Prevention of gob ignitions and explosions in longwall mining using dynamic seals

Most, if not all longwall gob areas accumulate explosive methane-air mixtures that pose a deadly hazard to miners. Numerous mine explosions have originated from explosive gas zones(EGZs) in the longwall gob. Since 2010, researchers at the Colorado School of Mines(CSM) have studied EGZ formation in longwall gobs under two long-term research projects funded by the National Institute for Occupational Safety and Health. Researchers used computational fluid dynamics along with in-mine measurements. For the first time, they demonstrated that EGZs form along the fringe areas between the methane-rich atmospheres and the fresh air ventilated areas along the working face and present an explosion and fire hazard to mine workers. In this study, researchers found that, for progressively sealed gobs, a targeted injection of nitrogen from the headgate and tailgate, along with a back return ventilation arrangement, will create a dynamic seal of nitrogen that effectively separates the methane zone from the face air and eliminates the EGZs to prevent explosions. Using this form of nitrogen injection to create dynamic seals should be a consideration for all longwall operators.

Cervical cancer prevention in China: where are we now, and what's next?

Cervical cancer(CC) epidemiology CC, the fourth most frequently diagnosed malignancy in women worldwide, is a major global health challenge, particularly in low-resource regions. Approximately 88.1% of the 604,000 CC new cases occurred in low-and middle-income countries in 2020, and more than 90% of the 342,000 CC deaths occurred in low-and middle-income countries in 2020~1.

A novel method for simulating nuclear explosion with chemical explosion to form an approximate plane wave: Field test and numerical simulation

A nuclear explosion in the rock mass medium can produce strong shock waves,seismic shocks,and other destructive effects,which can cause extreme damage to the underground protection infrastructures.With the increase in nuclear explosion power,underground protection engineering enabled by explosion-proof impact theory and technology ushered in a new challenge.This paper proposes to simulate nuclear explosion tests with on-site chemical explosion tests in the form of multi-hole explosions.First,the mechanism of using multi-hole simultaneous blasting to simulate a nuclear explosion to generate approximate plane waves was analyzed.The plane pressure curve at the vault of the underground protective tunnel under the action of the multi-hole simultaneous blasting was then obtained using the impact test in the rock mass at the site.According to the peak pressure at the vault plane,it was divided into three regions:the stress superposition region,the superposition region after surface reflection,and the approximate plane stress wave zone.A numerical simulation approach was developed using PFC and FLAC to study the peak particle velocity in the surrounding rock of the underground protective cave under the action of multi-hole blasting.The time-history curves of pressure and peak pressure partition obtained by the on-site multi-hole simultaneous blasting test and numerical simulation were compared and analyzed,to verify the correctness and rationality of the formation of an approximate plane wave in the simulated nuclear explosion.This comparison and analysis also provided a theoretical foundation and some research ideas for the ensuing study on the impact of a nuclear explosion.

Recent advances in promising drugs for primary prevention of gastroesophageal variceal bleeding with cirrhotic portal hypertension

Background:Gastroesophageal variceal bleeding is one of the most severe complications of patients with cirrhosis.Although primary prevention drugs,including non-selectiveβ-blockers,have effectively reduced the incidence of bleeding,their efficacy is limited due to side effects and related contraindications.With recent advances in precision medicine,precise drug treatment provides better treatment efficacy.Data sources:Literature search was conducted in PubMed,MEDLINE and Web of Science for relevant articles published up to May 2022.Information on clinical trials was obtained from https://clinicaltrials.gov/and http://www.chictr.org.cn/.Results:The in-depth understanding of the pathogenesis and advances of portal hypertension has enabled the discovery of multiple molecular targets for promising drugs.According to the site of action,these drugs could be classified into four classes:intrahepatic,extrahepatic,both intrahepatic and extrahepatic targets and others.All these classes of drugs offer advantages over traditional treatments in prevention of gastroesophageal variceal bleeding in patients with cirrhotic portal hypertension.Conclusions:This review classified and summarized the promising drugs,which prevent gastroesophageal variceal bleeding by targeting specific markers of pathogenesis of portal hypertension,demonstrating the significance of using the precision medicine strategy to discover and develop promising drugs for the primary prevention of gastroesophageal variceal bleeding in patients with cirrhotic portal hypertension.

Prevention and Control Strategies of Nosocomial Infection and Effectiveness Evaluation in a Tertiary Teaching Hospital during the Epidemic of COVID-19

Objective: To evaluate the role of prevention and control strategies for nosocomial infection in a tertiary teaching hospital during the sudden outbreak of Corona Virus Disease 2019 (COVID-19). Methods: The hospital initiated an emergency plan involving multi-departmental defense and control. It adopted a series of nosocomial infection prevention and control measures, including strengthening pre-examination and triage, optimizing the consultation process, improving the hospital’s architectural composition, implementing graded risk management, enhancing personal protection, and implementing staff training and supervision. Descriptive research was used to evaluate the short-term effects of these in-hospital prevention and control strategies. The analysis compared changes in related evaluation indicators between January 24, 2020 and February 12, 2020 (Chinese Lunar New Year’s Eve 2020 to lunar January 19) and the corresponding lunar period of the previous year. Results: Compared to the same period last year, the outpatient fever rate increased by 1.85-fold (P P Conclusion: The nosocomial infection prevention and control strategies implemented during this specific period improved the detection and control abilities for the COVID-19 source of infection and enhanced the compliance with measures. This likely contributed significantly to avoiding the occurrence of nosocomial infection.

Adolescent suicide risk factors and the integration of socialemotional skills in school-based prevention programs

Adolescents are considered one of the most vulnerable groups affected by suicide.Rapid changes in adolescents’physical and mental states,as well as in their lives,significantly and undeniably increase the risk of suicide.Psychological,social,family,individual,and environmental factors are important risk factors for suicidal behavior among teenagers and may contribute to suicide risk through various direct,indirect,or combined pathways.Social-emotional learning is considered a powerful intervention measure for addressing the crisis of adolescent suicide.When deliberately cultivated,fostered,and enhanced,selfawareness,self-management,social awareness,interpersonal skills,and responsible decision-making,as the five core competencies of social-emotional learning,can be used to effectively target various risk factors for adolescent suicide and provide necessary mental and interpersonal support.Among numerous suicide intervention methods,school-based interventions based on social-emotional competence have shown great potential in preventing and addressing suicide risk factors in adolescents.The characteristics of school-based interventions based on social-emotional competence,including their appropriateness,necessity,cost-effectiveness,comprehensiveness,and effectiveness,make these interventions an important means of addressing the crisis of adolescent suicide.To further determine the potential of school-based interventions based on social-emotional competence and better address the issue of adolescent suicide,additional financial support should be provided,the combination of socialemotional learning and other suicide prevention programs within schools should be fully leveraged,and cooperation between schools and families,society,and other environments should be maximized.These efforts should be considered future research directions.

Hydromechanical characterization of gas transport amidst uncertainty for underground nuclear explosion detection

Given the challenge of definitively discriminating between chemical and nuclear explosions using seismic methods alone,surface detection of signature noble gas radioisotopes is considered a positive identification of underground nuclear explosions(UNEs).However,the migration of signature radionuclide gases between the nuclear cavity and surface is not well understood because complex processes are involved,including the generation of complex fracture networks,reactivation of natural fractures and faults,and thermo-hydro-mechanical-chemical(THMC)coupling of radionuclide gas transport in the subsurface.In this study,we provide an experimental investigation of hydro-mechanical(HM)coupling among gas flow,stress states,rock deformation,and rock damage using a unique multi-physics triaxial direct shear rock testing system.The testing system also features redundant gas pressure and flow rate measurements,well suited for parameter uncertainty quantification.Using porous tuff and tight granite samples that are relevant to historic UNE tests,we measured the Biot effective stress coefficient,rock matrix gas permeability,and fracture gas permeability at a range of pore pressure and stress conditions.The Biot effective stress coefficient varies from 0.69 to 1 for the tuff,whose porosity averages 35.3%±0.7%,while this coefficient varies from 0.51 to 0.78 for the tight granite(porosity<1%,perhaps an underestimate).Matrix gas permeability is strongly correlated to effective stress for the granite,but not for the porous tuff.Our experiments reveal the following key engineering implications on transport of radionuclide gases post a UNE event:(1)The porous tuff shows apparent fracture dilation or compression upon stress changes,which does not necessarily change the gas permeability;(2)The granite fracture permeability shows strong stress sensitivity and is positively related to shear displacement;and(3)Hydromechanical coupling among stress states,rock damage,and gas flow appears to be stronger in tight granite than in porous tuff.

Unlocking the potential-vitamin D in prostate cancer prevention

Prostate cancer poses a significant health challenge globally,demanding proactive prevention strategies.This editorial explores the emerging role of vitamin D in prostate cancer prevention.While traditionally associated with bone health,vitamin D is increasingly recognized for its broader impact on immune function,cellular signaling,and cancer prevention.Epidemiological studies suggest an intriguing link between vitamin D deficiency and elevated prostate cancer risk,particularly in regions with limited sunlight exposure.Mechanistically,vitamin D regulates cellular processes,inhibiting unchecked cancer cell growth and bols-tering immune surveillance.Personalized prevention strategies,considering individual factors,are deemed essential for harnessing the full potential of vitamin D.To unlock this potential,the future calls for robust research,public awareness campaigns,dietary improvements,and vigilant medical guidance.Collaborative efforts are poised to pave the way toward a future where vitamin D stands as a sentinel in prostate cancer prevention,ushering in hope and improved health for men worldwide.

Navigating nephrotoxic waters:A comprehensive overview of contrast-induced acute kidney injury prevention

Contrast-induced acute kidney injury(CI-AKI)is the third leading cause of acute kidney injury deriving from the intravascular administration of contrast media in diagnostic and therapeutic procedures and leading to longer in-hospital stay and increased short and long-term mortality.Its pathophysiology,although not well-established,revolves around medullary hypoxia paired with the direct toxicity of the substance to the kidney.Critically ill patients,as well as those with pre-existing renal disease and cardiovascular comorbidities,are more susceptible to CI-AKI.Despite the continuous research in the field of CI-AKI prevention,clinical practice is based mostly on periprocedural hydration.In this review,all the investigated methods of prevention are presented,with an emphasis on the latest evidence regarding the potential of RenalGuard and contrast removal systems for CI-AKI prevention in high-risk individuals.

Effectiveness of serological markers of gastric mucosal atrophy in the gastric precancer screening and in cancer prevention

BACKGROUND New markers are needed to improve the effectiveness of serological screening for atrophic gastritis.AIM To develop a cost-effective method for serological screening of atrophic gastritis with a high level of sensitivity.METHODS Of the 169 patients with atrophic gastritis,selected by the visual endoscopic Kimura-Takemoto method,165 showed histological mucosal atrophy using the updated Kimura-Takemoto method.All 169 patients were examined for postprandial levels of gastrin-17(G17)and pepsinogen-1(PG1)using Gastro-Panel®(Biohit Plc,Helsinki,Finland).RESULTS We used the histological standard of five biopsies of the gastric mucosa,in accordance with the Kimura-Takemoto classification system to assess the sensitivity of G17 in detecting gastric mucosal atrophy.We also compared the morphofunctional relationships between the detected histological degree of gastric mucosal atrophy and the serological levels of G17 and PG1,as the markers of atrophic gastritis.The sensitivity of postprandial G17 was 62.2%for serological levels of G17(range:0-4 pmol/L)and 100%for serological G17(range:0-10 pmol/L)for the detection of monofocal severe atrophic gastritis.No strong correlation was found between the levels of PG1 and degree of histological atrophy determined by the Kimura-Takemoto classification system to identify the severity of mucosal atrophy of the gastric corpus.In the presented clinical case of a 63-year-old man with multifocal atrophic gastritis,there is a pronounced positive long-term dynamics of the serological marker of atrophy-postprandial G17,after five months of rennet replacement therapy.CONCLUSION Serological screening of multifocal atrophic gastritis by assessment of postprandial G17 is a cost-effective method with high sensitivity.Postprandial G17 is an earlier marker of regression of atrophic gastritis than a morphological examination of a gastric biopsy in accordance with the Sydney system.Therefore,postprandial G17 is recommended for dynamic monitoring of atrophic gastritis after treatment.

Explosion resistance performance of reinforced concrete box girder coated with polyurea:Model test and numerical simulation

To study the anti-explosion protection effect of polyurea coating on reinforced concrete box girder,two segmental girder specimens were made at a scale of 1:3,numbered as G(without polyurea coating)and PCG(with polyurea coating).The failure characteristics and dynamic responses of the specimens were compared through conducting explosion tests.The reliability of the numerical simulation using LS-DYNA software was verified by the test results.The effects of different scaled distances,reinforcement ratios,concrete strengths,coating thicknesses and ranges of polyurea were studied.The results show that the polyurea coating can effectively enhance the anti-explosion performance of the girder.The top plate of middle chamber in specimen G forms an elliptical penetrating hole,while that in specimen PCG only shows a very slight local dent.The peak vertical displacement and residual displacement of PCG decrease by 74.8% and 73.7%,respectively,compared with those of specimen G.For the TNT explosion with small equivalent,the polyurea coating has a more significant protective effect on reducing the size of fracture.With the increase of TNT equivalent,the protective effect of polyurea on reducing girder displacement becomes more significant.The optimal reinforcement ratio,concrete strength,thickness and range of polyurea coating were also drawn.

Numerical Analysis of Explosion Characteristics of Vent Gas From 18650 LiFePO_(4) Batteries With Different States of Charge

The combustion and explosion characteristics of lithium-ion battery vent gas is a key factor in determining the fire hazard of lithium-ion batteries.Investigating the combustion and explosion hazards of lithium-ion batteries vent gas can provide guidance for rescue and protection in explosion accidents in energy storage stations and new energy vehicles,thereby promoting the application and development of lithium-ion batteries.Based on this understanding and combined with previous research on gas production from lithium-ion batteries,this article conducted a study on the combustion and explosion risks of vent gas from thermal runaway of 18650 LFP batteries with different states of charge(SOCs).The explosion limit of mixed gases affected by carbon dioxide inert gas is calculated through the“elimination”method,and the Chemkin-Pro software is used to numerically simulate the laminar flame speed and adiabatic flame temperature of the battery vent gas.And the concentration of free radicals and sensitivity coefficients of major elementary reactions in the system are analyzed to comprehensively evaluate the combustion explosion hazard of battery vent gas.The study found that the 100%SOC battery has the lowest explosion limit of the vent gas.The inhibitory elementary reaction sensitivity coefficient in the reaction system is lower and the concentration of free radicals is higher.Therefore,it has the maximum laminar flame speed and adiabatic flame temperature.The combustion and explosion hazard of battery vent gas increases with the increase of SOC,and the risk of explosion is the greatest and most harmful when SOC reaches 100%.However,the related hazards decrease to varying degrees with overcharging of the battery.This article provides a feasible method for analyzing the combustion mechanism of vent gas from lithium-ion batteries,revealing the impact of SOC on the hazardousness of battery vent gas.It provides references for the safety of storage and transportation of lithium-ion batteries,safety protection of energy storage stations,and the selection of related fire extinguishing agents.

Beyond dentistry:could prevention and screening for neurodegenerative diseases start in the dental office?

The differential diagnosis of neurodegenerative diseases is complex and relies on clinical assessment,biomarker levels in cerebrospinal fluid,neuroimaging and neuropsychological assessment.The efforts of the scientific community are focused on two aspects:a)the discovery of minimally invasive biomarkers;b)the discovery of early biomarkers that can predict the progression to clinical disease in the presymptomatic stage of a disease.Considering the impact of the number of patients affected by chronic neurodegenerative diseases on public health expenditures,early diagnosis seems to be a primary need of our society.

Physical activity with or without dietary intervention for the prevention of cardiovascular diseases

We and others have published extensively on the benefits of physical activity(PA),exercise training,and cardiorespiratory fitness(CRF)to decrease the prevalence of cardiovascular diseases(CVDs)and CVD and all-cause morbidity and mortality.^(1-5)Both PA and CRF are important;however,CRF,which is mostly obtained through PA,although there is a genetic component,seems to be even more important than PA for predicting prognosis.^(1,4-6)Certainly,the wealth of data from across the world has indicated that increasing PA to enhance CRF while mitigating sedentary behavior would go a long way to lessen the world-wide obesity epidemic and reduce CVD and all-cause mortality.

Community-based prevention and treatment of cardiovascular diseases

The Annual Report on Cardiovascular Health and Diseases in China(2022)intricate landscape of cardiovascular health in China.This is the third section of the report with a specific focus on community-based prevention and treatment of cardiovascular diseases(CVD).This section of the report underscores the importance of initiatives outlined in the"Healthy China 2030 Plan,"emphasizing the comprehensive prevention and control strategy for chronic diseases.A key aspect of this plan involves the establishment of national demonstration areas aimed at comprehensive prevention and control of chronic diseases.By 2020,488 such areas had been set up across China,surpassing the initial target and covering a significant proportion of counties and districts.The report highlights the successful implementation of these strategies in Lishan district,Anshan city,where demonstration areas for comprehensive prevention and control of chronic diseases were launched in 2013.Over the course of seven years,the number of healthy units increased substantially,leading to improvements in managing risk factors for CVD among residents.Significant reductions in prevalence rates of overweight,obesity,smoking,passive smoking,and drinking were observed,along with the development of healthier behaviors among residents.Similarly,Qiaokou district in Wuhan City,designated as a national demonstration area in 2014,implemented comprehensive public health promotion initiatives.Notably,special clinics for hypertension intervention were established,contributing to an increase in self-reported rates of hypertension,a slight decrease in prevalence,and a remarkable improvement in the control rate among treated patients.Overall,these efforts underscore the effectiveness of community-based approaches in driving positive health outcomes and advancing the comprehensive prevention and control of chronic diseases,particularly cardiovascular diseases,in China.

Anti-explosion performance and dynamic response of an innovative multi-layer composite explosion containment vessel

An innovative multi-layer composite explosion containment vessel(CECV)utilizing a sliding steel platealuminum honeycomb-fiber cloth sandwich is put forward to improve the anti-explosion capacity of a conventional single-layer explosion containment vessel(SECV).Firstly,a series of experiments and finite element(FE)simulations of internal explosions are implemented to understand the basic anti-explosion characteristics of a SECV and the rationality of the computational models and methods is verified by the comparison between the experimental results and simulation results.Based on this,the CECV is designed in detail and a variety of FE simulations are carried out to investigate effects of the sandwich structure,the explosive quantity and the laying mode of the fiber cloth on anti-explosion performance and dynamic response of the CECV under internal explosions.Simulation results indicate that the end cover is the critical position for both the SECV and CECV.The maximum pressure of the explosion shock wave and the maximum strain of the CECV can be extremely declined compared to those of the SECV.As a result,the explosive quantity the CECV can sustain is up to 20 times of that the SECV can sustain.Besides,as the explosive quantity increases,the internal pressure of the CECV keeps growing and the plastic deformation and failure of the sandwich structure become more and more severe,yielding plastic strain of the CECV in addition to elastic strain.The results also reveal that the laying angles of the fiber cloth's five layers have an impact on the anti-explosion performance of the CECV.For example,the CECV with fiber cloth layered in 0°/45°/90°/45°/0°mode has the optimal anti-capacity,compared to 0°/0°/0°/0°/0°and 0°/30°/60°/30°/0°modes.Overall,owing to remarkable anti-explosion capacity,this CECV can be regarded as a promising candidate for explosion resistance.

Explosion damage effects of aviation kerosene storage tank under strong ignition

In order to study the blast damage effects of aviation kerosene storage tanks,the out-field explosion experiments of 8 m3fixed-roof tanks were carried out.The fragments,shock wave and fireball thermal radiation of the tank in the presence of bottom oil,half oil and full oil,as well as empty tank,were investigated under internal explosion by various TNT charge contents(1.8 kg,3.5 kg and 6.2 kg).The results showed that the tank roof was the only fragment produced,and the damage forms could be divided into three types.The increase of TNT charge content and oil volume enlarged the deformation of the tank,while the hole ratio presented a trend of increase first and then decrease.The H_r,maxand V_(max)values positively increased as increasing the TNT charge content and oil volume(from empty to half oil),but decreased in full oil.The Pmaxvalues had a progressive increase with the increment of TNT charge content,but not the case with the increase in oil volumes.The development of fireball was divided into three stages:tank roof‘towed'flame,jet flow flame tumbling and rising,and jet flow flame extinguishing.The Dmaxand Hf,maxvalues both increased as increasing TNT charge content and oil volumes.The oscillation phenomenon of fireball temperature was observed in the cooling process.The average temperature of fireball surface was positively correlated with TNT charge content,and negatively correlated with oil volumes.

Tuning microstructures of TC4 ELI to improve explosion resistance

A reasonable heat treatment process for TC4 ELI titanium alloy is crucial to tune microstructures to improve its explosion resistance.However,there is limited investigation on tuning microstructures of TC4 ELI to improve explosion resistance.Moreover,the current challenge is quantifying microstructural changes'effects on explosion resistance and incorporating microstructural changes into finite element models.This work aims to tune microstructures to improve explosion resistance and elucidate their anti-explosion mechanism,and find a suitable method to incorporate microstructural changes into finite element models.In this work,we systematically study the deformation and failure characteristics of TC4 ELI plates with varying microstructures using an air explosion test and LS-DYNA finite element modeling.The Johnson-Cook(JC)constitutive parameters are used to quantify the effects of microstructural changes on explosion resistance and incorporate microstructural changes into finite element models.Because of the heat treatment,one plate has equiaxed microstructure and the other has bimodal microstructure.The convex of the plate after the explosion has a quadratic relationship with the charge mass,and the simulation results demonstrate high reliability,with the error less than 17.5%.Therefore,it is feasible to obtain corresponding JC constitutive parameters based on the differences in microstructures and mechanical properties and characterize the effects of microstructural changes on explosion resistance.The bimodal target exhibits excellent deformation resistance.The response of bimodal microstructure to the shock wave may be more intense under explosive loading.The well-coordinated structure of the bimodal target enhances its resistance to deformation.

Influences of oscillation on the physical stability and explosion characteristics of solid-liquid mixed fuel

The stratification phenomenon resulting from differences in the physical properties of solid-liquid components seriously affect the final combustion and explosion characteristics of mixed fuel under the action of oscillation.The effects of oscillation on the physical stability of mixed fuel with two solid-liquid ratios and three liquid component distribution ratios have been investigated using a self-designed experimental system at oscillation frequencies of 60-300 r/min.The explosion characteristics of mixed fuel before and after oscillation are gained from a 20 L spherical explosion container system.When the mass ratio of liquid components is controlled at 66.9%,64.7%,62.6%the final explosion characteristics are stable,with a maximum difference of only 0.71%.The volume of liquid fuel precipitation increases with increasing oscillation frequency when the mass ratio of liquid components reaches 71.7%,69.6%,67.7%.The fuel explosion overpressure after oscillation decreases with increasing liquid precipitation volume,and the repeatability is poor,with a maximum standard deviation of 82.736,which is much higher than the ratio without stratification.Properly controlling the mass ratio of liquid components of the mixed fuel can effectively combat the impact of oscillation on the physical state and maintain the stability of the final explosion characteristics.

Helicobacter pylori eradication for primary prevention of gastric cancer:progresses and challenges

Gastric cancer remains a significant global health challenge,causing a substantial number of cancer-related deaths,particularly in China.While the exact causes of gastric cancer are still being investigated,Helicobac-ter pylori(H.pylori)infection has been identified as the primary risk factor,which triggers chronic inflammation and a multistage progression of gastric lesions that may lead to carcinogenesis over a long latency time.Since the 1990s,numerous efforts have focused on assessing the effectiveness of H.pylori eradication in preventing new cases of gastric cancer among both the general population and patients who have undergone early-stage cancer treatment.This body of work,including several community-based interventions and meta-analyses,has shown a reduction in both the incidence of and mortality from gastric cancer following H.pylori treatment,alongside a decreased risk of metachronous gastric cancer.In this review,we seek to consolidate current knowledge on the effects of H.pylori treatment on gastric cancer prevention,its systemic consequences,cost-effectiveness,and the influence of antibiotic resistance and host characteristics on treatment outcomes.We further discuss the potential for precision primary prevention of H.pylori treatment and comment on the efficient implementation of test-and-treat policies and allocation of health resources towards minimizing the burden of gastric cancer globally.