As part of my master’s programme in resource use and environmental science at China Agricultural University,I had the privilege of joining a study trip to the Shiyang River Basin and its surrounding areas from 17 to ...As part of my master’s programme in resource use and environmental science at China Agricultural University,I had the privilege of joining a study trip to the Shiyang River Basin and its surrounding areas from 17 to 21 July 2025.This trip to Gansu Province was organised under the China-Africa Joint Centre for Agricultural Demonstration and Training in Arid Regions programme,an initiative aligned with President Xi Jinping’s call for deeper China-Africa cooperation.展开更多
To examine the effect of bedding angle upon burst proneness in terms of energy,phyllites with seven various bedding angles are selected for conventional uniaxial compression and single-cyclic loading eunloading uniaxi...To examine the effect of bedding angle upon burst proneness in terms of energy,phyllites with seven various bedding angles are selected for conventional uniaxial compression and single-cyclic loading eunloading uniaxial compression tests.The ejection and failure during compression process of phyllites are monitored in real-time by high-speed camera system.The results demonstrate that the phyllites with different bedding angles all consistently follow the linear energy storage and dissipation(LESD)law during compression.The ultimate energy storage of phyllites with varying bedding angles can be calculated precisely via using the LESD law.Based on this,four kinds of energy-based rockburst indices are applied to quantitatively assess the burst proneness for phyllites.Combined with the recorded images of high-speed camera system,ejection distance,and mass of rock fragments and powder,the burst proneness for phyllites with various bedding angles is qualitatively evaluated adopting the far-field ejection mass ratio.Next,burst proneness of anisotropic phyllites is assessed quantitatively and qualitatively.It is found that phyllites with bedding angles of 0°,15°,and 90°have a high burst proneness,and that with bedding angle of 30°has a medium burst proneness,whereas the ones with bedding angles of 45°,60°,and 75°have a low burst proneness.Finally,the published experimental data of shale and sandstone specimens with different bedding angles are extracted,and it is preliminarily verified that the bedding angle does not change the LESD law of rocks.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
Accurate prediction of rockburst proneness is one of challenges for assessing the rockburst risk and selecting effective control measures.This study aims to assess rockburst proneness by considering the energy charact...Accurate prediction of rockburst proneness is one of challenges for assessing the rockburst risk and selecting effective control measures.This study aims to assess rockburst proneness by considering the energy characteristics and qualitative information during rock failure.Several representative rock types in cylindrical and cuboidal sample shapes were tested under uniaxial compression conditions and the failure progress was detected by a high-speed camera.The far-field ejection mass ratio(FEMR)was determined considering the qualitative failure information of the rock samples.The peak-strength energy impact index and the residual elastic energy index were used to quantitatively evaluate the rockburst proneness of both cylindrical and cuboidal samples.Further,the performance of these two indices was analyzed by comparing their estimates with the FEMR.The results show that the accuracy of the residual elastic energy index is significantly higher than that of the peak-strength energy impact index.The residual elastic energy index and the FEMR are in good agreement for both cylindrical and cuboidal rock materials.This is because these two indices can essentially reflect the common energy release mechanism characterized by the mass,ejection velocity,and ejection distance of rock fragments.It suggests that both the FEMR and the residual elastic energy index can be used to accurately measure the rockburst proneness of cylindrical and cuboidal samples based on uniaxial compression test.展开更多
Diabetes has been classified mainly into types 1 and 2.Some type 2 diabetes patients,when developing ketosis,have been labeled as having atypical diabetes.Lately,syndromes of ketosis-prone diabetes,primarily in patien...Diabetes has been classified mainly into types 1 and 2.Some type 2 diabetes patients,when developing ketosis,have been labeled as having atypical diabetes.Lately,syndromes of ketosis-prone diabetes,primarily in patients who we previously classified as type 2 diabetics,have emerged,and calls are being made to even reclassify diabetes.This mini-review will extensively deal with the historical,molecular,phenotypical,and clinical basis of why ketosis-prone diabetes is different than the traditional principles of type 1 and 2 diabetes and should be classified as such.Clinicians,especially those who are not diabetologists or endocrinologists,as well as hospitalists,intensivists,and primary care providers,will greatly benefit from this review.展开更多
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
Introduction: Lung protective ventilation therapy with low tidal volume-high PEEP is the standard treatment for the patients with acute respiratory distress syndrome (ARDS). Oscillators are occasionally used for salva...Introduction: Lung protective ventilation therapy with low tidal volume-high PEEP is the standard treatment for the patients with acute respiratory distress syndrome (ARDS). Oscillators are occasionally used for salvage ventilation in cases where poor compliance restricts the use of traditional ventilation with ARDS. In addition to ventilator therapy, prone positioning has been used to improve oxygenation. We presented a challenging case of ARDS, which failed medical management extracorporeal membrane oxygenation (ECMO) support and oscillatory ventilation. Prone positioning was initiated which improved oxygenation, respiratory compliance and posterior atelectasis. Case presentation: A 41-year-old morbid obese female developed ARDS due to influenza pneumonia. The patient remained hypoxic despite optimum medical and ventilator management and required veno-venous extracorporeal membrane oxygenation (VV ECMO). CT scan of the chest showed ARDS with posterior consolidation. Despite ARDSnet ventilation support, antiviral therapy and ECMO support, there was no clinical improvement. High frequency oscillatory ventilation was initiated on ECMO day #13, which resulted in no respiratory improvement over the next 5 days. On ECMO day #18, the patient was placed on a Rotaprone? bed Therapy, utilizing a proning strategy of 16 hours a day. The clinical improvements observed were resolving of the consolidation on CXR, improvements in ventilatory parameters and decreased oxygen requirements. The patient was successfully weaned off ECMO on POD#25 (8 days post prone bed). Conclusions: Prone position improved oxygen saturation and pulmonary compliance in severe ARDS requiring ECMO and it might facilitate early weaning.展开更多
In this paper,the estimation for a class of generalized varying coefficient models with error-prone covariates is considered.By combining basis function approximations with some auxiliary variables,an instrumental var...In this paper,the estimation for a class of generalized varying coefficient models with error-prone covariates is considered.By combining basis function approximations with some auxiliary variables,an instrumental variable type estimation procedure is proposed.The asymptotic results of the estimator,such as the consistency and the weak convergence rate,are obtained.The proposed procedure can attenuate the effect of measurement errors and have proved workable for finite samples.展开更多
Cardiac arrest in unusual positions represents an additional challenge for anesthesiologists. This paper reports a successful cardiopulmonary resuscitation during neurosurgical procedure in which high-quality chest co...Cardiac arrest in unusual positions represents an additional challenge for anesthesiologists. This paper reports a successful cardiopulmonary resuscitation during neurosurgical procedure in which high-quality chest compressions was performed in the prone position. The aim of this report is disclose the knowledge of resuscitation maneuvers in a position other than supine. A 77-year-old female patient presented for excision of parietal-occipital meningioma in the prone position with the head fixed on a Mayfield head-holder. During the surgical procedure the sagittal sinus was disrupted. The patient presented an abrupt hemorrhagic shock leading to a cardiac arrest by hypovolemia despite vigorous volume replacement. Cardiac massage was promptly initiated in the prone position. After two minutes, there was a return of spontaneous circulation. The patient was discharged without sequelae. We concluded that high-quality chest compressions in the prone position were able to generate sufficient cardiac output.展开更多
文摘As part of my master’s programme in resource use and environmental science at China Agricultural University,I had the privilege of joining a study trip to the Shiyang River Basin and its surrounding areas from 17 to 21 July 2025.This trip to Gansu Province was organised under the China-Africa Joint Centre for Agricultural Demonstration and Training in Arid Regions programme,an initiative aligned with President Xi Jinping’s call for deeper China-Africa cooperation.
基金supported by the National Natural Science Foundation of China(Grant No.42077244).
文摘To examine the effect of bedding angle upon burst proneness in terms of energy,phyllites with seven various bedding angles are selected for conventional uniaxial compression and single-cyclic loading eunloading uniaxial compression tests.The ejection and failure during compression process of phyllites are monitored in real-time by high-speed camera system.The results demonstrate that the phyllites with different bedding angles all consistently follow the linear energy storage and dissipation(LESD)law during compression.The ultimate energy storage of phyllites with varying bedding angles can be calculated precisely via using the LESD law.Based on this,four kinds of energy-based rockburst indices are applied to quantitatively assess the burst proneness for phyllites.Combined with the recorded images of high-speed camera system,ejection distance,and mass of rock fragments and powder,the burst proneness for phyllites with various bedding angles is qualitatively evaluated adopting the far-field ejection mass ratio.Next,burst proneness of anisotropic phyllites is assessed quantitatively and qualitatively.It is found that phyllites with bedding angles of 0°,15°,and 90°have a high burst proneness,and that with bedding angle of 30°has a medium burst proneness,whereas the ones with bedding angles of 45°,60°,and 75°have a low burst proneness.Finally,the published experimental data of shale and sandstone specimens with different bedding angles are extracted,and it is preliminarily verified that the bedding angle does not change the LESD law of rocks.
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.
基金supported by the National Natural Science Foundation of China(Grant Nos.41877272 and 42077244)the National Key Research and Development Program of China e 2023 Key Special Project(Grant No.2023YFC2907400).
文摘Accurate prediction of rockburst proneness is one of challenges for assessing the rockburst risk and selecting effective control measures.This study aims to assess rockburst proneness by considering the energy characteristics and qualitative information during rock failure.Several representative rock types in cylindrical and cuboidal sample shapes were tested under uniaxial compression conditions and the failure progress was detected by a high-speed camera.The far-field ejection mass ratio(FEMR)was determined considering the qualitative failure information of the rock samples.The peak-strength energy impact index and the residual elastic energy index were used to quantitatively evaluate the rockburst proneness of both cylindrical and cuboidal samples.Further,the performance of these two indices was analyzed by comparing their estimates with the FEMR.The results show that the accuracy of the residual elastic energy index is significantly higher than that of the peak-strength energy impact index.The residual elastic energy index and the FEMR are in good agreement for both cylindrical and cuboidal rock materials.This is because these two indices can essentially reflect the common energy release mechanism characterized by the mass,ejection velocity,and ejection distance of rock fragments.It suggests that both the FEMR and the residual elastic energy index can be used to accurately measure the rockburst proneness of cylindrical and cuboidal samples based on uniaxial compression test.
文摘Diabetes has been classified mainly into types 1 and 2.Some type 2 diabetes patients,when developing ketosis,have been labeled as having atypical diabetes.Lately,syndromes of ketosis-prone diabetes,primarily in patients who we previously classified as type 2 diabetics,have emerged,and calls are being made to even reclassify diabetes.This mini-review will extensively deal with the historical,molecular,phenotypical,and clinical basis of why ketosis-prone diabetes is different than the traditional principles of type 1 and 2 diabetes and should be classified as such.Clinicians,especially those who are not diabetologists or endocrinologists,as well as hospitalists,intensivists,and primary care providers,will greatly benefit from this review.
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.
文摘Introduction: Lung protective ventilation therapy with low tidal volume-high PEEP is the standard treatment for the patients with acute respiratory distress syndrome (ARDS). Oscillators are occasionally used for salvage ventilation in cases where poor compliance restricts the use of traditional ventilation with ARDS. In addition to ventilator therapy, prone positioning has been used to improve oxygenation. We presented a challenging case of ARDS, which failed medical management extracorporeal membrane oxygenation (ECMO) support and oscillatory ventilation. Prone positioning was initiated which improved oxygenation, respiratory compliance and posterior atelectasis. Case presentation: A 41-year-old morbid obese female developed ARDS due to influenza pneumonia. The patient remained hypoxic despite optimum medical and ventilator management and required veno-venous extracorporeal membrane oxygenation (VV ECMO). CT scan of the chest showed ARDS with posterior consolidation. Despite ARDSnet ventilation support, antiviral therapy and ECMO support, there was no clinical improvement. High frequency oscillatory ventilation was initiated on ECMO day #13, which resulted in no respiratory improvement over the next 5 days. On ECMO day #18, the patient was placed on a Rotaprone? bed Therapy, utilizing a proning strategy of 16 hours a day. The clinical improvements observed were resolving of the consolidation on CXR, improvements in ventilatory parameters and decreased oxygen requirements. The patient was successfully weaned off ECMO on POD#25 (8 days post prone bed). Conclusions: Prone position improved oxygen saturation and pulmonary compliance in severe ARDS requiring ECMO and it might facilitate early weaning.
基金Supported by the National Natural Science Foundation of China(11101119)the Natural Science Foundation of Guangxi(2010GXNSFB013051)the Philosophy and Social Sciences Foundation of Guangxi(11FTJ002)
文摘In this paper,the estimation for a class of generalized varying coefficient models with error-prone covariates is considered.By combining basis function approximations with some auxiliary variables,an instrumental variable type estimation procedure is proposed.The asymptotic results of the estimator,such as the consistency and the weak convergence rate,are obtained.The proposed procedure can attenuate the effect of measurement errors and have proved workable for finite samples.
文摘Cardiac arrest in unusual positions represents an additional challenge for anesthesiologists. This paper reports a successful cardiopulmonary resuscitation during neurosurgical procedure in which high-quality chest compressions was performed in the prone position. The aim of this report is disclose the knowledge of resuscitation maneuvers in a position other than supine. A 77-year-old female patient presented for excision of parietal-occipital meningioma in the prone position with the head fixed on a Mayfield head-holder. During the surgical procedure the sagittal sinus was disrupted. The patient presented an abrupt hemorrhagic shock leading to a cardiac arrest by hypovolemia despite vigorous volume replacement. Cardiac massage was promptly initiated in the prone position. After two minutes, there was a return of spontaneous circulation. The patient was discharged without sequelae. We concluded that high-quality chest compressions in the prone position were able to generate sufficient cardiac output.
