Influence of target temperature on femtosecond laser-ablated brass plasma spectroscopy

Spectral intensity,electron temperature and density of laser-induced plasma(LIP) are important parameters for affecting sensitivity of laser-induced breakdown spectroscopy(LIBS).Increasing target temperature is an easy and feasible method to improve the sensitivity.In this paper,a brass target in a temperature range from 25℃ to 200℃ was ablated to generate the LIP using femtosecond pulse.Time-resolved spectral emission of the femtosecond LIBS was measured under different target temperatures.The results showed that,compared with the experimental condition of 25℃,the spectral intensity of the femtosecond LIP was enhanced with more temperature target.In addition,the electron temperature and density were calculated by Boltzmann equation and Stark broadening,indicating that the changes in the electron temperature and density of femtosecond LIP with the increase of the target temperature were different from each other.By increasing the target temperature,the electron temperature increased while the electron density decreased.Therefore,in femtosecond LIBS,a hightemperature and low-density plasma with high emission can be generated by increasing the target temperature.The increase in the target temperature can improve the resolution and sensitivity of femtosecond LIBS.

Research progress in core body temperature measurement during target temperature management

Core body temperature(CBT)is increasingly attracting attention as crucial data during target temperature management(TTM).Accurate and continuous measurement of human CBT can effectively identify and monitor central high fever,and provide a basis for the effective implementation during TTM,which is therefore of great significance for human health care and disease monitoring.The reliable core measurement sites are nasopharynx,esophagus,bladder,rectum,pulmonary artery,etc.,but the measurement methods in these sites are all invasive.At present,the medical field is more inclined to noninvasive data collection methods through monitoring an appropriate site(such as forehead,mouth,or axilla)depending on clinical circumstances,so as to ensure the comfort and security of patients to the greatest extent.This review will provide reference choosing more safe and accurate temperature measurement methods for patients during TTM by reviewing the sites and accuracy of invasive and noninvasive CBT measurements.

Pharmacological induced target temperature management after cardiac arrest： the capsaicinoids

Cardiac or respiratory arrest lasting only a few minutes can inflict grave harm on numerous bodily organs, not least of all, the brain. Neurocognitive deficits, which are often severe and profoundly life altering, remain a major source of morbidity among survivors.

Decreased human leukocyte antigen-D-related expression on CD14^(+)monocytes in patients with out-of-hospital cardiac arrest provided target temperature management therapy:a prospective observational study

Background:Post–cardiac arrest syndrome involves systemic inflammation,which causes subsequent neurological impairments.We investigated the influence of targeted temperature management(TTM)therapy in patients with out-of-hospital cardiac arrest(OHCA)after return of spontaneous circulation(ROSC)by observing the changes in circulating CD14^(+)monocytes and the expression of human leukocyte antigen D–related(HLA-DR)and programmed cell death ligand 1(PD-L1)in CD14^(+)monocytes.Methods:Adult patients admitted to the emergency department of Beijing Chao-Yang Hospital after OHCA between January 2017 and March 2018 were included in this study.Thirty control subjects,10 patients with OHCA,and 37 patients with OHCA who received 72 hours of TTM therapy were enrolled.Peripheral blood samples of patients in the OHCA and TTM groups were collected on Days 1 and 3(D1 and D3)after ROSC and evaluated for HLA-DR and PD-L1 expression on CD14^(+)monocytes using flow cytometry.Results:Compared with control subjects,the percentage of circulating CD14^(+)monocytes,HLA-DR+/CD14^(+)monocyte ratios,and mean fluorescence intensity were significantly decreased in patients with OHCA.After ROSC,HLA-DR expression in CD14^(+)monocytes in the TTM group was lower than that in patients with OHCA.However,there were no significant differences in the percentage of PD-L1+/CD14^(+)monocytes or the mean fluorescence intensity between patients with OHCA and healthy volunteers.Conclusion:After ROSC,circulating CD14^(+)monocytes and HLA-DR+/CD14^(+)monocyte ratios decreased significantly in patients with OHCA.Human leukocyte antigen D–related expression in CD14^(+)monocytes was lower in patients treated with TTM.

Eff ect of post-rewarming fever after targeted temperature management in cardiac arrest patients: a systematic review and meta-analysis

BACKGROUND:Targeted temperature management(TTM),as a therapeutic temperature control strategy for cardiac arrest(CA),is recommended by guidelines.However,the relationship between postrewarming fever(PRF)and the prognosis of CA patients is unclear.Therefore,we aim to summarize the studies regarding the infl uence of PRF on patients with CA.METHODS:EMBASE,PubMed,and Cochrane Central databases were searched from inception to March 13,2022.Randomized clinical trials(RCTs)and cohort studies on PRF in CA patients were included.According to the heterogeneity,the meta-analysis was performed using a random eff ects model or fi xed eff ects model to calculate the pooled odds ratios(ORs)and corresponding 95%confi dence intervals(CIs).The outcome data were unfavorable neurological outcome and mortality.RESULTS:The meta-analysis included 11 observational studies involving 3,246 patients.The results of the meta-analysis show that PRF(body temperature>38.0℃)has no eff ect on the neurological outcome of CA patients(OR 0.71,95%CI 0.43–1.17,I282%)and has a signifi cant relationship with lower mortality(OR 0.63;95%CI 0.49–0.80,I239%).However,PRF with a stricter defi nition(body temperature>38.5℃)was associated with worse neurological outcome(OR 1.44,95%CI 1.08–1.92,I245%)and higher mortality(OR 1.71,95%CI 1.25–2.35,I247%).CONCLUSION:This study suggests that PRF>38.0℃ may not affect the neurological outcome and have a lower mortality in CA patients who completed TTM.However,PRF>38.5℃ is a potential prognostic factor for worse outcomes in CA patients.

Application of Target Temperature Management in Patients with Severe Neuropathy

Targeted temperature management(TTM)is a promising and multifaceted modern treatment modality that has been widely used in neurological intensive care patients in recent years.A comprehensive study on the treatment of neurocritical patients at home and abroad found that TTM is an intervention that can effectively improve the survival rate and neurological prognosis of patients;its implementation process consists of four stages:induction of hypothermia,maintenance of hypothermia,rewarming,and control of normal body temperature,and scientific nursing measures in each stage can reduce the occurrence of adverse reactions in patients and improve nursing satisfaction.This article provides an overview of TTM,including common methods,brain protection mechanisms,clinical applications in neurocritical patients,and nursing advances to provide a reference for clinical decision-making and the development of appropriate nursing interventions.

Targeted temperature management in neurological intensive care unit

Targeted temperature management(TTM) shows the most promising neuroprotective therapy against hypoxic/ischemic encephalopathy(HIE).In addition, TTM is also useful for treatment of elevated intracranial pressure(ICP).HIE and elevated ICP are common catastrophic conditions in patients admitted in Neurologic intensive care unit(ICU).The most common cause of HIE is cardiac arrest.Randomized control trials demonstrate clinical benefits of TTM in patients with post-cardiac arrest.Although clinical benefit of ICP control by TTM in some specific critical condition, for an example in traumatic brain injury, is still controversial, efficacy of ICP control by TTM is confirmed by both in vivo and in vitro studies.Several methods of TTM have been reported in the literature.TTM can apply to various clinical conditions associated with hypoxic/ischemic brain injury and elevated ICP in Neurologic ICU.

Femtosecond laser-induced Cu plasma spectra at different laser polarizations and sample temperatures

Laser-induced breakdown spectroscopy(LIBS) is a good technique for detecting and analyzing material elements due to the plasma emission produced by the high-power laser pulse. Currently, a significant topic of LIBS research is improving the emission intensity of LIBS. This study investigated the effect of laser-polarization on femtosecond laser-ablated Cu plasma spectra at different sample temperatures. The measured lines under circularly polarized lasers were higher than those under linearly and elliptically polarized lasers. The enhancement effect was evident at higher Cu temperatures when comparing the plasma spectra that have circular and linear polarizations for different target temperatures. To understand the influence of laser-polarization and sample temperature on signal intensity, we calculated the plasma temperature(PT)and electron density(ED). The change in PT and ED was consistent with the change in the atomic lines as the laser polarization was being adjusted. When raising the Cu temperature, the PT increased while the ED decreased. Raising the Cu temperature whilst adjusting the laser-polarization is effective for improving the signal of femtosecond LIBS compared to raising the initial sample temperature alone or only changing the laser polarization.

Comparison of sample temperature effect on femtosecond and nanosecond laser-induced breakdown spectroscopy

In this paper,we investigated the emission spectra of plasmas produced from femtosecond and nanosecond laser ablations at different target temperatures in air.A brass was selected as ablated target of the experiment.The results indicated that spectral emission intensity and plasma temperature showed similar trend for femtosecond and nanosecond lasers,and the two parameters were improved by increasing the sample temperature in both cases.Moreover,the temperature of nanosecond laser-excited plasma was higher compared with that of femtosecond laser-excited plasma,and the increase of the plasma temperature in the case of nanosecond laser was more evident.In addition,there was a significant difference in electron density between femtosecond and nanosecond laser-induced plasmas.The electron density for femtosecond laser decreased with increasing the target temperature,while for nanosecond laser,the electron density was almost unchanged at different sample temperatures.

Interpretations and comments for expert consensus on the diagnosis and treatment of heat stroke in China

Heat stroke is the most severe type of heat illness,it is often accompanied by severe multiorgan damage and has a high fatality rate.In January 2020,based on new research evidence and the experiences of Chinese experts in heat stroke,the Expert Group of Heat Stroke Prevention and Treatment of the Chinese People’s Liberation Army(PLA)and the Professional Committee of Critical Care Medicine of the Chinese PLA jointly issued a new Expert Consensus on the Diagnosis and Treatment of Heat Stroke in China.This article aims to interpret and supplement the major updates to the new consensus.