The natural property of rock material,whether impact occurs,is the key influencing factor of the occurrence of rock burst disaster.To accurately assess rock burst proneness,this study focuses on typical sandstone as t...The natural property of rock material,whether impact occurs,is the key influencing factor of the occurrence of rock burst disaster.To accurately assess rock burst proneness,this study focuses on typical sandstone as the research object.Uniaxial cyclic loading and unloading tests were conducted to measure the elastic strain energy accumulated in sandstone under different stress levels and a relationship between elastic strain energy and stress level was established.The results show that:(1)The peak stress under cyclic loading and unloading conditions is slightly lower than the uniaxial compressive strength.With an increase in the number of cycles,the internal damage of sandstone continues to accumulate,and the mechanical properties such as compressive strength continue to deteriorate;(2)With an increase in stress,the input strain energy,elastic strain energy,and dissipated strain energy also increase;(3)When the stress is low,the increase in elastic strain energy is large and shows a steady growth;with an increase in stress,the increase of elastic strain energy decreases;(4)The square of stress at any time has a good linear relationship with elastic strain energy.According to the relationship obtained from the test,the elastic strain energy at the peak stress time can be obtained;(5)A new criterion for assessing rock burst proneness is proposed:residual energy release rate index W_(T),which characterizes the energy release per unit time when the rock burst occurs.The intervals for evaluating the rock burst proneness of the residual energy release rate index W_(T) are as follows:W_(T)<0.025,indicating no rock burst proneness;0.025≤W_(T)<0.15,indicating weak rock burst proneness;0.15≤W_(T)<2,indicating medium rock burst proneness;W_(T)>2,indicating strong rock burst proneness;and(6)The rationality of the proposed residual energy release rate index W_(T) is verified by the multi-index method and the multi-sample method,and the proposed residual energy release rate index is used to determine the rock burst proneness of 10 kinds of rock samples.The evaluation accuracy is shown to be high,and it can reflect the actual rock burst proneness.展开更多
Understanding the spatial heterogeneity of debris-flow-prone areas holds significant implications for regional risk management, particularly in seismically active regions with geological faults. Despite the significan...Understanding the spatial heterogeneity of debris-flow-prone areas holds significant implications for regional risk management, particularly in seismically active regions with geological faults. Despite the significance of this knowledge, a comprehensive quantification of the influence of regional topographical and geological factors on the spatial heterogeneity of debris-flow-prone areas has been lacking. This study selected the Hengduan Mountains, an earthquake-prone region characterized by diverse surface conditions and complex landforms, as a representative study area. An improved units zoning and objective factors identification methodology was employed in earthquake and fault analysis to assess the impact of seismic activity and geological factors on spatial heterogeneity of debrisflow prone areas. Results showed that the application of GIS technology with hydrodynamic intensity and geographical units analysis can effectively analyze debris-flow prone areas. Meanwhile, earthquake and fault zones obviously increase the density of debrisflow prone catchments and make them unevenly distributed. The number of debris-flow prone areas shows a nonlinear variation with the gradual increase of geomorphic factor value. Specifically, the area with 1000 m-2500 m elevation difference, 25°-30° average slope, and 0.13-0.15 land use index is the most favorable conditions for debris-flow occurrence;The average annual rainfall from 600 to 1150 mm and landslides gradient from 16° to 35° are the main causal factors to trigger debris flow. Our study sheds light on the quantification of spatial heterogeneity in debris flow-prone areas in earthquake-prone regions, which can offer crucial support for post-debris flow risk management strategies.展开更多
Introduction: Covid-19 is defined as a pandemic disease by WHO, in November 2023, WHO recorded 772.1 million confirmed cases and 6.9 million deaths, including 68,382 confirmed cases and 1426 deaths in Madagascar. The ...Introduction: Covid-19 is defined as a pandemic disease by WHO, in November 2023, WHO recorded 772.1 million confirmed cases and 6.9 million deaths, including 68,382 confirmed cases and 1426 deaths in Madagascar. The management of severe cases of Covid-19 remains a challenge for the healthcare system in a resource-limited country, due to the consumption of human resources, the shortage of medical resources and the lack of capacity in resource-limited countries. Prone position (PP) improves survival in acute respiratory distress, and numerous studies have shown that during Covid-19, it reduces mortality rates at 28 and 90 days, and increases the number of days without mechanical ventilation. However, data on the beneficial effects of PP remain limited in low-income countries. In this context, our study aims to evaluate the benefits of the prone position for severe Covid-19 patients in a referral center in Madagascar. Method: This is a retrospective cohort study, during the 2<sup>nd</sup> and 3<sup>rd</sup> waves of COVID-19, over a period of 11 months in two wards managing COVID-19 cases. We included all patients aged 15 and over with severe forms of COVID-19 who required 6 l/min of oxygen therapy. Results: We enrolled 123 patients, including 40 in the prone position and 83 in the supine position, with a mean age of 60.5 ± 12 years. The prone position (DV) reduced the risk of probable complications of COVID-19 with a strong association in terms of use of respiratory assistance (OR = 0.15;95% CI = 0.05 - 0.47), respiratory deterioration (OR = 0.22;95% CI = 0.09 - 0.58), shock (OR = 0.30;95% CI = 0.11 - 0.79) and hemodynamic instability (OR = 0.33;95% CI = 0.12 - 0.95). Univariate analysis of the effect of prone position on SpO<sub>2</sub> showed improvement with significant associations with SpO<sub>2</sub> at Day 1- Day 3, D4 - D7, D8 - D14, and persisting even at D15 - D21, D3 and D2 before discharge, and at discharge. In the overall population, the mean length of hospital stay was 22.8 ± 22.1 days, with extremes of 1 and 67 days. Univariate analysis of the effect of the prone position showed a reduction in length of hospital stay with a strong association (p = 0.001) and a mean difference of 14 days. The prone position reduced mortality with a significant association (OR = 0.44;95% CI = 0.20 - 0.98). Conclusion: Awake prone position prevents complications of COVID, improves SPO<sub>2</sub> even up to hospital discharge and reduces hospital stay. This practice is simple, less costly and suitable in low income countries.展开更多
The residual elastic energy index is a scientific evaluation index for rockburst proneness.In laboratory test,it is sometimes difficult to obtain the post-peak curve or to test the rock sample several times,which make...The residual elastic energy index is a scientific evaluation index for rockburst proneness.In laboratory test,it is sometimes difficult to obtain the post-peak curve or to test the rock sample several times,which makes it impossible to calculate the residual elastic energy index accurately.Based on 241 sets of experimental data and four input indexes of density,elastic modulus,peak intensity and peak input strain energy,this study proposed a machine learning model combining k-means clustering algorithm and random forest regression model:cluster forest(CF)model.The research employed a stratified sampling method on the dataset to ensure the representativeness and balance of the samples.Subsequently,grid search and five-fold cross-validation were utilized to optimize the model’s hyperparameters,aiming to enhance its generalization capability and prediction accuracy.Finally,the performance of the optimal model was evaluated using a test set and compared with five other commonly used models.The results indicate that the CF model outperformed the other models on the testing set,with a mean absolute error of 6.6%,and an accuracy of 93.9%.The results of sensitivity analyses reveal the degree of influence of each variable on rockburst proneness and the applicability of the CF model when the input parameters are missing.The robustness and generalization ability of the model were verified by introducing experimental data from other studies,and the results confirmed the reliability and applicability of the model.Therefore,the model not only effectively simplifies the acquisition of the residual elastic energy index,but also shows excellent performance and wide applicability.展开更多
A mathematical model describing the risks of road accidents has been built on the basis of statistical data of drivers’ accident rate. It has been revealed that drivers can be divided by the degree of their accident ...A mathematical model describing the risks of road accidents has been built on the basis of statistical data of drivers’ accident rate. It has been revealed that drivers can be divided by the degree of their accident proneness into four categories with sharply differing probabilities of road accidents. It has been shown that there is a possibility of classification of drivers in accordance with specified categories.展开更多
Spinal surgery is usually performed in the prone position, which is a longer and more difficult procedure and is prone to complications such as circulatory dysfunction and stress injuries. Among them, stress injury is...Spinal surgery is usually performed in the prone position, which is a longer and more difficult procedure and is prone to complications such as circulatory dysfunction and stress injuries. Among them, stress injury is the main complication of prone spine surgery, but the reasons for stress injury in prone spine surgery are not clear, and whether prone cardiopulmonary resuscitation (CPR) can be used needs to be further verified. Supine cardiopulmonary resuscitation is commonly used in posterior spinal surgery, retroperitoneal surgery, and so on, which can effectively improve the patient’s hypoxemia. Such surgeries require a high level of anesthetic management, and cardiopulmonary resuscitation is necessary if a patient in a prone position experiences cardiac arrest. In the process of cardiopulmonary resuscitation, supine cardiopulmonary resuscitation is often used, especially for some obese patients, if they are immediately changed to the supine position, it takes up more time, there may be wound infection, and there is a possibility of missing the optimal rescue and resuscitation time. Based on this, this paper reviews the use of prone-position cardiopulmonary resuscitation for spinal surgery in the prone position.展开更多
Objective:To investigate the effects of prone ventilation in patients with severe traumatic brain injury combined with pulmonary infection.Methods:A total of 100 patients with severe traumatic brain injury combined wi...Objective:To investigate the effects of prone ventilation in patients with severe traumatic brain injury combined with pulmonary infection.Methods:A total of 100 patients with severe traumatic brain injury combined with pulmonary infection in the hospital were randomly divided into a prone ventilation group and a conventional ventilation group,with 50 patients in each group.The Glasgow Coma Scale(GCS)score,APACHE II score,sputum culture results,oxygenation indicators,and prognosis were compared between the two groups.Data were processed using SPSS 25.0 statistical software,and t-tests and chi-square tests were used to compare continuous and categorical variables,respectively.Results:The experimental group showed better oxygenation indicators,a lower positive rate of sputum cultures,and reduced intracranial pressure compared to the control group(all P<0.05).Multivariate Cox regression analysis indicated that GCS score,APACHE II score,and prone ventilation were independent risk factors affecting patient prognosis(all P<0.05).Conclusion:Prone ventilation can improve oxygenation,reduce the risk of pulmonary infection,and decrease intracranial pressure in patients with severe traumatic brain injury combined with pulmonary infection,thereby improving patient prognosis.GCS score and APACHE II score can serve as important indicators for prognostic evaluation.展开更多
Objective:To explore effective nursing strategies for patients undergoing prone-position laparoscopic partial nephrectomy.Methods:A total of 19 patients undergoing prone-position laparoscopic partial nephrectomy were ...Objective:To explore effective nursing strategies for patients undergoing prone-position laparoscopic partial nephrectomy.Methods:A total of 19 patients undergoing prone-position laparoscopic partial nephrectomy were selected,with hospital admission spanning from January 2024 to June 2024.Patients were randomly divided into the study group(n=10)and the control group(n=9).The control group received basic nursing care,while the study group received comprehensive high-quality nursing care.The recovery period,length of hospital stay,complication rates,SCL-90 scores,and nursing quality scores were compared between the two groups.Results:The recovery period and hospital stay were significantly shorter in the study group compared to the control group(P<0.05).The complication rate in the study group was lower than that in the control group(P<0.05).After the nursing intervention,the SCL-90 scores of the study group were lower than those of the control group(P<0.05).Nursing quality scores were higher in the study group than in the control group(P<0.05).Conclusion:Comprehensive high-quality nursing intervention for patients undergoing prone-position laparoscopic partial nephrectomy can shorten the recovery period and hospital stay,reduce the complication rate,improve mental health,and enhance nursing quality,making it suitable for wider application in medical institutions.展开更多
To review the rockburst proneness(or tendency)criteria of rock materials and compare the judgment accuracy of them,twenty criteria were summarized,and their judgment accuracy was evaluated and compared based on the la...To review the rockburst proneness(or tendency)criteria of rock materials and compare the judgment accuracy of them,twenty criteria were summarized,and their judgment accuracy was evaluated and compared based on the laboratory tests on fourteen types of rocks.This study begins firstly by introducing the twenty rockburst proneness criteria,and their origins,definitions,calculation methods and grading standards were summarized in detail.Subsequently,to evaluate and compare the judgment accuracy of the twenty criteria,a series of laboratory tests were carried out on fourteen types of rocks,and the rockburst proneness judgment results of the twenty criteria for the fourteen types of rocks were obtained accordingly.Moreover,to provide a unified basis for the judgment accuracy evaluation of above criteria,a classification standard(obtained according to the actual failure results and phenomena of rock specimen)of rockburst proneness in laboratory tests was introduced.The judgment results of the twenty criteria were compared with the judgment results of this classification standard.The results show that the judgment results of the criterion based on residual elastic energy(REE)index are completely consistent with the actual rockburst proneness,and the other criteria have some inconsistent situations more or less.Moreover,the REE index is based on the linear energy storage law and defined in form of a difference value and considered the whole failure process,and these superior characteristics ensure its accuracy.It is believed that the criterion based on REE index is comparatively more accurate and scientific than other criteria,and it can be recommended to be applied to judge the rockburst proneness of rock materials.展开更多
Acute respiratory distress syndrome(ARDS) is a syndrome with heterogeneous underlying pathological processes. It represents a common clinical problem in intensive care unit patients and it is characterized by high mor...Acute respiratory distress syndrome(ARDS) is a syndrome with heterogeneous underlying pathological processes. It represents a common clinical problem in intensive care unit patients and it is characterized by high mortality. The mainstay of treatment for ARDS is lung protective ventilation with low tidal volumes and positive end-expiratory pressure sufficient for alveolar recruitment. Prone positioning is a supplementary strategy available in managing patients with ARDS. It was first described 40 years ago and it proves to be in alignment with two major ARDS pathophysiological lung models; the "sponge lung"- and the "shape matching"-model. Current evidence strongly supports that prone positioning has beneficial effects on gas exchange, respiratory mechanics, lung protection and hemodynamics as it redistributes transpulmonary pressure, stress and strain throughout the lung and unloads the right ventricle. The factors that individually influence the time course of alveolar recruitment and the improvement in oxygenation during prone positioning have not been well characterized. Although patients' response to prone positioning is quite variable and hard to predict, large randomized trials and recent meta-analyses show that prone position in conjunction with a lung-protective strategy, when performed early and in sufficient duration, may improve survival in patients with ARDS. This pathophysiology-based review and recent clinical evidence strongly support the use of prone positioning in the early management of severe ARDS systematically and not as a rescue maneuver or a last-ditch effort.展开更多
Rock burst is a severe disaster in mining and underground engineering,and it is important to predict the rock burst risk for minimizing the loss during the constructing process.The rock burst proneness was connected w...Rock burst is a severe disaster in mining and underground engineering,and it is important to predict the rock burst risk for minimizing the loss during the constructing process.The rock burst proneness was connected with the acoustic emission(AE) parameter in this work,which contributes to predicting the rock burst risk using AE technique.Primarily,a rock burst proneness index is proposed,and it just depends on the heterogeneous degree of rock material.Then,the quantificational formula between the value of rock burst proneness index and the accumulative AE counts in rock sample under uniaxial compression with axial strain increases is developed.Finally,three kinds of rock samples,i.e.,granite,limestone and sandstone are tested about variation of the accumulative AE counts under uniaxial compression,and the test data are fitted well with the theoretic formula.展开更多
Complications associated with prone surgical positioning during elective spine surgery have the potential to cause serious patient morbidity.Although many ofthese complications remain uncommon,the range of possible mo...Complications associated with prone surgical positioning during elective spine surgery have the potential to cause serious patient morbidity.Although many ofthese complications remain uncommon,the range of possible morbidities is wide and includes multiple organ systems.Perioperative visual loss(POVL)is a well described,but uncommon complication that may occur due to ischemia to the optic nerve,retina,or cerebral cortex.Closed-angle glaucoma and amaurosis have been reported as additional etiologies for vision loss following spinal surgery.Peripheral nerve injuries,such as those caused by prolonged traction to the brachial plexus,are more commonly encountered postoperative events.Myocutaneous complications including pressure ulcers and compartment syndrome may also occur after prone positioning,albeit rarely.Other uncommon positioning complications such as tongue swelling resulting in airway compromise,femoral artery ischemia,and avascular necrosis of the femoral head have also been reported.Many of these are well-understood and largely avoidable through thoughtful attention to detail.Other complications,such as POVL,remain incompletely understood and thus more difficult to predict or prevent.Here,the current literature on the complications of prone positioning for spine surgery is reviewed to increase awareness of the spectrum of potential complications and to inform spine surgeons of strategies to minimize the risk of prone patient morbidity.展开更多
Many underground engineering projects show that rockburst can occur in rocks at great depth and high temperature, and temperature is a critical factor affecting the intensity of rockburst. In general, temperature can ...Many underground engineering projects show that rockburst can occur in rocks at great depth and high temperature, and temperature is a critical factor affecting the intensity of rockburst. In general, temperature can affect the energy storage, dissipation, and surplus in rock. To explore the influence of temperature on the energy storage and dissipation characteristics and rockburst proneness, the present study has carried out a range of the uniaxial compression(UC) and single-cyclic loading-unloading uniaxial compression(SCLUC) tests on pre-heated granite specimens at 20℃-700℃. The results demonstrate that the rockburst proneness of pre-heated granite initially increases and subsequently decreases with the increase of temperature. The temperature of 300℃ has been found to be the threshold for rockburst proneness. Meanwhile, it is found that the elastic strain energy density increases linearly with the total input strain energy density for the pre-heated granites, confirming that the linear energy property of granite has not been altered by temperature. According to this inherent property, the peak elastic strain energy of pre-heated granites can be calculated accurately. On this basis, utilising the residual elastic energy index, the rockburst proneness of pre-heated granite can be determined quantitatively. The obtained results from high to low are: 317.9 k J/m^(3)(300℃), 264.1 k J/m^(3)(100℃), 260.6 k J/m^(3)(20℃), 235.5 k J/m^(3)(500℃), 158.9 k J/m^(3)(700℃), which are consistent with the intensity of actual rockburst for specimens. In addition, the relationship between temperature and energy storage capacity(ESC) of granite was discussed, revealing that high temperature impairs ESC of rocks, which is essential for reducing the rockburst proneness. This study provides some new insights into the rockburst proneness evaluation in high-temperature rock engineering.展开更多
In this study,we examined 3-month-old female mice from the senescence-accelerated prone mouse 8 strain and age-matched homologous normal aging female mice from the senescence accelerated-resistant mouse 1 strain.Mice ...In this study,we examined 3-month-old female mice from the senescence-accelerated prone mouse 8 strain and age-matched homologous normal aging female mice from the senescence accelerated-resistant mouse 1 strain.Mice from each strain were housed in an enriched environment（including a platform,running wheels,tunnel,and some toys）or a standard environment for 3 months.The mice housed in the enriched environment exhibited shorter escape latencies and a greater percentage of time in the target quadrant in the Morris water maze test,and they exhibited reduced errors and longer latencies in step-down avoidance experiments compared with mice housed in the standard environment.Correspondently,brain-derived neurotrophic factor mRNA and protein ex- pression in the hippocampus was significantly higher in mice housed in the enriched environment compared with those housed in the standard environment,and the level of hippocampal brain-derived neurotrophic factor protein was positively correlated with the learning and memory abilities of mice from the senescence-accelerated prone mouse 8 strain.These results suggest that an enriched environment improved cognitive performance in mice form the senescence-accelerated prone mouse 8 strain by increasing brain-derived neurotrophic factor expression in the hippocampus.展开更多
We established a stroke-prone renovascular hypertensive rat model by bilateral constriction of the renal artery with sliver loop clips. After ten weeks, middle cerebral artery occlusion was induced for 2 hours. The ra...We established a stroke-prone renovascular hypertensive rat model by bilateral constriction of the renal artery with sliver loop clips. After ten weeks, middle cerebral artery occlusion was induced for 2 hours. The rats then received electro-acupuncture at Baihui （DU 20） and Dazhui （DU 14） after onset of ischemia for 30 days. In situ hybridization study showed that electroacupuncture significantly reduced the number of neurocan mRNA-positive cells in the ischemic penumbra and hippocampal tissues of rats. Electron microscopy results demonstrated that the structure of neurons and blood vessels in the ischemic tissues were restored with electroacupuncture. Overall, these data suggest that electroacupuncture may protect neurons against ischemic reperfusion injury in stroke-prone renovascular hypertensive rats, which may be regulated by downregulation of expression of nerve inhibitory factor neurocan mRNA.展开更多
A new method based on rough set theory and genetic algorithm was proposedto predict the rock burst proneness. Nine influencing factors were first selected, and then,the decision table was set up. Attributes were reduc...A new method based on rough set theory and genetic algorithm was proposedto predict the rock burst proneness. Nine influencing factors were first selected, and then,the decision table was set up. Attributes were reduced by genetic algorithm. Rough setwas used to extract the simplified decision rules of rock burst proneness. Taking the practical engineering for example, the rock burst proneness was evaluated and predicted bydecision rules. Comparing the prediction results with the actual results, it shows that theproposed method is feasible and effective.展开更多
BACKGROUND Acute respiratory distress syndrome(ARDS)is an acute,diffuse,inflammatory lung injury.Previous studies have shown prone position ventilation(PPV)to be associated with improvement in oxygenation.However,its ...BACKGROUND Acute respiratory distress syndrome(ARDS)is an acute,diffuse,inflammatory lung injury.Previous studies have shown prone position ventilation(PPV)to be associated with improvement in oxygenation.However,its role in patients with ARDS caused by sepsis remains unknown.AIM To analyze the clinical effects of PPV in patients with ARDS caused by sepsis.METHODS One hundred and two patients with ARDS were identified and divided into a control group(n=55)and a PPV treatment group(n=47).Outcomes included oxygenation index,lung compliance(Cst)and platform pressure(Pplat),which were compared between the two groups after ventilation.Other outcomes included heart rate(HR),mean arterial pressure(MAP),central venous pressure(CVP),left ventricular ejection fraction(LVEF),the length of mechanical ventilation time and intensive care unit(ICU)stay,and levels of C-reactive protein(CRP),procalcitonin(PCT),and interleukin-6(IL-6)after ventilation.Finally,mortality rate was also compared between the two groups.RESULTS On the first day after ventilation,the oxygenation index and Cst were higher and Pplat level was lower in the PPV group than in the conventional treatment group(P<0.05).There were no significant differences in oxygenation index,Cst,and Pplat levels between the two groups on the 2^(nd),4^(th),and 7^(th) day after ventilation(P>0.05).There were no significant differences in HR,MAP,CVP,LVEF,duration of mechanical ventilation and ICU stay,and the levels of CRP,PCT,and IL-6 between the two groups on the first day after ventilation(all P>0.05).The mortality rates on days 28 and 90 in the PPV and control groups were 12.77% and 29.09%,and 25.53% and 45.45%,respectively(P<0.05).CONCLUSION PPV may improve respiratory mechanics indices and may also have mortality benefit in patients with ARDS caused by sepsis.Finally,PPV was not shown to cause any adverse effects on hemodynamics and inflammation indices.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.52304142)basic scientific research fees of colleges and universities directly under Inner Mongolia Autonomous Region(Grant No.2023QNJS108).
文摘The natural property of rock material,whether impact occurs,is the key influencing factor of the occurrence of rock burst disaster.To accurately assess rock burst proneness,this study focuses on typical sandstone as the research object.Uniaxial cyclic loading and unloading tests were conducted to measure the elastic strain energy accumulated in sandstone under different stress levels and a relationship between elastic strain energy and stress level was established.The results show that:(1)The peak stress under cyclic loading and unloading conditions is slightly lower than the uniaxial compressive strength.With an increase in the number of cycles,the internal damage of sandstone continues to accumulate,and the mechanical properties such as compressive strength continue to deteriorate;(2)With an increase in stress,the input strain energy,elastic strain energy,and dissipated strain energy also increase;(3)When the stress is low,the increase in elastic strain energy is large and shows a steady growth;with an increase in stress,the increase of elastic strain energy decreases;(4)The square of stress at any time has a good linear relationship with elastic strain energy.According to the relationship obtained from the test,the elastic strain energy at the peak stress time can be obtained;(5)A new criterion for assessing rock burst proneness is proposed:residual energy release rate index W_(T),which characterizes the energy release per unit time when the rock burst occurs.The intervals for evaluating the rock burst proneness of the residual energy release rate index W_(T) are as follows:W_(T)<0.025,indicating no rock burst proneness;0.025≤W_(T)<0.15,indicating weak rock burst proneness;0.15≤W_(T)<2,indicating medium rock burst proneness;W_(T)>2,indicating strong rock burst proneness;and(6)The rationality of the proposed residual energy release rate index W_(T) is verified by the multi-index method and the multi-sample method,and the proposed residual energy release rate index is used to determine the rock burst proneness of 10 kinds of rock samples.The evaluation accuracy is shown to be high,and it can reflect the actual rock burst proneness.
基金supported by the Hubei Provincial Engineering Research Center of Slope Habitat Construction Technique Using Cement-based Materials Open Research Program (Grant No. 2022SNJ112022SNJ12)+4 种基金National Natural Science Foundation of China (Grant No. 42371014)Hubei Key Laboratory of Disaster Prevention and Mitigation (China Three Gorges University) Open Research Program (Grant No. 2022KJZ122023KJZ19)CRSRI Open Research Program (Grant No. CKWV2021888/KY)the Key Laboratory of Mountain Hazards and Earth Surface Processes, Chinese Academy of Sciences (Grant No. KLMHESP20-0)。
文摘Understanding the spatial heterogeneity of debris-flow-prone areas holds significant implications for regional risk management, particularly in seismically active regions with geological faults. Despite the significance of this knowledge, a comprehensive quantification of the influence of regional topographical and geological factors on the spatial heterogeneity of debris-flow-prone areas has been lacking. This study selected the Hengduan Mountains, an earthquake-prone region characterized by diverse surface conditions and complex landforms, as a representative study area. An improved units zoning and objective factors identification methodology was employed in earthquake and fault analysis to assess the impact of seismic activity and geological factors on spatial heterogeneity of debrisflow prone areas. Results showed that the application of GIS technology with hydrodynamic intensity and geographical units analysis can effectively analyze debris-flow prone areas. Meanwhile, earthquake and fault zones obviously increase the density of debrisflow prone catchments and make them unevenly distributed. The number of debris-flow prone areas shows a nonlinear variation with the gradual increase of geomorphic factor value. Specifically, the area with 1000 m-2500 m elevation difference, 25°-30° average slope, and 0.13-0.15 land use index is the most favorable conditions for debris-flow occurrence;The average annual rainfall from 600 to 1150 mm and landslides gradient from 16° to 35° are the main causal factors to trigger debris flow. Our study sheds light on the quantification of spatial heterogeneity in debris flow-prone areas in earthquake-prone regions, which can offer crucial support for post-debris flow risk management strategies.
文摘Introduction: Covid-19 is defined as a pandemic disease by WHO, in November 2023, WHO recorded 772.1 million confirmed cases and 6.9 million deaths, including 68,382 confirmed cases and 1426 deaths in Madagascar. The management of severe cases of Covid-19 remains a challenge for the healthcare system in a resource-limited country, due to the consumption of human resources, the shortage of medical resources and the lack of capacity in resource-limited countries. Prone position (PP) improves survival in acute respiratory distress, and numerous studies have shown that during Covid-19, it reduces mortality rates at 28 and 90 days, and increases the number of days without mechanical ventilation. However, data on the beneficial effects of PP remain limited in low-income countries. In this context, our study aims to evaluate the benefits of the prone position for severe Covid-19 patients in a referral center in Madagascar. Method: This is a retrospective cohort study, during the 2<sup>nd</sup> and 3<sup>rd</sup> waves of COVID-19, over a period of 11 months in two wards managing COVID-19 cases. We included all patients aged 15 and over with severe forms of COVID-19 who required 6 l/min of oxygen therapy. Results: We enrolled 123 patients, including 40 in the prone position and 83 in the supine position, with a mean age of 60.5 ± 12 years. The prone position (DV) reduced the risk of probable complications of COVID-19 with a strong association in terms of use of respiratory assistance (OR = 0.15;95% CI = 0.05 - 0.47), respiratory deterioration (OR = 0.22;95% CI = 0.09 - 0.58), shock (OR = 0.30;95% CI = 0.11 - 0.79) and hemodynamic instability (OR = 0.33;95% CI = 0.12 - 0.95). Univariate analysis of the effect of prone position on SpO<sub>2</sub> showed improvement with significant associations with SpO<sub>2</sub> at Day 1- Day 3, D4 - D7, D8 - D14, and persisting even at D15 - D21, D3 and D2 before discharge, and at discharge. In the overall population, the mean length of hospital stay was 22.8 ± 22.1 days, with extremes of 1 and 67 days. Univariate analysis of the effect of the prone position showed a reduction in length of hospital stay with a strong association (p = 0.001) and a mean difference of 14 days. The prone position reduced mortality with a significant association (OR = 0.44;95% CI = 0.20 - 0.98). Conclusion: Awake prone position prevents complications of COVID, improves SPO<sub>2</sub> even up to hospital discharge and reduces hospital stay. This practice is simple, less costly and suitable in low income countries.
基金Project(42077244)supported by the National Natural Science Foundation of ChinaProject(SDGZK2431)supported by the State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering,Sichuan University,China。
文摘The residual elastic energy index is a scientific evaluation index for rockburst proneness.In laboratory test,it is sometimes difficult to obtain the post-peak curve or to test the rock sample several times,which makes it impossible to calculate the residual elastic energy index accurately.Based on 241 sets of experimental data and four input indexes of density,elastic modulus,peak intensity and peak input strain energy,this study proposed a machine learning model combining k-means clustering algorithm and random forest regression model:cluster forest(CF)model.The research employed a stratified sampling method on the dataset to ensure the representativeness and balance of the samples.Subsequently,grid search and five-fold cross-validation were utilized to optimize the model’s hyperparameters,aiming to enhance its generalization capability and prediction accuracy.Finally,the performance of the optimal model was evaluated using a test set and compared with five other commonly used models.The results indicate that the CF model outperformed the other models on the testing set,with a mean absolute error of 6.6%,and an accuracy of 93.9%.The results of sensitivity analyses reveal the degree of influence of each variable on rockburst proneness and the applicability of the CF model when the input parameters are missing.The robustness and generalization ability of the model were verified by introducing experimental data from other studies,and the results confirmed the reliability and applicability of the model.Therefore,the model not only effectively simplifies the acquisition of the residual elastic energy index,but also shows excellent performance and wide applicability.
文摘A mathematical model describing the risks of road accidents has been built on the basis of statistical data of drivers’ accident rate. It has been revealed that drivers can be divided by the degree of their accident proneness into four categories with sharply differing probabilities of road accidents. It has been shown that there is a possibility of classification of drivers in accordance with specified categories.
文摘Spinal surgery is usually performed in the prone position, which is a longer and more difficult procedure and is prone to complications such as circulatory dysfunction and stress injuries. Among them, stress injury is the main complication of prone spine surgery, but the reasons for stress injury in prone spine surgery are not clear, and whether prone cardiopulmonary resuscitation (CPR) can be used needs to be further verified. Supine cardiopulmonary resuscitation is commonly used in posterior spinal surgery, retroperitoneal surgery, and so on, which can effectively improve the patient’s hypoxemia. Such surgeries require a high level of anesthetic management, and cardiopulmonary resuscitation is necessary if a patient in a prone position experiences cardiac arrest. In the process of cardiopulmonary resuscitation, supine cardiopulmonary resuscitation is often used, especially for some obese patients, if they are immediately changed to the supine position, it takes up more time, there may be wound infection, and there is a possibility of missing the optimal rescue and resuscitation time. Based on this, this paper reviews the use of prone-position cardiopulmonary resuscitation for spinal surgery in the prone position.
基金Research Project of the 900th Hospital of Joint Logistics Support Force(Project No.2020L30)。
文摘Objective:To investigate the effects of prone ventilation in patients with severe traumatic brain injury combined with pulmonary infection.Methods:A total of 100 patients with severe traumatic brain injury combined with pulmonary infection in the hospital were randomly divided into a prone ventilation group and a conventional ventilation group,with 50 patients in each group.The Glasgow Coma Scale(GCS)score,APACHE II score,sputum culture results,oxygenation indicators,and prognosis were compared between the two groups.Data were processed using SPSS 25.0 statistical software,and t-tests and chi-square tests were used to compare continuous and categorical variables,respectively.Results:The experimental group showed better oxygenation indicators,a lower positive rate of sputum cultures,and reduced intracranial pressure compared to the control group(all P<0.05).Multivariate Cox regression analysis indicated that GCS score,APACHE II score,and prone ventilation were independent risk factors affecting patient prognosis(all P<0.05).Conclusion:Prone ventilation can improve oxygenation,reduce the risk of pulmonary infection,and decrease intracranial pressure in patients with severe traumatic brain injury combined with pulmonary infection,thereby improving patient prognosis.GCS score and APACHE II score can serve as important indicators for prognostic evaluation.
文摘Objective:To explore effective nursing strategies for patients undergoing prone-position laparoscopic partial nephrectomy.Methods:A total of 19 patients undergoing prone-position laparoscopic partial nephrectomy were selected,with hospital admission spanning from January 2024 to June 2024.Patients were randomly divided into the study group(n=10)and the control group(n=9).The control group received basic nursing care,while the study group received comprehensive high-quality nursing care.The recovery period,length of hospital stay,complication rates,SCL-90 scores,and nursing quality scores were compared between the two groups.Results:The recovery period and hospital stay were significantly shorter in the study group compared to the control group(P<0.05).The complication rate in the study group was lower than that in the control group(P<0.05).After the nursing intervention,the SCL-90 scores of the study group were lower than those of the control group(P<0.05).Nursing quality scores were higher in the study group than in the control group(P<0.05).Conclusion:Comprehensive high-quality nursing intervention for patients undergoing prone-position laparoscopic partial nephrectomy can shorten the recovery period and hospital stay,reduce the complication rate,improve mental health,and enhance nursing quality,making it suitable for wider application in medical institutions.
基金Project(41877272)supported by the National Natural Science Foundation of ChinaProject(2020zzts715)supported by the Fundamental Research Funds for the Central Universities of Central South University,ChinaProject(2242020R10023)supported by the Fundamental Research Funds for the Central Universities of Southeast University,China。
文摘To review the rockburst proneness(or tendency)criteria of rock materials and compare the judgment accuracy of them,twenty criteria were summarized,and their judgment accuracy was evaluated and compared based on the laboratory tests on fourteen types of rocks.This study begins firstly by introducing the twenty rockburst proneness criteria,and their origins,definitions,calculation methods and grading standards were summarized in detail.Subsequently,to evaluate and compare the judgment accuracy of the twenty criteria,a series of laboratory tests were carried out on fourteen types of rocks,and the rockburst proneness judgment results of the twenty criteria for the fourteen types of rocks were obtained accordingly.Moreover,to provide a unified basis for the judgment accuracy evaluation of above criteria,a classification standard(obtained according to the actual failure results and phenomena of rock specimen)of rockburst proneness in laboratory tests was introduced.The judgment results of the twenty criteria were compared with the judgment results of this classification standard.The results show that the judgment results of the criterion based on residual elastic energy(REE)index are completely consistent with the actual rockburst proneness,and the other criteria have some inconsistent situations more or less.Moreover,the REE index is based on the linear energy storage law and defined in form of a difference value and considered the whole failure process,and these superior characteristics ensure its accuracy.It is believed that the criterion based on REE index is comparatively more accurate and scientific than other criteria,and it can be recommended to be applied to judge the rockburst proneness of rock materials.
文摘Acute respiratory distress syndrome(ARDS) is a syndrome with heterogeneous underlying pathological processes. It represents a common clinical problem in intensive care unit patients and it is characterized by high mortality. The mainstay of treatment for ARDS is lung protective ventilation with low tidal volumes and positive end-expiratory pressure sufficient for alveolar recruitment. Prone positioning is a supplementary strategy available in managing patients with ARDS. It was first described 40 years ago and it proves to be in alignment with two major ARDS pathophysiological lung models; the "sponge lung"- and the "shape matching"-model. Current evidence strongly supports that prone positioning has beneficial effects on gas exchange, respiratory mechanics, lung protection and hemodynamics as it redistributes transpulmonary pressure, stress and strain throughout the lung and unloads the right ventricle. The factors that individually influence the time course of alveolar recruitment and the improvement in oxygenation during prone positioning have not been well characterized. Although patients' response to prone positioning is quite variable and hard to predict, large randomized trials and recent meta-analyses show that prone position in conjunction with a lung-protective strategy, when performed early and in sufficient duration, may improve survival in patients with ARDS. This pathophysiology-based review and recent clinical evidence strongly support the use of prone positioning in the early management of severe ARDS systematically and not as a rescue maneuver or a last-ditch effort.
基金Project(2010CB226804)supported by the National Basic Research Program(973 Program)of ChinaProject(11202108)supported by the National Natural Science Foundation of ChinaProject(BK20130189)supported by the Natural Science Foundation of Jiangsu Province,China
文摘Rock burst is a severe disaster in mining and underground engineering,and it is important to predict the rock burst risk for minimizing the loss during the constructing process.The rock burst proneness was connected with the acoustic emission(AE) parameter in this work,which contributes to predicting the rock burst risk using AE technique.Primarily,a rock burst proneness index is proposed,and it just depends on the heterogeneous degree of rock material.Then,the quantificational formula between the value of rock burst proneness index and the accumulative AE counts in rock sample under uniaxial compression with axial strain increases is developed.Finally,three kinds of rock samples,i.e.,granite,limestone and sandstone are tested about variation of the accumulative AE counts under uniaxial compression,and the test data are fitted well with the theoretic formula.
文摘Complications associated with prone surgical positioning during elective spine surgery have the potential to cause serious patient morbidity.Although many ofthese complications remain uncommon,the range of possible morbidities is wide and includes multiple organ systems.Perioperative visual loss(POVL)is a well described,but uncommon complication that may occur due to ischemia to the optic nerve,retina,or cerebral cortex.Closed-angle glaucoma and amaurosis have been reported as additional etiologies for vision loss following spinal surgery.Peripheral nerve injuries,such as those caused by prolonged traction to the brachial plexus,are more commonly encountered postoperative events.Myocutaneous complications including pressure ulcers and compartment syndrome may also occur after prone positioning,albeit rarely.Other uncommon positioning complications such as tongue swelling resulting in airway compromise,femoral artery ischemia,and avascular necrosis of the femoral head have also been reported.Many of these are well-understood and largely avoidable through thoughtful attention to detail.Other complications,such as POVL,remain incompletely understood and thus more difficult to predict or prevent.Here,the current literature on the complications of prone positioning for spine surgery is reviewed to increase awareness of the spectrum of potential complications and to inform spine surgeons of strategies to minimize the risk of prone patient morbidity.
基金supported by the National Natural Science Foundation of China (Grant No. 41877272)the Fundamental Research Funds for the Central Universities (Grant No.2242022k30054)the Fundamental Research Funds for the Central Universities of Central South University (Grant No.2021zzts0861)。
文摘Many underground engineering projects show that rockburst can occur in rocks at great depth and high temperature, and temperature is a critical factor affecting the intensity of rockburst. In general, temperature can affect the energy storage, dissipation, and surplus in rock. To explore the influence of temperature on the energy storage and dissipation characteristics and rockburst proneness, the present study has carried out a range of the uniaxial compression(UC) and single-cyclic loading-unloading uniaxial compression(SCLUC) tests on pre-heated granite specimens at 20℃-700℃. The results demonstrate that the rockburst proneness of pre-heated granite initially increases and subsequently decreases with the increase of temperature. The temperature of 300℃ has been found to be the threshold for rockburst proneness. Meanwhile, it is found that the elastic strain energy density increases linearly with the total input strain energy density for the pre-heated granites, confirming that the linear energy property of granite has not been altered by temperature. According to this inherent property, the peak elastic strain energy of pre-heated granites can be calculated accurately. On this basis, utilising the residual elastic energy index, the rockburst proneness of pre-heated granite can be determined quantitatively. The obtained results from high to low are: 317.9 k J/m^(3)(300℃), 264.1 k J/m^(3)(100℃), 260.6 k J/m^(3)(20℃), 235.5 k J/m^(3)(500℃), 158.9 k J/m^(3)(700℃), which are consistent with the intensity of actual rockburst for specimens. In addition, the relationship between temperature and energy storage capacity(ESC) of granite was discussed, revealing that high temperature impairs ESC of rocks, which is essential for reducing the rockburst proneness. This study provides some new insights into the rockburst proneness evaluation in high-temperature rock engineering.
基金supported by the Program of Health Department of Hebei Province,No.20090338the Natural Science Foundation of Hebei Province,No.C2009001242Funding Project for Introduced Abroad Study Personnel of Hebei Province
文摘In this study,we examined 3-month-old female mice from the senescence-accelerated prone mouse 8 strain and age-matched homologous normal aging female mice from the senescence accelerated-resistant mouse 1 strain.Mice from each strain were housed in an enriched environment（including a platform,running wheels,tunnel,and some toys）or a standard environment for 3 months.The mice housed in the enriched environment exhibited shorter escape latencies and a greater percentage of time in the target quadrant in the Morris water maze test,and they exhibited reduced errors and longer latencies in step-down avoidance experiments compared with mice housed in the standard environment.Correspondently,brain-derived neurotrophic factor mRNA and protein ex- pression in the hippocampus was significantly higher in mice housed in the enriched environment compared with those housed in the standard environment,and the level of hippocampal brain-derived neurotrophic factor protein was positively correlated with the learning and memory abilities of mice from the senescence-accelerated prone mouse 8 strain.These results suggest that an enriched environment improved cognitive performance in mice form the senescence-accelerated prone mouse 8 strain by increasing brain-derived neurotrophic factor expression in the hippocampus.
基金Research Projects of Science and Technology Bureau of Foshan City, No. 04080131the Administration Bureau of Traditional Chinese Medicine of Guangdong Province, No. 1050006the Natural Science Foundation of Guangdong Province, No. 8152800007000001
文摘We established a stroke-prone renovascular hypertensive rat model by bilateral constriction of the renal artery with sliver loop clips. After ten weeks, middle cerebral artery occlusion was induced for 2 hours. The rats then received electro-acupuncture at Baihui （DU 20） and Dazhui （DU 14） after onset of ischemia for 30 days. In situ hybridization study showed that electroacupuncture significantly reduced the number of neurocan mRNA-positive cells in the ischemic penumbra and hippocampal tissues of rats. Electron microscopy results demonstrated that the structure of neurons and blood vessels in the ischemic tissues were restored with electroacupuncture. Overall, these data suggest that electroacupuncture may protect neurons against ischemic reperfusion injury in stroke-prone renovascular hypertensive rats, which may be regulated by downregulation of expression of nerve inhibitory factor neurocan mRNA.
基金Supported by the Youth Science Foundation of North China University of Water Conservancy and Electric Power(HSQJ2009016)
文摘A new method based on rough set theory and genetic algorithm was proposedto predict the rock burst proneness. Nine influencing factors were first selected, and then,the decision table was set up. Attributes were reduced by genetic algorithm. Rough setwas used to extract the simplified decision rules of rock burst proneness. Taking the practical engineering for example, the rock burst proneness was evaluated and predicted bydecision rules. Comparing the prediction results with the actual results, it shows that theproposed method is feasible and effective.
基金Supported by Science and Technology Plan of Jiangxi Provincial Health Commission,No.202130095.
文摘BACKGROUND Acute respiratory distress syndrome(ARDS)is an acute,diffuse,inflammatory lung injury.Previous studies have shown prone position ventilation(PPV)to be associated with improvement in oxygenation.However,its role in patients with ARDS caused by sepsis remains unknown.AIM To analyze the clinical effects of PPV in patients with ARDS caused by sepsis.METHODS One hundred and two patients with ARDS were identified and divided into a control group(n=55)and a PPV treatment group(n=47).Outcomes included oxygenation index,lung compliance(Cst)and platform pressure(Pplat),which were compared between the two groups after ventilation.Other outcomes included heart rate(HR),mean arterial pressure(MAP),central venous pressure(CVP),left ventricular ejection fraction(LVEF),the length of mechanical ventilation time and intensive care unit(ICU)stay,and levels of C-reactive protein(CRP),procalcitonin(PCT),and interleukin-6(IL-6)after ventilation.Finally,mortality rate was also compared between the two groups.RESULTS On the first day after ventilation,the oxygenation index and Cst were higher and Pplat level was lower in the PPV group than in the conventional treatment group(P<0.05).There were no significant differences in oxygenation index,Cst,and Pplat levels between the two groups on the 2^(nd),4^(th),and 7^(th) day after ventilation(P>0.05).There were no significant differences in HR,MAP,CVP,LVEF,duration of mechanical ventilation and ICU stay,and the levels of CRP,PCT,and IL-6 between the two groups on the first day after ventilation(all P>0.05).The mortality rates on days 28 and 90 in the PPV and control groups were 12.77% and 29.09%,and 25.53% and 45.45%,respectively(P<0.05).CONCLUSION PPV may improve respiratory mechanics indices and may also have mortality benefit in patients with ARDS caused by sepsis.Finally,PPV was not shown to cause any adverse effects on hemodynamics and inflammation indices.
