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Coronaviruses can infect humans, mammals, and birds, leading to respiratory, gastrointestinal, and neurological diseases. These viruses are significant zoonotic pathogens with nine known types capable of infecting humans. The coronavirus genome, approximately 30 kb in size, is the largest known ribonucleic acid (RNA) virus genome, and its complexity makes assembly and manipulation time-consuming and labor-intensive. Reverse genetic systems are widely used to engineer recombinant viruses that can be adapted at Biosafety Level 2 (BSL-2) for studying viral gene function, replication, pathogenesis, vaccines, and therapeutics. The infectious clones, which enabled the recovery of various viruses after DNA recombinant technology, were indispensable tools for the reverse genetics of viruses. Various techniques for constructing infectious clones of human coronaviruses (HCoV) have been developed, encompassing methods such as vaccinia virus vectors method, in vitro ligation, bacterial artificial chromosome systems, yeast artificial chromosome systems, circular polymerase extension reaction, and the recently reported infectious sub-genomic amplicons technology. This review summarizes the status of various techniques for constructing infectious clones of human coronaviruses and related applications.

Abstract Adherence to antiretroviral therapy (ART) is essential for the effective management of HIV, which includes keeping the HIV viral load undetectable. This study aimed to determine whether certain ART medications are more “forgiving” of poor adherence in achieving viral suppression. We identified subgroups of ART medication usage and determined the extent to which ART adherence is associated with viral suppression across those subgroups. Data came from claims and clinical records (2017–2019) of 3,552 HIV-positive adult members of a Medicaid managed care plan. Pharmacy fill data were examined to characterize ART medications using latent class analysis (LCA), which captures the complexity of real-world ART usage (i.e., multiple medications, ART switching). LCA yielded five ART medication patterns over three years, mostly characterized by recent medications and formulations of ART, though they varied in number of tablets and in medication class. Mixed effects logistic regression models were estimated to determine whether odds of viral suppression differed by ART adherence level. After adjusting for covariates, those with at least 90% adherence (i.e., 90 to

Close-distance coal seams are common in underground mining, and their spacing is short, which produces strong mining disturbance. In instances where the upper seam has been mined and a goaf has formed, a notable issue arises during the lower seam’s mining, characterized by substantial deformation of the roadway along the goaf. Field exploration and three-dimensional geological modeling have revealed that the fourth and sixth working faces and pillar of seam No. 5 are all under seam No. 2’s goaf, with an average distance of 16.70 m. Simultaneously, the double compression effect of the pillar, induced by the linkage rotation of key blocks of the lower and upper seams, is analyzed. The induction mechanism and path of the large deformation are expounded. It is thus proposed that the pillar’s width should be determined by gob-side entry, driving beneath the goaf, with the roof near the pillar being cut off in advance to realize the path of cutting off the compressed pillar. Through the simulation comparison of five kinds of pillar width combined with engineering practice, it has been determined that the best width is 8 m, and the abutment pressure is distributed in a double-peak saddle shape, with the result that the load-bearing ability is notably significant. Through the comparative simulation of roof-cutting, it was found that roof-cutting helps the roof to collapse near the pillar-side and decreases the vertical stress peak to 16.46 MPa, the shear stress peak to 5.93 MPa, and the J2 peak to 7.23 × 1013 Pa, which further alleviates the pressure on the pillar. In the field, the haulage roadway’s roof was cut by two-way shaped-charge blasting, and the sandy mudstone (5.90 m) was successfully cut off. Concurrently, anchor cable reinforcement was implemented on the roof and two ribs of the ventilation roadway in proximity to the pillar, thereby ensuring stabilization and mitigating the mining effect. The engineering research provides a case and scheme reference for the operation of gob-side entry driving beneath close-distance goafs worldwide.

With the gradual development of coal mining into deep strata, the large deformation failure and strong dynamic impact disasters of surrounding rock caused by deep mining are becoming more and more serious. Under the complex geomechanical conditions including high ground stress, high ground temperature, high permeability, strong mining disturbance, strong rheology, and multi-field coupling, the stress field characteristics, rock fragmentation properties, strata movement and energy accumulation and release laws of deep mining areas are significantly different compared with those in shallow mining areas. In response to the rock mechanics issues in deep mining, this paper discusses the research progress made by the authors and team in three aspects: deep coal mining methods, failure mechanism and control of surrounding rock in deep roadway, and deep thermal disaster and geothermal utilization. The main results are as follows: ① the theory of balanced mining and the 110/N00 methodology for achieving balanced mining were proposed and applied in kilometer deep mines. ② The deep shaft construction mode with non-uniform pressure was proposed, and a SAP system to realize the stable lifting was developed. A mine construction method which can greatly reduce the roadway quantities and improve the coal recovery rate was invented. ③ Multiple experimental systems suitable for studying the macroscopic failure of deep soft rock under the effects of water, high temperature, high pressure, structural effects, multi-field coupling were developed. A supercomputing system capable of performing microscopic-level calculations was established. Based on the experimental results, the mechanism of large-scale deformation and failure of deep soft rock and its multi-scale mechanical properties were revealed. ④ An experimental system for simulating deep shock-type and strain-type rock bursts was built, and it was revealed that the rock burst is a nonlinear dynamic behavior in which energy is instantaneously released along the excavation-free surface. ⑤ The theory of excavation compensation support for deep roadway was proposed, and a NPR materials with extraordinary mechanical properties such as high constant resistance, high elongation, strong energy absorption, and impact resistance were invented. ⑥ A thermodynamic experimental system which can simulate deep high temperature, high humidity, and high-pressure environments was constructed, and a high temperature exchange machinery system (HEMS) for heat disaster treatment and heat source resource utilization was established. The above research achievements have been applied in the field of deep mining and can provide guidance for the complex rock mechanics problems faced by deep mining.

Understanding how post-acute sequelae of SARS-CoV-2 infection (PASC) affects communities disproportionately affected by HIV is critically needed. This study aimed to identify the prevalence of PASC symptoms among Medicaid enrollees at risk for or living with HIV. Through a web survey, we received 138 valid responses from Medicaid-managed plan members who had received a COVID diagnosis. Participants' mean age was 45.4 years (SD = 11.9) and most were non-Hispanic Black (43.5%) or Hispanic (39.1%). Almost thirty-two percent reported inadequate incomes and 77.5% were HIV-positive. In the overall population, the frequently reported symptoms included neck/back/low back pain, brain fog/difficulty concentrating, bone/joint pain, muscle aches, and fatigue. Findings indicate that there is no statistically significant difference in the prevalence and intensity of PASC symptoms lasting 6 months or more between individuals living with and without HIV. Multiple regression analysis found that the number of PASC symptoms 6 months or longer was independently associated with inadequate incomes and comorbidities (cardiac problems, cancer, fibromyalgia) (R2 = .34). Those with inadequate incomes and comorbidities have more numerous PASC symptoms. Implications for health care delivery and long-term COVID services will be discussed.

Abstract Extra‐thick coal seams are widely distributed in the Datong mine area in China. The rapid stopping of mining and the support withdrawal technology for extra‐thick coal seams need to be developed urgently. The reasonable stopping top coal caving distance, main roof's fracture line position, and large section roadway during the stopping period (LSRSP) support method of the header face of 15 m extra‐thick coal seam are systematically studied by using field measurement, experiment, numerical simulation, and similar material simulation methods. With the increase in stopping coal caving distance, the range of the medium and low displacement zone of the LSRSP overburden gradually expands. In contrast, the depth of the plastic zone decreases. The scope and intensity of the high‐stress area of the overlying rock in front gradually decrease and shift from deep to the outside, while the peak stress area shifts from the top coal area to the coal rib of the retracement channel. Comparing the stopping of medium‐thick and thick coal seam working face, the interaction between “main roof−unmined top coal−supports” is analyzed. The unique characteristics of the extra‐thick coal seam working face are derived: when the stopping coal caving distance is shorter than the length of the key block, the dropped coal body cannot effectively restrict the movement of key blocks. Mutual compression and subsidence occur between key blocks, making the broken coal rock block squeeze into the supports. By the simulation study of each index, the stopping coal caving distance of the extra‐thick coal seam is optimal when it is slightly larger than the length of the key block (i.e., the periodic weighting step), simultaneously, the main roof fracture line behind the supports is most favorable for stopping mining. After ensuring the stability of the LSRSP's overburden structure, the differentiated support scheme of “controlled zoning−strength grading” was proposed, and the scheme was modified and verified by simulating the support prestress field. After field practice, the roof of the retracement channel is better controlled in deformation under the joint horizontal and vertical support, the robust control effect of the combined anchor cable is noticeable, the integrity of the polyurethane network is more substantial, and the working face supports have successfully achieved a safe and rapid evacuation.

Abstract Close-distance coal seams are widely distributed over China, and the coal pillars left by the overlying coal seams affect the retracement channel of the underlying coal seam in the stopping stage. Based on the engineering background of close-distance seam mining in a coal mine, the reasonable position of the underlying coal seam's stopping line and the support method of the large section roadway during stopping are investigated using field measurements, similar simulation experiments, and numerical simulations. There are three types of location relationships between the stopping line of the underlying coal seam and the stopping line of the overlying coal seam: "externally staggered with the upper stopping line" (ESUL, stops mining under the overlying goaf), "overlapped with upper stopping line" (OUL), and "internally staggered with the upper stopping line" (ISUL, ISUL-SD for shorter internal staggered distances, ISUL-LD for longer ones). There are different stress arch structures in the overlying strata of the above three positions, and the stress arch evolution process exists in the process of ESUL → OUL → ISUL-SD → ISUL-LD: a front and rear double stress arch structure → the front arch gradually decreases → the front arch dies out, and the double arch synthesizes the single arch → the single-arch range expands → the nested double arch. The relationship between the stress arch structure and the position of the stopping line is evaluated as follows: (1) ESUL: the stress concentration in the roof plate of the retracement channel of the underlying coal seam is the highest, because the overburden block of the extensive collapse zone acts directly on the roof plate of the retracement channel, resulting in relative difficulties in roof support. (2) OUL: although the retracement channel roof pressure is minimal, the overlying rock structure has the potential for rotation or slippage instability. (3) ISUL-SD: the pressure on the roof of the retracement channel is small and the overburden structure is stable, which is conducive to the safe retraction of the support and not limited by the width of the end-mining coal pillar. (4) ISUL-LD: it is basically the same as the condition of stopping under the non-goaf; however, it has a limitation on the width of the end-mining coal pillar. The location of the stopping line is selected as ISUL-SD, and the retraction process of the self-excavating retraction channel was adopted. A partition asymmetric support scheme which is proven by field practice is proposed, through a comprehensive analysis of the pre-stress field simulation of the support scheme, based on the different control requirements of the roof above the support and the roof of the retracement channel in the stopping area. This method realizes safe and smooth withdrawal of the support.

Abstract This paper studies the width of narrow coal pillars, mining‐induced failure characteristics, and surrounding rock control effect of gob‐side entry driving (GED) adjacent to 2‐1208 filling working face with an approximately 900 m depth. Laboratory experiments, numerical simulations, loosening circle tests, and engineering practices are conducted. The mechanical properties of the filling body, the distribution and evolution law of the second invariant deviatoric stress (J2), and the variation in the plastic zone of the surrounding rock in GED are studied. The conditions of various coal pillar widths and the gob backfilled or not of the adjacent working face are also considered. The results of roadway driving along the filling working face in the deep coal mine are that: (1) The evolution law of J2 and the plastic zone features of the surrounding rock in GED have changed significantly. Thus, it is unreasonable to still adopt the customary theory of narrow coal pillar determination and roadway support design method of GED adjacent to nonfilling working face. (2) The plastic zone of GED has typically asymmetric distribution characteristics during driving and retreating, which is mainly concentrated at the upper corner of the virgin coal rib. And the elastic zone changes slightly by the influence of mining‐induced pressure on the working face, indicating that support in this area is easier. (3) During the stable period of roadway driving, there includes a “ring‐shaped” J2 depression zone at the upper corner of the coal pillar rib. While the peak zone distribution of J2 in the virgin coal rib of GED is approximately “crescent‐shaped,” and the peak zone is inclined to the upper corner of the virgin coal rib, which implies that this area is a crucial control region. (4) During the retreating period of panel 2‐1210, the direction of the maximum principal stress of GED gradually deflects from the direction of the gob to that perpendicular to the roof and floor, which represents that the key support area of GED has changed. Therefore, the advanced support of GED needs to be reinforced by single hydraulic props. The width of the coal pillar was determined to be 5 m, and a targeted truss anchor cable support method with bidirectional resistance function is proposed for the roof and both ribs, which realized the stability control of GED during deep filling mining.

ObjectiveNon-invasive disease indicators are currently limited and need further research due to the increased non-alcoholic fatty liver disease (NAFLD) prevalence worldwide. The serum uric acid-to-high-density lipoprotein cholesterol ratio (UHR) has been recognized as a novel inflammatory and metabolic marker. Herein, we explored the correlation between UHR and the risk of NAFLD in-depth.MethodsA total of 3,766 participants were included in our survey, and the National Health and Nutrition Examination Survey (NHANES) 2017–2018 cycle provided the cross-sectional study population. Weighted multivariable logistic regression and multivariate linear regression analyses were performed to assess the association between the UHR and the odds of NAFLD and liver steatosis and fibrosis severity, respectively. Moreover, we explored the non-linear relationship between the UHR and NAFLD by the generalized additive model.ResultsNAFLD probabilities were statistically demonstrated to be positively correlated with the UHR (OR = 1.331 per SD increase, 95% CI: 1.100, 1.611). The positive connection of the UHR with NAFLD risk persisted significantly in female subjects but not in male subjects in subgroup analyses stratified by gender. The non-linear relationship analysis demonstrated that a UHR between ~20 and 30% suggested a saturation effect of NAFLD risk. Furthermore, a dramatically positive correlation was found between the UHR and hepatic steatosis severity but not fibrosis. Finally, the receiver operating characteristic analysis suggested that UHR had a better predictive value for NAFLD than either serum uric acid (sUA) or high-density lipoprotein cholesterol (HDL) alone [UHR (area under curve): 0.6910; 95% CI: 0.6737–0.7083; P < 0.0001].ConclusionOur investigation revealed that the elevated UHR level was independently related to an increased NAFLD risk and the severity of liver steatosis in American individuals. The correlation differed according to sex. This non-invasive indicator may enhance the capacity to predict the onset of NAFLD and may uncover alternative therapeutic interventional targets.

IntroductionAlthough Information and Communication Technology (ICT) has great potential to help older adults cope with challenges associated with aging, the intended benefits of ICT are not always realized in this population due to access barriers and low digital literacy. During the COVID-19 pandemic, numerous tech support initiatives for older adults got underway. However, evaluation of the effectiveness of these initiatives is less common. This research partnered with a large, multi-service organization in New York City that gave some groups of their clients ICT devices, unlimited broadband, and access to technology training in response to COVID-19 lockdowns. This study investigates older adults’ experiences with ICT and ICT support services to better inform the existing and emerging tech support for older adults during and beyond the pandemic.MethodsData were obtained from interviewer-administered surveys of 35 older adult recipients of ICT devices, connectivity, and training in New York City. The average age was 74 years (range = 55–90 years). The group was diverse regarding race/ethnicity (Black 29%, Latino 19%, White 43%). All had low incomes. Surveys consisted of multiple-choice items and open-ended responses.ResultsThe study found that one size does not fit all when it comes to ICT training and support for older adults. While connection to devices and services and tech support led to a degree of ICT adoption, the newly learned skills did not always lead to expanded device usage. The readily available tech support training and support do not guarantee service utilization, as success with tech services is related to one’s pre-existing ICT competence.DiscussionThe study concludes that customized training based on individuals’ skills rather than age is needed. Tech support training should start by understanding an individual’s interests and incorporate tech education to help users identify a wide range of existing and emerging online services that can meet their needs. Service organizations should consider including an assessment of ICT access, use, and skills into their standard intake protocols to ensure effective service delivery.

Abstract In deep underground mining, achieving stable support for roadways along with long service life is critical and the complex geological environment at such depths frequently presents a major challenge. Owing to the coupling action of multiple factors such as deep high stress, adjacent faults, cross-layer design, weak lithology, broken surrounding rock, variable cross-sections, wide sections up to 9.9 m, and clusters of nearby chambers, there was severe deformation and breakdown in the No. 10 intersection of the roadway of large-scale variable cross-section at the − 760 m level in a coal mine. As there are insufficient examples in engineering methods pertaining to the geological environment described above, the numerical calculation model was oversimplified and support theory underdeveloped; therefore, it is imperative to develop an effective support system for the stability and sustenance of deep roadways. In this study, a quantitative analysis of the geological environment of the roadway through field observations, borehole-scoping, and ground stress testing is carried out to establish the FLAC 3D variable cross-section crossing roadway model. This model is combined with the strain softening constitutive (surrounding rock) and Mohr–Coulomb constitutive (other deep rock formations) models to construct a compression arch mechanical model for deep soft rock, based on the quadratic parabolic Mohr criterion. An integrated control technology of bolting and grouting that is mainly composed of a high-strength hollow grouting cable bolt equipped with modified cement grouting materials and a high-elongation cable bolt is developed by analyzing the strengthening properties of the surrounding rock before and after bolting, based on the Heok-Brown criterion. As a result of on-site practice, the following conclusions are drawn: (1) The plastic zone of the roof of the cross roadway is approximately 6 m deep in this environment, the tectonic stress is nearly 30 MPa, and the surrounding rock is severely fractured. (2) The deformation of the roadway progressively increases from small to large cross-sections, almost doubling at the largest cross-section. The plastic zone is concentrated at the top plate and shoulder and decreases progressively from the two sides to the bottom corner. The range of stress concentration at the sides of the intersection roadway close to the passageway is wider and higher. (3) The 7 m-thick reinforced compression arch constructed under the strengthening support scheme has a bearing capacity enhanced by 1.8 to 2.3 times and increase in thickness of the bearing structure by 1.76 times as compared to the original scheme. (4) The increase in the mechanical parameters c and φ of the surrounding rock after anchoring causes a significant increase in σ t; the pulling force of the cable bolt beneath the new grouting material is more than twice that of ordinary cement grout, and according to the test, the supporting stress field shows that the 7.24 m surrounding rock is compacted and strengthened in addition to providing a strong foundation for the bolt (cable). On-site monitoring shows that the 60-days convergence is less than 30 mm, indicating that the stability control of the roadway is successful.

Background: The genetic factors in assessing therapeutic efficacy and predicting antihypertensive drug response are unclear. Therefore, this study aims to identify the associations between variants and antihypertensive drug response.Methods: A longitudinal study including 1837 hypertensive patients was conducted in Northern China and followed up for a median 2.24 years. The associations of 11 candidate variants with blood pressure changes in response to antihypertensive drugs and with the risk of cardiovascular events during the follow-up were examined. The dual-luciferase assay was carried out to assess the effect of genetic variants on gene transcriptional activity.Results: The variant rs11039149A>G in the promoter of nuclear receptor subfamily 1 group H member 3 (NR1H3) was associated with the change in systolic blood pressure (ΔSBP) in response to calcium channel blockers (CCBs) monotherapy. Patients carrying rs11039149AG genotype showed a significant increase of systolic blood pressure (SBP) at follow-up compared with AA carriers, and the difference of ΔSBP between AG and AA carriers was 5.94 mm Hg (95%CI: 2.09–9.78, p = 0.002). In 1,184 patients with CCBs therapy, SBP levels decreased in AA carriers, but increased in AG carriers, the difference of ΔSBP between AG and AA carriers was 8.04 mm Hg (95%CI: 3.28–12.81, p = 0.001). Further analysis in 359 patients with CCBs monotherapy, the difference of ΔSBP between AG and AA carriers was 15.25 mm Hg (95%CI: 6.48–24.02, p = 0.001). However, there was no significant difference in ΔSBP between AG and AA carriers with CCBs multitherapy. The rs11039149A>G was not associated with the cardiovascular events incidence during the follow-up. Additionally, transcriptional factor forkhead box C1 (FOXC1) bound to the NR1H3 promoter containing rs11039149A and significantly increased the transcriptional activity, while rs11039149 A to G change led to a loss-of-function and disabled FOXC1 binding. For the other 10 variants, associations with blood pressure changes or risk of cardiovascular events were not observed.Conclusion: Hypertensive patients with rs11039149AG genotype in the NR1H3 gene have a significant worse SBP control in response to CCBs monotherapy compared with AA carriers. Our findings suggest that the NR1H3 gene might act as a promising genetic factor to affect individual sensitivity to antihypertensive drugs.

Staying well informed about the evolving COVID-19 pandemic and vaccine recommendations is vital for older adults, especially for low-income older adults, who have been disproportionately impacted by the pandemic. However, the overwhelming infodemic poses a significant challenge, affecting vaccine decision-making. This study explores how a group of predominantly low-income older adults navigate health information and how their trust in information and vaccines evolves throughout the pandemic. Our objective is to provide insights that will guide future public health messaging for this demographic. Analyzing qualitative data from 77 older adults (aged 65 to 94) collected through focus groups and interviews, our findings reveal that participants’ experiences with information overload eroded their trust in authority, leading to vaccine hesitancy. Moreover, the need for a booster has affected belief in vaccine safety and efficacy. As participants lost faith in the media and authoritative sources, they increasingly leaned on personal networks for guidance. These results underscore the urgent necessity for clear, unambiguous ongoing vaccine guidance to restore institutional trust among older adults. Additionally, recognizing the influential role of direct networks in vaccine decisions, integrating care workers, service providers, and peer-to-peer support into health messaging mechanisms could prove valuable.

Introduction: Atherosclerosis is a chronic disease characterized by the inflammatory process and lipid depositions. We previously reported that microRNA-216a (miR-216a) can accelerate the progression of atherosclerosis by promoting the polarization of M1 pro-inflammatory phenotype. Ginsenoside Rb2 (Rb2), the major pharmacologically active compound extracted from ginseng, has a high affinity to miR-216a. In this study, we aimed to investigate whether Rb2 can counteract the effect of miR-216a in macrophages to ameliorate atherosclerosis.Methods: The apolipoprotein E deficiency (ApoE−/−) mice model was chronically infected with miR-216a adenovirus via the tail vein and then intraperitoneally injected with Rb2. The plaque lesion area and stability of thoracic aorta were examined. The human myeloid leukemia mononuclear cells (THP-1) or human peripheral blood mononuclear cells (PBMCs) were cultured in vitro, transfected with miR-216a mimics, and treated with Rb2 to explore the mechanisms of Rb2 on the polarization of M1 macrophages, inflammatory process, and lipid accumulation.Results: In the atherosclerotic ApoE−/− mice model, miR-216a greatly increased en face aortic lesion area of the thoracic aorta, lipid accumulation, and M1 macrophages infiltration in plaques, whereas these effects of miR-216a on atherosclerosis burden were significantly alleviated by Rb2 treatment. In the in vitro THP-1 model, the flow cytometry experiment showed that Rb2 treatment inhibited miR-216a–mediated polarization of M1 macrophages characterized by the surface marker CD86 expression but had no effects on M2 polarization characterized by the surface marker CD206 expression. Mechanistically, Rb2 suppressed the miR-216a–mediated inflammatory response through the Smad3/nuclear factor kappa B inhibitor alpha pathway. Moreover, Rb2 reduced the lipid uptake and promoted cholesterol efflux by counteracting the effects of miR-216a in the THP-1–derived foam cells and in the PBMC-derived foam cells under the oxidized low-density lipoproteins.Conclusion: Our findings indicated that Rb2 might be a potential therapeutic molecule for atherosclerosis by attenuating the atherosclerosis plaque lesion, lipid accumulation, and M1 macrophages polarization by targeting miR-216a. Given that accumulation of foam cells in the intima takes place chronically, the role of Rb2 in atherosclerosis progression needs further investigation.

A large coal pillar (usually more than 90 m) is generally left in place to ensure the stability of main roadway groups, due to its long service lifespan, which commonly also causes a significant loss of coal resources. The design of the width of the protective coal pillar and the control system of the surrounding rock are directly determined by the characteristics of the stress field and the damage mechanism under the influence of the mining activities. However, there are few studies on the effects of the partial-stress boosting and the direction deflection of the stress field on the failure evolution of the surrounding rock (especially in multi-seam mining). In this paper, theoretical analysis and numerical simulation are used to investigate the direction evolution of the maximum principal stress in front of the working face with malposition distances between the upper and lower working faces during the influence of double coal seams mining. Furthermore, a large-scale numerical model is used to study the deviatoric stress evolution of the surrounding rock and the propagation process of the plastic zone in the main roadway group with different widths of protective coal pillars. Then, an asymmetric cooperative anchoring classification method is proposed to strengthen the roadway support, depending on the critical area of the deviatoric stress in the roadway surrounding rock. The peak zone deflection of the deviatoric stress determines the evolution direction of the plastic area, and the peak value of the deviatoric stress presents a typical asymmetric stress boosting on both sides of the roadway. These findings are validated by the on-site ground pressure monitoring results and the practical failure modes of the surrounding rock.

Under the condition of fully mechanized top coal caving in close-distance coal seams, the surrounding rock of the stopping space easily loses stability during the withdrawal of mining equipment in the working face because the lower coal seam working face is located under the goaf and the overburden rock has a large range of complex interaction. Field investigation, theoretical analysis, laboratory experiment, similar simulation experiment, numerical simulation, and field industrial tests are used to carry out the research on the stability and control of the surrounding rock in the large section stopping space under the goaf in this paper. The research conclusions are as follows. (1) It is determined that the lower coal seam working face can only stop mining under the goaf, and the reasonable stopping position under the goaf should ensure that the key block fracture line of the main roof is behind the support. (2) The interaction law between the main roof’s key blocks of the upper and lower coal seams is analyzed, and the catastrophic conditions for sliding instability and rotary instability of the main roof’s key blocks of the upper and lower coal seams are obtained. (3) “Anchorage with push and pull equipment-Embedded anchorages and trays” integral anchoring technology is developed. The dimensions of the push and pull equipment are determined. (4) Through numerical simulation of the distribution characteristics of the anchor cable pre-stress field, the asymmetric control scheme of “Partition long and short anchor cables + Integral polyurethane mesh + Embedded anchorages and trays for roof protection” is determined. The rock pressure observation shows that the withdrawal of the working face equipment is implemented safely.

Motivated by the prominent catalytic performance and durability of nanoalloy catalysts, the Pd-based bimetallic nanoalloy catalysts were prepared using an aqueous reduction method. The Fe-Pd bimetallic nanoalloy catalyst (nano-Fe/Pd) demonstrated 98.4% yield and 99.7% selectivity for the unsaturated 1,4-dicarboxylic acid diesters. Moreover, the inductively coupled plasma (ICP) analysis shows that the Pd leaching of the catalyst can be effectively suppressed by alloying Fe atoms into the Pd crystal lattice for acetylene dicarbonylation. The detailed catalyst structure and morphology characterization demonstrate that introducing Fe into the Pd nanoparticles tunes the electronic–geometrical properties of the catalyst. Theoretical calculations indicate that the electrons of Fe transfer to Pd in the nano-Fe/Pd catalyst, enhancing activation of the C≡C bond in acetylene and weakening CO absorption capacity on catalyst surfaces. Alloying Fe into the Pd nanocatalyst effectively inhibits active metal leaching and improves catalyst activity and stability under high-pressure CO reactions.

According to the development requirements of green mining of coal resources, it is imperative to improve the extraction rate of coal and the application of safe and efficient mining technology. Pre-splitting and roof cutting technology is widely used in reducing residual coal pillars and safe pressure relief mining, which has become the crucial technology for pillar-free mining methods. Therefore, it is essential to review and discuss the research hotspots, cutting-edge methods, principles of action, and application areas of the development of this technology. Above all, the research data on pre-splitting and roof-cutting development in the past ten years are summarized and outlined. The research’s hot spots are pressure relief technology and gob-side entry retaining technology. Then, the functional forms of pre-splitting and roof cutting technology are discussed and compared, including explosive blasting (directional energy gathering blasting, liquid explosive blasting, and composite blasting), hydraulic fracturing, liquid CO2 gas fracturing, and mechanized roof cutting (chain arm saw machine and directional cutting roof rig). Through the analysis of field application cases, the application field is divided into three major areas: non-coal pillar mining (gob-side entry driving with narrow coal pillar, gob-side entry retaining with the filling body, completely gob-side entry retaining, and “N00” construction method), pressure relief at working face (thick and hard main roof cracking and end area hard roof cracking), and pressure relief at roadway (gob-side roadway pressure relief and blasting pressure relief technology for roadways). By detailing the process of each application technology one by one, the principle and mode of pre-splitting in each technology are expounded. Finally, the development prospects of pre-splitting and roof cutting in new technical methods, deep pressure relief mining, intelligent unmanned mining, and green and efficient mining are prospected, providing references for similar projects.

Close-distance coal seams are widely distributed in China, and the mining of overlying coal seams leads to floor damage. To grasp the properties and the fracture spans of the damaged main roof in the underlying coal seam, combining the calculation of the floor damage depth with rock damage theory and the formulas for calculating the first and periodic weighting intervals of the damaged main roof and the instability conditions of the damaged key blocks are obtained. Three interaction stability mechanics models are proposed for key blocks with different properties of the upper and lower main roof, and the instability conditions of the lower damaged key blocks are obtained when the fracture lines overlap. When combined with a specific example, the field monitoring verified the calculation results. The research results are as follows: (1) The first and periodic weighting intervals, horizontal thrust between blocks, and critical load of instability of the damaged main roof are significantly reduced. Still, there are differences in its reduction under different loads, rotation angles, and lumpiness. (2) When the fracture lines of the upper and lower main roofs overlap, the stability of the damaged key blocks is the lowest. There are three linkage stability regions in the critical load curves of the two key blocks. (3) In this case, the damage equivalent of the main roof is 0.397, which belongs to the local damage type. Its first and periodic weighting intervals are 40 m and 16 m, which is 22% and 24% less than when there is no damage. (4) A supporting load of 0.489 MPa is required to maintain the stability of the upper key block, and the lower damaged key block is prone to rotary and sliding instability during the first and periodic weighting, respectively. Thus, the supports need to bear a total of 0.988 MPa and 0.761 MPa to maintain the stability of the two key blocks simultaneously. The ground pressure data monitored on-site is in accord with the calculation results.

In multi-seam mining, the residual coal pillar (RCP) in the upper gob has an important influence on the layout of the roadway in the lower coal seam. At present, few papers have studied the characteristics of the surrounding rock of gob-side entry driving (GED) with different coal pillar widths under the influence of RCP. This research contributes to improving the recovery rate of the extra-thick coal seam under this condition. The main research contents were as follows: (1) The mechanical parameters of the rock and coal mass were obtained using laboratory experiments coupled with Roclab software. These parameters were substituted into the established main roof structure mechanics model to derive the breakage position of the main roof with the influence of RCP, and the rationality of the calculation results was verified by borehole-scoping. (2) Based on numerical simulation, the evolution laws of the lateral abutment stress in the lower working face at different relative distances to the RCP were studied. FLAC3D was used to study the whole space-time evolution law of deviatoric stress and plastic zone of GED during driving and retreating periods with various coal pillar widths under the influence of RCP. (3) The plasticization factor P was introduced to quantify the evolution of the plastic zone in different subdivisions of the roadway surrounding rock, so as to better evaluate the bearing performance of the surrounding rock, which enabled a more effective determination of the reasonable coal pillar width. The field application results showed that it was feasible to set up the gob-side entry with an 8 m coal pillar below the RCP. The targeted support techniques with an 8 m coal pillar could effectively control the surrounding rock deformation.

NEPE propellant has high energy and good mechanical properties. However, due to the lack of detailed research on its microscopic pyrolysis mechanism, the combustion rate and energy release rate are still difficult to control, which limits the further development of NEPE propellant. Based on this, quantum chemistry is used to study the pyrolysis mechanism of key components of NEPE propellant, including oxidants HMX and AP, binders PEG, NG and BTTN. The pyrolysis reaction path, rate-determining steps and main pyrolysis products of each component were calculated, and the pyrolysis kinetic parameters are calculated based on the transition state theory. The results show that HMX, BTTN and NG are all transformed into cyclic nitrogen compounds or chain carbon oxides by NO 2 or NO 3 shedding, and then gradually decomposed, while PEG is the gradual pyrolysis of long chain molecules. The main pyrolysis products are nitrogen oxides and various small fuel molecules containing C/H/N. The order of reaction rate constants of NEPE components is NG> AP> HMX> BTTN> PEG at 1500-2000 K. Among them, PEG and BTTN reaction rate constants are sensitive to temperature, and the reaction rate will rise rapidly with the increase of temperature. This study will provide an important theoretical reference for the regulation of NEPE high-energy catalyst pyrolysis behavior. [ABSTRACT FROM AUTHOR]

Introduction: Although Information and Communication Technology (ICT) has great potential to help older adults cope with challenges associated with aging, the intended benefits of ICT are not always realized in this population due to access barriers and low digital literacy. During the COVID-19 pandemic, numerous tech support initiatives for older adults got underway. However, evaluation of the effectiveness of these initiatives is less common. This research partnered with a large, multi-service organization in New York City that gave some groups of their clients ICT devices, unlimited broadband, and access to technology training in response to COVID-19 lockdowns. This study investigates older adults' experiences with ICT and ICT support services to better inform the existing and emerging tech support for older adults during and beyond the pandemic. Methods: Data were obtained from interviewer-administered surveys of 35 older adult recipients of ICT devices, connectivity, and training in New York City. The average age was 74 years (range = 55-90 years). The group was diverse regarding race/ethnicity (Black 29%, Latino 19%, White 43%). All had low incomes. Surveys consisted of multiple-choice items and open-ended responses. Results: The study found that one size does not fit all when it comes to ICT training and support for older adults. While connection to devices and services and tech support led to a degree of ICT adoption, the newly learned skills did not always lead to expanded device usage. The readily available tech support training and support do not guarantee service utilization, as success with tech services is related to one's pre-existing ICT competence. Discussion: The study concludes that customized training based on individuals' skills rather than age is needed. Tech support training should start by understanding an individual's interests and incorporate tech education to help users identify a wide range of existing and emerging online services that can meet their needs. Service organizations should consider including an assessment of ICT access, use, and skills into their standard intake protocols to ensure effective service delivery. [ABSTRACT FROM AUTHOR]

Abstract: The COVID-19 pandemic disrupted health care systems and resulted in some delays of care, challenging health care engagement among people living with HIV (PLWH). Using in-depth interviews, we explored the experiences of PLWH during the pandemic and identified barriers to and facilitators of care engagement. We recruited 40 participants from a managed-care Medicaid plan in New York City and conducted phone interviews during fall 2023. Thematic analysis identified 5 themes related to care engagement during the pandemic: (a) health care system strains led to some delays in care; (b) patient-provider connections suffered; (c) the pandemic led to personal crises and challenges to care engagement; (d) strong communication and connection reduced disruption and stress; and (e) the pandemic had a lasting effect on interpersonal connections. These findings highlight ways to help maintain care engagement among PLWH even during social and public health crises and contribute to ending the epidemic., (Copyright © 2025 Association of Nurses in AIDS Care.)