BACKGROUND The differential diagnosis between hepatocellular carcinoma(HCC)and intrahepatic cholangiocarcinoma(ICC)is crucial.The individual differences of patients increase the complexity of diagnosis.Currently,imagi...BACKGROUND The differential diagnosis between hepatocellular carcinoma(HCC)and intrahepatic cholangiocarcinoma(ICC)is crucial.The individual differences of patients increase the complexity of diagnosis.Currently,imaging diagnosis mainly relies on conventional computed tomography and magnetic resonance imaging(MRI),but few studies have investigated MRI functional imaging.This study combined MRI functional imaging including intravoxel incoherent motion(IVIM)and diffusion kurtosis imaging(DKI),facilitating differential diagnosis.AIM To explore the differential diagnostic value of IVIM imaging and DKI in differentiating between HCC and ICC.METHODS A total of 58 patients who underwent multi-b-value diffusion weighted imaging(DWI)on a 3.0 T magnetic MRI scanner were enrolled in this study.Standard apparent diffusion coefficient(SADC),IVIM quantitative parameters,including pure diffusion coefficient(D),pseudo diffusion coefficient(Dstar),and perfusion fraction(f),as well as the DKI quantitative parameters mean diffusion coefficient(MD)and mean kurtosis coefficient(MK)were computed by multi-b DWI images.Theχ2 test was used for classified data,and a one-way analysis of variance was performed for counted data.P<0.05 indicated statistical significance.The diagnostic value of parameters in HCC and ICC was analyzed using the receiver operating characteristic(ROC)curve.RESULTS The SADC,D,and MD values were significantly lower in the HCC group compared to the ICC group,whereas MK was significantly higher in the HCC group than in the ICC group(P<0.05).No significant difference in Dstar and f was observed between the HCC group and the ICC group(P>0.05).The optimal cutoff levels of the total values of SADC,D,MK,MD and all associated parameters were 1.25×10^(-3)mm^(2)/second,1.32×10^(-3)mm^(2)/second,650.2×10^(-3)mm^(2)/second,1.41×10^(-3)mm^(2)/second and 0.46×10^(-3)mm^(2)/second,respectively.The sensitivity of diagnosis was 95%,80%,90%,100%,and 70%,respectively,the specificity of diagnosis was 67.39%,69.57%,67.39%,43.48%,and 93.48%,respectively,and the area under the ROC curve was 0.874,0.793,0.733,0.757,and 0.895,respectively.CONCLUSION SADC,D,MK,and MD could be used to distinguish HCC from ICC,with the diagnostic value reaching a maximum after establishing a joint model.展开更多
BACKGROUND Paramyotonia congenita(PMC)stands as a rare sodium channelopaty of skeletal muscle,initially identified by Eulenburg.The identification of PMC often relies on electromyography(EMG),a diagnostic technique.Th...BACKGROUND Paramyotonia congenita(PMC)stands as a rare sodium channelopaty of skeletal muscle,initially identified by Eulenburg.The identification of PMC often relies on electromyography(EMG),a diagnostic technique.The child’s needle EMG unveiled trains of myotonic discharges with notably giant amplitudes,alongside irregular wave trains of myotonic discharges.This distinctive observation had not surfaced in earlier studies.CASE SUMMARY We report the case of a 3-year-old female child with PMC,who exhibited la-ryngeal stridor,muffled speech,myotonia from birth.Cold,exposure to cool water,crying,and physical activity exacerbated the myotonia,which was relieved in warmth,yet never normalized.Percussion myotonia was observable in bilateral biceps.Myotonia symptoms remained unchanged after potassium-rich food consumption like bananas.Hyperkalemic periodic paralysis was excluded.Cranial magnetic resonance imaging yielded normal results.Blood potassium remained within normal range,while creatine kinase showed slight elevation.Exome-wide genetic testing pinpointed a heterozygous mutation on chromosome SCN4A:c.3917G>A(p.G1306E).After a six-month mexiletine regimen,symptoms alleviated.CONCLUSION In this case revealed the two types of myotonic discharges,and had not been documented in other studies.We underscore two distinctive features:Giant-amplitude potentials and irregular waves.展开更多
Beyond the scientific progress in assisted reproductive technologies （ART）, it is necessary to discuss the ethical considerations behind these advances. Ethical issues concerning sperm donation have been considered ...Beyond the scientific progress in assisted reproductive technologies （ART）, it is necessary to discuss the ethical considerations behind these advances. Ethical issues concerning sperm donation have been considered and discussed by government and non-governmental agencies, the public, media and academic institutions in many countries. Recommendations and guidelines concerning sperm donation issues vary from country to country and between professional groups within countries. This paper attempts to present an overview of findings and reports from various agencies concerning the ethics of sperm donation. The following topics are considered： limiting the number of donor offspring; minimizing risk of infection and genetics from sperm donors; age requirements for sperm donors; and anonymity versus non-anonymity of sperm donors. The diversity of policies shows that each country has its unique set of guidelines tailored toward its own specific needs. Similarly, countries designing their own procedures and guidelines concerning reproductive medicine must tailor them toward their own needs and practical considerations. In China's Mainland, the anonymous policy for sperm donation should still be carried out, and the number of donor offspring should be revaluated. ART procedures must be conducted in a way that is respectful of those involved. Ethical principles must respect the interests and welfare of persons who will be born as well as the health and psychosocial welfare of all participants, including sperm donors.展开更多
The mutation status of KRAS is a significant biomarker in the prognosis of rectal cancer.This study investigated the feasibility of MRI-based radiomics in predicting the mutation status of KRAS with a composite index ...The mutation status of KRAS is a significant biomarker in the prognosis of rectal cancer.This study investigated the feasibility of MRI-based radiomics in predicting the mutation status of KRAS with a composite index which could be an important criterion for KRAS mutation in clinical practice.In this retrospective study,a total of 127 patients with rectal cancer were enrolled.The 3D Slicer was used to extract the radiomics features from the MRI images,and sparse support vector machine(SVM)with linear kernel was applied for feature reduction.The radiomics classifier for predicting the KRAS status was then constructed by Linear Discriminant Analysis(LDA)and its performance was evaluated.The composite index was determined with LDA model.Out of 127 rectal cancer subjects,there were 44 KRAS mutation cases and 83 wild cases.A total of 104 radiomics features were extracted,54 features were filtered by linear SVM with L1-norm regularization and 6 features that had no significant correlations within them were finally selected.The radiomics classifier constructed using the 6 features featured an AUC value of 0.669(specificity:0.506;sensitivity:0.773)with LDA.Furthermore,the composite index(Radscore)had statistically significant difference between the KRAS mutation and wild groups.It is suggested that the MRI-based radiomics has the potential in predicting the KRAS status in patients with rectal cancer,which may enhance the diagnostic value of MRI in rectal cancer.展开更多
Objective:This study aimed to identify microRNAs(miRNAs)involved in the development of perioperative neurocognitive disorders(PND).Methods:Plasma exosomal miRNA expression was examined in patients before and after car...Objective:This study aimed to identify microRNAs(miRNAs)involved in the development of perioperative neurocognitive disorders(PND).Methods:Plasma exosomal miRNA expression was examined in patients before and after cardiopulmonary bypass(CPB)using microarray and qRT-PCR and these patients were diagnosed as PND later.Elderly rats were subjected to CPB,and the cognitive functions were examined.Bioinformatics analysis was conducted to predict the targets of miR-214-3p.Rats were administered rno-miR-214-3p agomir before or after CPB to investigate the role of miR-214-3p in PND development.Results:We identified 76 differentially expressed plasma exosomal miRNAs in PND patients after surgery(P<0.05,|log2FC|>0.58),including the upregulated hsa-miR-214-3p(P=0.002399392).Prostaglandin-endoperoxide synthase 2(PTGS2)was predicted as a miR-214-3p target.In rats,CPB reduced the platform crossing numbers and target quadrant stay time,accompanied with hippocampal neuronal necrosis.The rno-miR-214-3p level was significantly increased in plasma exosomes but decreased in rat hippocampus after surgery,exhibiting a negative correlation(P<0.001,r=-0.762).A negative correlation between miR-214-3p and PTGS2 protein expression was also observed in the hippocampus after surgery.Importantly,rno-miR-214-3p agomir treatment,before or after surgery,significantly increased the platform crossing numbers(P=0.035)and target quadrant stay time(P=0.029)compared with negative control.Hippocampal PTGS2 protein level was increased in the untreated surgery group and decreased in response to rno-miR-214-3p agomir treatment before or after surgery(both P<0.05 vs.negative control).Conclusion:These data suggest that miR-214-3p/PTGS2 signaling contributes to the development of PND,serving as a potential therapeutic target for PND.展开更多
An Al-based composite reinforced with core–shell-structured Ti/Al_3Ti was fabricated through a powder metallurgy route followed by hot extrusion and was found to exhibit promising mechanical properties. The ultimate ...An Al-based composite reinforced with core–shell-structured Ti/Al_3Ti was fabricated through a powder metallurgy route followed by hot extrusion and was found to exhibit promising mechanical properties. The ultimate tensile strength and elongation of the composite sintered at 620°C for 5 h and extruded at a mass ratio of 12.75:1 reached 304 MPa and 14%, respectively, and its compressive deformation reached 60%. The promising mechanical properties are due to the core–shell-structured reinforcement, which is mainly composed of Al_3Ti and Ti and is bonded strongly with the Al matrix, and to the reduced crack sensitivity of Al_3Ti. The refined grains after hot extrusion also contribute to the mechanical properties of this composite. The mechanical properties might be further improved through regulating the relative thickness of Al–Ti intermetallics and Ti metal layers by adjusting the sintering time and the subsequent extrusion process.展开更多
The effect of Cr content and cooling rate on the microstructure of Al-Mn alloy was studied using well resistance furnace melting,and the alloy was analyzed using scanning electron microscopy(SEM)and X-ray diffraction(...The effect of Cr content and cooling rate on the microstructure of Al-Mn alloy was studied using well resistance furnace melting,and the alloy was analyzed using scanning electron microscopy(SEM)and X-ray diffraction(XRD).The experimental results showed that adding Cr could significantly improve the morphology of the primary phase in the Al-2.5Mn alloy.Without Cr,the primary phase in the alloy was thick,needle-like,and strip-like structure.After adding 0.2wt%-0.5wt%Cr,the primary phase in the upper part of the alloy was gradually fined and reached the best effect at 0.35wt%Cr.When the content of Cr was 0.5wt%,the microstructure of the primary phase in the upper part began to coarsen.The bottom of the alloy was a large bulk phase,but still much finer than that without adding Cr.XRD and SEM analysis showed that the precipitation phase at the bottom was mainly Al85Mn7Cr8,while the fine microstructure at the top was Al6Mn and Al3Mn.The results of the cooling rate experiments showed that the primary phase of Al-2.5Mn-0.35Cr was further refined,and the eutectic microstructure was partly achieved,under air-cooling condition.And when the cooling method was iron die-cooling,the microstructure of the Al-2.5Mn-0.35Cr alloy was changed into a eutectic microstructure.展开更多
Al-Fe-V-Si alloys were developed for use at elevated temperature and usually produced through a rapid solidification-powder metallurgy route. In this work, effort was made to produce the material via casting route. Th...Al-Fe-V-Si alloys were developed for use at elevated temperature and usually produced through a rapid solidification-powder metallurgy route. In this work, effort was made to produce the material via casting route. The studied alloys were cast under the condition of near-rapid cooling. The influence of Ce addition on microstructure and mechanical properties of near-rapid solidified alloys were investigated. The results indicate that the as-cast microstructure of Al-5.5 Fe-1.1 V-0.6 Si alloy is significantly refined when the alloy was solidified under nearrapid cooling. Adding Ce results in the further refinement of intermetallic compound and the formation of an Al-V-Ce phase which replaces the primary phase Al(Fe,V)Si. The mechanical properties of the alloy are significantly improved by Ce addition: More than 70% increase in tensile strength and elongation is achieved by adding 1.00 wt% Ce to the alloy. It is concluded that near-rapid cooling and Ce addition are effective in improving mechanical properties of cast Al-5.5 Fe-1.1 V-0.6 Si alloy.展开更多
BACKGROUND A large cervical cyst with a cervical high-grade squamous intraepithelial lesion arising from the cervical stump is rare.After supracervical hysterectomy,there is a risk of various lesions occurring in the ...BACKGROUND A large cervical cyst with a cervical high-grade squamous intraepithelial lesion arising from the cervical stump is rare.After supracervical hysterectomy,there is a risk of various lesions occurring in the cervical stump.We review the types and characteristics of cervical stump lesions and compare total hysterectomy with subtotal hysterectomy.Gynecologists should choose the most suitable surgical method based on both the patient’s condition and wishes.If the cervix is retained,patients require a close follow-up.CASE SUMMARY A 57-year-old woman was admitted to the Gynecology Department for a large pelvic mass.Her chief complaint was abdominal distention for two months.She had undergone subtotal supracervical hysterectomy for leiomyoma 14 years prior.Abdominal ultrasonography detected a 9.1 cm×8.5 cm×8.4 cm anechoic mass with silvery fluid in the pelvic cavity and high-risk human papilloma virus 53(HPV53)was positive.The admission diagnosis we first considered was a pelvic mass mimicking carcinoma of the cervical stump.We performed a laparotomy and a rapid frozen biopsy was suggestive of a fibrous cyst wall coated with a high squamous intraepithelial lesion.The pelvic mass was removed,and a bilateral adnexectomy was implemented.Final pathology confirmed that the pelvic mass was a large inflammatory cyst with a cervical high-grade squamous intraepithelial lesion.After successful intervention,the patient was discharged one week after surgery and there was no recurrence of the vaginal stump at 43 mo.CONCLUSION When addressing benign uterine diseases,gynecologists should pay adequate attention to retaining the cervix.If the cervix is retained,patients require a close follow-up.展开更多
Gallium-based liquid metal,as a high-performance thermal interface material,can improve the performance and service life of electronic equipment.This study focuses on the use of diamond as a thermal conductivity enhan...Gallium-based liquid metal,as a high-performance thermal interface material,can improve the performance and service life of electronic equipment.This study focuses on the use of diamond as a thermal conductivity enhancement phase to improve the thermal conductivity of GaInSn liquid metal and avoid the overflow of liquid metal during application.In this study,diamond/GaInSn composites were prepared by an ultrasonic-assisted wetting method.The thermal conductivity and contact thermal resistance of diamond/GaInSn composites were characterized by the transient method.The morphology and thermal conductivity of diamond/GalnSn composites were investigated when diamond particles of different diameters were added to GaInSn liquid metal.The addition of large-sized diamond particles can effectively improve the thermal conductivity of thermal interface materials (TIMs) but willcause liquid metal to pump out.展开更多
Detection at single-cell level plays a critical role in revealing cell behavior in different organisms.Nanoelectrodes with high temporal–spatial resolution can precisely and dynamically monitor the physiological and ...Detection at single-cell level plays a critical role in revealing cell behavior in different organisms.Nanoelectrodes with high temporal–spatial resolution can precisely and dynamically monitor the physiological and pathological processes of various single cells.The field of using nanoelectrodes in single-cell electroanalysis is blooming in recent years.In this review,we mainly summarize the recent advances of nanoelectrodes for single-cell electroanalysis from extracellular,intercellular to intracellular levels in the past decade.First,we introduce the main types of nanoelectrodes based on their geometry and characteristics for single-cell electroanalysis.Then,the representative works of using nanoelectrodes to investigate cellular signaling biomolecules and to understand various cellular processes from the extracellular,intercellular,and intracellular levels are introduced.Finally,the challenges and future prospects of nanoelectrodes for single-cell electroanalysis are proposed.This review gives a comprehensive summary of nanoelectrodes for single-cell electroanalysis in the prospects of monitoring cell physiological topography,understanding communication mechanism and revealing physiological functions,which can provide new insights into cell-based pharmacological screening and fundamental studies of disease development mechanisms.展开更多
基金Supported by Chutian Talents of Hubei,No.CTYC001Talent Project of Hubei Cancer Hospital,No.2025HBCHLHRC001Clinical Medical Science and Technology of Jinan,No.202134053.
文摘BACKGROUND The differential diagnosis between hepatocellular carcinoma(HCC)and intrahepatic cholangiocarcinoma(ICC)is crucial.The individual differences of patients increase the complexity of diagnosis.Currently,imaging diagnosis mainly relies on conventional computed tomography and magnetic resonance imaging(MRI),but few studies have investigated MRI functional imaging.This study combined MRI functional imaging including intravoxel incoherent motion(IVIM)and diffusion kurtosis imaging(DKI),facilitating differential diagnosis.AIM To explore the differential diagnostic value of IVIM imaging and DKI in differentiating between HCC and ICC.METHODS A total of 58 patients who underwent multi-b-value diffusion weighted imaging(DWI)on a 3.0 T magnetic MRI scanner were enrolled in this study.Standard apparent diffusion coefficient(SADC),IVIM quantitative parameters,including pure diffusion coefficient(D),pseudo diffusion coefficient(Dstar),and perfusion fraction(f),as well as the DKI quantitative parameters mean diffusion coefficient(MD)and mean kurtosis coefficient(MK)were computed by multi-b DWI images.Theχ2 test was used for classified data,and a one-way analysis of variance was performed for counted data.P<0.05 indicated statistical significance.The diagnostic value of parameters in HCC and ICC was analyzed using the receiver operating characteristic(ROC)curve.RESULTS The SADC,D,and MD values were significantly lower in the HCC group compared to the ICC group,whereas MK was significantly higher in the HCC group than in the ICC group(P<0.05).No significant difference in Dstar and f was observed between the HCC group and the ICC group(P>0.05).The optimal cutoff levels of the total values of SADC,D,MK,MD and all associated parameters were 1.25×10^(-3)mm^(2)/second,1.32×10^(-3)mm^(2)/second,650.2×10^(-3)mm^(2)/second,1.41×10^(-3)mm^(2)/second and 0.46×10^(-3)mm^(2)/second,respectively.The sensitivity of diagnosis was 95%,80%,90%,100%,and 70%,respectively,the specificity of diagnosis was 67.39%,69.57%,67.39%,43.48%,and 93.48%,respectively,and the area under the ROC curve was 0.874,0.793,0.733,0.757,and 0.895,respectively.CONCLUSION SADC,D,MK,and MD could be used to distinguish HCC from ICC,with the diagnostic value reaching a maximum after establishing a joint model.
文摘BACKGROUND Paramyotonia congenita(PMC)stands as a rare sodium channelopaty of skeletal muscle,initially identified by Eulenburg.The identification of PMC often relies on electromyography(EMG),a diagnostic technique.The child’s needle EMG unveiled trains of myotonic discharges with notably giant amplitudes,alongside irregular wave trains of myotonic discharges.This distinctive observation had not surfaced in earlier studies.CASE SUMMARY We report the case of a 3-year-old female child with PMC,who exhibited la-ryngeal stridor,muffled speech,myotonia from birth.Cold,exposure to cool water,crying,and physical activity exacerbated the myotonia,which was relieved in warmth,yet never normalized.Percussion myotonia was observable in bilateral biceps.Myotonia symptoms remained unchanged after potassium-rich food consumption like bananas.Hyperkalemic periodic paralysis was excluded.Cranial magnetic resonance imaging yielded normal results.Blood potassium remained within normal range,while creatine kinase showed slight elevation.Exome-wide genetic testing pinpointed a heterozygous mutation on chromosome SCN4A:c.3917G>A(p.G1306E).After a six-month mexiletine regimen,symptoms alleviated.CONCLUSION In this case revealed the two types of myotonic discharges,and had not been documented in other studies.We underscore two distinctive features:Giant-amplitude potentials and irregular waves.
文摘Beyond the scientific progress in assisted reproductive technologies （ART）, it is necessary to discuss the ethical considerations behind these advances. Ethical issues concerning sperm donation have been considered and discussed by government and non-governmental agencies, the public, media and academic institutions in many countries. Recommendations and guidelines concerning sperm donation issues vary from country to country and between professional groups within countries. This paper attempts to present an overview of findings and reports from various agencies concerning the ethics of sperm donation. The following topics are considered： limiting the number of donor offspring; minimizing risk of infection and genetics from sperm donors; age requirements for sperm donors; and anonymity versus non-anonymity of sperm donors. The diversity of policies shows that each country has its unique set of guidelines tailored toward its own specific needs. Similarly, countries designing their own procedures and guidelines concerning reproductive medicine must tailor them toward their own needs and practical considerations. In China's Mainland, the anonymous policy for sperm donation should still be carried out, and the number of donor offspring should be revaluated. ART procedures must be conducted in a way that is respectful of those involved. Ethical principles must respect the interests and welfare of persons who will be born as well as the health and psychosocial welfare of all participants, including sperm donors.
文摘The mutation status of KRAS is a significant biomarker in the prognosis of rectal cancer.This study investigated the feasibility of MRI-based radiomics in predicting the mutation status of KRAS with a composite index which could be an important criterion for KRAS mutation in clinical practice.In this retrospective study,a total of 127 patients with rectal cancer were enrolled.The 3D Slicer was used to extract the radiomics features from the MRI images,and sparse support vector machine(SVM)with linear kernel was applied for feature reduction.The radiomics classifier for predicting the KRAS status was then constructed by Linear Discriminant Analysis(LDA)and its performance was evaluated.The composite index was determined with LDA model.Out of 127 rectal cancer subjects,there were 44 KRAS mutation cases and 83 wild cases.A total of 104 radiomics features were extracted,54 features were filtered by linear SVM with L1-norm regularization and 6 features that had no significant correlations within them were finally selected.The radiomics classifier constructed using the 6 features featured an AUC value of 0.669(specificity:0.506;sensitivity:0.773)with LDA.Furthermore,the composite index(Radscore)had statistically significant difference between the KRAS mutation and wild groups.It is suggested that the MRI-based radiomics has the potential in predicting the KRAS status in patients with rectal cancer,which may enhance the diagnostic value of MRI in rectal cancer.
基金supported by grantsfrom the Department of Human Resources and Social Security of Sichuan Province(No.19058)the subject of Health Commission of Sichuan Province(No.20PJ130)+2 种基金the Science and Technology Strategic Cooperation Programs of Luzhou Municipal People's Government and Southwest Medical University(No.2019LZXNYDJ36)the subject of Affiliated Hospital of Southwest Medical University(No.2017-PT-45)the Doctoral Research Initiation Fund of Affiliated Hospital of Southwest Medical University(No.19023).
文摘Objective:This study aimed to identify microRNAs(miRNAs)involved in the development of perioperative neurocognitive disorders(PND).Methods:Plasma exosomal miRNA expression was examined in patients before and after cardiopulmonary bypass(CPB)using microarray and qRT-PCR and these patients were diagnosed as PND later.Elderly rats were subjected to CPB,and the cognitive functions were examined.Bioinformatics analysis was conducted to predict the targets of miR-214-3p.Rats were administered rno-miR-214-3p agomir before or after CPB to investigate the role of miR-214-3p in PND development.Results:We identified 76 differentially expressed plasma exosomal miRNAs in PND patients after surgery(P<0.05,|log2FC|>0.58),including the upregulated hsa-miR-214-3p(P=0.002399392).Prostaglandin-endoperoxide synthase 2(PTGS2)was predicted as a miR-214-3p target.In rats,CPB reduced the platform crossing numbers and target quadrant stay time,accompanied with hippocampal neuronal necrosis.The rno-miR-214-3p level was significantly increased in plasma exosomes but decreased in rat hippocampus after surgery,exhibiting a negative correlation(P<0.001,r=-0.762).A negative correlation between miR-214-3p and PTGS2 protein expression was also observed in the hippocampus after surgery.Importantly,rno-miR-214-3p agomir treatment,before or after surgery,significantly increased the platform crossing numbers(P=0.035)and target quadrant stay time(P=0.029)compared with negative control.Hippocampal PTGS2 protein level was increased in the untreated surgery group and decreased in response to rno-miR-214-3p agomir treatment before or after surgery(both P<0.05 vs.negative control).Conclusion:These data suggest that miR-214-3p/PTGS2 signaling contributes to the development of PND,serving as a potential therapeutic target for PND.
基金financially supported by the Science and Technology Plan Item of Liaoning Province (No.201601174)the National Natural Science Foundation of China (No.51371121)
文摘An Al-based composite reinforced with core–shell-structured Ti/Al_3Ti was fabricated through a powder metallurgy route followed by hot extrusion and was found to exhibit promising mechanical properties. The ultimate tensile strength and elongation of the composite sintered at 620°C for 5 h and extruded at a mass ratio of 12.75:1 reached 304 MPa and 14%, respectively, and its compressive deformation reached 60%. The promising mechanical properties are due to the core–shell-structured reinforcement, which is mainly composed of Al_3Ti and Ti and is bonded strongly with the Al matrix, and to the reduced crack sensitivity of Al_3Ti. The refined grains after hot extrusion also contribute to the mechanical properties of this composite. The mechanical properties might be further improved through regulating the relative thickness of Al–Ti intermetallics and Ti metal layers by adjusting the sintering time and the subsequent extrusion process.
基金financially supported by the Research Foundation of Shenyang Aerospace University
文摘The effect of Cr content and cooling rate on the microstructure of Al-Mn alloy was studied using well resistance furnace melting,and the alloy was analyzed using scanning electron microscopy(SEM)and X-ray diffraction(XRD).The experimental results showed that adding Cr could significantly improve the morphology of the primary phase in the Al-2.5Mn alloy.Without Cr,the primary phase in the alloy was thick,needle-like,and strip-like structure.After adding 0.2wt%-0.5wt%Cr,the primary phase in the upper part of the alloy was gradually fined and reached the best effect at 0.35wt%Cr.When the content of Cr was 0.5wt%,the microstructure of the primary phase in the upper part began to coarsen.The bottom of the alloy was a large bulk phase,but still much finer than that without adding Cr.XRD and SEM analysis showed that the precipitation phase at the bottom was mainly Al85Mn7Cr8,while the fine microstructure at the top was Al6Mn and Al3Mn.The results of the cooling rate experiments showed that the primary phase of Al-2.5Mn-0.35Cr was further refined,and the eutectic microstructure was partly achieved,under air-cooling condition.And when the cooling method was iron die-cooling,the microstructure of the Al-2.5Mn-0.35Cr alloy was changed into a eutectic microstructure.
基金financially supported by the National Natural Science Foundation of China (No. 51171120)the Research Foundation of Shenyang Aerospace University
文摘Al-Fe-V-Si alloys were developed for use at elevated temperature and usually produced through a rapid solidification-powder metallurgy route. In this work, effort was made to produce the material via casting route. The studied alloys were cast under the condition of near-rapid cooling. The influence of Ce addition on microstructure and mechanical properties of near-rapid solidified alloys were investigated. The results indicate that the as-cast microstructure of Al-5.5 Fe-1.1 V-0.6 Si alloy is significantly refined when the alloy was solidified under nearrapid cooling. Adding Ce results in the further refinement of intermetallic compound and the formation of an Al-V-Ce phase which replaces the primary phase Al(Fe,V)Si. The mechanical properties of the alloy are significantly improved by Ce addition: More than 70% increase in tensile strength and elongation is achieved by adding 1.00 wt% Ce to the alloy. It is concluded that near-rapid cooling and Ce addition are effective in improving mechanical properties of cast Al-5.5 Fe-1.1 V-0.6 Si alloy.
基金Supported by National Natural Science Foundation of China,No.81772790 and No.81602293Postgraduate Innovation Fund of 13th Five-year Comprehensive Investment,Tianjin Medical University,No.YJSCX201812
文摘BACKGROUND A large cervical cyst with a cervical high-grade squamous intraepithelial lesion arising from the cervical stump is rare.After supracervical hysterectomy,there is a risk of various lesions occurring in the cervical stump.We review the types and characteristics of cervical stump lesions and compare total hysterectomy with subtotal hysterectomy.Gynecologists should choose the most suitable surgical method based on both the patient’s condition and wishes.If the cervix is retained,patients require a close follow-up.CASE SUMMARY A 57-year-old woman was admitted to the Gynecology Department for a large pelvic mass.Her chief complaint was abdominal distention for two months.She had undergone subtotal supracervical hysterectomy for leiomyoma 14 years prior.Abdominal ultrasonography detected a 9.1 cm×8.5 cm×8.4 cm anechoic mass with silvery fluid in the pelvic cavity and high-risk human papilloma virus 53(HPV53)was positive.The admission diagnosis we first considered was a pelvic mass mimicking carcinoma of the cervical stump.We performed a laparotomy and a rapid frozen biopsy was suggestive of a fibrous cyst wall coated with a high squamous intraepithelial lesion.The pelvic mass was removed,and a bilateral adnexectomy was implemented.Final pathology confirmed that the pelvic mass was a large inflammatory cyst with a cervical high-grade squamous intraepithelial lesion.After successful intervention,the patient was discharged one week after surgery and there was no recurrence of the vaginal stump at 43 mo.CONCLUSION When addressing benign uterine diseases,gynecologists should pay adequate attention to retaining the cervix.If the cervix is retained,patients require a close follow-up.
基金financially supported by Beijing Natural Science Foundation (No.2224105)the Science and Technology Innovation Fund of GRINM (No.12366)。
文摘Gallium-based liquid metal,as a high-performance thermal interface material,can improve the performance and service life of electronic equipment.This study focuses on the use of diamond as a thermal conductivity enhancement phase to improve the thermal conductivity of GaInSn liquid metal and avoid the overflow of liquid metal during application.In this study,diamond/GaInSn composites were prepared by an ultrasonic-assisted wetting method.The thermal conductivity and contact thermal resistance of diamond/GaInSn composites were characterized by the transient method.The morphology and thermal conductivity of diamond/GalnSn composites were investigated when diamond particles of different diameters were added to GaInSn liquid metal.The addition of large-sized diamond particles can effectively improve the thermal conductivity of thermal interface materials (TIMs) but willcause liquid metal to pump out.
基金financially supported from the National Natural Science Foundation of China(22174106)the Natural Science Foundation of Shannxi Province,China(2020JC-06)the Fundamental Research Funds for the Central Universities(PY3A081,xjh012019044)
文摘Detection at single-cell level plays a critical role in revealing cell behavior in different organisms.Nanoelectrodes with high temporal–spatial resolution can precisely and dynamically monitor the physiological and pathological processes of various single cells.The field of using nanoelectrodes in single-cell electroanalysis is blooming in recent years.In this review,we mainly summarize the recent advances of nanoelectrodes for single-cell electroanalysis from extracellular,intercellular to intracellular levels in the past decade.First,we introduce the main types of nanoelectrodes based on their geometry and characteristics for single-cell electroanalysis.Then,the representative works of using nanoelectrodes to investigate cellular signaling biomolecules and to understand various cellular processes from the extracellular,intercellular,and intracellular levels are introduced.Finally,the challenges and future prospects of nanoelectrodes for single-cell electroanalysis are proposed.This review gives a comprehensive summary of nanoelectrodes for single-cell electroanalysis in the prospects of monitoring cell physiological topography,understanding communication mechanism and revealing physiological functions,which can provide new insights into cell-based pharmacological screening and fundamental studies of disease development mechanisms.
