BACKGROUND Pituitary stalk interruption syndrome(PSIS)is a rare anatomical defect of the pituitary gland falling under the spectrum of holoprosencephaly phenotypes.It is characterized by a deficiency in anterior pitui...BACKGROUND Pituitary stalk interruption syndrome(PSIS)is a rare anatomical defect of the pituitary gland falling under the spectrum of holoprosencephaly phenotypes.It is characterized by a deficiency in anterior pituitary hormones,such as growth hormone,gonadotropins,and thyroid hormones.Due to the syndrome's rarity and nonspecific manifestations,there is a lack of standardized treatment strategies.Consequently,early diagnosis through imaging and on-time intervention are crucial for improving patients’outcomes.CASE SUMMARY A 30-year-old man presented with absent secondary sexual characteristics and azoospermia.Laboratory evaluation revealed a deficiency in gonadotropins,while thyroid function was mostly within normal ranges.Magnetic resonance imaging of the pituitary gland showed pituitary stalk agenesis,hypoplasia of the anterior pituitary,and ectopic posterior pituitary,leading to the diagnosis of PSIS.Initially,the patient underwent 6 mo of gonadotropin therapy without significant changes in hormone levels and secondary sexual characteristics.Pulsatile gonadotropin-releasing hormone therapy was then administered,resulting in the detection of sperm in the semen analysis within 3 mo.After 6 mo,routine semen tests showed normal semen quality.The couple faced challenges in conceiving due to abstinence and underwent three cycles of artificial insemination,which was unsuccessful.They also attempted in vitro fertilization,but unfortunately,the woman experienced a miscarriage 10 wk after the embryo transfer.CONCLUSION Early detection,accurate diagnosis,and timely treatment are crucial in improving the quality of life and fertility of PSIS patients.展开更多
Objective:To improve the understanding of ectopic pregnancy after bilateral salpingectomy through case analysis and literature review.Method:A case of uterine serosal pregnancy after in vitro fertilization and embryo ...Objective:To improve the understanding of ectopic pregnancy after bilateral salpingectomy through case analysis and literature review.Method:A case of uterine serosal pregnancy after in vitro fertilization and embryo transfer(IVF-ET)in a woman with bilateral salpingectomy was reported in detail and summarized,and relevant literatures searched in Pubmed were analyzed.Results:The patient had a sudden abdominal pain 18 days after transplantation.Ultrasound showed no pregnancy sac in the intrauterine cavity and bilateral adnexal areas,but there was a large amount of fluid in the Pouch of Douglas,which was an indication for surgical exploration.During the operation,the pregnancy tissue was found on the uterine serosal and cleared in time.And the patient recovered well after surgery.Review of the literatures showed that most of ectopic pregnancies after bilateral salpingectomy were treated surgically and had a good prognosis.Conclusion:Ectopic pregnancy after bilateral salpingectomy is extremely rare and should be early judged by the patients’signs.Surgical treatment timely can achieve good outcome.展开更多
To solve the problem of low permeability and lower extraction rates of high-mud ores, a surfactant was added as a penetrant to the pregnant leaching solution during column leaching tests. On the basis of the theories ...To solve the problem of low permeability and lower extraction rates of high-mud ores, a surfactant was added as a penetrant to the pregnant leaching solution during column leaching tests. On the basis of the theories of physical chemistry and seepage flow mechanics, the mechanism by which seepage is enhanced under the effects of the surfactant was analyzed. The results show that the action modes of the surfactant were divided into four aspects: changing the wettability of the ore, reducing the viscosity of the leaching solution, adsorbing onto the surface of ore, and enhancing the permeability effect. The findings of column leaching tests demonstrated that permeability was substantially improved by the surfactant. In the later period of leaching, the permeability coefficient was two times higher than that of the control group. Meanwhile, the ore extraction rate increased by approximately 10%. During the leaching process, the surface tension of the solution did not substantially change, and that of the solution with surfactant increased slightly. The kinetics analysis of ore column leaching illustrated that the leaching processes were controlled by both internal diffusion(principal factor) and chemical reaction.展开更多
This study aims to comprehensively assess the environmental risks of microplastics in the Yellow River,achieving the following results through comprehensive research.The average microplastic abundances in the river wa...This study aims to comprehensively assess the environmental risks of microplastics in the Yellow River,achieving the following results through comprehensive research.The average microplastic abundances in the river waters and sediments are 5358-654000 n/m3 and 43.57-615 items/kg,respectively,and there are fewer microplastics in water samples than in sediments.Microplastics in the study area can be divided into five types according to their occurrence morphologies,namely fragments,foams,films,fibers,and particles.The most widely distributed pollution types in sediments include debris,fibers,and particles.In contrast,fibers are the dominant type in water samples,accounting for 68.18%‒98.93%.The chemical components of the microplastics include polyethylene,polypropylene,polystyrene,polyethylene terephthalate,and polyvinyl chloride.The microplastics are in four colors,with white accounting for a higher proportion.The grain size of the microplastics in tributaries or lakes of the Yellow River is less than 2 mm,which makes them liable to enter organisms for enrichment.Furthermore,the sources of the microplastics are closely related to agricultural and industrial production and biological activities in habitats and exhibit seasonal and hydrological characteristics.The microplastics in the study area show the adsorption of metals and nonmetals to different degrees,which increases the pollution risks of heavy metals combined with microplastics.In addition,microplastics can accumulate in organisms in the Yellow River and cause physical,biochemical,and other damage to aquatic organisms,thus further posing carcinogenic risks to human beings.Therefore,it is necessary to study,monitor,and control the pollution and effects of microplastics in the Yellow River,in order to provide theoretical references for the control of pollution and ecological risk of microplastics in the river.展开更多
Utilization of urban underground space has become a vital approach to alleviate the strain on urban land resources,and to optimize the structure and pattem of the city.It is also very important to improve the city env...Utilization of urban underground space has become a vital approach to alleviate the strain on urban land resources,and to optimize the structure and pattem of the city.It is also very important to improve the city environment,build livable city and increase the capacity of the city.Based on the analysis of existing evaluation methods and their problems,a method for evaluating underground space resources based on a negative list of adverse factors affecting underground space development is proposed,to be primarily used in urban planning stages.A list of the adverse factors is established,including limiting factors,constraining factors and influencing factors.Taking Xi'an as an example,using a geographical information system platform,a negative list of adverse factors for the underground space resources in Xi'an City are evaluated,and preventive measures are proposed.Natural resources,exploitable resources,and the potential growth of exploitable underground space resources are evaluated.Underground space assessment in the different development stages of the city,collaborative utilization and safety evaluation for multiple subsurface resources,environmental impact and assessment,as well as evaluation methods based on big data and intelligent optimization algorithms are all discussed with the aim of serving city planning and construction.展开更多
Background:To investigate the potential advantage of using low-dose clomiphene citrate to promote ovulation in women with overweight or obesity.Methods:The patients with overweight were divided randomly into regular c...Background:To investigate the potential advantage of using low-dose clomiphene citrate to promote ovulation in women with overweight or obesity.Methods:The patients with overweight were divided randomly into regular clomiphene citrate group(clomiphene citrate 50 mg/d,n=83)and low-dose clomiphene citrate group(clomiphene citrate 25 mg/d,n=105).All patients received treatment from the 5th day of their menstrual cycles.Results:Luteinizing hormone levels and estradiol levels were more increased in the low-dose group compared with the regular group(P<0.05).Low-dose group showed significantly thicker endometrium,fewer dosage and shorter days of human menopausal gonadotropin,less numbers of mature follicles and lower rates of cancellation(P<0.05)on human chorionic gonadotropin day.After human chorionic gonadotropin injection,the ovulation rate in the low-dose group was significantly higher than the regular group(P<0.05).No difference was detected in the biochemical pregnancy rates both groups(P>0.05).Conclusion:The low-dose clomiphene citrate treatment significantly reduced the number of mature follicles and increased the thickness of endometrium on the human chorionic gonadotropin day with less side effects.The low-dose clomiphene citrate also achieved the better ovulation rate.展开更多
Objective:The relationship between serum beta human chorionic gonadotropin(β-hCG)levels of patients(7 days after the transplantation of frozen-thawed embryos)and the pregnancy outcomes was investigated.Methods:This s...Objective:The relationship between serum beta human chorionic gonadotropin(β-hCG)levels of patients(7 days after the transplantation of frozen-thawed embryos)and the pregnancy outcomes was investigated.Methods:This study was designed as a retrospective clinical trial of 366 women who underwent frozen-thawed embryo transfers(FETs)in artificial cycles.Patients were divided into three groups:clinical pregnancy group,biochemical pregnancy group,and non-pregnant group according to their pregnancy outcomes.Serumβ-hCG levels were tested on day 4,7,9,11 and 14 after FET.Results:In the clinical pregnancy group,the serumβ-hCG levels after 7-day post-transplantation were significantly elevated(16.20 IU/L vs.3.07 vs.0.1 IU/L;P<0.05)compared with the other two groups.Furthermore,it was found that Area Under Curve(AUC=0.96)was significant with cut-off value higher than 4.26 IU/L(sensitivity=92.3%,specificity=90.2%)to predict the clinical pregnancy outcomes in the receiver operating characteristic(ROC)analysis ofβ-hCG concentrations on day 7 of post-transplantation.Conclusion:Our results suggested that the elevated serumβ-hCG levels on day 7 of post-transplantation could predict the positive clinical pregnancy outcomes in artificial FET cycles.展开更多
Imbalanced charge-carrier extraction remains an issue aggravating interfacial charge accumulation and recombination.More hopping transport channels could accelerate the extraction of charge.Here,we demonstrated an eff...Imbalanced charge-carrier extraction remains an issue aggravating interfacial charge accumulation and recombination.More hopping transport channels could accelerate the extraction of charge.Here,we demonstrated an effective“bridging interface”strategy between the perovskite/2,2′,7,7′-tetrakis(N,N-di-pmethoxyphenylamine)-9,9′-spirobifluorene(spiro-OMeTAD)that modulates interfacial charge transfer and improves hole mobility using radical-containing donor-acceptor nanographenes(D-A NGs)possessing electron-deficient perchlorinated NGs and electron-rich aniline derivatives.The fully delocalized backbone of nanographene formed a conjugated bridge for intermolecular charge transfer and generated stable radical cations,verified by electron spin resonance.Lamellar andπ-πstacking orientation of D-A NGs also provided advantageous hopping transport channels.Besides favorable charge transfer within D-A NGs,systematic explorations indicated a strong interface coupling and noticeable charge transfer across the D-A NGs and perovskite interface,where electrons would flow from D-A NGs to perovskite,and holes would flow from perovskite to D-A NGs.Moreover,the hole mobility of spiro-OMeTAD was also enhanced because the D-A NGs would diffuse into the spiro-OMeTAD layer.As a result,planar n-i-p perovskite solar cellsmodified byD-ANG-OMe/D-ANG-tBudeliveredchampion power conversion efficiencies(PCEs)of 23.25%and 23.51%,respectively.展开更多
Rapid development of perovskite solar cells is challenged by the fact that current semiconductors hardly act as efficient electron transport materials that can feature both high electron mobility and a well-matched en...Rapid development of perovskite solar cells is challenged by the fact that current semiconductors hardly act as efficient electron transport materials that can feature both high electron mobility and a well-matched energy level to that of the perovskite.Here we show that T-carbon,a newly emerging carbon allotrope,could be an ideal candidate to meet this challenge.By using first-principles calculations and deformation potential theory,it is found that T-carbon is a semiconductor with a direct bandgap of 2.273 eV,and the energy level in the conduction band is lower than that of perovskite by 0.5 eV,showing a larger force of electron injection.Moreover,the calculated electron mobility can reach up to 2.36×10^(3) cm^(2) s^(–1) V^(–1),superior to conventional electron transport materials such as TiO2,ZnO and SnO2,which will facilitate more efficient electron separation and more rapid diffusion away from their locus of generation within the perovskite absorbers.Furthermore,the bandgap of T-carbon is highly sensitive to strain,thus providing a convenient method to tune the carrier transport capability.Overall,T-carbon satisfies the requirements for a potential efficient electron transport material and could therefore be capable of accelerating the development of perovskite solar cells.展开更多
基金Weifang Fundamental Research Projects,No.WFWSJK-2023-052.
文摘BACKGROUND Pituitary stalk interruption syndrome(PSIS)is a rare anatomical defect of the pituitary gland falling under the spectrum of holoprosencephaly phenotypes.It is characterized by a deficiency in anterior pituitary hormones,such as growth hormone,gonadotropins,and thyroid hormones.Due to the syndrome's rarity and nonspecific manifestations,there is a lack of standardized treatment strategies.Consequently,early diagnosis through imaging and on-time intervention are crucial for improving patients’outcomes.CASE SUMMARY A 30-year-old man presented with absent secondary sexual characteristics and azoospermia.Laboratory evaluation revealed a deficiency in gonadotropins,while thyroid function was mostly within normal ranges.Magnetic resonance imaging of the pituitary gland showed pituitary stalk agenesis,hypoplasia of the anterior pituitary,and ectopic posterior pituitary,leading to the diagnosis of PSIS.Initially,the patient underwent 6 mo of gonadotropin therapy without significant changes in hormone levels and secondary sexual characteristics.Pulsatile gonadotropin-releasing hormone therapy was then administered,resulting in the detection of sperm in the semen analysis within 3 mo.After 6 mo,routine semen tests showed normal semen quality.The couple faced challenges in conceiving due to abstinence and underwent three cycles of artificial insemination,which was unsuccessful.They also attempted in vitro fertilization,but unfortunately,the woman experienced a miscarriage 10 wk after the embryo transfer.CONCLUSION Early detection,accurate diagnosis,and timely treatment are crucial in improving the quality of life and fertility of PSIS patients.
文摘Objective:To improve the understanding of ectopic pregnancy after bilateral salpingectomy through case analysis and literature review.Method:A case of uterine serosal pregnancy after in vitro fertilization and embryo transfer(IVF-ET)in a woman with bilateral salpingectomy was reported in detail and summarized,and relevant literatures searched in Pubmed were analyzed.Results:The patient had a sudden abdominal pain 18 days after transplantation.Ultrasound showed no pregnancy sac in the intrauterine cavity and bilateral adnexal areas,but there was a large amount of fluid in the Pouch of Douglas,which was an indication for surgical exploration.During the operation,the pregnancy tissue was found on the uterine serosal and cleared in time.And the patient recovered well after surgery.Review of the literatures showed that most of ectopic pregnancies after bilateral salpingectomy were treated surgically and had a good prognosis.Conclusion:Ectopic pregnancy after bilateral salpingectomy is extremely rare and should be early judged by the patients’signs.Surgical treatment timely can achieve good outcome.
基金financially supported by the National Natural Science Foundation of China (No. 51604138)the Open Fund of the Key Laboratory of Ministry of Education of China for Efficient Mining and Safety of Metal Mines (No. ustbmslab201806)
文摘To solve the problem of low permeability and lower extraction rates of high-mud ores, a surfactant was added as a penetrant to the pregnant leaching solution during column leaching tests. On the basis of the theories of physical chemistry and seepage flow mechanics, the mechanism by which seepage is enhanced under the effects of the surfactant was analyzed. The results show that the action modes of the surfactant were divided into four aspects: changing the wettability of the ore, reducing the viscosity of the leaching solution, adsorbing onto the surface of ore, and enhancing the permeability effect. The findings of column leaching tests demonstrated that permeability was substantially improved by the surfactant. In the later period of leaching, the permeability coefficient was two times higher than that of the control group. Meanwhile, the ore extraction rate increased by approximately 10%. During the leaching process, the surface tension of the solution did not substantially change, and that of the solution with surfactant increased slightly. The kinetics analysis of ore column leaching illustrated that the leaching processes were controlled by both internal diffusion(principal factor) and chemical reaction.
基金This study was funded by the survey projects initiated by the China Geological Survey(DD20189220,DD20211317,DD20211398,1212011220224,and 121201011000150022)the project of 2015 Natural Science Basic Research Plan of Shaanxi Province(2015JM4129)+2 种基金the project of 2016 Fundamental Research Funds for the Central Universities(open fund310829161128)the project of 2021 Fundamental Research Funds for the Central Universities(open fund).
文摘This study aims to comprehensively assess the environmental risks of microplastics in the Yellow River,achieving the following results through comprehensive research.The average microplastic abundances in the river waters and sediments are 5358-654000 n/m3 and 43.57-615 items/kg,respectively,and there are fewer microplastics in water samples than in sediments.Microplastics in the study area can be divided into five types according to their occurrence morphologies,namely fragments,foams,films,fibers,and particles.The most widely distributed pollution types in sediments include debris,fibers,and particles.In contrast,fibers are the dominant type in water samples,accounting for 68.18%‒98.93%.The chemical components of the microplastics include polyethylene,polypropylene,polystyrene,polyethylene terephthalate,and polyvinyl chloride.The microplastics are in four colors,with white accounting for a higher proportion.The grain size of the microplastics in tributaries or lakes of the Yellow River is less than 2 mm,which makes them liable to enter organisms for enrichment.Furthermore,the sources of the microplastics are closely related to agricultural and industrial production and biological activities in habitats and exhibit seasonal and hydrological characteristics.The microplastics in the study area show the adsorption of metals and nonmetals to different degrees,which increases the pollution risks of heavy metals combined with microplastics.In addition,microplastics can accumulate in organisms in the Yellow River and cause physical,biochemical,and other damage to aquatic organisms,thus further posing carcinogenic risks to human beings.Therefore,it is necessary to study,monitor,and control the pollution and effects of microplastics in the Yellow River,in order to provide theoretical references for the control of pollution and ecological risk of microplastics in the river.
基金This research is supported by National Key Research and Development Project,Ministry of Science and Technology of the People’s Republic of China(2018YFC1504700).
文摘Utilization of urban underground space has become a vital approach to alleviate the strain on urban land resources,and to optimize the structure and pattem of the city.It is also very important to improve the city environment,build livable city and increase the capacity of the city.Based on the analysis of existing evaluation methods and their problems,a method for evaluating underground space resources based on a negative list of adverse factors affecting underground space development is proposed,to be primarily used in urban planning stages.A list of the adverse factors is established,including limiting factors,constraining factors and influencing factors.Taking Xi'an as an example,using a geographical information system platform,a negative list of adverse factors for the underground space resources in Xi'an City are evaluated,and preventive measures are proposed.Natural resources,exploitable resources,and the potential growth of exploitable underground space resources are evaluated.Underground space assessment in the different development stages of the city,collaborative utilization and safety evaluation for multiple subsurface resources,environmental impact and assessment,as well as evaluation methods based on big data and intelligent optimization algorithms are all discussed with the aim of serving city planning and construction.
文摘Background:To investigate the potential advantage of using low-dose clomiphene citrate to promote ovulation in women with overweight or obesity.Methods:The patients with overweight were divided randomly into regular clomiphene citrate group(clomiphene citrate 50 mg/d,n=83)and low-dose clomiphene citrate group(clomiphene citrate 25 mg/d,n=105).All patients received treatment from the 5th day of their menstrual cycles.Results:Luteinizing hormone levels and estradiol levels were more increased in the low-dose group compared with the regular group(P<0.05).Low-dose group showed significantly thicker endometrium,fewer dosage and shorter days of human menopausal gonadotropin,less numbers of mature follicles and lower rates of cancellation(P<0.05)on human chorionic gonadotropin day.After human chorionic gonadotropin injection,the ovulation rate in the low-dose group was significantly higher than the regular group(P<0.05).No difference was detected in the biochemical pregnancy rates both groups(P>0.05).Conclusion:The low-dose clomiphene citrate treatment significantly reduced the number of mature follicles and increased the thickness of endometrium on the human chorionic gonadotropin day with less side effects.The low-dose clomiphene citrate also achieved the better ovulation rate.
文摘Objective:The relationship between serum beta human chorionic gonadotropin(β-hCG)levels of patients(7 days after the transplantation of frozen-thawed embryos)and the pregnancy outcomes was investigated.Methods:This study was designed as a retrospective clinical trial of 366 women who underwent frozen-thawed embryo transfers(FETs)in artificial cycles.Patients were divided into three groups:clinical pregnancy group,biochemical pregnancy group,and non-pregnant group according to their pregnancy outcomes.Serumβ-hCG levels were tested on day 4,7,9,11 and 14 after FET.Results:In the clinical pregnancy group,the serumβ-hCG levels after 7-day post-transplantation were significantly elevated(16.20 IU/L vs.3.07 vs.0.1 IU/L;P<0.05)compared with the other two groups.Furthermore,it was found that Area Under Curve(AUC=0.96)was significant with cut-off value higher than 4.26 IU/L(sensitivity=92.3%,specificity=90.2%)to predict the clinical pregnancy outcomes in the receiver operating characteristic(ROC)analysis ofβ-hCG concentrations on day 7 of post-transplantation.Conclusion:Our results suggested that the elevated serumβ-hCG levels on day 7 of post-transplantation could predict the positive clinical pregnancy outcomes in artificial FET cycles.
基金the financial support from the National Natural Science Foundation of China(grant nos.21975260 and 22175180)the National Natural Science Foundation of China-National Research Council of Italy(NSFC-CNR)Exchange Program of NSFC(grant no.22011530391)The GIWAXS measurements were performed at SPring-8 with the approval of the Japan Synchrotron Radiation Research Institute(grant nos.2022A1654,2022A1777,and 2022A1822).
文摘Imbalanced charge-carrier extraction remains an issue aggravating interfacial charge accumulation and recombination.More hopping transport channels could accelerate the extraction of charge.Here,we demonstrated an effective“bridging interface”strategy between the perovskite/2,2′,7,7′-tetrakis(N,N-di-pmethoxyphenylamine)-9,9′-spirobifluorene(spiro-OMeTAD)that modulates interfacial charge transfer and improves hole mobility using radical-containing donor-acceptor nanographenes(D-A NGs)possessing electron-deficient perchlorinated NGs and electron-rich aniline derivatives.The fully delocalized backbone of nanographene formed a conjugated bridge for intermolecular charge transfer and generated stable radical cations,verified by electron spin resonance.Lamellar andπ-πstacking orientation of D-A NGs also provided advantageous hopping transport channels.Besides favorable charge transfer within D-A NGs,systematic explorations indicated a strong interface coupling and noticeable charge transfer across the D-A NGs and perovskite interface,where electrons would flow from D-A NGs to perovskite,and holes would flow from perovskite to D-A NGs.Moreover,the hole mobility of spiro-OMeTAD was also enhanced because the D-A NGs would diffuse into the spiro-OMeTAD layer.As a result,planar n-i-p perovskite solar cellsmodified byD-ANG-OMe/D-ANG-tBudeliveredchampion power conversion efficiencies(PCEs)of 23.25%and 23.51%,respectively.
基金The authors gratefully acknowledge financial support from Ministry of Education,Singapore(Academic Research Fund TIER 1-RG128/14)by Economic Development Board of Singapore and Infineon Technologies Asia Pacific Pte Ltd.
文摘Rapid development of perovskite solar cells is challenged by the fact that current semiconductors hardly act as efficient electron transport materials that can feature both high electron mobility and a well-matched energy level to that of the perovskite.Here we show that T-carbon,a newly emerging carbon allotrope,could be an ideal candidate to meet this challenge.By using first-principles calculations and deformation potential theory,it is found that T-carbon is a semiconductor with a direct bandgap of 2.273 eV,and the energy level in the conduction band is lower than that of perovskite by 0.5 eV,showing a larger force of electron injection.Moreover,the calculated electron mobility can reach up to 2.36×10^(3) cm^(2) s^(–1) V^(–1),superior to conventional electron transport materials such as TiO2,ZnO and SnO2,which will facilitate more efficient electron separation and more rapid diffusion away from their locus of generation within the perovskite absorbers.Furthermore,the bandgap of T-carbon is highly sensitive to strain,thus providing a convenient method to tune the carrier transport capability.Overall,T-carbon satisfies the requirements for a potential efficient electron transport material and could therefore be capable of accelerating the development of perovskite solar cells.
基金supported by the National Natural Science Foundation of China(No.41372283)the European Project CREEP(No.PIAPP-GA-2011-286397)the French Ministry of Research through ANR-RISMOGEO
