Objective: Human induced pluripotent stem(i PS) cells exhibit great potential for generating functional human cells for medical therapies. In this paper, we report for use of human i PS cells labeled with fluorescent ...Objective: Human induced pluripotent stem(i PS) cells exhibit great potential for generating functional human cells for medical therapies. In this paper, we report for use of human i PS cells labeled with fluorescent magnetic nanoparticles(FMNPs) for targeted imaging and synergistic therapy of gastric cancer cells in vivo. Methods: Human i PS cells were prepared and cultured for 72 h. The culture medium was collected, and then was coincubated with MGC803 cells. Cell viability was analyzed by the MTT method. FMNP-labeled human i PS cells were prepared and injected into gastric cancer-bearing nude mice. The mouse model was observed using a small-animal imaging system. The nude mice were irradiated under an external alternating magnetic field and evaluated using an infrared thermal mapping instrument. Tumor sizes were measured weekly. Results: iP S cells and the collected culture medium inhibited the growth of MGC803 cells. FMNP-labeled human iP S cells targeted and imaged gastric cancer cells in vivo, as well as inhibited cancer growth in vivo through the external magnetic field. Conclusion: FMNP-labeled human i PS cells exhibit considerable potential in applications such as targeted dual-mode imaging and synergistic therapy for early gastric cancer.展开更多
Objective: Hyperthermia is an attractive addition to multidisciplinary approaches to clinical cancer treatment. The efficiency of hyperthermia depends on the elevation of the temperature and the duration of treatment...Objective: Hyperthermia is an attractive addition to multidisciplinary approaches to clinical cancer treatment. The efficiency of hyperthermia depends on the elevation of the temperature and the duration of treatment. It has been reported that in vitro and in vivo hyperthermia enhanced the cytotoxic effect of certain anticancer drugs. However, this enhancement varies, depending on the drug used and the scheduling of treatments. Thus, the combination effect of chemotherapy and hyperthermia remains unclear. In this study, we aimed to investigate whether concurrent exposure of human hepatocellular carcinoma cells SMMC-7721 to chemotherapeutic agents andhyperthermia could increase anticancer effects. Methods : Two chemotherapeutic agents, cisplatin and hydroxycamptothecin, were applied. The MTT assay was performed to evaluate the growth inhibition of SMMC-7721 induced by anticancer drugs with and without hyperthermia. Flow cytometric analysis was used for the assessment of apoptosis after treatments. Results: The percentages of growth inhibition of SMMC-7721 induced by cisplatin (10μg/ml) alone, hydroxycamptothecin (1μg/ml)alone, hyperthermia alone, cisplatin and hyperthermia, hydroxycamptothecin and hyperthermia, were 20.77%, 13.65%, 32.46%, 62.76%, 71.89%, respectively. The percentages of apoptosis of five treatments are 5.56%, 3.96%, 10.16%, 24.32%, 20.42%, respectively. Conclusion: While both hyperthermia and anticancer drugs can individually induce apoptosis and anti-proliferation effect, the combination of the two treatments induce significantly higher apoptosis and cytotoxicity than hyperthermia or anticancer drugs treatment alone. These data suggest a synergistic benefit when hyperthermia and anticancer drugs used concurrently.展开更多
Hyperthermia effects (39-44 ℃) induced by pulsed high-intensity focused ultrasound (HIFU) have been regarded as a promising therapeutic tool for boosting immune responses or enhancing drug delivery into a solid t...Hyperthermia effects (39-44 ℃) induced by pulsed high-intensity focused ultrasound (HIFU) have been regarded as a promising therapeutic tool for boosting immune responses or enhancing drug delivery into a solid tumor. However, previous studies also reported that the cell death occurs when cells are maintained at 43 ℃ for more than 20 minutes. The aim of this study is to investigate thermal responses inside in vivo rabbit auricular veins exposed to pulsed HIFU (1.17 MHz, 5300 W/cm2, with relatively low-duty ratios (0.2%-4.3%). The results show that: (1) with constant pulse repetition frequency (PRF) (e.g., 1 Hz), the thermal responses inside the vessel will increase with the increasing duty ratio; (2) a temperature elevation to 43 ℃ can be identified at the duty ratio of 4.3%; (3) with constant duty ratios, the change of PRF will not significantly affect the temperature measurement in the vessel; (4) as the duty ratios lower than 4.3%, the presence of microbubbles will not significantly enhance the thermal responses in the vessel, but will facilitate HIFU-induced inertial cavitation events.展开更多
Objective: To study the role of apoptosis in tumor cell of malignant glioma death following treatment with hyperthermia and calcium ionophore. Methods: The apoptosis induced by hyperthermia and calcium ionophore, A231...Objective: To study the role of apoptosis in tumor cell of malignant glioma death following treatment with hyperthermia and calcium ionophore. Methods: The apoptosis induced by hyperthermia and calcium ionophore, A23187, in human glioblastoma cell line TJ905 and murine glioblastoma G422 was evaluated by characteristic findings in DNA agarose gel electrophresis, ultrastructural examination and flow cytometric analysis. Results: Apoptosis could be induced by moderate hyperthermia, but not by mild hyperthermia, calcium ionophore enhanced significantly the effect of mild hyperthermia on the induction of apoptosis. Conclusion: This result indicates that apoptotic cell death is one of the mechanisms of hyperthermic therapy for malignant glioma and taking measures to increase the cytolic calcium may enhance the effect of hyperthermia.展开更多
Purpose: In this project, we developed novel methods to quantify changes in tumor hypoxia following a mild tempera-ture hyperthermia (MTH) treatment in rat HT29 human colon adenocarcinoma xenograft. Materials and Meth...Purpose: In this project, we developed novel methods to quantify changes in tumor hypoxia following a mild tempera-ture hyperthermia (MTH) treatment in rat HT29 human colon adenocarcinoma xenograft. Materials and Methods: An exogenous hypoxia marker (IAZGP) was labeled with two radioisotopes of iodine (131I and 123I, respectively) to form two distinct tracers. The two tracers were injected into HT29-bearing nude rats 4-hour before and immediately following 41.5℃, 45-minute mild hyperthermia treatment. The distributions of the two hypoxia tracers were obtained by performing digital autoradiography on tumor sections, and image processing resulted in quantitative information at 50 μm pixel size. Results: Following the hyperthermia treatment, there was a remarkable decrease in hypoxia tracer binding. The average whole tumor hypoxia tracer targeted fraction in five animals changed from 30.3% ± 9.7% to 13.0% ± 5.3% after the hyperthermia treatment (P = 0.001). Detailed pixelby-pixel analysis of the image data revealed a decline in hypoxia tracer uptake after hyperthermia in most regions. However, there was concomitant emergence of some new regions of hypoxia identified by increased tracer uptake. In the control group, the overall hypoxia tracer targeted fraction remained almost constant, with some hypoxic tracer redistribution (putative acute hypoxia) observed. Conclusion: Reoxygenation occurred in the rat HT29 xenograft following MTH treatment. This was evident with preponderance of decreased hypoxia specific tracer uptake on tumor sections. Our methodology might be a useful tool in hypoxia study.展开更多
AIM:To evaluate the surgical treatment methods of giant cell tumors(GCT) of long bone in conjunction with inserted microwave antennas induced hyperthermia.METHODS:46patients,included the surgical procedures,the onco...AIM:To evaluate the surgical treatment methods of giant cell tumors(GCT) of long bone in conjunction with inserted microwave antennas induced hyperthermia.METHODS:46patients,included the surgical procedures,the oncology results,the functions of the limbs and the complications were analyzed.RESULTS:Follow-up 3.5 to 9 years(mean 5.5years).All patients were evaluated according to oncological and orthopaedic criteria.Two tumors were recurred.Orthopaedic furction were perfect in 44 patients and were fair in 2.Infection was found in 2 patients.CONCLUSION:The surgical procedure to treat the giant cell tumors of long bone by inserted microwave antennas induced hyperthermia is a definitive surgical method which is safe and confident.展开更多
In recent years,the progression of stem cell therapies has shown great promise in advancing the nascent field of regenerative medicine.Considering the non-regenerative nature of the mature central nervous system,the c...In recent years,the progression of stem cell therapies has shown great promise in advancing the nascent field of regenerative medicine.Considering the non-regenerative nature of the mature central nervous system,the concept that“blank”cells could be reprogrammed and functionally integrated into host neural networks remained intriguing.Previous work has also demonstrated the ability of such cells to stimulate intrinsic growth programs in post-mitotic cells,such as neurons.While embryonic stem cells demonstrated great potential in treating central nervous system pathologies,ethical and technical concerns remained.These barriers,along with the clear necessity for this type of treatment,ultimately prompted the advent of induced pluripotent stem cells.The advantage of pluripotent cells in central nervous system regeneration is multifaceted,permitting differentiation into neural stem cells,neural progenitor cells,glia,and various neuronal subpopulations.The precise spatiotemporal application of extrinsic growth factors in vitro,in addition to microenvironmental signaling in vivo,influences the efficiency of this directed differentiation.While the pluri-or multipotency of these cells is appealing,it also poses the risk of unregulated differentiation and teratoma formation.Cells of the neuroectodermal lineage,such as neuronal subpopulations and glia,have been explored with varying degrees of success.Although the risk of cancer or teratoma formation is greatly reduced,each subpopulation varies in effectiveness and is influenced by a myriad of factors,such as the timing of the transplant,pathology type,and the ratio of accompanying progenitor cells.Furthermore,successful transplantation requires innovative approaches to develop delivery vectors that can mitigate cell death and support integration.Lastly,host immune responses to allogeneic grafts must be thoroughly characterized and further developed to reduce the need for immunosuppression.Translation to a clinical setting will involve careful consideration when assessing both physiologic and functional outcomes.This review will highlight both successes and challenges faced when using human induced pluripotent stem cell-derived cell transplantation therapies to promote endogenous regeneration.展开更多
AIM:To study the effect and tolerance of intraperitoneal perfusion of cytokine-induced killer(CIK) cells in combination with local radio frequency(RF) hyperthermia in patients with advanced primary hepatocellular carc...AIM:To study the effect and tolerance of intraperitoneal perfusion of cytokine-induced killer(CIK) cells in combination with local radio frequency(RF) hyperthermia in patients with advanced primary hepatocellular carcinoma(HCC).METHODS:Patients with advanced primary HCC were included in this study.CIK cells were perfused intraperitoneal twice a week,using 3.2 × 10 9 to 3.6 × 10 9 cells each session.Local RF hyperthermia was performed 2 h after intraperitoneal perfusion.Following an interval of one month,the next course of treatment was administered.Patients received treatment until disease progression.Tumor size,immune indices(CD3 +,CD4 +,CD3 + CD8 +,CD3 + CD56 +),alpha-fetoprotein(AFP) level,abdominal circumference and adverse events were recorded.Time to progression and overall survival(OS) were calculated.RESULTS:From June 2010 to July 2011,31 patients diagnosed with advanced primary HCC received intraperitoneal perfusion of CIK cells in combination with local RF hyperthermia in our study.Patients received an average of 4.2 ± 0.6 treatment courses(range,1-8 courses).Patients were followed up for 8.3 ± 0.7 mo(range,2-12 mo).Following combination treatment,CD4 +,CD3 + CD8 + and CD3 + CD56 + cells increased from 35.78% ± 3.51%,24.61% ± 4.19% and 5.94% ± 0.87% to 45.83% ± 2.48%(P = 0.016),39.67% ± 3.38%(P = 0.008) and 10.72% ± 0.67%(P = 0.001),respectively.AFP decreased from 167.67 ± 22.44 to 99.89 ± 22.05 ng/mL(P = 0.001) and abdominal circumference decreased from 97.50 ± 3.45 cm to 87.17 ± 4.40 cm(P = 0.002).The disease control rate was 67.7%.The most common adverse events were low fever and slight abdominal erubescence,which resolved without treatment.The median time to progression was 6.1 mo.The 3-,6-and 9-mo and 1-year survival rates were 93.5%,77.4%,41.9% and 17.4%,respectively.The median OS was 8.5 mo.CONCLUSION:Intraperitoneal perfusion of CIK cells in combination with local RF hyperthermia is safe,can efficiently improve immunological status,and may prolong survival in HCC patients.展开更多
AIM:To investigate the effect of hyperthermia on hy-poxia-induced epithelial-mesenchymal transition (EMT) in HepG2 hepatocellular carcinoma (HCC) cells, and its mechanism. METHODS:Cells were treated with hyperthermia ...AIM:To investigate the effect of hyperthermia on hy-poxia-induced epithelial-mesenchymal transition (EMT) in HepG2 hepatocellular carcinoma (HCC) cells, and its mechanism. METHODS:Cells were treated with hyperthermia at 43 ℃ for 0.5 h, followed by incubation under hypoxic or normoxic conditions for 72 h. Cell morphology was observed. Expressions of E-cadherin and vimentin were determined by immunofluorescence assay or Western blot. The protein and mRNA expressions of Snail were also determined by Western blot and reverse transcrip-tion-polymerase chain reaction. Cell migratory capacity was evaluated. RESULTS:Hypoxia induced EMT in HepG2 cells, which was evidenced by morphological, molecular and func-tional changes, including the formation of a spindle shape and the loss of cell contact. The expression of E-cadherin was decreased but the expression of vimentin was increased; also, the migratory capability was increased by 2.2 ± 0.20-fold as compared with normoxia. However, those effects were inhibited by hyperthermia pretreatment. Furthermore, protein synthesis and mRNA expression of Snail in the cells were enhanced by hy-poxia as compared with normoxia, and also significantly inhibited by hyperthermia pretreatment. CONCLUSION:Hyperthermia may inhibit hypoxia-induced EMT in HepG2 HCC cells, and the mechanism may involve inhibition of induced expression of Snail.展开更多
Malignant hyperthermia(MH)is a genetic disorder of skeletal muscle cells that affects muscle cytoplasmic calcium homeostasis,with high mortality and low morbidity.Generally,it presents with non-specific signs of a hyp...Malignant hyperthermia(MH)is a genetic disorder of skeletal muscle cells that affects muscle cytoplasmic calcium homeostasis,with high mortality and low morbidity.Generally,it presents with non-specific signs of a hypermetabolic response,including high fever,tachycardia,and elevated end-tidal carbon dioxide(ETCO_(2)).The successful treatment lies in the timely recognition and early use of dantrolene.[1]As an inhibitor of Ca2+release through ryanodine receptor(RYR)channels,the skeletal muscle relaxant dantrolene has proven to be both a valuable experimental probe of intracellular Ca2+signaling and a lifesaving treatment for MH.[2]Dominant mutations in the skeletal muscle RYR1 gene are well-recognized causes of both malignant hyperthermia susceptibility(MHS)and central core disease(CCD).展开更多
The aim in this study is to examine the effect of tirapazamine (TPZ) and mild temperature hyperthermia (MTH) on the repair of radiation-induced damage in pimonidazole-unlabeled quiescent (Q) tumor cells. Labeling of p...The aim in this study is to examine the effect of tirapazamine (TPZ) and mild temperature hyperthermia (MTH) on the repair of radiation-induced damage in pimonidazole-unlabeled quiescent (Q) tumor cells. Labeling of proliferating (P) cells in C57BL/6J mice bearing EL4 tumors was achieved by continuous administration of 5-bromo-2-deoxyuridine (BrdU). Tumors were irradiated with γ-rays at 1 h after the administration of pimonidazole followed by TPZ treatment or MTH. Twenty-four hours later, assessment of the responses of Q and total (= P + Q) cells were based on the frequencies of micronucleation and apoptosis using immunofluorescence staining for BrdU. The response of the pimonidazole-unlabeled tumor cell fractions was assessed by means of apoptosis frequency using immunofluorescence staining for pimonidazole. With γ-rays only, the pimonidazole-unlabeled cell fraction showed significantly enhanced radio-sensitivity compared with the whole cell fraction more remarkably in Q cells than total cells. However, a significantly greater decrease in radio-sensitivity in the pimonidazole-unlabeled than the whole cell fraction, evaluated using a delayed assay, was more clearly observed in Q cells than total cells. Post-irradiation MTH more remarkably repressed the decrease in radio-sensitivity in the Q cell than the total cells. Post-irradiation TPZ administration produced a large radio-sensitizing effect on both total and Q cells, especially on Q cells. On the other hand, in pimonidazole-unlabeled cell fractions in both total and Q cells, TPZ suppressed the reduction in sensitivity due to delayed assay much more efficiently than MTH, whereas no radio-sensitizing effect was produced. Not only through suppressing the recovery from radiation-induced damage but also through radio-sensitizing effect, post-irradiation TPZ administration is very useful for repressing the increase in the difference in radio-sensitivity due to the delayed assay not only between total and Q tumor cells but also between the pimonidazole-unlabeled and the whole cell fractions within the total and Q tumor cells.展开更多
Methamphetamine(METH)is one of the most widely abused synthetic drugs in the world,with the abuser present hyperthermia(HT)and psychiatric symptoms.However,the mechanism involved in METH/HT-induced neurotoxicity remai...Methamphetamine(METH)is one of the most widely abused synthetic drugs in the world,with the abuser present hyperthermia(HT)and psychiatric symptoms.However,the mechanism involved in METH/HT-induced neurotoxicity remains elusive.Here,we investigated the role of heat shock protein 90 alpha(HSP90a)in METH/HT(39.5C)-induced necroptosis in rat striatum neurons and rat in vivo model.Western blot showed that the expression of HSP90a increased,and HSP90a specific inhibitor geldanamycin(GA)and shRNA of HSP90a could attenuate METH/HT-induced upregulation of receptor interacting protein 3(RIP3),pRIP3,mixed lineage kinase domain-like protein(MLKL)and pMLKL in cultured striatum neurons and in vivo model.Propidium iodide staining and lactate dehydrogenase assay results showed that METH/HT-induced necroptosis is partially inhibited by both necrostain-1,GA and shRNA of HSP90a in vitro and in vivo model.展开更多
The study presents a comprehensive coupled thermo-bio-chemo-hydraulic(T-BCH)modeling framework for stabilizing soils using microbially induced calcite precipitation(MICP).The numerical model considers relevant multiph...The study presents a comprehensive coupled thermo-bio-chemo-hydraulic(T-BCH)modeling framework for stabilizing soils using microbially induced calcite precipitation(MICP).The numerical model considers relevant multiphysics involved in MICP,such as bacterial ureolytic activities,biochemical reactions,multiphase and multicomponent transport,and alteration of the porosity and permeability.The model incorporates multiphysical coupling effects through well-established constitutive relations that connect parameters and variables from different physical fields.It was implemented in the open-source finite element code OpenGeoSys(OGS),and a semi-staggered solution strategy was designed to solve the couplings,allowing for flexible model settings.Therefore,the developed model can be easily adapted to simulate MICP applications in different scenarios.The numerical model was employed to analyze the effect of various factors,including temperature,injection strategies,and application scales.Besides,a TBCH modeling study was conducted on the laboratory-scale domain to analyze the effects of temperature on urease activity and precipitated calcium carbonate.To understand the scale dependency of MICP treatment,a large-scale heterogeneous domain was subjected to variable biochemical injection strategies.The simulations conducted at the field-scale guided the selection of an injection strategy to achieve the desired type and amount of precipitation.Additionally,the study emphasized the potential of numerical models as reliable tools for optimizing future developments in field-scale MICP treatment.The present study demonstrates the potential of this numerical framework for designing and optimizing the MICP applications in laboratory-,prototype-,and field-scale scenarios.展开更多
The combination therapy of magnetic hyperthermia and thermosensitive liposomes(TSL)is an emerging and effective cancer treatment method.The heat generation of magnetic nanoparticles(MNPs)due to an external alternating...The combination therapy of magnetic hyperthermia and thermosensitive liposomes(TSL)is an emerging and effective cancer treatment method.The heat generation of magnetic nanoparticles(MNPs)due to an external alternating magnetic field can not only directly damage tumor cells,but also serves as a triggering factor for the release of doxorubicin from TSL.The aim of this study is to investigate the effects in the degree of tumor cell damage of two proposed injection strategies that consider intravenous administration.Since both MNPs and TSL enter the tumor region intravenously,this study establishes a biological geometric model based on an experiment-based vascular distribution.Furthermore,this study derives the flow velocity of interstitial fluid after coupling the pressure distribution inside blood vessels and the pressure distribution of interstitial fluid,which then provides the convective velocity for the calculation of subsequent nanoparticle concentration.Different injection strategies for the proposed approach are evaluated by drug delivery result,temperature distribution,and tumor cell damage.Simulation results demonstrate that the proposed delayed injection strategy after optimization can not only result in a wider distribution for MNPs and TSL due to the sufficient diffusion time,but also improves the distribution of the temperature and drug concentration fields for the overall efficacy of combination therapy.展开更多
The preparation of γ-Fe<sub>2</sub>O<sub>3</sub>/Gd<sub>2</sub>O<sub>3</sub> nanocomposite for possible use in magnetic hyperthermia application was done by ball millin...The preparation of γ-Fe<sub>2</sub>O<sub>3</sub>/Gd<sub>2</sub>O<sub>3</sub> nanocomposite for possible use in magnetic hyperthermia application was done by ball milling technique. The nanocomposite was characterized by X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The heating efficiency and the effect of milling time (5 h and 30 h) on the structural and magnetic properties of the nanocomposite were reported. XRD analysis confirms the formation of the nanocomposite, while magnetization measurements show that the milled sample present hysteresis with low coercivity and remanence. The specific absorption rate (SAR) under an alternating magnetic field is investigated as a function of the milling time. A mean heating efficiency of 68 W/g and 28.7 W/g are obtained for 5 h and 30 h milling times respectively at 332 kHz and 170 Oe. The results showed that the obtained nanocomposite for 5 h milling time is a promising candidate for magnetic hyperthermia due to his properties which show an interesting magnetic behavior and high specific absorption rate.展开更多
In this review,the development and application of microbially induced carbonate precipitation(MICP)technology for the sealing of underground engineering fractures are discussed in detail.The importance of sealing micr...In this review,the development and application of microbially induced carbonate precipitation(MICP)technology for the sealing of underground engineering fractures are discussed in detail.The importance of sealing micro-fractures in an environmentally friendly and efficient manner is emphasized,and the potential of the MICP method in controlling pore and fracture seepage is highlighted.The fundamental mechanisms,key influencing factors,numerical models,and applications of the MICP in the fields of geological CO_(2) storage and oil resources development are comprehensively summarized in the paper.At the same time,the limitations of the existing research and the future research directions are discussed,especially in terms of improving the processing efficiency,environmental impacts,and cost considerations.Overall,the development of MICP technology provides a new environmentally friendly reinforcement method for geotechnical engineering and is expected to play a key role in the future development of underground space engineering.展开更多
Flow-slip damage commonly destabilizes coastal slopes.Finding a slope stabilization method for calcareous sands in the South China Sea is crucial.Microbially induced calcite precipitation is a promising,eco-friendly m...Flow-slip damage commonly destabilizes coastal slopes.Finding a slope stabilization method for calcareous sands in the South China Sea is crucial.Microbially induced calcite precipitation is a promising,eco-friendly method for soil stabilization.This study investigates the effect of microbial treatments,initial relative density,initial cell pressure,and initial stress ratio on the flow-slip stability of calcareous sand specimens by using constant shear drained tests.These tests lay the foundation to study the mechanical instability of sand slopes.Results show that the microbial-treated specimens maintain stable stresses longer,take longer to reach the instability,and withstand larger volumetric strains.Microbial treatment effectively enhances sand stability under constant shear drainage,with improvements amplified by higher initial relative density and initial cell pressure.In addition,a smaller initial stress ratio reduces shear effects on the specimen and increases resistance to flow slides.Microanalysis reveals that the flow-slip stability of calcareous sand slopes is enhanced by contact cementation,particle coating,void filling,and mutual embedment of calcium carbonate crystals.展开更多
We present the electromagnetically induced transparency(EIT)spectra of cold Rydberg four-level cascade atoms consisting of the 6S_(1/2)→6P_(3/2)→7S_(1/2)→60P_(3/2) scheme.A coupling laser drives the Rydberg transit...We present the electromagnetically induced transparency(EIT)spectra of cold Rydberg four-level cascade atoms consisting of the 6S_(1/2)→6P_(3/2)→7S_(1/2)→60P_(3/2) scheme.A coupling laser drives the Rydberg transition,a dressing laser couples two intermediate levels and a weak probe laser probes the EIT signal.We numerically solve the Bloch equations and investigate the dependence of the probe transmission rate signal on the coupling and dressing lasers.We find that the probe transmission rate can display an EIT or electromagnetically induced absorption(EIA)profile,depending on the Rabi frequencies of the coupling and dressing lasers.When we increase the Rabi frequency of the coupling laser and keep the Rabi frequency of the probe and dressing laser fixed,flipping of the EIA to EIT spectrum occurs at the critical coupling Rabi frequency.When we apply a microwave field coupling the transition 60P_(3/2)→61S_(1/2),the EIT spectrum shows Autler–Townes splitting,which is employed to measure the microwave field.The theoretical measurement sensitivity can be 1.52×10^(−2) nV・cm^(−1)・Hz−^(1/2) at the EIA–EIT flipping point.展开更多
We theoretically investigate the magnomechanically induced transparency phenomenon,Fano resonance and the slow-fast light effect in the situation where an atomic ensemble is placed inside the hybrid cavity of an optom...We theoretically investigate the magnomechanically induced transparency phenomenon,Fano resonance and the slow-fast light effect in the situation where an atomic ensemble is placed inside the hybrid cavity of an optomagnomechanical system.The system is driven by dual optical and phononic drives.We show double magnomechanically induced transparency in the probe output spectrum by exploiting the phonon-photon coupling strength.Then,we study the effects of the decay rate of the cavity and the atomic ensemble on magnomechanically induced transparency.In addition,we demonstrate that effective detuning of the cavity field frequency changes the transparency window from a symmetrical to an asymmetrical profile,resembling Fano resonances.Further,the fast and slow light effects in the system are explored.We show that the slow light profile is enhanced by adjusting the phonon-photon coupling strength.This result may have potential applications in quantum information processing and communication.展开更多
Evaluating the physical mechanisms that link hydraulic fracturing(HF) operations to induced earthquakes and the anticipated form of the resulting events is significant in informing subsurface fluid injection operation...Evaluating the physical mechanisms that link hydraulic fracturing(HF) operations to induced earthquakes and the anticipated form of the resulting events is significant in informing subsurface fluid injection operations. Current understanding supports the overriding role of the effective stress magnitude in triggering earthquakes, while the impact of change rate of effective stress has not been systematically addressed. In this work, a modified critical stiffness was brought up to investigate the likelihood, impact,and mitigation of induced seismicity during and after hydraulic fracturing by developing a poroelastic model based on rate-and-state fraction law and linear stability analysis. In the new criterion, the change rate of effective stress was considered a key variable to explore the evolution of this criterion and hence the likelihood of instability slip of fault. A coupled fluid flow-deformation model was used to represent the entire hydraulic fracturing process in COMSOL Multiphysics. The possibility of triggering an earthquake throughout the entire hydraulic fracturing process, from fracturing to cessation, was investigated considering different fault locations, orientations, and positions along the fault. The competition between the effects of the magnitude and change rate of effective stress was notable at each fracturing stage. The effective stress magnitude is a significant controlling factor during fracturing events, with the change rate dominating when fracturing is suddenly started or stopped. Instability dominates when the magnitude of the effective stress increases(constant injection at each fracturing stage) and the change rate of effective stress decreases(the injection process is suddenly stopped). Fracturing with a high injection rate, a fault adjacent to the hydraulic fracturing location and the position of the junction between the reservoir and fault are important to reduce the Coulomb failure stress(CFS) and enhance the critical stiffness as the significant disturbance of stresses at these positions in the coupled process. Therefore,notable attention should be given to the injection rate during fracturing, fault position, and position along faults as important considerations to help reduce the potential for induced seismicity. Our model was verified and confirmed using the case of the Longmaxi Formation in the Sichuan Basin, China, in which the reported microseismic data were correlated with high critical stiffness values. This work supplies new thoughts of the seismic risk associated with HF engineering.展开更多
基金supported by National Natural Science Foundation of China (Grant No. 81225010, 20803040, 81028009, and 31170961)National Key Basic Research Program of China (973 Program) (Grant No. 2010CB933902 and 2015CB931802)+1 种基金National Key Technology Research and Development Program (863 Program) (Grant No. 2012AA022703 and 2014AA020700)Shanghai Science and Technology Fund (Grant No.13NM1401500)
文摘Objective: Human induced pluripotent stem(i PS) cells exhibit great potential for generating functional human cells for medical therapies. In this paper, we report for use of human i PS cells labeled with fluorescent magnetic nanoparticles(FMNPs) for targeted imaging and synergistic therapy of gastric cancer cells in vivo. Methods: Human i PS cells were prepared and cultured for 72 h. The culture medium was collected, and then was coincubated with MGC803 cells. Cell viability was analyzed by the MTT method. FMNP-labeled human i PS cells were prepared and injected into gastric cancer-bearing nude mice. The mouse model was observed using a small-animal imaging system. The nude mice were irradiated under an external alternating magnetic field and evaluated using an infrared thermal mapping instrument. Tumor sizes were measured weekly. Results: iP S cells and the collected culture medium inhibited the growth of MGC803 cells. FMNP-labeled human iP S cells targeted and imaged gastric cancer cells in vivo, as well as inhibited cancer growth in vivo through the external magnetic field. Conclusion: FMNP-labeled human i PS cells exhibit considerable potential in applications such as targeted dual-mode imaging and synergistic therapy for early gastric cancer.
文摘Objective: Hyperthermia is an attractive addition to multidisciplinary approaches to clinical cancer treatment. The efficiency of hyperthermia depends on the elevation of the temperature and the duration of treatment. It has been reported that in vitro and in vivo hyperthermia enhanced the cytotoxic effect of certain anticancer drugs. However, this enhancement varies, depending on the drug used and the scheduling of treatments. Thus, the combination effect of chemotherapy and hyperthermia remains unclear. In this study, we aimed to investigate whether concurrent exposure of human hepatocellular carcinoma cells SMMC-7721 to chemotherapeutic agents andhyperthermia could increase anticancer effects. Methods : Two chemotherapeutic agents, cisplatin and hydroxycamptothecin, were applied. The MTT assay was performed to evaluate the growth inhibition of SMMC-7721 induced by anticancer drugs with and without hyperthermia. Flow cytometric analysis was used for the assessment of apoptosis after treatments. Results: The percentages of growth inhibition of SMMC-7721 induced by cisplatin (10μg/ml) alone, hydroxycamptothecin (1μg/ml)alone, hyperthermia alone, cisplatin and hyperthermia, hydroxycamptothecin and hyperthermia, were 20.77%, 13.65%, 32.46%, 62.76%, 71.89%, respectively. The percentages of apoptosis of five treatments are 5.56%, 3.96%, 10.16%, 24.32%, 20.42%, respectively. Conclusion: While both hyperthermia and anticancer drugs can individually induce apoptosis and anti-proliferation effect, the combination of the two treatments induce significantly higher apoptosis and cytotoxicity than hyperthermia or anticancer drugs treatment alone. These data suggest a synergistic benefit when hyperthermia and anticancer drugs used concurrently.
基金Project supported by the National Basic Research Program of China (Grant No. 2011CB707900)the National Natural Science Foundation of China (Grant Nos. 11074123, 10974095, 10904068, and 10204014)+2 种基金the Fundamental Research Funds for the Central Universities of China (Grant Nos. 111602040 and 1095020409)the Natural Science Foundation of Jiangsu Province of China (Grant No. BK2011812)the Priority Academic Program Development of Jiangsu Higher Educaton Institutions of China
文摘Hyperthermia effects (39-44 ℃) induced by pulsed high-intensity focused ultrasound (HIFU) have been regarded as a promising therapeutic tool for boosting immune responses or enhancing drug delivery into a solid tumor. However, previous studies also reported that the cell death occurs when cells are maintained at 43 ℃ for more than 20 minutes. The aim of this study is to investigate thermal responses inside in vivo rabbit auricular veins exposed to pulsed HIFU (1.17 MHz, 5300 W/cm2, with relatively low-duty ratios (0.2%-4.3%). The results show that: (1) with constant pulse repetition frequency (PRF) (e.g., 1 Hz), the thermal responses inside the vessel will increase with the increasing duty ratio; (2) a temperature elevation to 43 ℃ can be identified at the duty ratio of 4.3%; (3) with constant duty ratios, the change of PRF will not significantly affect the temperature measurement in the vessel; (4) as the duty ratios lower than 4.3%, the presence of microbubbles will not significantly enhance the thermal responses in the vessel, but will facilitate HIFU-induced inertial cavitation events.
文摘Objective: To study the role of apoptosis in tumor cell of malignant glioma death following treatment with hyperthermia and calcium ionophore. Methods: The apoptosis induced by hyperthermia and calcium ionophore, A23187, in human glioblastoma cell line TJ905 and murine glioblastoma G422 was evaluated by characteristic findings in DNA agarose gel electrophresis, ultrastructural examination and flow cytometric analysis. Results: Apoptosis could be induced by moderate hyperthermia, but not by mild hyperthermia, calcium ionophore enhanced significantly the effect of mild hyperthermia on the induction of apoptosis. Conclusion: This result indicates that apoptotic cell death is one of the mechanisms of hyperthermic therapy for malignant glioma and taking measures to increase the cytolic calcium may enhance the effect of hyperthermia.
文摘Purpose: In this project, we developed novel methods to quantify changes in tumor hypoxia following a mild tempera-ture hyperthermia (MTH) treatment in rat HT29 human colon adenocarcinoma xenograft. Materials and Methods: An exogenous hypoxia marker (IAZGP) was labeled with two radioisotopes of iodine (131I and 123I, respectively) to form two distinct tracers. The two tracers were injected into HT29-bearing nude rats 4-hour before and immediately following 41.5℃, 45-minute mild hyperthermia treatment. The distributions of the two hypoxia tracers were obtained by performing digital autoradiography on tumor sections, and image processing resulted in quantitative information at 50 μm pixel size. Results: Following the hyperthermia treatment, there was a remarkable decrease in hypoxia tracer binding. The average whole tumor hypoxia tracer targeted fraction in five animals changed from 30.3% ± 9.7% to 13.0% ± 5.3% after the hyperthermia treatment (P = 0.001). Detailed pixelby-pixel analysis of the image data revealed a decline in hypoxia tracer uptake after hyperthermia in most regions. However, there was concomitant emergence of some new regions of hypoxia identified by increased tracer uptake. In the control group, the overall hypoxia tracer targeted fraction remained almost constant, with some hypoxic tracer redistribution (putative acute hypoxia) observed. Conclusion: Reoxygenation occurred in the rat HT29 xenograft following MTH treatment. This was evident with preponderance of decreased hypoxia specific tracer uptake on tumor sections. Our methodology might be a useful tool in hypoxia study.
文摘AIM:To evaluate the surgical treatment methods of giant cell tumors(GCT) of long bone in conjunction with inserted microwave antennas induced hyperthermia.METHODS:46patients,included the surgical procedures,the oncology results,the functions of the limbs and the complications were analyzed.RESULTS:Follow-up 3.5 to 9 years(mean 5.5years).All patients were evaluated according to oncological and orthopaedic criteria.Two tumors were recurred.Orthopaedic furction were perfect in 44 patients and were fair in 2.Infection was found in 2 patients.CONCLUSION:The surgical procedure to treat the giant cell tumors of long bone by inserted microwave antennas induced hyperthermia is a definitive surgical method which is safe and confident.
基金supported by Ohio State Start Up FundNational Institutes of Health(NIH)+12 种基金Department of Defense(DoD)Wings for Life Spinal Cord Research Foundation,Wings for Life Spinal Cord Research Foundation(Austria)California Institute of Regenerative Medicine(CIRM)International Spinal Research Trust(United Kingdom)Stanford University Bio-X Program Interdisciplinary Initiatives Seed Grant IIP-7Dennis Chan FoundationKlein Family FundLucile Packard Foundation for Children's HealthStanford Institute for Neuro-Innovation and Translational Neurosciences(SINTN)Saunders Family Neuroscience FundJames Doty Neurosurgery FundHearst Neuroscience FundEileen Bond Research Fund(to GP)。
文摘In recent years,the progression of stem cell therapies has shown great promise in advancing the nascent field of regenerative medicine.Considering the non-regenerative nature of the mature central nervous system,the concept that“blank”cells could be reprogrammed and functionally integrated into host neural networks remained intriguing.Previous work has also demonstrated the ability of such cells to stimulate intrinsic growth programs in post-mitotic cells,such as neurons.While embryonic stem cells demonstrated great potential in treating central nervous system pathologies,ethical and technical concerns remained.These barriers,along with the clear necessity for this type of treatment,ultimately prompted the advent of induced pluripotent stem cells.The advantage of pluripotent cells in central nervous system regeneration is multifaceted,permitting differentiation into neural stem cells,neural progenitor cells,glia,and various neuronal subpopulations.The precise spatiotemporal application of extrinsic growth factors in vitro,in addition to microenvironmental signaling in vivo,influences the efficiency of this directed differentiation.While the pluri-or multipotency of these cells is appealing,it also poses the risk of unregulated differentiation and teratoma formation.Cells of the neuroectodermal lineage,such as neuronal subpopulations and glia,have been explored with varying degrees of success.Although the risk of cancer or teratoma formation is greatly reduced,each subpopulation varies in effectiveness and is influenced by a myriad of factors,such as the timing of the transplant,pathology type,and the ratio of accompanying progenitor cells.Furthermore,successful transplantation requires innovative approaches to develop delivery vectors that can mitigate cell death and support integration.Lastly,host immune responses to allogeneic grafts must be thoroughly characterized and further developed to reduce the need for immunosuppression.Translation to a clinical setting will involve careful consideration when assessing both physiologic and functional outcomes.This review will highlight both successes and challenges faced when using human induced pluripotent stem cell-derived cell transplantation therapies to promote endogenous regeneration.
基金Supported by The National Natural Science Foundation of China,No.81273814
文摘AIM:To study the effect and tolerance of intraperitoneal perfusion of cytokine-induced killer(CIK) cells in combination with local radio frequency(RF) hyperthermia in patients with advanced primary hepatocellular carcinoma(HCC).METHODS:Patients with advanced primary HCC were included in this study.CIK cells were perfused intraperitoneal twice a week,using 3.2 × 10 9 to 3.6 × 10 9 cells each session.Local RF hyperthermia was performed 2 h after intraperitoneal perfusion.Following an interval of one month,the next course of treatment was administered.Patients received treatment until disease progression.Tumor size,immune indices(CD3 +,CD4 +,CD3 + CD8 +,CD3 + CD56 +),alpha-fetoprotein(AFP) level,abdominal circumference and adverse events were recorded.Time to progression and overall survival(OS) were calculated.RESULTS:From June 2010 to July 2011,31 patients diagnosed with advanced primary HCC received intraperitoneal perfusion of CIK cells in combination with local RF hyperthermia in our study.Patients received an average of 4.2 ± 0.6 treatment courses(range,1-8 courses).Patients were followed up for 8.3 ± 0.7 mo(range,2-12 mo).Following combination treatment,CD4 +,CD3 + CD8 + and CD3 + CD56 + cells increased from 35.78% ± 3.51%,24.61% ± 4.19% and 5.94% ± 0.87% to 45.83% ± 2.48%(P = 0.016),39.67% ± 3.38%(P = 0.008) and 10.72% ± 0.67%(P = 0.001),respectively.AFP decreased from 167.67 ± 22.44 to 99.89 ± 22.05 ng/mL(P = 0.001) and abdominal circumference decreased from 97.50 ± 3.45 cm to 87.17 ± 4.40 cm(P = 0.002).The disease control rate was 67.7%.The most common adverse events were low fever and slight abdominal erubescence,which resolved without treatment.The median time to progression was 6.1 mo.The 3-,6-and 9-mo and 1-year survival rates were 93.5%,77.4%,41.9% and 17.4%,respectively.The median OS was 8.5 mo.CONCLUSION:Intraperitoneal perfusion of CIK cells in combination with local RF hyperthermia is safe,can efficiently improve immunological status,and may prolong survival in HCC patients.
基金Supported by Medical Science and Technology Innovation Foundation of Nanjing Military Command of Chinese People’s Liberation Army, No. 11MA036Natural Science Foundation of China, No. 81000998
文摘AIM:To investigate the effect of hyperthermia on hy-poxia-induced epithelial-mesenchymal transition (EMT) in HepG2 hepatocellular carcinoma (HCC) cells, and its mechanism. METHODS:Cells were treated with hyperthermia at 43 ℃ for 0.5 h, followed by incubation under hypoxic or normoxic conditions for 72 h. Cell morphology was observed. Expressions of E-cadherin and vimentin were determined by immunofluorescence assay or Western blot. The protein and mRNA expressions of Snail were also determined by Western blot and reverse transcrip-tion-polymerase chain reaction. Cell migratory capacity was evaluated. RESULTS:Hypoxia induced EMT in HepG2 cells, which was evidenced by morphological, molecular and func-tional changes, including the formation of a spindle shape and the loss of cell contact. The expression of E-cadherin was decreased but the expression of vimentin was increased; also, the migratory capability was increased by 2.2 ± 0.20-fold as compared with normoxia. However, those effects were inhibited by hyperthermia pretreatment. Furthermore, protein synthesis and mRNA expression of Snail in the cells were enhanced by hy-poxia as compared with normoxia, and also significantly inhibited by hyperthermia pretreatment. CONCLUSION:Hyperthermia may inhibit hypoxia-induced EMT in HepG2 HCC cells, and the mechanism may involve inhibition of induced expression of Snail.
文摘Malignant hyperthermia(MH)is a genetic disorder of skeletal muscle cells that affects muscle cytoplasmic calcium homeostasis,with high mortality and low morbidity.Generally,it presents with non-specific signs of a hypermetabolic response,including high fever,tachycardia,and elevated end-tidal carbon dioxide(ETCO_(2)).The successful treatment lies in the timely recognition and early use of dantrolene.[1]As an inhibitor of Ca2+release through ryanodine receptor(RYR)channels,the skeletal muscle relaxant dantrolene has proven to be both a valuable experimental probe of intracellular Ca2+signaling and a lifesaving treatment for MH.[2]Dominant mutations in the skeletal muscle RYR1 gene are well-recognized causes of both malignant hyperthermia susceptibility(MHS)and central core disease(CCD).
文摘The aim in this study is to examine the effect of tirapazamine (TPZ) and mild temperature hyperthermia (MTH) on the repair of radiation-induced damage in pimonidazole-unlabeled quiescent (Q) tumor cells. Labeling of proliferating (P) cells in C57BL/6J mice bearing EL4 tumors was achieved by continuous administration of 5-bromo-2-deoxyuridine (BrdU). Tumors were irradiated with γ-rays at 1 h after the administration of pimonidazole followed by TPZ treatment or MTH. Twenty-four hours later, assessment of the responses of Q and total (= P + Q) cells were based on the frequencies of micronucleation and apoptosis using immunofluorescence staining for BrdU. The response of the pimonidazole-unlabeled tumor cell fractions was assessed by means of apoptosis frequency using immunofluorescence staining for pimonidazole. With γ-rays only, the pimonidazole-unlabeled cell fraction showed significantly enhanced radio-sensitivity compared with the whole cell fraction more remarkably in Q cells than total cells. However, a significantly greater decrease in radio-sensitivity in the pimonidazole-unlabeled than the whole cell fraction, evaluated using a delayed assay, was more clearly observed in Q cells than total cells. Post-irradiation MTH more remarkably repressed the decrease in radio-sensitivity in the Q cell than the total cells. Post-irradiation TPZ administration produced a large radio-sensitizing effect on both total and Q cells, especially on Q cells. On the other hand, in pimonidazole-unlabeled cell fractions in both total and Q cells, TPZ suppressed the reduction in sensitivity due to delayed assay much more efficiently than MTH, whereas no radio-sensitizing effect was produced. Not only through suppressing the recovery from radiation-induced damage but also through radio-sensitizing effect, post-irradiation TPZ administration is very useful for repressing the increase in the difference in radio-sensitivity due to the delayed assay not only between total and Q tumor cells but also between the pimonidazole-unlabeled and the whole cell fractions within the total and Q tumor cells.
文摘Methamphetamine(METH)is one of the most widely abused synthetic drugs in the world,with the abuser present hyperthermia(HT)and psychiatric symptoms.However,the mechanism involved in METH/HT-induced neurotoxicity remains elusive.Here,we investigated the role of heat shock protein 90 alpha(HSP90a)in METH/HT(39.5C)-induced necroptosis in rat striatum neurons and rat in vivo model.Western blot showed that the expression of HSP90a increased,and HSP90a specific inhibitor geldanamycin(GA)and shRNA of HSP90a could attenuate METH/HT-induced upregulation of receptor interacting protein 3(RIP3),pRIP3,mixed lineage kinase domain-like protein(MLKL)and pMLKL in cultured striatum neurons and in vivo model.Propidium iodide staining and lactate dehydrogenase assay results showed that METH/HT-induced necroptosis is partially inhibited by both necrostain-1,GA and shRNA of HSP90a in vitro and in vivo model.
基金support from the OpenGeoSys communitypartially funded by the Prime Minister Research Fellowship,Ministry of Education,Government of India with the project number SB21221901CEPMRF008347.
文摘The study presents a comprehensive coupled thermo-bio-chemo-hydraulic(T-BCH)modeling framework for stabilizing soils using microbially induced calcite precipitation(MICP).The numerical model considers relevant multiphysics involved in MICP,such as bacterial ureolytic activities,biochemical reactions,multiphase and multicomponent transport,and alteration of the porosity and permeability.The model incorporates multiphysical coupling effects through well-established constitutive relations that connect parameters and variables from different physical fields.It was implemented in the open-source finite element code OpenGeoSys(OGS),and a semi-staggered solution strategy was designed to solve the couplings,allowing for flexible model settings.Therefore,the developed model can be easily adapted to simulate MICP applications in different scenarios.The numerical model was employed to analyze the effect of various factors,including temperature,injection strategies,and application scales.Besides,a TBCH modeling study was conducted on the laboratory-scale domain to analyze the effects of temperature on urease activity and precipitated calcium carbonate.To understand the scale dependency of MICP treatment,a large-scale heterogeneous domain was subjected to variable biochemical injection strategies.The simulations conducted at the field-scale guided the selection of an injection strategy to achieve the desired type and amount of precipitation.Additionally,the study emphasized the potential of numerical models as reliable tools for optimizing future developments in field-scale MICP treatment.The present study demonstrates the potential of this numerical framework for designing and optimizing the MICP applications in laboratory-,prototype-,and field-scale scenarios.
基金Project supported in part by the National Natural Science Foundation of China(Grant Nos.62471144 and 62071124)in part by the Conselho Nacional de Desenvolvimento Científico e Tecnológico(BR)(CNPq)(Grant No.315546/2021-2)。
文摘The combination therapy of magnetic hyperthermia and thermosensitive liposomes(TSL)is an emerging and effective cancer treatment method.The heat generation of magnetic nanoparticles(MNPs)due to an external alternating magnetic field can not only directly damage tumor cells,but also serves as a triggering factor for the release of doxorubicin from TSL.The aim of this study is to investigate the effects in the degree of tumor cell damage of two proposed injection strategies that consider intravenous administration.Since both MNPs and TSL enter the tumor region intravenously,this study establishes a biological geometric model based on an experiment-based vascular distribution.Furthermore,this study derives the flow velocity of interstitial fluid after coupling the pressure distribution inside blood vessels and the pressure distribution of interstitial fluid,which then provides the convective velocity for the calculation of subsequent nanoparticle concentration.Different injection strategies for the proposed approach are evaluated by drug delivery result,temperature distribution,and tumor cell damage.Simulation results demonstrate that the proposed delayed injection strategy after optimization can not only result in a wider distribution for MNPs and TSL due to the sufficient diffusion time,but also improves the distribution of the temperature and drug concentration fields for the overall efficacy of combination therapy.
文摘The preparation of γ-Fe<sub>2</sub>O<sub>3</sub>/Gd<sub>2</sub>O<sub>3</sub> nanocomposite for possible use in magnetic hyperthermia application was done by ball milling technique. The nanocomposite was characterized by X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The heating efficiency and the effect of milling time (5 h and 30 h) on the structural and magnetic properties of the nanocomposite were reported. XRD analysis confirms the formation of the nanocomposite, while magnetization measurements show that the milled sample present hysteresis with low coercivity and remanence. The specific absorption rate (SAR) under an alternating magnetic field is investigated as a function of the milling time. A mean heating efficiency of 68 W/g and 28.7 W/g are obtained for 5 h and 30 h milling times respectively at 332 kHz and 170 Oe. The results showed that the obtained nanocomposite for 5 h milling time is a promising candidate for magnetic hyperthermia due to his properties which show an interesting magnetic behavior and high specific absorption rate.
基金support provided by the National Natural Science Foundation of China(No.42177141).
文摘In this review,the development and application of microbially induced carbonate precipitation(MICP)technology for the sealing of underground engineering fractures are discussed in detail.The importance of sealing micro-fractures in an environmentally friendly and efficient manner is emphasized,and the potential of the MICP method in controlling pore and fracture seepage is highlighted.The fundamental mechanisms,key influencing factors,numerical models,and applications of the MICP in the fields of geological CO_(2) storage and oil resources development are comprehensively summarized in the paper.At the same time,the limitations of the existing research and the future research directions are discussed,especially in terms of improving the processing efficiency,environmental impacts,and cost considerations.Overall,the development of MICP technology provides a new environmentally friendly reinforcement method for geotechnical engineering and is expected to play a key role in the future development of underground space engineering.
基金supported by the Taishan Scholars Program of Shandong Province,China(No.tsqn202306098)supported by the National Natural Science Foundations of China(No.52171282)the Shandong Provincial Key Research and Development Plan,China(No.2021ZLGX04).
文摘Flow-slip damage commonly destabilizes coastal slopes.Finding a slope stabilization method for calcareous sands in the South China Sea is crucial.Microbially induced calcite precipitation is a promising,eco-friendly method for soil stabilization.This study investigates the effect of microbial treatments,initial relative density,initial cell pressure,and initial stress ratio on the flow-slip stability of calcareous sand specimens by using constant shear drained tests.These tests lay the foundation to study the mechanical instability of sand slopes.Results show that the microbial-treated specimens maintain stable stresses longer,take longer to reach the instability,and withstand larger volumetric strains.Microbial treatment effectively enhances sand stability under constant shear drainage,with improvements amplified by higher initial relative density and initial cell pressure.In addition,a smaller initial stress ratio reduces shear effects on the specimen and increases resistance to flow slides.Microanalysis reveals that the flow-slip stability of calcareous sand slopes is enhanced by contact cementation,particle coating,void filling,and mutual embedment of calcium carbonate crystals.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.U2341211,62175136,12241408,and 12120101004)the Innovation Program for Quantum Science and Technology(Grant No.2023ZD0300902)+1 种基金the Fundamental Research Program of Shanxi Province(Grant No.202303021224007)the 1331 Project of Shanxi Province.
文摘We present the electromagnetically induced transparency(EIT)spectra of cold Rydberg four-level cascade atoms consisting of the 6S_(1/2)→6P_(3/2)→7S_(1/2)→60P_(3/2) scheme.A coupling laser drives the Rydberg transition,a dressing laser couples two intermediate levels and a weak probe laser probes the EIT signal.We numerically solve the Bloch equations and investigate the dependence of the probe transmission rate signal on the coupling and dressing lasers.We find that the probe transmission rate can display an EIT or electromagnetically induced absorption(EIA)profile,depending on the Rabi frequencies of the coupling and dressing lasers.When we increase the Rabi frequency of the coupling laser and keep the Rabi frequency of the probe and dressing laser fixed,flipping of the EIA to EIT spectrum occurs at the critical coupling Rabi frequency.When we apply a microwave field coupling the transition 60P_(3/2)→61S_(1/2),the EIT spectrum shows Autler–Townes splitting,which is employed to measure the microwave field.The theoretical measurement sensitivity can be 1.52×10^(−2) nV・cm^(−1)・Hz−^(1/2) at the EIA–EIT flipping point.
基金the financial support of the National Center for Scientific and Technical Research(CNRST)through the‘PhD-Associate Scholarship-PASS’program。
文摘We theoretically investigate the magnomechanically induced transparency phenomenon,Fano resonance and the slow-fast light effect in the situation where an atomic ensemble is placed inside the hybrid cavity of an optomagnomechanical system.The system is driven by dual optical and phononic drives.We show double magnomechanically induced transparency in the probe output spectrum by exploiting the phonon-photon coupling strength.Then,we study the effects of the decay rate of the cavity and the atomic ensemble on magnomechanically induced transparency.In addition,we demonstrate that effective detuning of the cavity field frequency changes the transparency window from a symmetrical to an asymmetrical profile,resembling Fano resonances.Further,the fast and slow light effects in the system are explored.We show that the slow light profile is enhanced by adjusting the phonon-photon coupling strength.This result may have potential applications in quantum information processing and communication.
基金funded by the joint fund of the National Key Research and Development Program of China(No.2021YFC2902101)National Natural Science Foundation of China(Grant No.52374084)+1 种基金Open Foundation of National Energy shale gas R&D(experiment) center(2022-KFKT-12)the 111 Project(B17009)。
文摘Evaluating the physical mechanisms that link hydraulic fracturing(HF) operations to induced earthquakes and the anticipated form of the resulting events is significant in informing subsurface fluid injection operations. Current understanding supports the overriding role of the effective stress magnitude in triggering earthquakes, while the impact of change rate of effective stress has not been systematically addressed. In this work, a modified critical stiffness was brought up to investigate the likelihood, impact,and mitigation of induced seismicity during and after hydraulic fracturing by developing a poroelastic model based on rate-and-state fraction law and linear stability analysis. In the new criterion, the change rate of effective stress was considered a key variable to explore the evolution of this criterion and hence the likelihood of instability slip of fault. A coupled fluid flow-deformation model was used to represent the entire hydraulic fracturing process in COMSOL Multiphysics. The possibility of triggering an earthquake throughout the entire hydraulic fracturing process, from fracturing to cessation, was investigated considering different fault locations, orientations, and positions along the fault. The competition between the effects of the magnitude and change rate of effective stress was notable at each fracturing stage. The effective stress magnitude is a significant controlling factor during fracturing events, with the change rate dominating when fracturing is suddenly started or stopped. Instability dominates when the magnitude of the effective stress increases(constant injection at each fracturing stage) and the change rate of effective stress decreases(the injection process is suddenly stopped). Fracturing with a high injection rate, a fault adjacent to the hydraulic fracturing location and the position of the junction between the reservoir and fault are important to reduce the Coulomb failure stress(CFS) and enhance the critical stiffness as the significant disturbance of stresses at these positions in the coupled process. Therefore,notable attention should be given to the injection rate during fracturing, fault position, and position along faults as important considerations to help reduce the potential for induced seismicity. Our model was verified and confirmed using the case of the Longmaxi Formation in the Sichuan Basin, China, in which the reported microseismic data were correlated with high critical stiffness values. This work supplies new thoughts of the seismic risk associated with HF engineering.