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The thin flyer is a small-scale flying object, which is well known as the core functional element of the initiator. Understanding how flyers perform has been a long-standing issue in detonator science. However, it remains a significant challenge to explore how the flyer is formed and functions in the barrel of the initiator via tabletop devices. In this study, we present dynamic and unprecedented images of flyer in barrel via high intensity short-pulse laser. Advanced radiography, coupled with a high-intensity picosecond laser X-ray source, has enabled the provision of state-of-the-art radiographs in a single-shot experiment for observing micron-scale flyer formation in a hollow cylinder in nanoseconds. The flyer was clearly visible in the barrel and was accelerated and restricted differently from that without the barrel. This first implementation of a tabletop X-ray source provided a new approach for capturing dynamic photographs of small-scale flying objects, which were previously reported to be accessible only via an X-ray phase-contrast imaging system at the advanced photon source. These efforts have led to a significant improvement of radiographic capability and a greater understanding of the mechanisms of "burst" of exploding foil initiators for this application.
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Perioperative neurocognitive disorder (PND) is a common complication of surgery and anesthesia, especially among older patients. Microglial activation plays a crucial role in the occurrence and development of PND and transforming growth factor beta 1 (TGF-ß1) can regulate microglial homeostasis. In the present study, abdominal surgery was performed on 12-14 months-old C57BL/6 mice to establish a PND model. The expression of TGF-ß1, TGF-ß receptor 1, TGF-ß receptor 2, and phosphor-smad2/smad3 (psmad2/smad3) was assessed after anesthesia and surgery. Additionally, we examined changes in microglial activation, morphology, and polarization, as well as neuroinflammation and dendritic spine density in the hippocampus. Behavioral tests, including the Morris water maze and open field tests, were used to examine cognitive function, exploratory locomotion, and emotions. We observed decreased TGF-ß1 expression after surgery and anesthesia. Intranasally administered exogenous TGF-ß1 increased psmad2/smad3 colocalization with microglia positive for ionized calcium-binding adaptor molecule 1. TGF-ß1 treatment attenuated microglial activation, reduced microglial phagocytosis, and reduced surgery- and anesthesia-induced changes in microglial morphology. Compared with the surgery group, TGF-ß1 treatment decreased M1 microglial polarization and increased M2 microglial polarization. Additionally, surgery- and anesthesia-induced increase in interleukin 1 beta and tumor necrosis factor-alpha levels was ameliorated by TGF-ß1 treatment at postoperative day 3. TGF-ß1 also ameliorated cognitive function after surgery and anesthesia as well as rescue dendritic spine loss. In conclusion, surgery and anesthesia induced decrease in TGF-ß1 levels in older mice, which may contribute to PND development; however, TGF-ß1 ameliorated microglial activation and cognitive dysfunction in PND mice.
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Microglia , Fator de Crescimento Transformador beta1 , Humanos , Camundongos , Animais , Lactente , Fator de Crescimento Transformador beta1/metabolismo , Fator de Crescimento Transformador beta1/farmacologia , Microglia/metabolismo , Camundongos Endogâmicos C57BL , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Transtornos Neurocognitivos/metabolismo , Fator de Crescimento Transformador betaRESUMO
Studying dynamic fragmentation in shock-loaded metals and evaluating the geometrical and kinematical properties of the resulting fragments are of significant importance in shock physics, material science as well as microstructural modeling. In this paper, we performed the laser-driven shock-loaded experiment on the Shenguang-Ш (SGШ) prototype laser facility, and employed X-ray micro-tomography technique to give a whole insight into the actual fragmentation process. To investigate the size distribution of the soft recovered fragments from Poly 4-methyl-1-pentene (PMP) foam sample, we further developed an automatic analysis approach based on the improved watershed segmentation. Comparison results of segmenting fragments in slices with different methods demonstrated that our proposed segmentation method can overcome the drawbacks of under-segmentation and over-segmentation, and has the best performance in both segmentation accuracy and robustness. With the proposed automatic analysis approach, other parameters such as the position distribution and penetration depth are also obtained, which are very helpful for understanding the dynamic failure mechanisms.
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The spatial distributions of the Kα emission from foil targets irradiated with ultra-intensity laser pulses have been studied using the x-ray coded imaging technique. Due to the effect of hard x-ray background contamination, noise as well as imperfection of imaging system, it is hard to determine the PSF analytically or measure it experimentally. Therefore, we propose a blind deconvolution method to restore both the spatial distributions of the Kα emission and the system's PSF from the coded images based on the maximum-likelihood scheme. Experimental restoration results from penumbral imaging and ring coded imaging demonstrated that both the structure integrity and the rich detail information can be well preserved.
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Legionella, one of the main pathogens that causes community-acquired pneumonia, can lead to Legionella pneumonia, a condition characterized predominantly by severe pneumonia. This disease, caused by the bacterium Legionella pneumophila, can quickly progress to critical pneumonia and is often associated with damage to multiple organs. As a result, it requires close attention in terms of clinical diagnosis and treatment. Omadacycline, a new type of tetracycline derivative belonging to the aminomethylcycline class of antibiotics, is a semi-synthetic compound derived from minocycline. Its key structural feature, the aminomethyl modification, allows omadacycline to overcome bacterial resistance and broadens its range of effectiveness against bacteria. Clinical studies have demonstrated that omadacycline is not metabolized in the body, and patients with hepatic and renal dysfunction do not need to adjust their dosage. This paper reports a case of successful treatment of Legionella pneumonia with omadacycline in a patient who initially did not respond to empirical treatment with moxifloxacin. The patient also experienced electrolyte disturbance, as well as dysfunction in the liver and kidneys, delirium, and other related psychiatric symptoms.
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Antibacterianos , Legionella pneumophila , Doença dos Legionários , Tetraciclinas , Humanos , Tetraciclinas/uso terapêutico , Antibacterianos/uso terapêutico , Antibacterianos/farmacologia , Doença dos Legionários/tratamento farmacológico , Doença dos Legionários/microbiologia , Legionella pneumophila/efeitos dos fármacos , Resultado do Tratamento , Masculino , Infecções Comunitárias Adquiridas/tratamento farmacológico , Infecções Comunitárias Adquiridas/microbiologia , Moxifloxacina/uso terapêutico , Pessoa de Meia-IdadeRESUMO
A linear optical technique for chirp characteristics measurement based on frequency domain interference is developed. This technique can be applied to measure the temporal structure of linearly chirped pulses which have become increasingly important in ultrafast optics. To confirm this technique, an experiment is carried out to measure the chirp rate and duration of a picosecond chirped pulse with an imaging spectrometer.
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STUDY DESIGN: A systematic review and meta-analysis. OBJECTIVE: To compare impact of different anesthesia techniques on perioperative outcomes in patients undergoing lumbar spine surgery. SUMMARY OF BACKGROUND DATA: Both general anesthesia and spinal anesthesia/epidural anesthesia can be used for lumbar spine surgery. There is still much controversy that which anesthesia technique is much more suitable for lumbar spine surgery with less complications, general anesthesia or regional anesthesia. METHODS: A comprehensive search of the literature was conducted using Excerpta Medica database (EMBASE), PubMed, and Cochrane library for randomized controlled trials and independent reviewers assessed eligibility for included studies. Primary outcomes included incidences of intraoperative hypertension, hypotension, tachycardia, and bradycardia. Secondary outcomes included postoperative analgesic requirement, postoperative nausea and vomiting (PONV), headache, urinary retention, blood loss, and length of hospital stay. RESULTS: Ten randomized controlled trials consisting of 733 adult patients undergoing lumbar spine surgery were included. Spinal anesthesia/epidural anesthesia group had significant lower incidences of intraoperative hypertension [odds ratio (OR), 0.18; 95% confidence interval (CI), 0.08-0.38; P <0.00001; I2 =0.0%] and tachycardia (OR, 0.45; 95% CI, 0.26-0.79; P =0.006; I2 =0.0%), analgesic requirement in postanesthesia care unit (OR, 0.13; 95% CI, 0.08-0.22; P <0.00001; I2 =0.0%), PONV within 24 hours after surgery (OR, 0.27; 95% CI, 0.16-0.46; P <0.00001; I2 =6.0%), and shorter length of postoperative hospital stay (mean difference, -0.28; 95% CI, -0.37 to -0.18; P <0.00001; I2 =32.0%). There were no significant differences in incidences of intraoperative hypotension and bradycardia, PONV in postanesthesia care unit, analgesic requirement, urinary retention, and headache within 24 hours after surgery. CONCLUSIONS: Low to moderate quality of evidence revealed that patient undergoing lumbar spine surgery might benefit from spinal or epidural anesthesia.
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Anestesia Epidural , Raquianestesia , Hipertensão , Hipotensão , Retenção Urinária , Adulto , Humanos , Raquianestesia/efeitos adversos , Náusea e Vômito Pós-Operatórios/etiologia , Náusea e Vômito Pós-Operatórios/complicações , Bradicardia/complicações , Retenção Urinária/complicações , Anestesia Epidural/efeitos adversos , Anestesia Geral/efeitos adversos , Hipotensão/etiologia , Analgésicos , Hipertensão/complicaçõesRESUMO
Background: Perioperative neurocognitive disorders (PNDs) are common complications of surgical patients, which can lead to prolonged hospitalization, increased complications, and decreased independence and quality of life. However, the underlying molecular mechanisms of PND remain largely obscure. Microglia activation and synapse loss were observed in PND. Cluster of differentiation 47 (CD47), which can bind to its receptor signal regulatory protein alpha (SIRPα) and generate "do not eat me" signal, protects synapses from excessive pruning. Therefore, we aimed to evaluate the potential role of CD47-SIRPα signaling in PND. Methods: The tibial fracture surgery was performed in aged C57BL/6 mice for PND model establishment. The expression of CD47 and SIRPα in the hippocampus was assessed. Synaptic plasticity, dendritic spine density, microglial engulfment, and hippocampal-dependent memory function were evaluated after model establishment and intervention with SIRPα overexpression. Results: CD47 and SIRPα expression in the hippocampus were both decreased after the surgery. SIRPα overexpression showed reduced engulfment within host microglia, but a total effect of excessive synapse engulfment decreased dendritic spine density and post-synaptic density protein 95 (PSD95) expression. SIRPα overexpression could not improve the synaptic dysfunction and cognitive impairment in PND. In addition, SIRPα overexpression led to increased CD47 and Iba1 expression. Conclusion: Anesthesia and surgery affect CD47-SIRPα signaling. SIRPα overexpression could not ameliorate the cognitive impairment in PND mice. One reason may be that the increased Iba1 expression leads to a total effect of excessive synapse engulfment, which results in decreased dendritic spine density and PSD95 expression.
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Postoperative cognitive dysfunction (POCD) is a disturbing neurological complication in patients undergoing anesthesia and surgical procedures. Brain-derived neurotrophic factor (BDNF) and its precursor proBDNF binding to their corresponding receptors tyrosine kinase (TrkB) and p75 neurotrophin receptor (p75NTR) exert quite an opposite biological function in neuron survival and synaptic function. This study aimed to demonstrate the critical role of the BDNF/proBDNF ratio in modulating synaptic plasticity, which further leads to anesthesia-/surgery-induced POCD. It also showed that the exogenous BDNF or p75NTR inhibitor could ameliorate cognitive dysfunction. In detail, 16-month-old C57BL/6 mice were subjected to a stabilized tibial fracture surgery with isoflurane anesthesia to establish the POCD animal model. The mice were then microinjected with either p75NTR inhibitor or exogenous BDNF into the dorsal hippocampus. Behavioral experiments were performed by open field and fear conditioning tests (FCTs). Western blotting was also used to measure the expression levels of BDNF, proBDNF, TrkB, p-TrkB, p75NTR, and synapse proteins. Golgi staining and electrophysiology were applied to evaluate the neuronal synaptic plasticity. Here, we demonstrated that anesthesia/surgery induced a reduction of BDNF/proBDNF, which negatively regulates the synaptic function in hippocampus, subsequently leading to cognitive impairment in aged mice. P75NTR inhibitor and exogenous BDNF could attenuate cognitive deficits by rescuing the dendritic spine loss and long-term potentiation (LTP) via altering the BDNF/proBDNF ratio. This study unveiled that the BDNF/proBDNF ratio in the hippocampus played a key role in anesthesia-/surgery-induced POCD. Thereby, tuning the ratio of BDNF/proBDNF is supposed to be a promising therapeutic target for POCD.
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BACKGROUND: Intravenous and inhalational agents are commonly used in general anesthesia. However, it is still controversial which technique is superior for the quality of postoperative recovery. This meta-analysis aimed at comparing impact of total intravenous anesthesia (TIVA) versus inhalational maintenance of anesthesia on the quality of recovery in patients undergoing non-cardiac surgery. METHODS: We systematically searched EMBASE, PubMed, and Cochrane library for randomized controlled trials (RCTs), with no language or publication status restriction. Two authors independently performed data extraction and assessed risk of bias. The outcomes were expressed as mean difference (MD) with 95% confidence interval (CI) based on a random-effect model. We performed trial sequential analysis (TSA) for total QoR-40 scores and calculated the required information size (RIS) to correct the increased type I error. RESULTS: A total of 156 records were identified, and 9 RCTs consisting of 922 patients were reviewed and included in the meta-analysis. It revealed a significant increase in total QoR-40 score on the day of surgery with TIVA (MD, 5.91 points; 95% CI, 2.14 to 9.68 points; P = 0.002; I2 = 0.0%). The main improvement was in four dimensions, including "physical comfort", "emotional status", "psychological support" and "physical independence". There was no significant difference between groups in total QoR-40 score (P = 0.120) or scores of each dimension on POD1. The TSA showed that the estimated required information size for total QoR-40 scores was not surpassed by recovered evidence in our meta-analysis. And the adjusted Z-curves did not cross the conventional boundary and the TSA monitoring boundary. CONCLUSION: Low-certainty evidence suggests that propofol-based TIVA may improve the QoR-40 score on the day of surgery. But more evidence is needed for a firm conclusion and clinical significance.
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Período de Recuperação da Anestesia , Anestesia por Inalação/efeitos adversos , Anestesia Intravenosa/efeitos adversos , Complicações Pós-Operatórias/epidemiologia , Humanos , Complicações Pós-Operatórias/etiologia , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
Nonlinear absorption of a newly synthesized organic inner salt Ge-150 dissolved in four different solvents (DMF, DMSO, acetonitrile and acetone) is investigated by the Z-scan technique with both nanosecond and picosecond pulses. When pulse energy surpasses a threshold and pulse-to-pulse separation is shorter than a characteristic time, all the four solutions show absorption weakening induced by cross-pulse effects in the picosecond regime. However, only two of them (Ge-150 dissolved in DMF and DMSO) show this weakening in the nanosecond regime. By conducting a simple verification experiment, we verify this absorption weakening is induced by solute damage related to solvent effect rather than solute migration. A simple theoretical model is proposed to interpret the experimental phenomenon.
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Modelos Químicos , Nefelometria e Turbidimetria/métodos , Compostos Orgânicos/química , Sais/química , Solventes/química , Simulação por ComputadorRESUMO
Using the nonlinear-imaging technique with a phase object (NIT-PO), we have studied third-order nonlinearities of various samples. In this work, we develop, for pure nonlinear refractive materials, an approximate method to calculate the nonlinear refractive coefficient analytically. By decomposing the object field passing through the phase object into two top-hat beams of different phases and beam radius, we acquire the approximate phase contrast, from which we extract the nonlinear refractive coefficient. This approximation is valid when the on-axis nonlinear phase shift by the sample is less than π. In addition, this approximation serves to estimate the sensitivity and monotonic interval for nonlinearity measurements more easily and thus helps us to maximize both the sensitivity and monotonic interval of measurements. We test this method with CS(2), a well-characterized third-order nonlinear refractive material using 21 ps laser pulses at 532 nm. We expect this method can be applied to high-order nonlinear refraction cases.
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BACKGROUND: Many studies have reported that the effects of danhong injection on idiopathic pulmonary fibrosis. However, its effects are still not well understood. The aim of this study is to assess the effects of danhong injection in the management of idiopathic pulmonary fibrosis. METHODS: Electronic databases such as PubMed, MEDLINE, EMbase, Web of Science, Cochrane Library, China National Knowledge Infrastructure, WanFang, the Chongqing VIP Chinese Science and Technology Periodical Database, and China biomedical literature database will be searched without limitations of language and geographical location. Two researchers will independently conduct research selection, data extraction, and research quality assessment. The RevMan 5.3 software and Stata 14.0 software are used for statistical analysis. RESULTS: This study will provide high-quality comprehensive evidence for the effectiveness and safety of danhong injection in the treatment of idiopathic pulmonary fibrosis. CONCLUSIONS: The results obtained from this study will define the basis for the effectiveness and safety of danhong injection in the treatment of idiopathic pulmonary fibrosis.
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Medicamentos de Ervas Chinesas/uso terapêutico , Fibrose Pulmonar Idiopática/tratamento farmacológico , Metanálise como Assunto , Revisões Sistemáticas como Assunto , Medicamentos de Ervas Chinesas/efeitos adversos , Humanos , InjeçõesRESUMO
A new time-resolved pump-probe system with phase object, which is based on the PO Z-scan technique and the standard pump-probe system, is presented. This new method can simultaneously investigate the dynamic of nonlinear absorption and refraction conveniently. On the other hand, both degenerate and nondegenerate pump and probe beams in any polarization states can be used in this system. The nonlinear optical properties of tetrasulfonated copper phthalocyanine dissolved in dimethyl sulfoxide solution are investigated by using this system.
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Análise de Falha de Equipamento/instrumentação , Análise de Falha de Equipamento/métodos , Lasers de Estado Sólido , Dispositivos Ópticos , Desenho Assistido por Computador , Desenho de Equipamento , Dinâmica não Linear , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
A new and simple technique is presented to investigate nonlinear optical properties. In this technique, a phase object is introduced into the measurement system. Both the nonlinear absorption coefficient and nonlinear refraction index can be determined conveniently by measuring the transmittance of the sample. The optical nonlinearities of the ZnSe are investigated by using this technique with 19 ps pulses at 532 nm wavelength as a test.
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The dynamic fragmentation of shock-loaded high-Z metal is of considerable importance for both basic and applied science. The areal density and mass-velocity distribution of dynamic fragmentation are crucial factors in understanding this issue. Experimental methods, such as pulsed X-ray radiography and proton radiography, have been utilized to obtain information on such factors; however, they are restricted to a complex device, and the spatial resolution is in the order of 100 µm. In this work, we present the high-quality radiography of the dynamic fragmentation of laser shock-loaded tin, with good two-dimensional (2D) spatial resolution. Dynamic fragmentation is generated via high-intensity ns-laser shock-loaded tin. A high-energy X-ray source in the 50-200 keV range is realized by the interaction of a high-intensity ps-pulse with an Au microwire target, attached to a low-Z substrate material. A high 2D resolution of 12 µm is achieved by point-projection radiography. The dynamic-fragmentation radiography is clear, and the signal-to-noise ratio is sufficiently high for a single-shot experiment. This unique technique has potential application in high-energy density experiments.
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Two-photon absorption induced excited state absorption in the solution of a new fluorenyl-based chromophore is investigated by a time-resolved pump-probe technique using femtosecond pulses. With the help of an additional femtosecond open-aperture Z-scan technique, numerical simulations based on a three-energy level model are used to interpret the experimental results, and we determine the nonlinear optical parameters of this new chromophore uniquely. Large two-photon absorption cross section and excited state absorption cross section for singlet excited state are obtained, indicating a good candidate for optical limiting devices. Moreover, the influence of two-beam coupling induced energy transfer in neat N,N'-dimethylformamide solvent is also considered, although this effect is strongly restrained by the instantaneous two-photon absorption.