mortality among ischemic stroke patients.MethodsAll raw data were obtained from the Medical Information Mart for Intensive Care IV database. Clinical features associated with long-term mortality (1-year mortality) among ischemic stroke patients were identified using least absolute shrinkage and selection operator regression. Then, binary logistic regression was used to construct a nomogram, the discrimination of which was evaluated by the concordance index (C-index), integrated discrimination improvement (IDI), and net reclassification index (NRI). Finally, a calibration curve and decision curve analysis (DCA) were employed to study calibration and net clinical benefit, compared to the Glasgow Coma Scale (GCS) and the commonly used disease severity scoring system.ResultsPatients who were identified with ischemic stroke were randomly assigned into developing (n = 1,443) and verification (n = 646) cohorts. The following factors were associated with 1-year mortality among ischemic stroke patients, including age on ICU admission, marital status, underlying dementia, underlying malignant cancer, underlying metastatic solid tumor, heart rate, respiratory rate, oxygen saturation, white blood cells, anion gap, mannitol injection, invasive mechanical ventilation, and GCS. The construction of the nomogram was based on the abovementioned features. The C-index of the nomogram in the developing and verification cohorts was 0.820 and 0.816, respectively. Compared with GCS and the commonly used disease severity scoring system, the IDI and NRI of the constructed nomogram had a statistically positive improvement in predicting long-term mortality in both developing and verification cohorts (all with p

The mechanism of fluorescence detection of diethyl chlorophosphate (DCP) based on 2-substituted benzothiazole (BZ-DAM) was studied by a theoretical calculation method. It should not be ignored that both the BZ-DAM and the detection product BZ-CHO have two excited-state intramolecular proton transfer (ESIPT) channels. Density functional theory (DFT) and time-dependent DFT (TDDFT) theory were used to study the photophysical mechanism of two compounds in two channels in (acetonitrile) ACN solvent, and the temperature dependence of the two channels was given. Channel 1 is more likely to exist at low temperatures and channel 2 is more likely to exist at high temperatures. By theoretical analysis of the constructed potential energy curve, the hydrogen bond energy and electron-hole analysis, we confirmed that both molecules undergo ESIPT and intramolecular charge transfer (ICT) processes in channel 1 and ESIPT and twisted intramolecular charge transfer (TICT) coupling processes in channel 2. The formation of product BZ-CHO molecules led to a significant fluorescence blue-shift phenomenon and inhibited the ICT process, which confirmed that BZ-DAM could be used as a fluorescence probe for fluorescence detection. We sincerely hope that this work will not only help to clarify the excited-state dynamics behavior of the BZ-DAM probe but also provide a new idea for designing and optimizing a new chemical dosimeter.

The variation of shock-wave velocity with time induced by a millisecond-nanosecond combined pulse laser (CPL) on silicon is investigated. The convolution neural network (CNN) is used to predict the shock-wave velocity induced by a single ns laser and CPL with a ns laser energy density of 6, 12 and 24 J/cm2, ms laser energy density of 0 and 226.13 J/cm2, and pulse delay of 0, 0.4 and 0.8 ms. The four-layer CNN model was applied, ns laser energy density, ms laser energy density, pulse delay and time were set as the input parameter, while the shock-wave velocity was set as the output parameter. The correlation coefficient (R2), mean absolute error (MAE) and root mean square error (RMSE) of the CNN model on the test data set was 0.9865, 3.54 and 3.01, respectively. This indicated that the CNN model shows a high reliability in the prediction of CPL-induced shock-wave velocity with limited experimental data.

We create a rate equation theoretical model of a continuous-wave end-pumped Pr3+:YLF SLM laser that characterizes the output properties of a single-longitudinal-mode (SLM) green laser. After inserting two Fabry–Perot (F–P) etalons with thicknesses of 0.3 mm and 0.5 mm and angles of 1.42° and 0.69° into the cavity, a single-longitudinal-mode green laser was generated. The maximum output power in single-longitudinal mode was 183 mW. The maximum absorbed pump power was 6.2 W. The corresponding linewidth is about 18 MHz. This work presents a simple method for generating a single-longitudinal-mode laser in the green spectral region, providing a practical approach for various green-laser-related applications.

This article describes a master oscillator and power amplifier (MOPA) system with a single longitudinal mode (SLM) and high-repetition-frequency Pr3+:YLF active medium that was end-pumped by two 444 nm laser diodes. The Pr3+:YLF MOPA laser system produced a maximum pulse energy of 13.5 μJ with a pulse width of 130.2 ns at a pulse repetition frequency of 20 kHz, translating to a peak power of around 103.7 W. The Pr3+:YLF MOPA laser system’s output wavelength was 639.7 nm, and the line-width of its laser spectra was roughly 168 MHz. Additionally, at the highest output level, the laser beam quality did not decrease much due to amplification.

A dual-wavelength alternating electro-optic (EO) Q-switched laser operating at 1064 and 1319 nm is designed, which takes the structure of double the gain crystals and a single EO modulator with the common Q-switching bias voltage (CQBV). The output characteristics of alternating dual-wavelength pulse lasers are studied via simulations and experiments. The results show that the energy ratio of the two lasing wavelengths can be controlled by changing the CQBV. This is because the CQBV affects the loss of two resonators, 1064 and 1319 nm, at the same time. The gain–loss relationship in the dual-wavelength laser resonators can be controlled by changing the CQBV in a certain range.

The high-speed development and applications of modern automation production, high-capacity high-speed telecommunications, and aerospace are promoting the detection and sensing of various electric fields. In this article, we investigate a three-dimensional high-frequency electric-field sensor with a barium titanate (BaTiO3) crystal film waveguide due to an extremely high electrooptic (EO) coefficient, r51 = r42. First, the dependences of the lowest electric field, namely, the sensitivity of the sensor to the electric field and the most sensitive direction, are modeled through the nonlinear EO modulation equation of the EO coefficient, r51, and birefringence, beo, with an embedded waveguide/electrode regime. Then, for the given r51/beo values, broad dependences of device sensitivities are numerically simulated with a broad design of electrodes. Thus, as a result, for a given BaTiO3 crystal thin-film having an EO coefficient value of r51 = ≥500 pm/V and an absolute beo value of ≤0.01, the lowest electric field of tens of kilovolt/m level and the electric-field direction could also be detected with a sensing length of millimeters. Meanwhile, the frequency dependence of a scattering parameter of the microwave sensor antenna, S11, is simulated and the frequency point of 2.15 GHz for the highest gain antenna is found.

Abstract Background Sepsis-associated encephalopathy (SAE) is a common complication of sepsis that may result in worse outcomes. This study was designed to determine the epidemiology, clinical features, and risk factors of SAE. Methods This was a retrospective study of all patients with sepsis who were admitted to the Critical Care Medicine Department of Hangzhou First People’s Hospital Affiliated with Zhejiang University School of Medicine from January 2015 to December 2019. Results A total of 291 sepsis patients were screened, and 127 (43.6%) were diagnosed with SAE. There were significant differences in median age, proportion of underlying diseases such as hypertension, Sequential Organ Failure Assessment (SOFA) score, Acute Physiology and Chronic Health Evaluation II (APACHE II) score, gastrointestinal infections, detection rate of Enterococcus, and 28-day mortality between the SAE and non-SAE groups. Both the SOFA score and APACHE II score were independent risk factors for SAE in patients with sepsis. All 127 SAE patients were divided into survival and non-survival groups. The age, SOFA score, and APACHE II score were independently associated with 28-day mortality in SAE patients. Conclusion In the present retrospective study, nearly half of patients with sepsis developed SAE, which was closely related to poor outcomes. Both the SOFA score and APACHE II score were independent risk factors for predicting the occurrence and adverse outcome of SAE.

Abstract Background Hypertriglyceridemia-induced acute pancreatitis during pregnancy (HTG-APP) is a rare but severe disease with high maternal-fetal mortality risk, which constitutes a systemic inflammatory process accompanied by thrombosis and bleeding disorders. However, the role of mean platelet volume (MPV) in HTG-APP remains unclear. Methods In the retrospective study, we collected 45 patients with HTG-APP as the HTG-APP group and 49 pregnant females with hypertriglyceridemia as the control group. MPV and other relevant variables at onset and remission were collected and compared. Results MPV were significantly higher in the HTG-APP group than in the control group (P

The propagating evolution of shock waves induced by a nanosecond pulse laser (ns laser) irradiating silicon assisted by a millisecond pulse laser (ms laser) is investigated experimentally. A numerical model of 2D axisymmetric two-phase flow is established to obtain the spatial distribution of shock wave velocity. Two types of shock wave acceleration phenomenon are found. The mechanism of the shock wave acceleration phenomenon is discussed. The experimental and numerical results show that the initial stage of ms laser-induced plasma can provide the initial ions to increase probability of collision ionization between free electrons and vapor atoms. The velocity of the ns laser-induced shock wave is accelerated. Furthermore, the ms laser-induced plasma as the propagation medium can also accelerate the ns laser-induced shock wave. The shock wave acceleration methods obtained in this paper can promote the development of laser propulsion technology.

This paper presents an external-cavity dual-wavelength mid-infrared multiple optical parametric oscillator based on a single MgO:APLN crystal, which is pumped by a pulsed 1.064 μm laser. The output power and beam qualities of parametric lasers at different repetition rates and transmittance were studied. When the pump power of the 1.064 μm laser was 34.5 W, the repetition rate was 63 kHz, the maximum output powers of 2.79 W@3.30 μm and 4.92 W@3.84 μm were obtained with the transmittance T = 60%@1.57 μm, corresponding to optical–optical conversion efficiencies of 8.1% and 14.3%, respectively. Meanwhile, the beam qualities of two mid-infrared laser beams were effectively optimized and the pulse widths of 9.72 ns@3.30 μm and 9.67 ns@3.84 μm were obtained synchronously.

Carbon fiber reinforced polymers (CFRP) are a widely used composite material applied in both commercial and industrial utilization. Based on the heat conduction theory, a theoretical model for the temperature rise of braided CFRP irradiated by long pulse laser is established in this work, and the time required for the maximum temperature rise of CFRP (with different thicknesses) to be acted by long pulse laser with different energy densities and pulse widths is simulated. At the same time, the temperature rise experiment and damage morphology of a long pulse laser with braided CFRP were carried out. The theoretical simulation results are in good agreement with the experimental results, which verifies the correctness of the theoretical model. The results of this paper will provide a theoretical basis for laser processing of CFRP.

In this study, different coatings (gray epoxy primer, white epoxy varnish and red alkyd paint) of 7075 aluminum alloy are cleaned with a 500 W continuous-wave (CW) fiber laser. We analyzed the influence of the laser power density on the temperature evolution and target surface morphology. Under the condition of continuous laser irradiation for 1 s, the experimental results indicated that the suitable cleaning thresholds of epoxy primer, epoxy primer and epoxy varnish, as well as epoxy primer, epoxy varnish and alkyd paint were 177.74, 192.89 and 147.44 W/mm2. The results show that the cleaning threshold of thicker three-layer paint target was smaller than the single-layer paint layer, and we analyze the mechanism of this phenomenon.

A continuous-wave 1.57 and 3.84 μm intracavity multiple optical parametric oscillator based on a single MgO:APLN crystal is reported for the first time. The synchronized dual-wavelength laser is obtained by using a folded-type double cavity, which consists of a 1064-nm resonator and a multiple optical parametric oscillator. With T = 10% at 1.47 and 3.3 μm output couplers, maximum output powers of 3.13 W at 1.57 μm and 0.85 W at 3.84 μm are obtained, corresponding to slope efficiencies of 6.8% and 1.9%, respectively. The power stabilities are better than 1.8% and 3% at the maximum output power in half an hour.

The application of laser fabrication of fiber-reinforced polymer (FRP) has an irreplaceable advantage. However, the effect of the plasma generated in laser fabrication on the damage process is rarely mentioned. In order to further study the law and mechanism of laser processing, the laser process was measured. CFRP and GFRP materials were damaged by a 1064 nm millisecond pulsed laser. Moreover, the propagation velocity and breakdown time of plasma plume were compared. The results show that GFRP is more vulnerable to breakdown than CFRP under the same conditions. In addition, the variation of plasma plume and material surface temperature with the number of pulses was also studied. The results show that the variation trend is correlated, that is, the singularities occur at the second pulse. Based on the analysis of experimental phenomena, this paper provides guidance for plasma phenomena in laser processing of composite materials.

The generation of droplets is one of the most critical steps in the droplet digital polymerase chain reaction (ddPCR) procedure. In this study, the mechanism of droplet formation in microchannel structure and factors affecting droplet formation were studied. The physical field of laminar two-phase flow level was used to simulate the process of droplet generation through microfluidic technology. The effect of the parameters including flow rate, surface tension, and viscosity on the generated droplet size were evaluated by the simulation. After that, the microfluidic chip that has the same dimension as the simulation was then, fabricated and evaluated. The chip was made by conventional SU-8 photolithography and injection molding. The accuracy of the simulation was validated by comparing the generated droplets in the real scenario with the simulation result. The relative error (RE) between experimentally measured droplet diameter and simulation results under different flow rate, viscosity, surface tension and contact angle was found less than 3.5%, 1.8%, 1.4%, and 1.2%, respectively. Besides, the coefficient of variation (CV) of the droplet diameter was less than 1%, which indicates the experimental droplet generation was of high stability and reliability. This study provides not only fundamental information for the design and experiment of droplet generation by microfluidic technology but also a reliable and efficient investigation method in the ddPCR field.