BACKGROUND Partial splenic embolization(PSE)has been suggested as an alternative to splenectomy in the treatment of hypersplenism.However,some patients may experience recurrence of hypersplenism after PSE and require ...BACKGROUND Partial splenic embolization(PSE)has been suggested as an alternative to splenectomy in the treatment of hypersplenism.However,some patients may experience recurrence of hypersplenism after PSE and require splenectomy.Currently,there is a lack of evidence-based medical support regarding whether preoperative PSE followed by splenectomy can reduce the incidence of complications.AIM To investigate the safety and therapeutic efficacy of preoperative PSE followed by splenectomy in patients with cirrhosis and hypersplenism.METHODS Between January 2010 and December 2021,321 consecutive patients with cirrhosis and hypersplenism underwent splenectomy at our department.Based on whether PSE was performed prior to splenectomy,the patients were divided into two groups:PSE group(n=40)and non-PSE group(n=281).Patient characteristics,postoperative complications,and follow-up data were compared between groups.Propensity score matching(PSM)was conducted,and univariable and multivariable analyses were used to establish a nomogram predictive model for intraoperative bleeding(IB).The receiver operating characteristic curve,Hosmer-Lemeshow goodness-of-fit test,and decision curve analysis(DCA)were employed to evaluate the differentiation,calibration,and clinical performance of the model.RESULTS After PSM,the non-PSE group showed significant reductions in hospital stay,intraoperative blood loss,and operation time(all P=0.00).Multivariate analysis revealed that spleen length,portal vein diameter,splenic vein diameter,and history of PSE were independent predictive factors for IB.A nomogram predictive model of IB was constructed,and DCA demonstrated the clinical utility of this model.Both groups exhibited similar results in terms of overall survival during the follow-up period.CONCLUSION Preoperative PSE followed by splenectomy may increase the incidence of IB and a nomogram-based prediction model can predict the occurrence of IB.展开更多
In this paper,we introduce the design principle of the oscillating excited spray cooling experimental device.We then designed an oscillating excited spray cooling experimental device.By using the device,the swaying mo...In this paper,we introduce the design principle of the oscillating excited spray cooling experimental device.We then designed an oscillating excited spray cooling experimental device.By using the device,the swaying motion can be realized through the control system,and the motion of the droplet under different vibration frequencies can be observed.By measuring the liquid flow rate and pressure,the changes in liquid flow rate,pressure,and temperature with time under different vibration frequencies were studied.The trajectory of the droplet and the temperature distribution of the droplet under different vibration frequencies could be observed.The device has a simple structure,is easy to control,and can achieve continuous observation of the spray cooling process.展开更多
1.Objectives Changshan Islands are located on the geographical boundary between the Bohai Sea and the North Yellow Sea,China.Intensively tectonic deformation developed in this area,which is an important connection poi...1.Objectives Changshan Islands are located on the geographical boundary between the Bohai Sea and the North Yellow Sea,China.Intensively tectonic deformation developed in this area,which is an important connection point to study the tectonics of the Shandong Peninsula and Liaoning Peninsula.Previous studies have shown that the lithologies of the three northern islands(Beihuangcheng Island,Nanhuangcheng Island,and Xiaoqin Island)of the Changshan Islands include Neoproterozoic quartzite,phyllite,and slate(Fuzikuang Formation of the Penglai Group),and a few areas are covered by Quaternary slope deposits,marine deposits and loess(Fig.1 a;Qiao EW et al.,2019).Recently,a set of volcanic rocks was firstly discovered in Nanhuangcheng Island(Fig.1 a).展开更多
Industrial production and domestic discharge produce a large amount of oily wastewater, which seriously affects the stability of the ecological environment. Membrane separation technology provides another path to trea...Industrial production and domestic discharge produce a large amount of oily wastewater, which seriously affects the stability of the ecological environment. Membrane separation technology provides another path to treating oily wastewater. And appropriate surface modification of the membrane helps to achieve high efficiency of treating oily wastewater. With green, economy and stability been more concerned.The focal research reports a completely biodegradable all cellulose composite filter paper(ACCFP) composed of Ⅰ-cellulose macrofibers and Ⅱ-cellulose matrix. It is a simple one-step impregnation method to adjust the surface microstructure of the pristine filter paper(PFP), and it does not involve with chemical reaction. The pre-wetted ACCFP consist of Ⅱ-cellulose hydrogel and Ⅰ-cellulose reinforcement in the process of oil-water separation. This layer of hydrogel is the fundamental to underwater superoleophobicity, which determines their eligibility for applications of efficient oil-water mixture or oil-in-water(oil/water) emulsion separation. The separation efficiency of oil-water mixture and oil/water emulsion exceed 95% and 99.9%, respectively. In addition, excellent mechanical properties of ACCFP in dry and wet conditions ensure its stability in service and prolong service life in applications. The focal study provides a new method for high-performance oil-water separation and it is more in line with sustainable chemistry.展开更多
Purpose: To study the effect of the Qfix kVue Calypso-compatible couch top on the dosimetry of Spine Stereotactic Body Radiation Therapy (SBRT). Methods and Materials: The computed tomography (CT) data set for Qfix kV...Purpose: To study the effect of the Qfix kVue Calypso-compatible couch top on the dosimetry of Spine Stereotactic Body Radiation Therapy (SBRT). Methods and Materials: The computed tomography (CT) data set for Qfix kVue Calypso-compatible couch top with rails were imported into the treatment planning system (TPS). Nine patients who underwent spine SBRT were selected for this study. The inclusion criteria included patients who were treated on a stereotactic linear accelerator with 5 fractions or less from 2016 to 2017 without the couch model. Seven patients were treated with static intensity-modulated radiation therapy (IMRT) fields and two patients were treated using volumetric modulated arc therapy (VMAT) technique. The dose was recalculated for 1) couch top and rails setup (CR) 2) couch-top no rails setup (CNR), and then compared to 3) no couch no-rails setup (NCNR). Dose to 100% of the target volume (D100%), Dose to cover 99% of the target volume (D99%), Dose to cover 95% of the target volume (D95%), Dose to cover 90% of the target volume (D90%), volume receiving 100% of the prescription dose (V100%), conformity index (CI), dose gradient index (DGI), and spinal cord threshold and maximum dose were compared to the plan with NCNR. Results: The average D100% was 77.89% ± 11.78%, 74.51% ± 12.24%, and 75.83 ± 12.67% for NCNR, CR, CNR (р = 0.84), respectively. The average D99% was 91.64% ± 9.57%, 89.93% ± 9.48%, and 91.15% ± 9.55% for NCNR, CR, CNR (р = 0.98), respectively. The average D95% was 99.14% ± 9.96%, 95.23% ± 9.76, and 96.78% ± 9.84% for NCNR, CR, CNR (р = 0.047), respectively. The average D90% was 101.3% ± 0.65%, 97.11% ± 2.48%, and 98.75% ± 2.12% for NCNR, CR, CNR (р = 0.0004), respectively. The maximum dose to the spinal cord was 1750.79 ± 41.84, 1672.90 ± 40.90, and 1709.91 ± 41.35 (cGy) for NCNR, CR, CNR (р = 0.97), respectively. In all cases, the spinal cord threshold dose was far below the tolerances and the differences were insignificant. Average CI was 1.18 ± 0.16, 0.53 ± 0.39, and 0.86 ± 0.24 for NCNR, CR, CNR (р = 0.0002), respectively. Conclusions: The study investigated the dosimetric impact of Qfix kVue Calypso-compatible couch top on the quality of the spinal SBRT treatment using static IMRT or VMAT techniques. IMRT plans showed more sensitivity to the couch being in the plan than the VMAT plans.展开更多
Retinal surgery continues to be one of the most technical demanding surgeries for its high manipulation accuracy requirement, small and constrained workspace, and delicate retinal tissue. Robotic systems have the pote...Retinal surgery continues to be one of the most technical demanding surgeries for its high manipulation accuracy requirement, small and constrained workspace, and delicate retinal tissue. Robotic systems have the potential to enhance and expand the capabilities of surgeons during retinal surgery. Thus, focusing on retinal vessel bypass surgery, a master-slave robot system is developed in this paper. This robotic system is designed based on characteristics of retinal vascular bypass surgery and analysis of the surgical workspace in eyeball. A novel end-effector of two degrees of freedom is designed and a novel remote center of motion mechanism is adopted in the robot structure.The kinematics and the mapping relationship are then established, the gravity compensation control strategy and the hand tremor elimination algorithm are applied to achieve the high motion accuracy. The experiments on an artificial eyeball and an in vitro porcine eye are conducted, verifying the feasibility of this system.展开更多
Source rocks are the material basis of oil and gas generation and determine the potential resources of exploration blocks and have important research value. This paper studies the lithology, thickness, and geochemistr...Source rocks are the material basis of oil and gas generation and determine the potential resources of exploration blocks and have important research value. This paper studies the lithology, thickness, and geochemistry of Mesozoic source rocks in the southeastern East China Sea continental shelf. The results show that the Mesozoic source rocks are mainly dark mudstone and coal-bearing strata. The total thickness of Lower–Middle Jurassic source rocks ranges from 100 m to 700 m, and that of Lower Cretaceous source rocks ranges from 50 m to 350 m. The overall thickness of Mesozoic source rocks is distributed in the NE direction and their thickness center is located in the Jilong Depression. The Lower–Middle Jurassic source rocks are mainly developed shallow marine dark mudstone and transitional coal measure strata. Those of the Lower Cretaceous are mainly mudstone of a fan delta front. Lower –Middle Jurassic and Lower Cretaceous hydrocarbon source rocks are dominated by type III kerogen, with Lower –Middle Jurassic hydrocarbon source rocks having high organic matter abundance and being medium –good hydrocarbon source rocks, while Lower Cretaceous hydrocarbon source rocks have relatively poor quality. From northwest to southeast, the vitrinite reflectance Ro of Mesozoic source rocks increases gradually. Source rocks in the study area are divided into three types. The first hydrocarbon-generating area is mainly located in the southeastern region of the study area, and the Jilong Depression is the hydrocarbongenerating center. The results of this study can provide a basis for exploration of Mesozoic oil and gas resources in the southeastern East China Sea continental shelf.展开更多
BACKGROUND Frontline nurses in Wuhan directly fighting severe acute respiratory syndrome coronavirus-2 diseases are at a high risk of infection and are extremely susceptible to psychological stress,especially due to t...BACKGROUND Frontline nurses in Wuhan directly fighting severe acute respiratory syndrome coronavirus-2 diseases are at a high risk of infection and are extremely susceptible to psychological stress,especially due to the global coronavirus disease 2019(COVID-19)pandemic.The psychological after-effects of this public health emergency on frontline nurses will last for years.AIM To assess factors influencing post-traumatic stress disorder(PTSD)among frontline nurses in Wuhan 6 mo after the COVID-19 pandemic began.METHODS A total of 757 frontline nurses from five hospitals in Wuhan,China,participated in an online survey from July 27 to August 13,2020.This cross-sectional online study used a demographic information questionnaire,the PTSD Checklist for the Diagnostic and Statistical Manual of Mental Disorders,the Connor-Davidson Resilience Scale,and the Patient Health Questionnaire-4.The chisquare test and logistic regression were used to analyze the association of demographics,COVID-19-related variables,and PTSD.Logistic regression was also conducted to investigate which variables were associated with PTSD outcomes.RESULTS A total of 13.5%,24.3%,and 21.4%of the frontline nurses showed symptoms of PTSD,depression,and anxiety,respectively.The multivariate logistic regression analysis showed that the following factors were strongly associated with PTSD:Having a relative,friend,or colleague who died of COVID-19;experiencing stigma;or having psychological assistance needs,depressive symptoms or anxiety.Showing resilience and receiving praise after the COVID-19 outbreak were protective factors.CONCLUSION Frontline nurses still experienced PTSD(13.5%)six months after the COVID-19 outbreak began.Peer support,social support,official recognition,reward mechanisms,exercise,better sleep,and timely provision of information(such as vaccine research progress)by the government via social media,and adequate protective supplies could mitigate the level of PTSD among nurses responding to COVID-19.Stigmatization,depression,and anxiety might be associated with a greater risk of PTSD among nurses.展开更多
Lichi melange,located in the southern coastal range,eastern Taiwan,China,is a typical tectonic melange of the plate's boundary zone between the Eurasian Plate and the Philippine Sea Plate.It formed during the coll...Lichi melange,located in the southern coastal range,eastern Taiwan,China,is a typical tectonic melange of the plate's boundary zone between the Eurasian Plate and the Philippine Sea Plate.It formed during the collision of the Luzon arc with the Eurasian Continent (arc-continent collision).It is composed of sandstone and/or mudstone matrix and many kinds and sizes of rock fragments,including some sedimentary rocks,volcanic rocks and a few metamorphic rocks.The serpentinite is one of the common fragments in the Lichi melange.By the petrographic characteristics and the zircon U-Pb chronology analyses,protolith of the serpentinite is peridotite,the age is 17.7 ±0.5 Ma.Taking the tectonic background into account,it is inferred that the serpentinite (serpentinised peridotite)come from the forearc basin (the North Luzon Trough)and was taken into the melange by a second thrust westwards.The origin of the serpentimte in Lichi melange is helpful to understand the formation of the Lichi melange and can provide reliable detailed information for the study of the arc-continent collision orogenic activity in and offshore Taiwan.展开更多
Natural hybridization,which often occurs between closely related species exhibiting sympatric or parapatric distributions,is an important source of genetic variation within populations.The closely related Jankowski’s...Natural hybridization,which often occurs between closely related species exhibiting sympatric or parapatric distributions,is an important source of genetic variation within populations.The closely related Jankowski’s Bunting(Emberiza jankowskii)and Meadow Bunting(E.cioides)are similar in morphology and genetics,occupy overlapping niches,and are sympatric in eastern Inner Mongolia.Previous studies have reported trans-species polymorphisms of alleles between the two species,as well as an unexpectedly high genetic diversity of the endangered E.jankowskii.We speculate that introgressive hybridization has occurred between the two species and contributed to the additional unexpected variation to E.jankowskii.We used mitochondrial NADH dehydrogenase subunit 2(ND2)gene and 15 nuclear microsatellite markers to compare the genetic diversity of E.jankowskii and E.cioides,and inferred the origin of trans-species polymorphisms between the two species by phylogenetic reconstruction and Bayesian cluster analysis.The two species could be clearly distinguished by population cluster analysis.Despite the large number of mutational differences,we still detected sharing of major haplotypes and the presence of hybrids between the two species.Our study confirmed that weak introgressive hybridization has occurred between sympatric E.jankowskii and E.cioides,which may be mediated by female E.cioides individuals,and that interspecific introgression has contributed to the maintenance of high genetic diversity in E.jankowskii.While being wary of the potential negative effects of introgressive hybridization,we suggest that expanding the habitat of E.jankowskii remains the most effective conservation strategy at present.展开更多
A high-quality optical microcavity can enhance optical nonlinear effects by resonant recirculation,which provides a reliable platform for nonlinear optics research.When a soliton microcomb and a probe optical field ar...A high-quality optical microcavity can enhance optical nonlinear effects by resonant recirculation,which provides a reliable platform for nonlinear optics research.When a soliton microcomb and a probe optical field are coexisting in a micro-resonator,a concomitant microcomb(CMC)induced by cross-phase modulation(XPM)will be formed synchronously.Here,we characterize the CMC comprehensively in a micro-resonator through theory,numerical simulation,and experimental verification.It is found that the CMCs spectra are modulated due to resonant radiation(RR)resulting from the interaction of dispersion and XPM effects.The group velocity dispersion induces symmetric RRs on the CMC,which leads to a symmetric spectral envelope and a dual-peak pulse in frequency and temporal domains,respectively,while the group velocity mismatch breaks the symmetry of RRs and leads to asymmetric spectral and temporal profiles.When the group velocity is linearly varying with frequency,two RR frequencies are hyperbolically distributed about the pump,and the probe light acts as one of the asymptotic lines.Our results enrich the CMC dynamics and guide microcomb design and applications such as spectral extension and dark pulse generation.展开更多
目的在血压明显增高的患者中证实舌下含服硝苯地平控释片30 mg的有效性和安全性,并比较两种制剂(拜新同和欣然)的差别。方法2018年8月至2019年5月间纳入收缩压≥175或≥160 mm Hg伴有头痛的门诊高血压患者,分别进行安慰剂对照研究(采用...目的在血压明显增高的患者中证实舌下含服硝苯地平控释片30 mg的有效性和安全性,并比较两种制剂(拜新同和欣然)的差别。方法2018年8月至2019年5月间纳入收缩压≥175或≥160 mm Hg伴有头痛的门诊高血压患者,分别进行安慰剂对照研究(采用单盲、随机对照的设计,以1∶1∶1分为拜新同、欣然或安慰剂3组,每组23例)和扩大样本量临床研究(从197例舌下含服硝苯地平控释片治疗的高血压患者中,以病例配对方法选取72例使用拜新同和72例使用欣然的患者)。使用同一电子血压计,重复测量含服后5、10、15和20 min的血压和脉率(代表心率)。计算各时点血压和心率的降低幅度和百分降幅(降低幅度/基线水平×100%)。两项试验的有效性指标为:治疗后20 min的收缩压或平均动脉压(MAP)降低幅度>10%;安全性指标:20 min时MAP百分降幅≤25%或收缩压≥140 mm Hg;同时伴有心率增加≤10次/min;或不出现心悸、头晕为安全。结果(1)安慰剂对照研究:3组的年龄、性别、高血压用药情况、基线收缩压、舒张压、MAP和心率均具有可比性。含服5 min时两治疗组的收缩压即降低。在20 min时,拜新同组[(159.6±9.6)比(182.0±4.7)mm Hg,P<0.05]和欣然组[(164.5±13.4)比(184.0±7.8)mm Hg,P<0.05]收缩压较基线明显降低,而安慰剂组下降无统计学意义[(177.7±12.2)比(182.7±9.4)mm Hg,P=0.154]。3组MAP百分降幅平均值分别为7.3%、7.7%和1.7%,心率减少1~2次/min。(2)临床研究:144例患者的平均年龄为(65.6±11.4)岁(最大88岁)。拜新同组和欣然两组的性别构成、平均年龄、既往降压药使用以及服用钙通道阻滞剂的比例相似。含服20 min时两组收缩压百分降幅和MAP百分降幅相似。有5例患者在治疗过程中收缩压<140 mm Hg,收缩压为130 mm Hg者1例,其余4例收缩压>135 mm Hg。1例患者发生无症状的心率增加(从88.5升到104.0次/min)。有10例收缩压降低幅度<5 mm Hg;其中6例收缩压较基线轻度升高。结论对收缩压明显增高的高血压患者,舌下含服硝苯地平控释片30 mg能在20 min时有效而适度地降低收缩压和MAP,同时无不良反应发生。拜新同和欣然两种制剂的效果和安全性相似。展开更多
基金Supported by National Natural Science Foundations of China,No.82174160and Anhui Natural Science Foundation,No.2008085QH389。
文摘BACKGROUND Partial splenic embolization(PSE)has been suggested as an alternative to splenectomy in the treatment of hypersplenism.However,some patients may experience recurrence of hypersplenism after PSE and require splenectomy.Currently,there is a lack of evidence-based medical support regarding whether preoperative PSE followed by splenectomy can reduce the incidence of complications.AIM To investigate the safety and therapeutic efficacy of preoperative PSE followed by splenectomy in patients with cirrhosis and hypersplenism.METHODS Between January 2010 and December 2021,321 consecutive patients with cirrhosis and hypersplenism underwent splenectomy at our department.Based on whether PSE was performed prior to splenectomy,the patients were divided into two groups:PSE group(n=40)and non-PSE group(n=281).Patient characteristics,postoperative complications,and follow-up data were compared between groups.Propensity score matching(PSM)was conducted,and univariable and multivariable analyses were used to establish a nomogram predictive model for intraoperative bleeding(IB).The receiver operating characteristic curve,Hosmer-Lemeshow goodness-of-fit test,and decision curve analysis(DCA)were employed to evaluate the differentiation,calibration,and clinical performance of the model.RESULTS After PSM,the non-PSE group showed significant reductions in hospital stay,intraoperative blood loss,and operation time(all P=0.00).Multivariate analysis revealed that spleen length,portal vein diameter,splenic vein diameter,and history of PSE were independent predictive factors for IB.A nomogram predictive model of IB was constructed,and DCA demonstrated the clinical utility of this model.Both groups exhibited similar results in terms of overall survival during the follow-up period.CONCLUSION Preoperative PSE followed by splenectomy may increase the incidence of IB and a nomogram-based prediction model can predict the occurrence of IB.
基金The Natural Science Foundation of the Jiangsu Higher Education Institutions of China(22KJD580001)Jiangsu Maritime Institute Innovation Technology Funding Project(kicx2020-2)。
文摘In this paper,we introduce the design principle of the oscillating excited spray cooling experimental device.We then designed an oscillating excited spray cooling experimental device.By using the device,the swaying motion can be realized through the control system,and the motion of the droplet under different vibration frequencies can be observed.By measuring the liquid flow rate and pressure,the changes in liquid flow rate,pressure,and temperature with time under different vibration frequencies were studied.The trajectory of the droplet and the temperature distribution of the droplet under different vibration frequencies could be observed.The device has a simple structure,is easy to control,and can achieve continuous observation of the spray cooling process.
基金financially supported by the project of the China Geological Survey(DD20190208)。
文摘1.Objectives Changshan Islands are located on the geographical boundary between the Bohai Sea and the North Yellow Sea,China.Intensively tectonic deformation developed in this area,which is an important connection point to study the tectonics of the Shandong Peninsula and Liaoning Peninsula.Previous studies have shown that the lithologies of the three northern islands(Beihuangcheng Island,Nanhuangcheng Island,and Xiaoqin Island)of the Changshan Islands include Neoproterozoic quartzite,phyllite,and slate(Fuzikuang Formation of the Penglai Group),and a few areas are covered by Quaternary slope deposits,marine deposits and loess(Fig.1 a;Qiao EW et al.,2019).Recently,a set of volcanic rocks was firstly discovered in Nanhuangcheng Island(Fig.1 a).
基金the financial support from the National Key R&D Program of China (no. 2018YFB1501602)Science Foundation of Shanxi Province, China (Grant no. 201901D111006ZD)+1 种基金Fund for Shanxi “1331 project”Shanxi Province Platform Base and Talent Special Fund (no. 201705D211023)。
文摘Industrial production and domestic discharge produce a large amount of oily wastewater, which seriously affects the stability of the ecological environment. Membrane separation technology provides another path to treating oily wastewater. And appropriate surface modification of the membrane helps to achieve high efficiency of treating oily wastewater. With green, economy and stability been more concerned.The focal research reports a completely biodegradable all cellulose composite filter paper(ACCFP) composed of Ⅰ-cellulose macrofibers and Ⅱ-cellulose matrix. It is a simple one-step impregnation method to adjust the surface microstructure of the pristine filter paper(PFP), and it does not involve with chemical reaction. The pre-wetted ACCFP consist of Ⅱ-cellulose hydrogel and Ⅰ-cellulose reinforcement in the process of oil-water separation. This layer of hydrogel is the fundamental to underwater superoleophobicity, which determines their eligibility for applications of efficient oil-water mixture or oil-in-water(oil/water) emulsion separation. The separation efficiency of oil-water mixture and oil/water emulsion exceed 95% and 99.9%, respectively. In addition, excellent mechanical properties of ACCFP in dry and wet conditions ensure its stability in service and prolong service life in applications. The focal study provides a new method for high-performance oil-water separation and it is more in line with sustainable chemistry.
文摘Purpose: To study the effect of the Qfix kVue Calypso-compatible couch top on the dosimetry of Spine Stereotactic Body Radiation Therapy (SBRT). Methods and Materials: The computed tomography (CT) data set for Qfix kVue Calypso-compatible couch top with rails were imported into the treatment planning system (TPS). Nine patients who underwent spine SBRT were selected for this study. The inclusion criteria included patients who were treated on a stereotactic linear accelerator with 5 fractions or less from 2016 to 2017 without the couch model. Seven patients were treated with static intensity-modulated radiation therapy (IMRT) fields and two patients were treated using volumetric modulated arc therapy (VMAT) technique. The dose was recalculated for 1) couch top and rails setup (CR) 2) couch-top no rails setup (CNR), and then compared to 3) no couch no-rails setup (NCNR). Dose to 100% of the target volume (D100%), Dose to cover 99% of the target volume (D99%), Dose to cover 95% of the target volume (D95%), Dose to cover 90% of the target volume (D90%), volume receiving 100% of the prescription dose (V100%), conformity index (CI), dose gradient index (DGI), and spinal cord threshold and maximum dose were compared to the plan with NCNR. Results: The average D100% was 77.89% ± 11.78%, 74.51% ± 12.24%, and 75.83 ± 12.67% for NCNR, CR, CNR (р = 0.84), respectively. The average D99% was 91.64% ± 9.57%, 89.93% ± 9.48%, and 91.15% ± 9.55% for NCNR, CR, CNR (р = 0.98), respectively. The average D95% was 99.14% ± 9.96%, 95.23% ± 9.76, and 96.78% ± 9.84% for NCNR, CR, CNR (р = 0.047), respectively. The average D90% was 101.3% ± 0.65%, 97.11% ± 2.48%, and 98.75% ± 2.12% for NCNR, CR, CNR (р = 0.0004), respectively. The maximum dose to the spinal cord was 1750.79 ± 41.84, 1672.90 ± 40.90, and 1709.91 ± 41.35 (cGy) for NCNR, CR, CNR (р = 0.97), respectively. In all cases, the spinal cord threshold dose was far below the tolerances and the differences were insignificant. Average CI was 1.18 ± 0.16, 0.53 ± 0.39, and 0.86 ± 0.24 for NCNR, CR, CNR (р = 0.0002), respectively. Conclusions: The study investigated the dosimetric impact of Qfix kVue Calypso-compatible couch top on the quality of the spinal SBRT treatment using static IMRT or VMAT techniques. IMRT plans showed more sensitivity to the couch being in the plan than the VMAT plans.
基金supported by the Ministry of Science and Technology (No.2017YFF0104500)the Chinese Academy of Sciences (No.XDB17000000)the National Natural Science Foundation of China (No.21573226, No.21822305)
基金Supported by National Natural Science Foundation of China(Grant Nos.50675008,51175013)National Hi-tech Research and Development Program of China(863 Program,Grant No.2017YFB1302702)
文摘Retinal surgery continues to be one of the most technical demanding surgeries for its high manipulation accuracy requirement, small and constrained workspace, and delicate retinal tissue. Robotic systems have the potential to enhance and expand the capabilities of surgeons during retinal surgery. Thus, focusing on retinal vessel bypass surgery, a master-slave robot system is developed in this paper. This robotic system is designed based on characteristics of retinal vascular bypass surgery and analysis of the surgical workspace in eyeball. A novel end-effector of two degrees of freedom is designed and a novel remote center of motion mechanism is adopted in the robot structure.The kinematics and the mapping relationship are then established, the gravity compensation control strategy and the hand tremor elimination algorithm are applied to achieve the high motion accuracy. The experiments on an artificial eyeball and an in vitro porcine eye are conducted, verifying the feasibility of this system.
基金financially supported by Geological Survey Program of China Geological Survey (DD20160137, DD20190205, DD20190208)the National Natural Science Foundation of China (41606079).
文摘Source rocks are the material basis of oil and gas generation and determine the potential resources of exploration blocks and have important research value. This paper studies the lithology, thickness, and geochemistry of Mesozoic source rocks in the southeastern East China Sea continental shelf. The results show that the Mesozoic source rocks are mainly dark mudstone and coal-bearing strata. The total thickness of Lower–Middle Jurassic source rocks ranges from 100 m to 700 m, and that of Lower Cretaceous source rocks ranges from 50 m to 350 m. The overall thickness of Mesozoic source rocks is distributed in the NE direction and their thickness center is located in the Jilong Depression. The Lower–Middle Jurassic source rocks are mainly developed shallow marine dark mudstone and transitional coal measure strata. Those of the Lower Cretaceous are mainly mudstone of a fan delta front. Lower –Middle Jurassic and Lower Cretaceous hydrocarbon source rocks are dominated by type III kerogen, with Lower –Middle Jurassic hydrocarbon source rocks having high organic matter abundance and being medium –good hydrocarbon source rocks, while Lower Cretaceous hydrocarbon source rocks have relatively poor quality. From northwest to southeast, the vitrinite reflectance Ro of Mesozoic source rocks increases gradually. Source rocks in the study area are divided into three types. The first hydrocarbon-generating area is mainly located in the southeastern region of the study area, and the Jilong Depression is the hydrocarbongenerating center. The results of this study can provide a basis for exploration of Mesozoic oil and gas resources in the southeastern East China Sea continental shelf.
基金Supported by Anhui Provincial Department of Education College Outstanding Talent Cultivation Funding Project,No.gxgwfx2019032the Teaching Quality and Teaching Reform Project of Anhui Provincial Department of Education,No.2020jyxm2090+1 种基金Anhui Wuhu Novel Coronavirus Pneumonia Epidemic Prevention and Control Science and Technology Emergency Project,No.2020rkx1-5Wannan Medical College Teaching Quality and Teaching Reform Project,No.2019jyxm20.
文摘BACKGROUND Frontline nurses in Wuhan directly fighting severe acute respiratory syndrome coronavirus-2 diseases are at a high risk of infection and are extremely susceptible to psychological stress,especially due to the global coronavirus disease 2019(COVID-19)pandemic.The psychological after-effects of this public health emergency on frontline nurses will last for years.AIM To assess factors influencing post-traumatic stress disorder(PTSD)among frontline nurses in Wuhan 6 mo after the COVID-19 pandemic began.METHODS A total of 757 frontline nurses from five hospitals in Wuhan,China,participated in an online survey from July 27 to August 13,2020.This cross-sectional online study used a demographic information questionnaire,the PTSD Checklist for the Diagnostic and Statistical Manual of Mental Disorders,the Connor-Davidson Resilience Scale,and the Patient Health Questionnaire-4.The chisquare test and logistic regression were used to analyze the association of demographics,COVID-19-related variables,and PTSD.Logistic regression was also conducted to investigate which variables were associated with PTSD outcomes.RESULTS A total of 13.5%,24.3%,and 21.4%of the frontline nurses showed symptoms of PTSD,depression,and anxiety,respectively.The multivariate logistic regression analysis showed that the following factors were strongly associated with PTSD:Having a relative,friend,or colleague who died of COVID-19;experiencing stigma;or having psychological assistance needs,depressive symptoms or anxiety.Showing resilience and receiving praise after the COVID-19 outbreak were protective factors.CONCLUSION Frontline nurses still experienced PTSD(13.5%)six months after the COVID-19 outbreak began.Peer support,social support,official recognition,reward mechanisms,exercise,better sleep,and timely provision of information(such as vaccine research progress)by the government via social media,and adequate protective supplies could mitigate the level of PTSD among nurses responding to COVID-19.Stigmatization,depression,and anxiety might be associated with a greater risk of PTSD among nurses.
基金Geological Survey Program of China Geological Survey (DD20160218, DD20160137)the National Natural Science Foundation of China (41506083,41606086,41606087,41606050, 91858208)National Key Research and Development Program of China (2017 YFC0307600,2017YFC0307704).
文摘Lichi melange,located in the southern coastal range,eastern Taiwan,China,is a typical tectonic melange of the plate's boundary zone between the Eurasian Plate and the Philippine Sea Plate.It formed during the collision of the Luzon arc with the Eurasian Continent (arc-continent collision).It is composed of sandstone and/or mudstone matrix and many kinds and sizes of rock fragments,including some sedimentary rocks,volcanic rocks and a few metamorphic rocks.The serpentinite is one of the common fragments in the Lichi melange.By the petrographic characteristics and the zircon U-Pb chronology analyses,protolith of the serpentinite is peridotite,the age is 17.7 ±0.5 Ma.Taking the tectonic background into account,it is inferred that the serpentinite (serpentinised peridotite)come from the forearc basin (the North Luzon Trough)and was taken into the melange by a second thrust westwards.The origin of the serpentimte in Lichi melange is helpful to understand the formation of the Lichi melange and can provide reliable detailed information for the study of the arc-continent collision orogenic activity in and offshore Taiwan.
基金supported by the National Natural Science Foundation of China(Grant Nos.31601856 and 31670398)。
文摘Natural hybridization,which often occurs between closely related species exhibiting sympatric or parapatric distributions,is an important source of genetic variation within populations.The closely related Jankowski’s Bunting(Emberiza jankowskii)and Meadow Bunting(E.cioides)are similar in morphology and genetics,occupy overlapping niches,and are sympatric in eastern Inner Mongolia.Previous studies have reported trans-species polymorphisms of alleles between the two species,as well as an unexpectedly high genetic diversity of the endangered E.jankowskii.We speculate that introgressive hybridization has occurred between the two species and contributed to the additional unexpected variation to E.jankowskii.We used mitochondrial NADH dehydrogenase subunit 2(ND2)gene and 15 nuclear microsatellite markers to compare the genetic diversity of E.jankowskii and E.cioides,and inferred the origin of trans-species polymorphisms between the two species by phylogenetic reconstruction and Bayesian cluster analysis.The two species could be clearly distinguished by population cluster analysis.Despite the large number of mutational differences,we still detected sharing of major haplotypes and the presence of hybrids between the two species.Our study confirmed that weak introgressive hybridization has occurred between sympatric E.jankowskii and E.cioides,which may be mediated by female E.cioides individuals,and that interspecific introgression has contributed to the maintenance of high genetic diversity in E.jankowskii.While being wary of the potential negative effects of introgressive hybridization,we suggest that expanding the habitat of E.jankowskii remains the most effective conservation strategy at present.
基金National Key Research and Development Program of China(2021YFB2800603)National Natural Science Foundation of China(62075238)+1 种基金Foundation of Science and Technology on Metrology and Calibration Laboratory(JLJK2021001A004)West Light Foundation of the Chinese Academy of Sciences(E0291113)。
文摘A high-quality optical microcavity can enhance optical nonlinear effects by resonant recirculation,which provides a reliable platform for nonlinear optics research.When a soliton microcomb and a probe optical field are coexisting in a micro-resonator,a concomitant microcomb(CMC)induced by cross-phase modulation(XPM)will be formed synchronously.Here,we characterize the CMC comprehensively in a micro-resonator through theory,numerical simulation,and experimental verification.It is found that the CMCs spectra are modulated due to resonant radiation(RR)resulting from the interaction of dispersion and XPM effects.The group velocity dispersion induces symmetric RRs on the CMC,which leads to a symmetric spectral envelope and a dual-peak pulse in frequency and temporal domains,respectively,while the group velocity mismatch breaks the symmetry of RRs and leads to asymmetric spectral and temporal profiles.When the group velocity is linearly varying with frequency,two RR frequencies are hyperbolically distributed about the pump,and the probe light acts as one of the asymptotic lines.Our results enrich the CMC dynamics and guide microcomb design and applications such as spectral extension and dark pulse generation.
文摘目的在血压明显增高的患者中证实舌下含服硝苯地平控释片30 mg的有效性和安全性,并比较两种制剂(拜新同和欣然)的差别。方法2018年8月至2019年5月间纳入收缩压≥175或≥160 mm Hg伴有头痛的门诊高血压患者,分别进行安慰剂对照研究(采用单盲、随机对照的设计,以1∶1∶1分为拜新同、欣然或安慰剂3组,每组23例)和扩大样本量临床研究(从197例舌下含服硝苯地平控释片治疗的高血压患者中,以病例配对方法选取72例使用拜新同和72例使用欣然的患者)。使用同一电子血压计,重复测量含服后5、10、15和20 min的血压和脉率(代表心率)。计算各时点血压和心率的降低幅度和百分降幅(降低幅度/基线水平×100%)。两项试验的有效性指标为:治疗后20 min的收缩压或平均动脉压(MAP)降低幅度>10%;安全性指标:20 min时MAP百分降幅≤25%或收缩压≥140 mm Hg;同时伴有心率增加≤10次/min;或不出现心悸、头晕为安全。结果(1)安慰剂对照研究:3组的年龄、性别、高血压用药情况、基线收缩压、舒张压、MAP和心率均具有可比性。含服5 min时两治疗组的收缩压即降低。在20 min时,拜新同组[(159.6±9.6)比(182.0±4.7)mm Hg,P<0.05]和欣然组[(164.5±13.4)比(184.0±7.8)mm Hg,P<0.05]收缩压较基线明显降低,而安慰剂组下降无统计学意义[(177.7±12.2)比(182.7±9.4)mm Hg,P=0.154]。3组MAP百分降幅平均值分别为7.3%、7.7%和1.7%,心率减少1~2次/min。(2)临床研究:144例患者的平均年龄为(65.6±11.4)岁(最大88岁)。拜新同组和欣然两组的性别构成、平均年龄、既往降压药使用以及服用钙通道阻滞剂的比例相似。含服20 min时两组收缩压百分降幅和MAP百分降幅相似。有5例患者在治疗过程中收缩压<140 mm Hg,收缩压为130 mm Hg者1例,其余4例收缩压>135 mm Hg。1例患者发生无症状的心率增加(从88.5升到104.0次/min)。有10例收缩压降低幅度<5 mm Hg;其中6例收缩压较基线轻度升高。结论对收缩压明显增高的高血压患者,舌下含服硝苯地平控释片30 mg能在20 min时有效而适度地降低收缩压和MAP,同时无不良反应发生。拜新同和欣然两种制剂的效果和安全性相似。
