A study on rapid simulation of mine roadway fires for emergency decision-making.

In traditional mine fire simulation, the FDS simulation software has been verified by large-scale and full-size fire experiments. The resulting calculations closely align with real-world scenarios, making it a valuable tool for simulating mine fires. However, when a fire occurs in a mine, utilizing FDS software to predict the fire situation in the mine entails a sequence of steps, including modeling, environmental parameter setting, arithmetic, and data processing, which takes time in terms of days, thus making it difficult to meet the demand for emergency decision-making timelines. To address the need for rapid predictions of mine tunnel fire development, a method for swiftly estimating environmental parameters and the concentration of causative factors at various times and locations post-fire has been devised. FDS software was employed to simulate numerous roadway fires under diverse conditions. Parameters such as fire source intensity, roadway cross-sectional area, roadway wind speed, roadway inclination angle, time, and others were utilized as the input layer for a neural network. In contrast, wind flow temperature, carbon monicide (CO) concentration, fire wind pressure, visibility, and others were designated as the output layer for training the neural network model. This approach established a fire prediction model to resolve issues related to time-consuming numerical simulations and the inability to provide a rapid response to disaster emergencies. The trained neural network model can instantaneously predict the environmental parameters and concentrations of the causative factors at different times and locations. The model exhibits an average relative error of 12.12% in temperature prediction, a mean absolute error of 0.87 m for visibility, a mean absolute error of 3.49 ppm for CO concentration, and a mean absolute error of 16.78 Pa for fire wind pressure. Additionally, the mean relative error in density is 2.9%. These predictions serve as crucial references for mine fire emergency decision-making.

Association of GNRI, NLR, and FT3 with the Clinical Prognosis of Older Patients with Heart Failure.

We investigated the relationship between heart failure and malnutrition, inflammation, and thyroid function and evaluated the predictive potential of these markers for major adverse cardiovascular events (MACEs).This study included 454 patients aged over 65 years with heart failure as the main diagnosis for 18 months follow-up. The nutritional and inflammatory status were assessed using the geriatric nutritional risk index (GNRI) and neutrophil-to-lymphocyte ratio (NLR), respectively. Free triiodothyronine (FT3) in thyroid hormone was divided into low, medium, and high FT3. Older patients were divided into two groups according to whether they had endpoint events. Differences in nutrition, inflammation, and thyroid hormone were compared between the two groups. The prognostic value of the combination of GNRI, NLR, and FT3 was analyzed.Older patients in the MACEs (+) group had lower levels of GNRI and FT3 and higher NLR than those in the MACEs (-) group. Low GNRI and FT3 and high NLR were associated with MACEs (P < 0.05). Multivariate Cox regression analysis revealed that low FT3 was an independent predictor of MACEs (P < 0.05). Regardless of how the LVEF changed, when patients had low GNRI and FT3 and high NLR risk factors, the risk of developing MACEs significantly increased. The addition of GNRI, NLR, and FT3 to the basic model significantly increased the predictability of MACEs in patients.Low GNRI and FT3 and high NLR were associated with MACEs. The combination of GNRI, NLR, and FT3 increased the predictive value of MACEs in older patients with heart failure.

Cardiorenal Syndrome in COVID-19 Patients: A Systematic Review.

Aims: To perform a systematic review assessing the clinical manifestations and outcomes of cardiorenal syndrome or the presence of both cardiac and renal complications in the 2019 coronavirus disease (COVID-19) patients. Methods: All relevant studies about cardiorenal syndrome or both cardiac and renal complications in COVID-19 patients were retrieved on PUBMED, MEDLINE, and EMBASE from December 1, 2019 to February 20, 2022. Results: Our search identified 15 studies including 637 patients with a diagnosis of cardiorenal syndrome or evidence of both cardiac and renal complications followingSARS-CoV-2 infection. They were male predominant (66.2%, 422/637), with a mean age of 58 years old. Cardiac complications included myocardial injury (13 studies), heart failure (7 studies), arrhythmias (5 studies), or myocarditis and cardiomyopathy (2 studies). Renal complications manifested as acute kidney injury with or without oliguria. Patients with cardiorenal injury were often associated with significantly elevated levels of inflammatory markers (CRP, PCT, IL-6). Patients with a diagnosis of cardiorenal syndrome or evidence of both cardiac and renal complications had more severe disease and poorer prognosis (9 studies). Conclusion: The presence of either cardiorenal syndrome or concurrent cardiac and renal complications had a significant impact on the severity of the disease and the mortality rate among patients with COVID-19 infection. Therefore, careful assessment and management of potential cardiac and renal complications in patients with COVID-19 infection are important to improve their outcomes.

Novel KCNJ10 Compound Heterozygous Mutations Causing EAST/SeSAME-Like Syndrome Compromise Potassium Channel Function.

Inwardly rectifying K+ channel 4.1 (Kir4.1), encoded by KCNJ10, is a member of the inwardly rectifying potassium channel family. In the brain, Kir4.1 is predominant in astrocytic glia and accounts for the spatial buffering of K+ released by neurons during action potential propagation. A number of studies have shown that mutations in KCNJ10 are associated with SeSAME/EAST syndrome, which is characterized by seizures, ataxia, sensorineural deafness, and electrolyte imbalance. Herein, we identified two siblings presenting with seizures and motor delays in one outbred kindred. Customized targeted-exome sequencing showed that both affected siblings are compound heterozygous for two KCNJ10 missense mutations (NM_002241.4: c.601G > A: p.A201T and c.626T > C: p.I209T). Prediction tools suggested that both amino acid substitutions were deleterious or disease causing. Further functional studies showed that Chinese hamster ovary (CHO) cells expressing either A201T and/or I209T Kir4.1 channels exhibited lower K+ currents, indicating compromised Kir4.1 biological function. Intriguingly, the A201T but not I209T mutation decreased total and cell surface Kir4.1 levels. Kir4.1 channels with the A201T mutation were unstable and degraded through lysosomal pathway. In conclusion, these data indicated that both A201T and I209T mutations disrupt Kir4.1 activity and are the cause of SeSAME/EAST-like syndrome in the siblings.

High-speed multi-pass tunable diode laser absorption spectrometer based on frequency-modulation spectroscopy.

We report a multi-pass tunable diode laser absorption spectrometer based on the frequency-modulation spectroscopy (FMS) technique. It has the advantage of high scan speed and is immune to the etalon effect. A multi-pass Herriott-type cell was used in the spectrometer to increase the effective optical length to 17.5 m and compact the physical dimensions of the spectrometer to 60×30×30 cm3. Noise due to low-frequency fluctuation of the laser power and the 1/f noise in the rapid detection are sufficiently reduced by FMS. Interference fringes are effectively suppressed when the modulation frequency equals to integer or half-integer times of their free spectral range (FSR). An absorption line of C2H2 around 1.51 µm was recorded with the spectrometer to demonstrate its capabilities. The response frequency of the spectrometer is up to 100 kHz (10 µs) thanks to the high modulation frequency of FMS. The detection sensitivity of the spectrometer is about 240 ppb (3σ) at 100 kHz measurement repetition rate. The amplitude of the absorption signal is highly linear to the C2H2 concentration in the range of 300 ppb -100 ppm. Based on the Allan variation, the detection limit was determined to be 18 ppb with a detection time of 166 s.

Effect of hepatic steatosis on the progression of chronic hepatitis B: A prospective cohort and in vitro study.

AIM: To characterize the effect of hepatic steatosis (HS) on the progression of chronic hepatitis B. METHODS: A total of 162 chronic hepatitis B (CHB) patients confirmed by liver biopsy were involved in this study. All subjects were prospectively followed-up for 5 years in real-life clinical practice. Fibrosis stage was determined using aspartate aminotransferase-to-platelet ratio index (APRI). The end-point was cirrhosis, liver cancer or death. The effects of steatosis on the biological behavior of hepatocellular carcinoma cells were investigated using oleic acid-induced lipid accumulation in HepG2, HLE, PLC, and SMMC-7721 cells. RESULTS: Mean age, body mass index, and serum cholesterol were significantly higher in CHB patients with HS than those without HS at baseline (p< 0.05). The APRI was lower in patients without HS at baseline (p<0.05). Compared to patients with HS, APRI of patients without HS decreased significantly during the follow-up period (p<0.05). The 5-year cumulative incidence of cirrhosis were 4.17% and 5.19% in patients without and with HS, respectively (p>0.05). The multivariate analysis showed that older (RR 1.07, 95% CI 0.996-1.149, p = 0.065) and S3 stage of liver fibrosis (RR 3.50, 95% CI 0.812-15.117, p=0.093) were risk factors for the progression to cirrhosis. In vitro, cell steatosis promoted proliferation and migration of HCC cells and conferred cell cycle at S phase. CONCLUSION: The older and S3 stage of fibrosis may be risk factors for progression to cirrhosis in CHB patients with HS. HS may aggravate liver disease, promoting HCC progression.

High-resolution observation and analysis of the I2+ A2Π(3/2,u)-X2Π(3/2,g) system.

Rotationally resolved absorption spectra of I(2)(+) were recorded in 12,065-13,062 cm(-1) region by employing optical heterodyne velocity modulation absorption spectroscopy. In total, 4054 lines were assigned to 24 bands in the A(2)Π(3/2,u)-X(2)Π(3/2,g) system spanning the vibrational levels υ'' = 1-4 and υ(n)' = 11-19. The assigned lines were globally fitted and an error of 0.003 cm(-1) was obtained. Rotational constants, B(υ), were used to derive equilibrium parameters B(e)'' = 0.03977725(77) cm(-1), a(e)'' = 1.1819(24)×10(-4) cm(-1), r(e)'' = 2.584386(25) Å of the X(2)Π(3/2,g) state, and B(e)' = 0.0305787(37) cm(-1), a(e)' = 1.2353(23)×10(-4) cm(-1), r(e)' = 2.94758(18) Å of the A(2)Π(3/2,u) state. Vibrational energies were used to derive ω(e)'' = 239.0397(55) cm(-1), ω(e)x(e)'' = 0.64951(87) cm(-1) of the X(2)Π(3/2,g) state and ω(e)' = 138.103(11) cm(-1), ω(e)x(e)' = 0.45027(34) cm(-1) of the A(2)Π(3/2,u) state. The A(2)Π(3/2,u) (υ(n) = 13) state was found to be rotationally perturbed by the a(4)Σ(1/2,u)(-) (υ(n) = 17) state through second-order spin-orbit coupling.

Perturbation analysis of the υ = 6 level in the d3Δ state of CS based on its near-infrared absorption spectrum.

The spectrum of CS was recorded in the region of 12,086-12,630 cm(-1) by employing optical heterodyne concentration modulation laser absorption spectroscopy. Nearly 350 transitions were assigned to the (6, 0) band in the d(3)Δ-a(3)Π system of CS. The overtone transitions of the (12, 0) band in the a(3)Π(2)-a(3)Π(0) transition were first observed due to the perturbation interaction between d(3)Δ(1) and a(3)Π(2). The Λ doubling in the a(3)Π(1) state was also resolved at high rotational levels. The molecular constants of the a(3)Π (υ = 0) and d(3)Δ (υ = 6) levels and the perturbation parameters of the d(3)Δ (υ = 6) level were determined through nonlinear least-squares fitting using effective hamiltonians. The calculations of mixing fractions of the perturbed states were performed in order to obtain precise information on the perturbations of the d(3)Δ (υ = 6) levels. The mechanisms for perturbations of d(3)Δ (υ = 6) with the a(3)Π (υ = 12) and A(1)Π (υ = 1) levels, especially for the second-order perturbation, were discussed and explained according to first-order nondegenerate perturbation theory.

[LIF spectroscopic study of OH radical].

Hydroxyl radical molecular beam was generated by DC pulsed high voltage discharge. The rotational resolution excitation fluorescence spectra of the OH A 2sigma+ -X 2pi (1, 0) band were observed by using second harmonious output of a nanosecond dye laser (around 282 nm). The rotational temperature of the (1, 0) band was determined to be (30 +/- 1) K based on the analysis of the intensity distribution of the OH spectra. Moreover, the fluorescence decay curves of the (1, 1) band and the (0, 0) band and were obtained and the fluorescence lifetimes of A 2sigma+ (v' = 1) state and the X 2pi (v" = 0) state were fitted to be (637 +/- 16) and (675 +/- 13) ns, respectively.

[Study on decomposition products of methanol in AC discharge by spectroscopy].

The intermediate decomposition products of methanol (CH3OH) in an AC discharge were diagnosticated via concentration modulation spectroscopy. Several main vibrational bands of CO Angström beta 1 sigma+ -alpha 1pi system, CH alpha 2 delta-X2pi system at 430 nm and beta 2 sigma- -X2pi at 390 nm, as well as CHO (329.82 nm), CH2O (369.8 nm), CH3O (347.8 nm) and Balmer series spectra of H atom were identified in the region between 300 and 670 nm. Furthermore, the dependences of the emission spectral intensities of the intermediate decomposition products on the discharge voltage and parent gas pressure were investigated in detail. The experiments indicated that the relative population ratio of CO (beta 1 sigma+) and H increases with increasing discharge voltage more quickly than that of CH (alpha 2 delta). Several possible reaction passages were given and discussed. Additionally, the vibrational and rotational temperatures of CH (alpha 2 delta) were determined to be about 4200 and 1100 K respectively, and the vibrational temperatures of CO (beta 1 sigma+) were determined to be about 2500 K by analyzing the intensity distribution using LIFEBASE computer program. The decomposition mechanism of methanol in the discharge plasma was discussed as well.

[Study on the emission spectra of N2 plasma jet by AC glow discharge].

N2 plasma jet was generated from a nozzle using an AC discharge at about 15 kV. The emission spectra were obtained by using the concentration modulation spectroscopic technique. The dependence of spectral signal on the discharge current was discussed. It was found that the vibrational temperature decreased first and then increased downstream from the nozzle by measuring the emission spectra from different axial positions in the jet. A phenomenological model was presented to explain the vibrational temperature variation with different axial position z. The N2+/N2 ratio varied along the axis and the property of discharge in the experimental system was studied.

[Study on concentration modulation spectra of the molecular ion beam by AC glow discharge].

An experimental apparatus using an AC discharge was developed for producing molecular ion beam. The emission spectral intensity of N2+ is stronger than that of N2, and a very high ratio of N2+ (B)/N2 (C) up to 6:1, was achieved in N2 discharge. The effects and processes of N2 discharge, and the concentration modulation spectra were studied. The vibrational temperature and rotational temperature of N2+ molecular ions beam were calculated to be 3 310 and 282 K respectively from the emission spectra.

[Study on the comet-tail system of 12C16O+ in the near-infrared region].

The molecular cation CO+ is a very important transient molecular radical, and the spectra of the ion has been investigated by numerous researchers. Optical-heterodyne-magnetic-rotation-enhanced velocity modulation spectroscopy(OH-MR-VMS) was employed to measure the comet-tail system (A2 pi(i)-X2 sigma+) of 12C16O+ molecular ion. The vibrational rotation absorption spectra wereobserved in the near-infrared region, including three bands of (0, 3), (1, 4) and (3, 6). A set of precise molecular constants for the A2 pi(i) (v' = 0, 1, 3) were determined using the least-squares fit. This experiment has further proved that OH-MR-VMS is very valuable in measuring absorption spectra of molecular ions.

[Investigation of the (6, 1) and (7, 2) bands in the A 2IIi-X 2sigma+ red system of CN radical].

The CN radical was produced by Penning AC discharge of the mixture of trace acetonitrile (36 Pa) and helium (660 Pa) and the ro-vibrational spectra were measured by optical heterodyne magnetic rotation enhanced concentration modulation spectroscopy in the range of 16 850-17 480 cm(-1). 138 lines and 118 lines were assigned to the (6, 1) and (7, 2) bands in red system A 2IIi-X 2sigma+ of CN respectively, while others were due to (8, 3) band in CN red system and C2 Swan band system. More accurate molecular constants of A 2IIi (v = 6, 7) state and perturbation parameters zeta and eta between A and X states were derived based on nonlinear least-square fitting, individually, by diagonalizing the effective Hamiltonian matrix involving the perturbation elements of two electronical states and the standard deviation of fitting was less than the experimental uncertainty 0.007 cm(-1), which implied the accuracy of our results.

[The method of wavelength calibration in high resolution absorption spectroscopy].

A new method for the calibration of wavelength in a measurement of high resolution molecular absorption spectra by referring the standard spectrum of iodine molecule is presented in this paper. Segment offset is employed in the calibration of wavelength, while the data smoothing, baseline determining and peak fitting are applied to preprocess the spectral data. A visual software is provided for automatically calibrating wavelength with a friendly style of mutual dialogue between human and computer. The software has been used to calibrate the absorption spectra of N2+ molecular ion in the visible region 16,422-17,896 cm-1, the absolute accuracy is about 0.006 cm-1.