Targeted versus Empiric Embolization for Delayed Postpancreatectomy Hemorrhage: A Retrospective Study of 312 Patients.

PURPOSE: To assess the safety and clinical effectiveness of empiric embolization (EE) compared with targeted embolization (TE) in the treatment of delayed postpancreatectomy hemorrhage (PPH). MATERIALS AND METHODS: The data of patients with delayed PPH between January 2012 and August 2022 were analyzed retrospectively. In total, 312 consecutive patients (59.6 years ± 10.8; 239 men) were included. The group was stratified into 3 cohorts according to angiographic results and treatment strategies: TE group, EE group, and no embolization (NE) group. The χ2 or Fisher exact test was implemented for comparing the clinical success and 30-day mortality. The variables related to clinical failure and 30-day mortality were identified by univariable and multivariable analyses. RESULTS: Clinical success of transcatheter arterial embolization was achieved in 70.0% (170/243) of patients who underwent embolization. There was no statistical difference in clinical success and 30-day mortality between the EE and TE groups. Multivariate analyses demonstrated that malignant disease (odds ratio [OR] = 5.76), Grade C pancreatic fistula (OR = 7.59), intra-abdominal infection (OR = 2.54), and concurrent extraluminal and intraluminal hemorrhage (OR = 2.52) were risk factors for clinical failure. Moreover, 33 patients (13.6%) died within 30 days after embolization. Advanced age (OR = 2.59) and intra-abdominal infection (OR = 5.55) were identified as risk factors for 30-day mortality. CONCLUSIONS: EE is safe and as effective as TE in preventing rebleeding and mortality in patients with angiographically negative delayed PPH.

Multi-channel current electro-optic isolated measurement and discharge current characteristics in a parallel plate transmission line driver.

In this paper, a 96 kJ compact synchronous discharge driver is designed. The issue of the current measurement of the six parallel gas spark switches is resolved by a multi-channel isolated current measuring system, and the driver's circuit simulation model is constructed. Then, the discharge current characteristics of each branch and load are investigated, and the results show that when the operating voltage is at least 50 kV, the parallel switches are conducted synchronously. The designed multi-channel isolated current measuring system meets the use requirements at a maximum operating voltage of 80 kV, the peak current measured by a single channel is 500 kA at this time, which corresponds to the load current of 3 MA, and the current rise time (0%-100% rise time) is about 1.15 µs. However, the asynchronous conduction of these switches will increase the branch circuit's peak current by a maximum of 25%, and the maximum value of the inverse peak current ratio of the branch will increase to 1.16, which will threaten the safe operation of the components. At this time, there is a redistribution of charge between the already conducting branches, so the impact of the load current is less than that of the basic branch current. When the conduction dispersion of the switchers is less than 452 ns, the peak current of the load reduction is less than 3%, and the current waveform meets the application requirements. The research is essential for understanding the operating status of the driver and assessing the through-current capability of the device's components, such as gas switches and capacitors.

The basic chemical substances of total alkaloids of Menispermi Rhizoma and their anti-inflammatory activities.

Menispermi Rhizoma is the dried rhizome of Menispermum dauricum DC. (Menispermaceae), which commonly used to treat sore throat, enteritis, and dysentery in traditional Chinese medicine. To clarify the chemical basis of the total alkaloids of M. Rhizoma, HPLC was used to analyze total alkaloids, and then representative chemical constituents were separated by tracking. Nineteen compounds, including two new alkaloids (1R-methymenidaurine A-α-N-oxide (1) and 1R-7'-hydroxymethyl-menidaurine A (2)), thirteen known alkaloids, and four known flavonoids were isolated and identified using spectroscopic methods. Meanwhile, seven characteristic peaks were identified from the total alkaloids using HPLC analysis. Furthermore, compounds 1-18 were screened in vitro for their inhibitory effect against nitric oxide production in BV-2 microglia cells stimulated by lipopolysaccharide. Among them, six compounds showed weak inhibition, and the IC50 values of compounds 1 and 2 were 56.87 ± 1.61 and 53.67 ± 1.52 mM, respectively.

Atom-based sensing technique of microwave electric and magnetic fields via a single rubidium vapor cell.

We present an atom-based approach for determining microwave electric and magnetic fields by using a single rubidium vapor cell in a microwave waveguide. For a 87Rb cascade three-level system employed in our experiment, a weak probe laser driving the lower transition, 5S1/2→5P3/2, is first used to measure the microwave magnetic field based on the atomic Rabi resonance. When a counter-propagating strong coupling laser is subsequently turned on to drive the Rydberg transition, 5P3/2→67D5/2, the same probe laser is then used as a Rydberg electromagnetically induced transparency (EIT) probe to measure the microwave electric field by investigating the resonant microwave dressed Autler-Townes splitting (ATS). By tuning the hyperfine transition frequency of the ground state using an experimentally feasible static magnetic field, we first achieved a measurement of the microwave electric and magnetic field strength at the same microwave frequency of 6.916 GHz. Based on the ideal relationship between the electric and magnetic field components, we obtained the equivalent microwave magnetic fields by fitting the inversion to the measured microwave electric fields, which demonstrated that the results were in agreement with the experimental measurement of the microwave magnetic fields in the same microwave power range. This study provides new experimental evidence for quantum-based microwave measurements of electric and magnetic fields by a single sensor in the same system.

The basic chemical substances of three medicinal parts from Rhododendron molle G. Don.

Rhododendron Molle G. Don belongs to Ericaceae family. As a toxic traditional Chinese medicine, its roots, flowers, and fruit are often mixed and substituted arbitrarily to treat rheumatoid arthritis in clinic. To clarify the main chemical basis of each medicinal part, and provide sufficient scientific basis for clinical application, analysis using HPLC-ELSD of the roots, flowers, and fruit from R. molle was established, and characteristic chemical constituents of them were separated by tracking. The structures were determined by NMR methods. Finally, 16, 21, and 18 compounds were obtained from the roots, flowers, and fruit, respectively. Overall, 49 compounds were obtained, of which 25 were identified for the first time in R. molle. Meanwhile, among the obtained compounds, 12, 11, and 6 characteristic peaks were identified from the roots, flowers, and fruit, respectively. Thus, the basic chemical substances of the medicinal parts of R. molle were determined initially.

Rydberg-atom-based digital communication using a continuously tunable radio-frequency carrier.

Up to now, the measurement of radio-frequency (RF) electric field achieved using the electromagnetically-induced transparency (EIT) of Rydberg atoms has proved to be of high-sensitivity and shows a potential to produce a promising atomic RF receiver at resonance between two chosen Rydberg states. In this paper, we study the extension of the feasibility of digital communication via this quantum-based antenna over a continuously tunable RF-carrier at off-resonance. Our experiment shows that the digital communication at a rate of 500 kbps can be performed reliably within a tunable bandwidth of 200 MHz near a 10.22 GHz carrier. Outside of this range, the bit error rate (BER) increases, rising to, for example, 15% at an RF-detuning of ±150 MHz. In the measurement, the time-varying RF field is retrieved by detecting the optical power of the probe laser at the center frequency of RF-induced symmetric or asymmetric Autler-Townes splitting in EIT. Prior to the digital test, we studied the RF-reception quality as a function of various parameters including the RF detuning and found that a choice of linear gain response to the RF-amplitude can suppress the signal distortion. The modulating signal can be decoded at speeds up to 500 kHz in the tunable bandwidth. Our test consolidates the physical basis for reliable communication and spectral sensing over a wider broadband RF-carrier, which paves a way for the concurrent multi-channel communications founded on the same pair of Rydberg states.

Field Distortion and Optimization of a Vapor Cell in Rydberg Atom-Based Radio-Frequency Electric Field Measurement.

Highly excited Rydberg atoms in a room-temperature vapor cell are promising for developing a radio-frequency (RF) electric field (E-field) sensor and relevant measurement standards with high accuracy and sensitivity. The all-optical sensing approach is based on electromagnetically-induced transparency and Autler-Townes splitting induced by the RF E-field. Systematic investigation of measurement uncertainty is of great importance for developing a national measurement standard. The presence of a dielectric vapor cell containing alkali atoms changes the magnitude, polarization, and spatial distribution of the incident RF field. In this paper, the field distortion of rubidium vapor cells is investigated, in terms of both field strength distortion and depolarization. Full-wave numerical simulation and analysis are employed to determine general optimization solutions for minimizing such distortion and validated by measuring the E-field vector distribution inside different vapor cells. This work can improve the accuracy of atom-based RF E-field measurements and contributes to the development of related RF quantum sensors.

Protective role of astragalus injection in spinal cord ischemia-reperfusion injury in rats.

OBJECTIVE: To investigate the neuroprotective effect of Astragalus injection in a spinal cord ischemia-reperfusion (I/R) injury model. METHODS: A total of 27 Sprague Dawley rats were randomly divided into 3 groups: control group (n=3), I/R group (n=12), and Astragalus injection group (Ast group, n=12). Spinal cord ischemia was induced by occlusion of the abdominal aorta above the right renal artery for 32 min. Animals in the Ast group were administered Astragalus injection (6.42 mL/kg) at 30 min before the induction of ischemia. After reperfusion for 8, 12, 24, or 48 hours, the serum neuron-specific enolase (NSE) concentration was measured by enzyme-linked immunosorbent assay (ELISA) and the aquaporin-4 (AQP4) protein level was detected by western blotting. RESULTS: The pathological changes, as assessed by hematoxylin and eosin (HE) staining, were milder in the spinal cords of the Ast group compared to the I/R group. Enzyme-linked immunosorbent assay demonstrated that the NSE concentration of the Ast group was significantly lower than that of the I/R group (p<0.05). However, the NSE concentrations of the I/R and Ast groups were significantly higher than that of the control group (p=0.05). Additionally, the expression of AQP4 in the Ast group was lower than that of the I/R group at each time point. CONCLUSION: These findings indicate that Astragalus injection has a neuroprotective effect in spinal cord I/R injury by decreasing the AQP4 expression.

Anisotropic responses and initial decomposition of condensed-phase ß-HMX under shock loadings via molecular dynamics simulations in conjunction with multiscale shock technique.

Molecular dynamics simulations in conjunction with multiscale shock technique (MSST) are performed to study the initial chemical processes and the anisotropy of shock sensitivity of the condensed-phase HMX under shock loadings applied along the a, b, and c lattice vectors. A self-consistent charge density-functional tight-binding (SCC-DFTB) method was employed. Our results show that there is a difference between lattice vector a (or c) and lattice vector b in the response to a shock wave velocity of 11 km/s, which is investigated through reaction temperature and relative sliding rate between adjacent slipping planes. The response along lattice vectors a and c are similar to each other, whose reaction temperature is up to 7000 K, but quite different along lattice vector b, whose reaction temperature is only up to 4000 K. When compared with shock wave propagation along the lattice vectors a (18 Å/ps) and c (21 Å/ps), the relative sliding rate between adjacent slipping planes along lattice vector b is only 0.2 Å/ps. Thus, the small relative sliding rate between adjacent slipping planes results in the temperature and energy under shock loading increasing at a slower rate, which is the main reason leading to less sensitivity under shock wave compression along lattice vector b. In addition, the C-H bond dissociation is the primary pathway for HMX decomposition in early stages under high shock loading from various directions. Compared with the observation for shock velocities V(imp) = 10 and 11 km/s, the homolytic cleavage of N-NO2 bond was obviously suppressed with increasing pressure.