High content of asphaltenes and waxes leads to the high pour point and the poor flowability of heavy oil,which is adverse to its efficient development and its transportation in pipe.Understanding the interaction mecha...High content of asphaltenes and waxes leads to the high pour point and the poor flowability of heavy oil,which is adverse to its efficient development and its transportation in pipe.Understanding the interaction mechanism between asphaltene-wax is crucial to solve these problems,but it is still unclear.In this paper,molecular dynamics simulation was used to investigate the interaction between asphaltenewax and its effects on the crystallization behavior of waxes in heavy oil.Results show that molecules in pure wax are arranged in a paralleled geometry.But wax molecules in heavy oil,which are close to the surface of asphaltene aggregates,are bent and arranged irregularly.When the mass fraction of asphaltenes in asphaltene-wax system(ω_(asp))is 0-25 wt%,the attraction among wax molecules decreases and the bend degree of wax molecules increases with the increase ofω_(asp).Theω_(asp)increases from 0 to 25 wt%,and the attraction between asphaltene-wax is stronger than that among waxes.This causes that the wax precipitation point changes from 353 to 333 K.While theω_(asp)increases to 50 wt%,wax molecules are more dispersed owing to the steric hindrance of asphaltene aggregates,and the interaction among wax molecules transforms from attraction to repulsion.It causes that the ordered crystal structure of waxes can't be formed at normal temperature.Simultaneously,the asphaltene,with the higher molecular weight or the more hetero atoms,has more obvious inhibition to the formation of wax crystals.Besides,resins also have an obvious inhibition on the wax crystal due to the formation of asphalteneresin aggregates with a larger radius.Our results reveal the interaction mechanism between asphaltene-wax,and provide useful guidelines for the development of heavy oil.展开更多
BACKGROUND Venous air embolism(VAE)is a potentially lethal condition,with a reported incidence rate of about 0.13%,and the true incidence may be higher since many VAE are asymptomatic.The current treatments for VAE in...BACKGROUND Venous air embolism(VAE)is a potentially lethal condition,with a reported incidence rate of about 0.13%,and the true incidence may be higher since many VAE are asymptomatic.The current treatments for VAE include Durant's maneuver,aspiration and removal of air through venous catheters,and hyperbaric oxygen therapy.For critically ill patients,use of cardiotonic drugs and chest compressions remain useful strategies.The wider availability of extracorporeal membrane oxygenation(ECMO)has brought a new option for VAE patients.CASE SUMMARY A 53-year-old female patient with VAE presented to the emergency clinic due to abdominal pain with fever for 1 d and unconsciousness for 2 h.One day ago,the patient suffered from abdominal pain,fever,and diarrhea.She suddenly became unconscious after going to the toilet during the intravenous infusion of ciprofloxacin 2 h ago,accompanied by nausea and vomiting,during which a small amount of gastric contents were discharged.She was immediately sent to a local hospital,where cranial and chest computed tomography showed bilateral pneumonia as well as accumulated air visible in the right ventricle and pulmonary artery.The condition deteriorated despite endotracheal intubation,rehydration,and other treatments,and the patient was then transferred to our hospital.Veno-arterial ECMO was applied in our hospital,and the patient's condition gradually improved.The patient was successfully weaned from ECMO and extubated after two days.CONCLUSION ECMO may be an important treatment for patients with VAE in critical condition.展开更多
A porous 3D cross-linked conductive network pierced by multi-wall carbon nanotubes(MWCNTs) was successfully designed from zeolitic imidazolate framework-8(ZIF-8). Zn@NPC@MWCNTs composites were tailored by the facile r...A porous 3D cross-linked conductive network pierced by multi-wall carbon nanotubes(MWCNTs) was successfully designed from zeolitic imidazolate framework-8(ZIF-8). Zn@NPC@MWCNTs composites were tailored by the facile regulating the mass ratios and thermal annealing treatment. Due to the combination of less eddy current loss and dielectric loss together with multiple reflection attenuation caused by a unique structure. With a 10 wt% filler loading, the Zn@NPC@MWCNTs composites carbonized at 800℃ show two high reflection loss(RL) values with different thicknesses. An RL value is-53.18 dB with 4.09 mm thickness in the C-Band(4-8 GHz), and a minimum RL can reach-74.83 d B(10.8 GHz)with a matching thickness of 2.749 mm. The effective absorption bandwidth is 4 GHz(from 8 to 12 GHz,RL ≤-10 d B), which just covers the full X-band. Low cost and easy preparation can also provide advantages to develop MOF-based materials as effective EMW absorbents.展开更多
The electromagnetic time-reversal(TR)technique has the characteristics of spatiotemporal focusing in a time-reversal cavity(TRC),which can be used for pulse compression,thus forming an electromagnetic pulse with high ...The electromagnetic time-reversal(TR)technique has the characteristics of spatiotemporal focusing in a time-reversal cavity(TRC),which can be used for pulse compression,thus forming an electromagnetic pulse with high peak power.A time-reversed pulse-compression method in a single channel has high pulse compression gain.However,single channel pulse compression can only generate limited gain.This paper proposes a novel TR power-combination method in a multichannel TRC to obtain higher peak power based on TR pulse-compression theory.First,the TR power-combination model is given,and the crosstalk properties of the associated channel and the influence of the reversal performance are studied.Then,the power-combination performances for the TR pulse compression,such as combined signal to noise ratio(SNR)and combined compression gain,are analyzed by numerical simulation and experimental methods.The results show that the proposed method has obvious advantages over pulse-compression methods using a single channel cavity,and is more convenient for power combination.展开更多
To effectively reuse high-titanium blast furnace slag （TS）, foam glass-ceramics were successfully prepared by powder sintering at 1000℃. TS and waste glass were used as the main raw materials, aluminium nitride （...To effectively reuse high-titanium blast furnace slag （TS）, foam glass-ceramics were successfully prepared by powder sintering at 1000℃. TS and waste glass were used as the main raw materials, aluminium nitride （AIN） as the foaming agent, and borax as the fluxing agent. The influence of the amount of A1N added （lwt%-5wt%） on the crystalline phases, microstructure, and properties of the produced foam glass-ceramics was studied. The results showed that the main crystal phases were perovskite, diopside, and augite. With increasing A1N content, a transformation from diopside to augite occurred and the crystallinity of the pyroxene phases slightly decreased. Initially, the aver- age pore size and porosity of the foam glass-ceramics increased and subsequently decreased; similarly, their bulk density and compressive strength decreased and subsequently increased. The optimal properties were obtained when the foam glass-ceramics were prepared by adding 4wt% AIN.展开更多
Accelerated corrosion tests of the 7005-T4 aluminum alloy were conducted to determine a suitable service life prediction method by using alternating wet–dry cycles in three kinds of solutions. The morphology and comp...Accelerated corrosion tests of the 7005-T4 aluminum alloy were conducted to determine a suitable service life prediction method by using alternating wet–dry cycles in three kinds of solutions. The morphology and composition analysis of the corrosion product revealed that slight corrosion occurred on the surfaces of the samples immersed in a 0.25 wt% Na_2S_2O_8 solution. However, pitting corrosion occurred on the surfaces of the samples immersed in a 3.5 wt% NaCl solution, whereas exfoliation corrosion occurred on the surfaces of the samples immersed in a mixture of 0.25 wt% Na_2S_2O_8 and 3.5 wt% NaCl solutions. A power exponent relationship was observed between the mass loss and exposure time of the 7005-T4 aluminum alloy immersed in the three kinds of solutions. In the mixture of 0.25 wt% Na_2S_2O_8 and 3.5 wt% NaCl solutions, the mass loss of the aluminum alloy yielded the maximum value. Based on the calculation of the correlation coefficients, the alternating wet–dry procedure in a 3.5 wt% NaCl solution could be used to predict the corrosion behavior of 7005-T4 aluminum alloy exposed in the atmosphere of Qingdao, China. The prediction model is as follows: T = 104.28×t^(0.91), where T is the equivalent time and t is the exposure time.展开更多
The much-anticipated change in the practice of organ donation and transplantation in China is now underway and affirmed by an important Hangzhou Resolution promulgated at the 2013 China Transplant Congress.Support of ...The much-anticipated change in the practice of organ donation and transplantation in China is now underway and affirmed by an important Hangzhou Resolution promulgated at the 2013 China Transplant Congress.Support of the National Health and Family Planning Commission On October 29,2013,in a meeting of the National Health and Family Planning Commission (NHFPC)officials with Jie-Fu Huang,Head of National Organ Transplant Committee(OTC), Hai-Bo Wang,Director of China Organ Transplant Response System (COTRS)展开更多
BACKGROUND： Functional imaging such as CT perfusion can detect morphological and hemodynamic changes in he- patocellular carcinoma （HCC）. Pre-carcinoma and early HCC nodules are difficult to differentiate by observ...BACKGROUND： Functional imaging such as CT perfusion can detect morphological and hemodynamic changes in he- patocellular carcinoma （HCC）. Pre-carcinoma and early HCC nodules are difficult to differentiate by observing only their hemodynamics changes. The present study aimed to investi- gate hemodynamic parameters and evaluate their differential diagnostic cut-off between pre-carcinoma and early HCC nodules using CT perfusion and receiver operating characteristic （ROC） curves. METHODS： Male Wistar rats were randomly divided into control （n=20） and experimental （n=70） groups. Diethylnitrosamine （DEN） was used to induce pre-carcinoma and early HCC nodules in the experimental group. Perfusion scanning was carried out on all survival rats discontinuously from 8 to 16 weeks. Hepatic portal perfusion （HPP）, hepatic arterial fraction （HAF）, hepatic arterial perfusion （HAP）, hepatic blood volume （HBV）, hepatic blood flow （HBF）, mean transit time （MTT） and permeability of capillary vessel surface （PS） data were provided by mathematical deconvolution model. The perfusion parameters were compared among the three groups of rats （control, pre-carcinoma and early HCC groups） using the Kruskal-Wallis test and analyzed with ROC curves. Histological examination of the liver tissues with hematoxylin and eosin staining was performed after CT scan.RESULTS： For HPP, HAF, HBV, HBF and MTT, there were significant differences among the three groups （P〈0.05）. HAF had the highest areas under the ROC curves： 0.80 （control vs pre-carcinoma groups） and 0.95 （control vs early HCC groups） with corresponding optimal cut-offs of 0.37 and 0.42, respectively. The areas under the ROC curves for HPP was 0.79 （control vs pre-carcinoma groups） and 0.92 （control vs early HCC groups） with corresponding optimal cut-offs of 136.60 mL/min/100 mg and 108.47 mL/min/100 mg, respectively. CONCLUSIONS： CT perfusion combined with ROC curve analysis is a new diagnosis model for distinguishing between pre-carcinoma and early HCC nodules. HAF and HPP are the ideal reference indices.展开更多
The influence of initial groove angle on strain rate inside and outside groove of Ti6Al4V alloy was investigated.Based on the evolution of strain rate inside and outside groove,the effect of strain rate difference on ...The influence of initial groove angle on strain rate inside and outside groove of Ti6Al4V alloy was investigated.Based on the evolution of strain rate inside and outside groove,the effect of strain rate difference on the evolution of normal stress and effective stress inside and outside groove was also analyzed.The results show that when linear loading path changes from uniaxial tension to equi-biaxial tension,the initial groove angle plays a weaker role in the evolution of strain rate in the M-K model.Due to the constraint of force equilibrium between inside and outside groove,the strain rate difference makes the normal stress inside groove firstly decrease and then increase during calculation,which makes the prediction algorithm of forming limit convergent at elevated temperature.The decrease of normal stress inside groove is mainly caused by high temperature softening effect and the rotation of groove,while the increase of normal stress inside groove is mainly due to strain rate hardening effect.展开更多
BACKGROUND Tibial plateau fracture is one of the common fracture types.It occurs mainly in teenagers and is usually caused by a fall.After the occurrence of fracture,knee swelling,pain,limited activity,etc.greatly aff...BACKGROUND Tibial plateau fracture is one of the common fracture types.It occurs mainly in teenagers and is usually caused by a fall.After the occurrence of fracture,knee swelling,pain,limited activity,etc.greatly affect the patient’s exercise habits and lifestyle.X-ray,computed tomography(CT)and magnetic resonance imaging(MRI)were used in this examination.X-rays are relatively new and easy to operate.However,there are some errors in the observation of fracture collapse and fracture displacement.In recent years,CT and MRI have been actively used to diagnose various types of clinical fractures.They have more diagnostic power than X-ray film.However,some scholars believe that CT is also prone to errors in clinical application.The volume effect leads to missed diagnosis and misdiagnosis in some cases,while the multidirection scanning of MRI technology can effectively overcome the shortcomings of CT.To facilitate the selection of clinical examination regimens,this study further observed the diagnostic ability of these two regimens in the diagnosis of tibial plateau fractures.AIM To explore the value of nuclear MRI and CT in the clinical diagnosis of tibial plateau fractures.METHODS A total of 120 patients with tibial plateau fractures admitted from September 2017 to August 2019 were included.All patients were examined by nuclear MRI and CT scanning.The results were sent to senior physicians in our hospital to complete the diagnosis.RESULTS Nuclear magnetic resonance showed the same effects as CT in four aspects:fracture displacement,bone defect,fracture site and fracture comminution.There was no significant difference in the score data(P>0.05).Nuclear magnetic resonance and CT tended to be consistent in the B3,C2 and C3 fracture diagnosis coincidence rate,combined injury detection rate and fracture detection rate.The diagnostic coincidence rate of type B1,B2 and C1 fractures and the accuracy rate of overall fracture classification indicated that the MRI technique was significantly better than that of CT(P>0.05).CONCLUSION MRI and CT have good diagnostic typing in the diagnosis of tibial plateau fractures,but MRI is more accurate and may be preferred.展开更多
The purpose of the present study was to study the characteristics of epidemic growth factor receptor(EGFR)gene distribution in patients with non-small cell lung cancer(NSCLC),and to detect the mutation rate of EGFR ge...The purpose of the present study was to study the characteristics of epidemic growth factor receptor(EGFR)gene distribution in patients with non-small cell lung cancer(NSCLC),and to detect the mutation rate of EGFR gene by Sanger sequencing and amplification refractory mutation system(ARMS)-PCR.Paraffin-embedded sections of NSCLC tissues from 399 NSCLC patients diagnosed in Renmin Hospital of Wuhan University were collected,103 of them were detected for exons 18-21 mutation of EGFR by Sanger sequencing method,296 cases were detected for exons 18-21 mutation by ARMS-PCR method.DNA extraction of both groups was performed with Qiagen QLAamp DNA FFPE Tissue KIT.Comparisons of detection rates between the two methods were conducted by row X list chi-square test.The total mutation rate of EGFR gene detected by Sanger sequencing was 21.4%,exons 18-21 and combined mutation rates were 1.0%,9.7%,1.0%,7.8%and 2.0%,respectively.And the proportions were 4.7%,45.2%,4.7%,36.3%and 9.4%respectively.The total mutation rate detected by ARMS-PCR was 51.4%,exons 18-21 and combined mutation rates were 2.7%,27%,1.7%,18.2%and 1.7%,respectively.The proportions were 5.3%,52.6%,3.3%,35.5%and 3.3%respectively.Further analysis of mutation rate showed that there was significant difference between the two methods in detecting total mutation of EGFR gene(P<0.001).There were significant differences in mutation detection rates of exons 19 and 21(P<0.001,P<0.05),but there were no significant differences in other exons.And there was no significant difference in mutation detection rates between the two methods.The mutation rate of EGFR gene in NSCLC patients was 50%.And exon 19 deletion was the most common mutation type,followed by exon 21 mutation.Compared with Sanger sequencing method,ARMS method is more sensitive with significant advantages in detecting exon 19 deletions and exon 21 mutations,which can be widely used in clinical detection of EGFR gene mutations.The results of this study will further guide patients with advanced NSCLC to select TKI targeted drugs,and provide clinical diagnostic basis for targeted therapy of NSCLC patients.展开更多
BACKGROUND At present,there is controversy on the role of microvessel density(MVD)in tumors as a prognostic indicator of bladder transitional cell carcinoma(BTCC).However,the MVD in tumors is simply classified based o...BACKGROUND At present,there is controversy on the role of microvessel density(MVD)in tumors as a prognostic indicator of bladder transitional cell carcinoma(BTCC).However,the MVD in tumors is simply classified based on the expression of several different vascular markers,which has not been related to analytical research on the prognosis of patients with BTCC.AIM To explore the classification of blood vessels in tumors and studied the relationship between MVD and the prognosis of patients with BTCC.METHODS The tissue mass was detected by tissue microarray and immunohistochemical analysis with monoclonal antibodies against CD31,CD34,CD105,and vascular smooth muscle actin to investigate the MVD in BTCC.The measurement data are expressed as the mean±SD.The difference between the groups was analyzed by the t-test,the counting data were analyzed byχ2 test.The Kaplan-Meier survival curve was estimated by the product-limit method.The log-rank time-series test was employed to compare the tumor-free survival curves.RESULTS The MVD was closely related to the pathological grade,invasive depth,and prognosis of BTCC.Significant differences were found between grade I and grade II,grade II and grade III,superficial and invasive type,and the tumor-free survival group and the recurrence or metastasis group(P<0.01).Multivariate analysis showed that undifferentiated MVD was an independent prognostic factor for patient survival time.An inverse correlation between undifferentiated tumor MVD and differentiated tumor MVD in BTCC was also shown.CONCLUSION The classification of blood vessels in BTCC could act as an important prognostic indicator and may also be of great significance in the treatment of cancer.展开更多
BACKGROUND Catheter ablation for atrial fibrillation(AF)is commonly performed worldwide.However,the clinical charac-teristics of hospitalized patients with AF and national trends in catheter ablation at tertiary hospi...BACKGROUND Catheter ablation for atrial fibrillation(AF)is commonly performed worldwide.However,the clinical charac-teristics of hospitalized patients with AF and national trends in catheter ablation at tertiary hospitals in China remain unreported.METHODS This study used the Chinese national database(Hospital Quality Monitoring System)from 2013 to 2016,which is a mandatory database that collects the front page of patients’medical records for hospital accreditation,to describe the clinical cha-racteristics of patients with AF as an overall cohort and as subgroups divided by catheter ablation and sex.RESULTS Of 597,919 AF patients first admitted,57,983 patients underwent catheter ablation[56,384 cases(97.2%)of radiofre-quency ablation and 1599 cases(2.8%)of cryoablation]at 746 tertiary hospitals.Nearly 10%of patients hospitalized with AF at ter-tiary hospitals in China underwent catheter ablation,and the percentage of patients undergoing catheter ablation was on the rise bet-ween 2013 and 2016,and the number of cases increased by 2.5 times.Compared with AF patients who did not undergo catheter ablation,those who did were younger,more frequently male,and had fewer baseline comorbidities.Although the overall CHA_(2)DS_(2)-VASc score revealed over half of the patients were high-risk,patients who underwent catheter ablation were mostly low-risk(71.2%of males and 59.1%of females).Considering in-hospital adverse events,the overall pericardial tamponade and all-cause death incidences were 0.2%(0.6%in the ablation group)and 1.2%(0.1%in the ablation group),respectively;both of which were higher in females than males.CONCLUSIONS In this study,AF patients who underwent catheter ablation were relatively young,had a low thrombosis risk,and had few comorbidities and adverse events.Females were older and experienced more complications than males.展开更多
The DNA damage response is critical for cells to maintain genome stability and survival. In this review, we discuss approaches to targeting critical elements of the DNA damage response for radiosensitization and chemo...The DNA damage response is critical for cells to maintain genome stability and survival. In this review, we discuss approaches to targeting critical elements of the DNA damage response for radiosensitization and chemosensitization. In addition, we also discuss strategies for targeting DNA damage response and DNA repair defects in cancer cells for synthetic lethality.展开更多
A new low temperature Pmmm(120 K) phase was found in high temperature superconductor Sr_2 CuO_(3+δ), which was indicated as a pure electronic phase by resonant x-ray diffraction at Cu K-edge. As shown by x-ray absorp...A new low temperature Pmmm(120 K) phase was found in high temperature superconductor Sr_2 CuO_(3+δ), which was indicated as a pure electronic phase by resonant x-ray diffraction at Cu K-edge. As shown by x-ray absorption fine structure(EXAFS) and x-ray absorption near edge structure(XANES) at Cu K-edge, the strong charge density redistribution and local lattice fluctuations around Cu site at the onset of phase transition were due to the occurrence of superconductive coherence, the redistribution and fluctuation finished at Tc. Finally, the electron–lattice interaction was mainly elaborated to understand the superconductivity of Sr_2 CuO_(3+δ).展开更多
Using the first-principles method, we predict an orthorhombic boron–carbon binary structure with sp^ace group Imm2.This structure is verified to be dynamically and mechanically stable, and possesses a cavity of 27.5 ...Using the first-principles method, we predict an orthorhombic boron–carbon binary structure with sp^ace group Imm2.This structure is verified to be dynamically and mechanically stable, and possesses a cavity of 27.5 ~2 that makes it a potential molecular sieve material. The C sp^2 and sp^3 hybridized bonding in Imm2 BC is an important factor for its structural stability. The energy band calculations reveal that Imm2 BC is a semiconductor with a band gap of 1.3 eV and has a promising application in the electro-optic field. The lattice thermal conductivity along the crystal [100] direction at room temperature is 186 W·m^(-1)·K^(-1), that is about 5 times higher than those along the [010] and [001] directions, which stems from the different group velocity along the crystal direction. Moreover, the acoustic-optical coupling is important for heat transp^ort in Imm2 BC, and the contribution of optical phonons to lattice thermal conductivity in the [100], [010], and [001]directions is 49%, 59%, and 61%, resp^ectively. This study gives a fundamental understanding of the structural, electronic,elastic, and heat transp^ort properties in Imm2 BC, further enriching the family of boron–carbon binary compounds.展开更多
Background and Aims:Patients with biliary atresia(BA)are prone to hepatic decompensation,which might eventually lead to death.This study aimed to identify the possible risk factors affecting in-hospital death in BA pa...Background and Aims:Patients with biliary atresia(BA)are prone to hepatic decompensation,which might eventually lead to death.This study aimed to identify the possible risk factors affecting in-hospital death in BA patients in China.Methods:We collected data from the Hospital Quality Monitoring System,a national inpatient database.All patients aged up to 2 years old with a diagnosis of BA were included.The subjects were divided to three groups,including Kasai portoenterostomy(KP),liver transplantation(LT),and no surgery.Logistic regression with Firth’s method was performed to identify potential influencing variables associated with in-hospital death.Results:During the year 2013 to 2017,there were 14,038 pediatric admissions with a diagnosis of BA.The proportion of in-hospital death in pediatric BA admissions was 1.08%.Compared with patients under six months,there was a higher risk of in-hospital death for children aged six months to 1 year and 1–2 years old.Clinical signs,including cirrhosis,variceal bleeding,and hepatic encephalopathy,were significantly associated with the risk of in-hospital death.In no surgery group,compared to those in Beijing and Shanghai,BA patients admitted in other districts had a lower risk of in-hospital death(OR=0.39,95%CI:0.21,0.70).However,in the LT group,patients admitted in other districts had a higher risk of in-hospital death(OR=9.13,95%CI:3.99,20.87).Conclusions:In-hospital survival remains unsatisfactory for pediatric BA patients with severe complications.Furthermore,more resources and training for BA treatment,especially LT,are essential for districts with poor medical care in the future.展开更多
基金financially supported by the Project funded by China Postdoctoral Science Foundation (NO.2022M723500)the National Natural Science Foundation of China (NO.52204069)the Sinopec Science and Technology Project of China (NO.P22015)。
文摘High content of asphaltenes and waxes leads to the high pour point and the poor flowability of heavy oil,which is adverse to its efficient development and its transportation in pipe.Understanding the interaction mechanism between asphaltene-wax is crucial to solve these problems,but it is still unclear.In this paper,molecular dynamics simulation was used to investigate the interaction between asphaltenewax and its effects on the crystallization behavior of waxes in heavy oil.Results show that molecules in pure wax are arranged in a paralleled geometry.But wax molecules in heavy oil,which are close to the surface of asphaltene aggregates,are bent and arranged irregularly.When the mass fraction of asphaltenes in asphaltene-wax system(ω_(asp))is 0-25 wt%,the attraction among wax molecules decreases and the bend degree of wax molecules increases with the increase ofω_(asp).Theω_(asp)increases from 0 to 25 wt%,and the attraction between asphaltene-wax is stronger than that among waxes.This causes that the wax precipitation point changes from 353 to 333 K.While theω_(asp)increases to 50 wt%,wax molecules are more dispersed owing to the steric hindrance of asphaltene aggregates,and the interaction among wax molecules transforms from attraction to repulsion.It causes that the ordered crystal structure of waxes can't be formed at normal temperature.Simultaneously,the asphaltene,with the higher molecular weight or the more hetero atoms,has more obvious inhibition to the formation of wax crystals.Besides,resins also have an obvious inhibition on the wax crystal due to the formation of asphalteneresin aggregates with a larger radius.Our results reveal the interaction mechanism between asphaltene-wax,and provide useful guidelines for the development of heavy oil.
基金Construction and Application of Management Program for Prevention and Treatment of Inpatients with Venous Thromboembolism,No.WFWSJK-2022-111and Shandong Provincial Medical and Health Science and Technology Development Program,No.202103050856.
文摘BACKGROUND Venous air embolism(VAE)is a potentially lethal condition,with a reported incidence rate of about 0.13%,and the true incidence may be higher since many VAE are asymptomatic.The current treatments for VAE include Durant's maneuver,aspiration and removal of air through venous catheters,and hyperbaric oxygen therapy.For critically ill patients,use of cardiotonic drugs and chest compressions remain useful strategies.The wider availability of extracorporeal membrane oxygenation(ECMO)has brought a new option for VAE patients.CASE SUMMARY A 53-year-old female patient with VAE presented to the emergency clinic due to abdominal pain with fever for 1 d and unconsciousness for 2 h.One day ago,the patient suffered from abdominal pain,fever,and diarrhea.She suddenly became unconscious after going to the toilet during the intravenous infusion of ciprofloxacin 2 h ago,accompanied by nausea and vomiting,during which a small amount of gastric contents were discharged.She was immediately sent to a local hospital,where cranial and chest computed tomography showed bilateral pneumonia as well as accumulated air visible in the right ventricle and pulmonary artery.The condition deteriorated despite endotracheal intubation,rehydration,and other treatments,and the patient was then transferred to our hospital.Veno-arterial ECMO was applied in our hospital,and the patient's condition gradually improved.The patient was successfully weaned from ECMO and extubated after two days.CONCLUSION ECMO may be an important treatment for patients with VAE in critical condition.
基金supported by the Natural Science Foundation of Anhui Province (Grant No. 2008085MF217, Grant No. 2008085QF287)the University Natural Science Research Project of Anhui Province (Grant No. KJ2021A0912, Grant No. KJ2020A0091, Grant No. KJ2019A0714)+1 种基金the Program Fund for Excellent Young Talents of Higher Education Institutions of Anhui Province (Grant No. gxyq2020042)Anhui Province Key Laboratory of Simulation and Design for Electronic Information System (Grant No. 2019ZDSYSZB02)
文摘A porous 3D cross-linked conductive network pierced by multi-wall carbon nanotubes(MWCNTs) was successfully designed from zeolitic imidazolate framework-8(ZIF-8). Zn@NPC@MWCNTs composites were tailored by the facile regulating the mass ratios and thermal annealing treatment. Due to the combination of less eddy current loss and dielectric loss together with multiple reflection attenuation caused by a unique structure. With a 10 wt% filler loading, the Zn@NPC@MWCNTs composites carbonized at 800℃ show two high reflection loss(RL) values with different thicknesses. An RL value is-53.18 dB with 4.09 mm thickness in the C-Band(4-8 GHz), and a minimum RL can reach-74.83 d B(10.8 GHz)with a matching thickness of 2.749 mm. The effective absorption bandwidth is 4 GHz(from 8 to 12 GHz,RL ≤-10 d B), which just covers the full X-band. Low cost and easy preparation can also provide advantages to develop MOF-based materials as effective EMW absorbents.
基金Project supported by the National Key R&D Program of China(Grant No.2021YFC2203503)。
文摘The electromagnetic time-reversal(TR)technique has the characteristics of spatiotemporal focusing in a time-reversal cavity(TRC),which can be used for pulse compression,thus forming an electromagnetic pulse with high peak power.A time-reversed pulse-compression method in a single channel has high pulse compression gain.However,single channel pulse compression can only generate limited gain.This paper proposes a novel TR power-combination method in a multichannel TRC to obtain higher peak power based on TR pulse-compression theory.First,the TR power-combination model is given,and the crosstalk properties of the associated channel and the influence of the reversal performance are studied.Then,the power-combination performances for the TR pulse compression,such as combined signal to noise ratio(SNR)and combined compression gain,are analyzed by numerical simulation and experimental methods.The results show that the proposed method has obvious advantages over pulse-compression methods using a single channel cavity,and is more convenient for power combination.
基金the Science and Technology Support Projects of Sichuan Province (No. 2014GZ0011)the Industry Promotion Projects of Panzhihua in China (No.2013CY-C-2) for their financial support
文摘To effectively reuse high-titanium blast furnace slag （TS）, foam glass-ceramics were successfully prepared by powder sintering at 1000℃. TS and waste glass were used as the main raw materials, aluminium nitride （AIN） as the foaming agent, and borax as the fluxing agent. The influence of the amount of A1N added （lwt%-5wt%） on the crystalline phases, microstructure, and properties of the produced foam glass-ceramics was studied. The results showed that the main crystal phases were perovskite, diopside, and augite. With increasing A1N content, a transformation from diopside to augite occurred and the crystallinity of the pyroxene phases slightly decreased. Initially, the aver- age pore size and porosity of the foam glass-ceramics increased and subsequently decreased; similarly, their bulk density and compressive strength decreased and subsequently increased. The optimal properties were obtained when the foam glass-ceramics were prepared by adding 4wt% AIN.
基金supported by the National Key Research and Development Program of China (No. 2017YFB0702300)the National Natural Science Foundation of China (No. 51222106)+1 种基金the Fundamental Research Funds for the Central Universities of China (No. FRF-TP-14-011C1)the National Basic Research Program of China (973 Program, No. 2014CB643300)
文摘Accelerated corrosion tests of the 7005-T4 aluminum alloy were conducted to determine a suitable service life prediction method by using alternating wet–dry cycles in three kinds of solutions. The morphology and composition analysis of the corrosion product revealed that slight corrosion occurred on the surfaces of the samples immersed in a 0.25 wt% Na_2S_2O_8 solution. However, pitting corrosion occurred on the surfaces of the samples immersed in a 3.5 wt% NaCl solution, whereas exfoliation corrosion occurred on the surfaces of the samples immersed in a mixture of 0.25 wt% Na_2S_2O_8 and 3.5 wt% NaCl solutions. A power exponent relationship was observed between the mass loss and exposure time of the 7005-T4 aluminum alloy immersed in the three kinds of solutions. In the mixture of 0.25 wt% Na_2S_2O_8 and 3.5 wt% NaCl solutions, the mass loss of the aluminum alloy yielded the maximum value. Based on the calculation of the correlation coefficients, the alternating wet–dry procedure in a 3.5 wt% NaCl solution could be used to predict the corrosion behavior of 7005-T4 aluminum alloy exposed in the atmosphere of Qingdao, China. The prediction model is as follows: T = 104.28×t^(0.91), where T is the equivalent time and t is the exposure time.
基金The Peking Union Medical College has received grant support from the China Medical Board for the time,meetings,and travel associated with the work described in this manuscript
文摘The much-anticipated change in the practice of organ donation and transplantation in China is now underway and affirmed by an important Hangzhou Resolution promulgated at the 2013 China Transplant Congress.Support of the National Health and Family Planning Commission On October 29,2013,in a meeting of the National Health and Family Planning Commission (NHFPC)officials with Jie-Fu Huang,Head of National Organ Transplant Committee(OTC), Hai-Bo Wang,Director of China Organ Transplant Response System (COTRS)
基金supported by grants from the National Natural Science Foundation of China(81301275,81471736 and 81671760)the National Science and Technology Pillar Program during the Twelfth Five-Year Plan Period(2015BAI01B09)Heilongjiang Province Foundation for Returness(LC2013C38)
文摘BACKGROUND： Functional imaging such as CT perfusion can detect morphological and hemodynamic changes in he- patocellular carcinoma （HCC）. Pre-carcinoma and early HCC nodules are difficult to differentiate by observing only their hemodynamics changes. The present study aimed to investi- gate hemodynamic parameters and evaluate their differential diagnostic cut-off between pre-carcinoma and early HCC nodules using CT perfusion and receiver operating characteristic （ROC） curves. METHODS： Male Wistar rats were randomly divided into control （n=20） and experimental （n=70） groups. Diethylnitrosamine （DEN） was used to induce pre-carcinoma and early HCC nodules in the experimental group. Perfusion scanning was carried out on all survival rats discontinuously from 8 to 16 weeks. Hepatic portal perfusion （HPP）, hepatic arterial fraction （HAF）, hepatic arterial perfusion （HAP）, hepatic blood volume （HBV）, hepatic blood flow （HBF）, mean transit time （MTT） and permeability of capillary vessel surface （PS） data were provided by mathematical deconvolution model. The perfusion parameters were compared among the three groups of rats （control, pre-carcinoma and early HCC groups） using the Kruskal-Wallis test and analyzed with ROC curves. Histological examination of the liver tissues with hematoxylin and eosin staining was performed after CT scan.RESULTS： For HPP, HAF, HBV, HBF and MTT, there were significant differences among the three groups （P〈0.05）. HAF had the highest areas under the ROC curves： 0.80 （control vs pre-carcinoma groups） and 0.95 （control vs early HCC groups） with corresponding optimal cut-offs of 0.37 and 0.42, respectively. The areas under the ROC curves for HPP was 0.79 （control vs pre-carcinoma groups） and 0.92 （control vs early HCC groups） with corresponding optimal cut-offs of 136.60 mL/min/100 mg and 108.47 mL/min/100 mg, respectively. CONCLUSIONS： CT perfusion combined with ROC curve analysis is a new diagnosis model for distinguishing between pre-carcinoma and early HCC nodules. HAF and HPP are the ideal reference indices.
基金Project(51775023)supported by the National Natural Science Foundation of ChinaProject(YWF-18-BJ-J-75)supported by the Fundamental Research Funds for the Central Universities,China
文摘The influence of initial groove angle on strain rate inside and outside groove of Ti6Al4V alloy was investigated.Based on the evolution of strain rate inside and outside groove,the effect of strain rate difference on the evolution of normal stress and effective stress inside and outside groove was also analyzed.The results show that when linear loading path changes from uniaxial tension to equi-biaxial tension,the initial groove angle plays a weaker role in the evolution of strain rate in the M-K model.Due to the constraint of force equilibrium between inside and outside groove,the strain rate difference makes the normal stress inside groove firstly decrease and then increase during calculation,which makes the prediction algorithm of forming limit convergent at elevated temperature.The decrease of normal stress inside groove is mainly caused by high temperature softening effect and the rotation of groove,while the increase of normal stress inside groove is mainly due to strain rate hardening effect.
文摘BACKGROUND Tibial plateau fracture is one of the common fracture types.It occurs mainly in teenagers and is usually caused by a fall.After the occurrence of fracture,knee swelling,pain,limited activity,etc.greatly affect the patient’s exercise habits and lifestyle.X-ray,computed tomography(CT)and magnetic resonance imaging(MRI)were used in this examination.X-rays are relatively new and easy to operate.However,there are some errors in the observation of fracture collapse and fracture displacement.In recent years,CT and MRI have been actively used to diagnose various types of clinical fractures.They have more diagnostic power than X-ray film.However,some scholars believe that CT is also prone to errors in clinical application.The volume effect leads to missed diagnosis and misdiagnosis in some cases,while the multidirection scanning of MRI technology can effectively overcome the shortcomings of CT.To facilitate the selection of clinical examination regimens,this study further observed the diagnostic ability of these two regimens in the diagnosis of tibial plateau fractures.AIM To explore the value of nuclear MRI and CT in the clinical diagnosis of tibial plateau fractures.METHODS A total of 120 patients with tibial plateau fractures admitted from September 2017 to August 2019 were included.All patients were examined by nuclear MRI and CT scanning.The results were sent to senior physicians in our hospital to complete the diagnosis.RESULTS Nuclear magnetic resonance showed the same effects as CT in four aspects:fracture displacement,bone defect,fracture site and fracture comminution.There was no significant difference in the score data(P>0.05).Nuclear magnetic resonance and CT tended to be consistent in the B3,C2 and C3 fracture diagnosis coincidence rate,combined injury detection rate and fracture detection rate.The diagnostic coincidence rate of type B1,B2 and C1 fractures and the accuracy rate of overall fracture classification indicated that the MRI technique was significantly better than that of CT(P>0.05).CONCLUSION MRI and CT have good diagnostic typing in the diagnosis of tibial plateau fractures,but MRI is more accurate and may be preferred.
基金grants from the National Natural Science Foundation of China(No.81100959)Natural Science Fund of Hubei Province(No.2015CFB185).
文摘The purpose of the present study was to study the characteristics of epidemic growth factor receptor(EGFR)gene distribution in patients with non-small cell lung cancer(NSCLC),and to detect the mutation rate of EGFR gene by Sanger sequencing and amplification refractory mutation system(ARMS)-PCR.Paraffin-embedded sections of NSCLC tissues from 399 NSCLC patients diagnosed in Renmin Hospital of Wuhan University were collected,103 of them were detected for exons 18-21 mutation of EGFR by Sanger sequencing method,296 cases were detected for exons 18-21 mutation by ARMS-PCR method.DNA extraction of both groups was performed with Qiagen QLAamp DNA FFPE Tissue KIT.Comparisons of detection rates between the two methods were conducted by row X list chi-square test.The total mutation rate of EGFR gene detected by Sanger sequencing was 21.4%,exons 18-21 and combined mutation rates were 1.0%,9.7%,1.0%,7.8%and 2.0%,respectively.And the proportions were 4.7%,45.2%,4.7%,36.3%and 9.4%respectively.The total mutation rate detected by ARMS-PCR was 51.4%,exons 18-21 and combined mutation rates were 2.7%,27%,1.7%,18.2%and 1.7%,respectively.The proportions were 5.3%,52.6%,3.3%,35.5%and 3.3%respectively.Further analysis of mutation rate showed that there was significant difference between the two methods in detecting total mutation of EGFR gene(P<0.001).There were significant differences in mutation detection rates of exons 19 and 21(P<0.001,P<0.05),but there were no significant differences in other exons.And there was no significant difference in mutation detection rates between the two methods.The mutation rate of EGFR gene in NSCLC patients was 50%.And exon 19 deletion was the most common mutation type,followed by exon 21 mutation.Compared with Sanger sequencing method,ARMS method is more sensitive with significant advantages in detecting exon 19 deletions and exon 21 mutations,which can be widely used in clinical detection of EGFR gene mutations.The results of this study will further guide patients with advanced NSCLC to select TKI targeted drugs,and provide clinical diagnostic basis for targeted therapy of NSCLC patients.
文摘BACKGROUND At present,there is controversy on the role of microvessel density(MVD)in tumors as a prognostic indicator of bladder transitional cell carcinoma(BTCC).However,the MVD in tumors is simply classified based on the expression of several different vascular markers,which has not been related to analytical research on the prognosis of patients with BTCC.AIM To explore the classification of blood vessels in tumors and studied the relationship between MVD and the prognosis of patients with BTCC.METHODS The tissue mass was detected by tissue microarray and immunohistochemical analysis with monoclonal antibodies against CD31,CD34,CD105,and vascular smooth muscle actin to investigate the MVD in BTCC.The measurement data are expressed as the mean±SD.The difference between the groups was analyzed by the t-test,the counting data were analyzed byχ2 test.The Kaplan-Meier survival curve was estimated by the product-limit method.The log-rank time-series test was employed to compare the tumor-free survival curves.RESULTS The MVD was closely related to the pathological grade,invasive depth,and prognosis of BTCC.Significant differences were found between grade I and grade II,grade II and grade III,superficial and invasive type,and the tumor-free survival group and the recurrence or metastasis group(P<0.01).Multivariate analysis showed that undifferentiated MVD was an independent prognostic factor for patient survival time.An inverse correlation between undifferentiated tumor MVD and differentiated tumor MVD in BTCC was also shown.CONCLUSION The classification of blood vessels in BTCC could act as an important prognostic indicator and may also be of great significance in the treatment of cancer.
基金supported by the China-WHO Biennial Collaborative Projects 2016–2017(No.2016/648722–0).
文摘BACKGROUND Catheter ablation for atrial fibrillation(AF)is commonly performed worldwide.However,the clinical charac-teristics of hospitalized patients with AF and national trends in catheter ablation at tertiary hospitals in China remain unreported.METHODS This study used the Chinese national database(Hospital Quality Monitoring System)from 2013 to 2016,which is a mandatory database that collects the front page of patients’medical records for hospital accreditation,to describe the clinical cha-racteristics of patients with AF as an overall cohort and as subgroups divided by catheter ablation and sex.RESULTS Of 597,919 AF patients first admitted,57,983 patients underwent catheter ablation[56,384 cases(97.2%)of radiofre-quency ablation and 1599 cases(2.8%)of cryoablation]at 746 tertiary hospitals.Nearly 10%of patients hospitalized with AF at ter-tiary hospitals in China underwent catheter ablation,and the percentage of patients undergoing catheter ablation was on the rise bet-ween 2013 and 2016,and the number of cases increased by 2.5 times.Compared with AF patients who did not undergo catheter ablation,those who did were younger,more frequently male,and had fewer baseline comorbidities.Although the overall CHA_(2)DS_(2)-VASc score revealed over half of the patients were high-risk,patients who underwent catheter ablation were mostly low-risk(71.2%of males and 59.1%of females).Considering in-hospital adverse events,the overall pericardial tamponade and all-cause death incidences were 0.2%(0.6%in the ablation group)and 1.2%(0.1%in the ablation group),respectively;both of which were higher in females than males.CONCLUSIONS In this study,AF patients who underwent catheter ablation were relatively young,had a low thrombosis risk,and had few comorbidities and adverse events.Females were older and experienced more complications than males.
基金supported in part by grants from the National Institutes of Health,USA (No.R01CA133093 and R01ES016354)the National Natural Science Foundation of China(No.81001027)
文摘The DNA damage response is critical for cells to maintain genome stability and survival. In this review, we discuss approaches to targeting critical elements of the DNA damage response for radiosensitization and chemosensitization. In addition, we also discuss strategies for targeting DNA damage response and DNA repair defects in cancer cells for synthetic lethality.
基金Project supported by the National Basic Research Program of China(Grant Nos.2012CB922004/3,2010CB934501,and 2009CB929502)the Funds of Jilin Province,China(Grant No.JJKH20180860KJ)+1 种基金the National Natural Science Foundation of Chinathe Fundamental Research Funds for the Central Universities,China(Grant No.WK2310000043)
文摘A new low temperature Pmmm(120 K) phase was found in high temperature superconductor Sr_2 CuO_(3+δ), which was indicated as a pure electronic phase by resonant x-ray diffraction at Cu K-edge. As shown by x-ray absorption fine structure(EXAFS) and x-ray absorption near edge structure(XANES) at Cu K-edge, the strong charge density redistribution and local lattice fluctuations around Cu site at the onset of phase transition were due to the occurrence of superconductive coherence, the redistribution and fluctuation finished at Tc. Finally, the electron–lattice interaction was mainly elaborated to understand the superconductivity of Sr_2 CuO_(3+δ).
基金Project supported by the National Basic Research Program of China(Grant No.2013CB632900)the Science and Technology Planning Project of Sichuan Province,China(Grant Nos.2018JY0422 and 2018JY0325)+1 种基金the Department of Education of Sichuan Province,China(Grant No.18ZA0290)the Doctor Research Start-up Foundation of Panzhihua University,China(Grant No.0210600049)
文摘Using the first-principles method, we predict an orthorhombic boron–carbon binary structure with sp^ace group Imm2.This structure is verified to be dynamically and mechanically stable, and possesses a cavity of 27.5 ~2 that makes it a potential molecular sieve material. The C sp^2 and sp^3 hybridized bonding in Imm2 BC is an important factor for its structural stability. The energy band calculations reveal that Imm2 BC is a semiconductor with a band gap of 1.3 eV and has a promising application in the electro-optic field. The lattice thermal conductivity along the crystal [100] direction at room temperature is 186 W·m^(-1)·K^(-1), that is about 5 times higher than those along the [010] and [001] directions, which stems from the different group velocity along the crystal direction. Moreover, the acoustic-optical coupling is important for heat transp^ort in Imm2 BC, and the contribution of optical phonons to lattice thermal conductivity in the [100], [010], and [001]directions is 49%, 59%, and 61%, resp^ectively. This study gives a fundamental understanding of the structural, electronic,elastic, and heat transp^ort properties in Imm2 BC, further enriching the family of boron–carbon binary compounds.
基金supported by grants from Capital’s Funds for Health Improvement and Research (Grant Number:2020-1-2024)Research Foundation of Beijing Friendship Hospital,Capital Medical University (No.yyqdkt2017-27).
文摘Background and Aims:Patients with biliary atresia(BA)are prone to hepatic decompensation,which might eventually lead to death.This study aimed to identify the possible risk factors affecting in-hospital death in BA patients in China.Methods:We collected data from the Hospital Quality Monitoring System,a national inpatient database.All patients aged up to 2 years old with a diagnosis of BA were included.The subjects were divided to three groups,including Kasai portoenterostomy(KP),liver transplantation(LT),and no surgery.Logistic regression with Firth’s method was performed to identify potential influencing variables associated with in-hospital death.Results:During the year 2013 to 2017,there were 14,038 pediatric admissions with a diagnosis of BA.The proportion of in-hospital death in pediatric BA admissions was 1.08%.Compared with patients under six months,there was a higher risk of in-hospital death for children aged six months to 1 year and 1–2 years old.Clinical signs,including cirrhosis,variceal bleeding,and hepatic encephalopathy,were significantly associated with the risk of in-hospital death.In no surgery group,compared to those in Beijing and Shanghai,BA patients admitted in other districts had a lower risk of in-hospital death(OR=0.39,95%CI:0.21,0.70).However,in the LT group,patients admitted in other districts had a higher risk of in-hospital death(OR=9.13,95%CI:3.99,20.87).Conclusions:In-hospital survival remains unsatisfactory for pediatric BA patients with severe complications.Furthermore,more resources and training for BA treatment,especially LT,are essential for districts with poor medical care in the future.
