Metasurfaces offer a unique platform to precisely control optical wavefronts and enable the realization of flat lenses,or metalenses,which have the potential to substantially reduce the size and complexity of imaging ...Metasurfaces offer a unique platform to precisely control optical wavefronts and enable the realization of flat lenses,or metalenses,which have the potential to substantially reduce the size and complexity of imaging systems and to realize new imaging modalities.However,it is a major challenge to create achromatic metalenses that produce a single focal length over a broad wavelength range because of the difficulty in simultaneously engineering phase profiles at distinct wavelengths on a single metasurface.For practical applications,there is a further challenge to create broadband achromatic metalenses that work in the transmission mode for incident light waves with any arbitrary polarization state.We developed a design methodology and created libraries of meta-units—building blocks of metasurfaces—with complex cross-sectional geometries to provide diverse phase dispersions(phase as a function of wavelength),which is crucial for creating broadband achromatic metalenses.We elucidated the fundamental limitations of achromatic metalens performance by deriving mathematical equations that govern the tradeoffs between phase dispersion and achievable lens parameters,including the lens diameter,numerical aperture(NA),and bandwidth of achromatic operation.We experimentally demonstrated several dielectric achromatic metalenses reaching the fundamental limitations.These metalenses work in the transmission mode with polarization-independent focusing efficiencies up to 50%and continuously provide a near-constant focal length over λ=1200–1650 nm.These unprecedented properties represent a major advance compared to the state of the art and a major step toward practical implementations of metalenses.展开更多
Metasurfaces are optically thin metamaterials that promise complete control of the wavefront of light but are primarily used to control only the phase of light.Here,we present an approach,simple in concept and in prac...Metasurfaces are optically thin metamaterials that promise complete control of the wavefront of light but are primarily used to control only the phase of light.Here,we present an approach,simple in concept and in practice,that uses meta-atoms with a varying degree of form birefringence and rotation angles to create high-efficiency dielectric metasurfaces that control both the optical amplitude and phase at one or two frequencies.This opens up applications in computer-generated holography,allowing faithful reproduction of both the phase and amplitude of a target holographic scene without the iterative algorithms required in phase-only holography.We demonstrate all-dielectric metasurface holograms with independent and complete control of the amplitude and phase at up to two optical frequencies simultaneously to generate two-and three-dimensional holographic objects.We show that phaseamplitude metasurfaces enable a few features not attainable in phase-only holography;these include creating artifactfree two-dimensional holographic images,encoding phase and amplitude profiles separately at the object plane,encoding intensity profiles at the metasurface and object planes separately,and controlling the surface textures of three-dimensional holographic objects.展开更多
Several studies have demonstrated that the Chinese herb Gastrodia elata Blume can protect against amyloid beta-peptide （Ap）-induced cell death. To investigate the possible therapeutic effects of Gastrodia elata Blum...Several studies have demonstrated that the Chinese herb Gastrodia elata Blume can protect against amyloid beta-peptide （Ap）-induced cell death. To investigate the possible therapeutic effects of Gastrodia elata Blume on Alzheimer＇s disease, we established a rat model of AIzheimer＇s disease by injecting A325-35 into bilateral hippocampi. These rats were intragastrically administered 500 or 1 000 mg/kg Gastrodia elata Blume per day for 52 consecutive days. Morris water maze tests showed that Gastrodia elata Blume treatment significantly improved the spatial memory of Alzheimer＇s disease rats. Congo red staining revealed that Gastrodia elata Blume significantly reduced the number of amyloid deposits in the hippocampus of these rats. Western blot analysis showed that choline acetyltransferase expression in the medial septum and hippocampus was significantly increased by the treatment of Gastrodia elata Blume, while EIIman method showed significant decrease in the activity of acetylcholinesterase in all three regions （prefrontal cortex, medial septum and hippocampus）. These findings suggest that long-term administration of Gastrodia elata Blume has therapeutic potential for Alzheimer＇s disease.展开更多
Transdermal drug delivery refers to a means of delivering drugs through the surface of the skin for local or systemic treatment. The drug functions after absorption through the skin into the systemic circulation via c...Transdermal drug delivery refers to a means of delivering drugs through the surface of the skin for local or systemic treatment. The drug functions after absorption through the skin into the systemic circulation via capillary action at a certain rate. Use of traditional physical and chemical enhancers to improve the transdermal permeation rate by increasing drug solubility, diffusion coefficient, and reservoir effect is not feasible owing to the toxic side effects of the overuse of chemical penetration enhancers. Nanoformulations generally vary in size and range from 10 nm to 100 nm. The smaller particle size leads to increased drug permeability, stability, retention, and targeting, making nano-formulations suitable for transdermal drug delivery. The different applications of nano-formulations(vesicles or nanoparticles and nanoemulsions) have been widely studied. Here, the classification, characteristics, transdermal mechanism, and application of the most popular nano-formulations in transdermal drug delivery system are reviewed.展开更多
目的探讨产前应用皮质激素(ACS)联合产后应用外源性肺表面活性物质(PS)与单一应用防治新生儿呼吸窘迫综合征(RDS)的疗效。方法选取2003年1月-2007年1月本院NICU收治的143例RDS新生儿。随机分为4组:第1组为产前应用ACS联合产后应用PS (n=...目的探讨产前应用皮质激素(ACS)联合产后应用外源性肺表面活性物质(PS)与单一应用防治新生儿呼吸窘迫综合征(RDS)的疗效。方法选取2003年1月-2007年1月本院NICU收治的143例RDS新生儿。随机分为4组:第1组为产前应用ACS联合产后应用PS (n=36);第2组为单一产前应用ACS (n=33);第3组为单一产后应用PS (n=39);第4组为2种治疗措施均未采用(n=35)。对4组患儿的一般资料如性别、胎龄、出生体质量、分娩方式、Apgar评分、产时复苏情况、围生期并发症进行分析,并对不同组间应用鼻导管吸氧、头罩吸氧、持续呼吸道正压(CPAP)、机械通气(MV)等不同氧疗模式的时间,治愈的平均治疗时间及疗效进行比较。结果 4组患儿的一般资料和临床特征相似(Pa>0.05)。第1、2、3、4组采用鼻导管吸氧时间分别为(75.81±15.63)、(130.09±27.32)、(150.67±28.59)、(174.32±25.92) h (P=0.041);头罩吸氧时间分别为(37.16±5.51)、(55.29±11.71)、(62.69±12.39)、(100.75±28.10) h (P=0.047);CPAP时间分别为(24.33±4.41)、(27.44±4.47)、(26.53±3.13)、(56.50±5.50) h (P=0.005);MV时间分别为(56.12±15.65)、(110.19±21.59)、(127.79±26.36)、(156.61±12.92) h (P=0.009);第1组采用MV的几率最低。4组患儿住院天数分别为(15.89±1.29)、(21.61±2.30)、(28.31±3.40)、(32.73±4.57) d(P=0);治愈率分别为63.89%、51.52%、35.90%、20.0%(P=0.005)。结论产前应用ACS联合产后外源性补充PS是治疗RDS的最佳措施,单一产前应用ACS对RDS的疗效优于单一产后应用PS。展开更多
In the Vehicular Ad-hoc NETworks(VANET),the collection and dissemination of life-threatening traffic event information by vehicles are of utmost importance.However,traditional VANETs face several security issues.We pr...In the Vehicular Ad-hoc NETworks(VANET),the collection and dissemination of life-threatening traffic event information by vehicles are of utmost importance.However,traditional VANETs face several security issues.We propose a new type of blockchain to resolve critical message dissemination issues in the VANET.We create a local blockchain for real-world event message exchange among vehicles within the boundary of a country,which is a new type of blockchain suitable for the VANET.We present a public blockchain that stores the node trustworthiness and message trustworthiness in a distributed ledger that is appropriate for secure message dissemination.展开更多
The cotton aphid, Aphis gossypii Glover, predation rate of convergent lady beetle, Hippodamia convergens Guerin-Meneville, was determined by assigning a single predator randomly to each of four prey density treatments...The cotton aphid, Aphis gossypii Glover, predation rate of convergent lady beetle, Hippodamia convergens Guerin-Meneville, was determined by assigning a single predator randomly to each of four prey density treatments in the laboratory. Prey densities included 25, 50, 100, and 200 aphids per Petri dish arena. Predation response was recorded at 1, 4, 8, 16, 24, and 48 h after assigning predators to their prey treatments. Rate of consumption increased through time, with all 25 aphids consumed during the first 4 h of the experiment. At the highest density, adult lady beetle consumed on average 49, 99, 131, 163, 183, and 200 aphids within 1, 4, 8, 16, 24 and 48 h, respectively. Predators showed a curvilinear feeding response in relation to total available time, indicating that convergent lady beetles have the potential to suppress larger populations of aphids through continuous feeding by regulating their predation efficiency during feeding. The analysis of age-specific mortality in absence of prey revealed that lady beetles could survive for an extended period of time （more than 2 weeks） without prey. The ability of a predator to survive without prey delays or prevents the rebound of pest populations that is a significant factor in natural biological control. A two-year field sampling of 10 cotton arthropod predator species showed that spiders （27%） were the most dominant foliage dwelling predators in the Texas High Plains cotton followed by convergent lady beetles （23.5%）, hooded beetles （13.5%）, minute pirate bugs （11%）, green lacewings （9.5%）, bigeyed bugs （7.5%）, scymnus beetles （3%）, soft-winged flower beetles （2%）, damsel bugs （1.5%）, and assassin bugs （1.5%）. A field cage study showed that one H. convergens adult per plant released at prey density of one aphid per leaf kept the aphid population below economic threshold for the entire growing season.展开更多
AIM: To review and evaluate the diagnostic dilemma of xanthogranulomatous cholecystitis(XGC) clinically.METHODS: From July 2008 to June 2014, a total of 142 cases of pathologically diagnosed XGC were reviewed at our h...AIM: To review and evaluate the diagnostic dilemma of xanthogranulomatous cholecystitis(XGC) clinically.METHODS: From July 2008 to June 2014, a total of 142 cases of pathologically diagnosed XGC were reviewed at our hospital, among which 42 were misdiagnosed as gallbladder carcinoma(GBC) based on preoperative radiographs and/or intra-operative findings. The clinical characteristics, preoperative imaging, intra-operative findings, frozen section(FS) analysis and surgical procedure data of these patients were collected and analyzed.RESULTS: The most common clinical syndrome in these 42 patients was chronic cholecystitis, followed by acute cholecystitis. Seven(17%) cases presented with mild jaundice without choledocholithiasis. Thirtyfive(83%) cases presented with heterogeneous enhancement within thickened gallbladder walls on imaging, and 29(69%) cases presented with abnormal enhancement in hepatic parenchyma neighboring the gallbladder, which indicated hepatic infiltration. Intra-operatively, adhesions to adjacent organs were observed in 40(95.2%) cases, including the duodenum, colon and stomach. Thirty cases underwent FS analysis and the remainder did not. The accuracy rate of FS was 93%, and that of surgeon's macroscopic diagnosis was 50%. Six cases were misidentified as GBC by surgeon's macroscopic examination and underwent aggressive surgical treatment. No statistical difference was encountered in the incidence of postoperative complications between total cholecystectomy and subtotal cholecystectomy groups(21% vs 20%, P > 0.05).CONCLUSION: Neither clinical manifestations and laboratory tests nor radiological methods provide apractical and effective standard in the differential diagnosis between XGC and GBC.展开更多
Aims Morphological variation of leaves is a key indicator of plant response to climatic change.Leaf size and shape are associated with carbon,water and energy exchange of plants with their environment.However,whether ...Aims Morphological variation of leaves is a key indicator of plant response to climatic change.Leaf size and shape are associated with carbon,water and energy exchange of plants with their environment.However,whether and how leaf size and shape responded to climate change over the past decades remains poorly studied.Moreover,many studies have only explored inter-but not intraspecific variation in leaf size and shape across space and time.Methods We collected>6000 herbarium specimens spanning 98 years(1910–2008)in China for seven representative dicot species and measured their leaf length and width.We explored geographical patterns and temporal trends in leaf size(i.e.leaf length,leaf width and length×width product)and shape(i.e.length/width ratio),and investigated the effects of changes in precipitation and temperature over time and space on the variation in leaf size and shape.Important Findings After accounting for the effects of sampling time,leaf size decreased with latitude for all species combined,but the relationship varied among species.Leaf size and shape were positively correlated with temperature and precipitation across space.After accounting for the effects of sampling locations,leaf size of all species combined increased with time.Leaf size changes over time were mostly positively correlated with precipitation,whereas leaf shape changes were mostly correlated with temperature.Overall,our results indicate significant spatial and temporal intraspecific variation in leaf size and shape in response to climate.Our study also demonstrates that herbarium specimens collected over a considerable period of time provide a good resource to study the impacts of climate change on plant morphological traits.展开更多
BACKGROUND:Basic life support(BLS),a key component of the chain of survival decreases the arrest-cardiopulmonary resuscitation interval and increases the rate of hospital discharge.The study aimed to explore the knowl...BACKGROUND:Basic life support(BLS),a key component of the chain of survival decreases the arrest-cardiopulmonary resuscitation interval and increases the rate of hospital discharge.The study aimed to explore the knowledge of and attitude towards basic life support(BLS)among medical/paramedical professionals.METHODS:An observational study was conducted by assessing response to self prepared questionnaire consisting of the demographic information of the medical/paramedical staff,their personnel experience/attitude and knowledge of BLS based on the 2005 BLS Guidelines of European Resuscitation Council.RESULTS:After excluding incomplete questionnaires,the data from 121 responders(27 clinical faculty members,21 dental and basic sciences faculty members,29 house officers and 44 nurses and health assistants)were analyzed.Only 9(7.4%)of the 121 responders answered≥11,53(43%)answered 7-10,and 58(48%)answered<7 of 15 questions correctly.The clinical faculty members,house officers and nurses/HA had a mean score of 7.4±3.15,7.37±2.02 and 6.63±2.16 respectively,while dental/basic sciences faculty members attained a least mean score of 4.52±2.13(P<0.001).Those who had received cardiopulmonary resuscitation(CPR)training within 5 years obtained a highest mean score of 8.62±2.49,whereas those who had the training more than 5 years back or no training obtained a mean score of 5.54±2.38 and 6.1±2.29 respectively(P=0.001).Those who were involved in resuscitation frequently had a higher median score of 8 in comparison to those who were seldom involved or not involved at all(P<0.001).CONCLUSIONS:The average health personnel in our hospital lack adequate knowledge in CPR/BLS.Training and experience can enhance knowledge of CPR of these personnel.Thus standard of CPR/BLS training and assessment are recommended at our hospital.展开更多
This study investigated possible effective treatments for cervical pregnancy, a rare form of ectopic pregnancy. The clinical records of 11 cases of ectopic pregnancy admitted to the Third Affiliated Hospital of Sun Ya...This study investigated possible effective treatments for cervical pregnancy, a rare form of ectopic pregnancy. The clinical records of 11 cases of ectopic pregnancy admitted to the Third Affiliated Hospital of Sun Yat-sen University from 1998 to 2010 were analyzed. All patients were treated with intermuscular injection of methotrexate （MTX, 50 mg）, and oral mifepristone （25 mg, bid）. All cases were successfully cured by conservative treatments using methotrexate plus mifepristone. Cervical pregnancy is a contributive factor to mutiple abortions and curettages. Methotrexate plus mifepristone, curettage through hysteroscopy and intracervical obturation with gauze are effective treatments of cervical pregnancy without the need for surgical intervention.展开更多
基金supported by the Defense Advanced Research Projects Agency(no.D15AP00111 and no.HR0011-17-2-0017)the Air Force Office of Scientific Research(no.FA9550-14-1-0389 and no.FA9550-16-1-0322)+2 种基金the National Science Foundation(no.ECCS-1307948)support from the NSF IGERT program(no.DGE-1069240)supported by the US Department of Energy,Office of Basic Energy Sciences(contract no.DE-SC0012704)。
文摘Metasurfaces offer a unique platform to precisely control optical wavefronts and enable the realization of flat lenses,or metalenses,which have the potential to substantially reduce the size and complexity of imaging systems and to realize new imaging modalities.However,it is a major challenge to create achromatic metalenses that produce a single focal length over a broad wavelength range because of the difficulty in simultaneously engineering phase profiles at distinct wavelengths on a single metasurface.For practical applications,there is a further challenge to create broadband achromatic metalenses that work in the transmission mode for incident light waves with any arbitrary polarization state.We developed a design methodology and created libraries of meta-units—building blocks of metasurfaces—with complex cross-sectional geometries to provide diverse phase dispersions(phase as a function of wavelength),which is crucial for creating broadband achromatic metalenses.We elucidated the fundamental limitations of achromatic metalens performance by deriving mathematical equations that govern the tradeoffs between phase dispersion and achievable lens parameters,including the lens diameter,numerical aperture(NA),and bandwidth of achromatic operation.We experimentally demonstrated several dielectric achromatic metalenses reaching the fundamental limitations.These metalenses work in the transmission mode with polarization-independent focusing efficiencies up to 50%and continuously provide a near-constant focal length over λ=1200–1650 nm.These unprecedented properties represent a major advance compared to the state of the art and a major step toward practical implementations of metalenses.
基金supported by the Defense Advanced Research Projects Agency(grant no.D15AP00111 and HR0011-17-2-0017)the National Science Foundation(grant no.ECCS-1307948 and QII-TAQS-1936359)+2 种基金the Air Force Office of Scientific Research(grant no.FA9550-14-1-0389 and FA9550-16-1-0322)support from the NSF IGERT program(grant no.DGE-1069240)supported by the US Department of Energy,Office of Basic Energy Sciences(contract no.DESC0012704).
文摘Metasurfaces are optically thin metamaterials that promise complete control of the wavefront of light but are primarily used to control only the phase of light.Here,we present an approach,simple in concept and in practice,that uses meta-atoms with a varying degree of form birefringence and rotation angles to create high-efficiency dielectric metasurfaces that control both the optical amplitude and phase at one or two frequencies.This opens up applications in computer-generated holography,allowing faithful reproduction of both the phase and amplitude of a target holographic scene without the iterative algorithms required in phase-only holography.We demonstrate all-dielectric metasurface holograms with independent and complete control of the amplitude and phase at up to two optical frequencies simultaneously to generate two-and three-dimensional holographic objects.We show that phaseamplitude metasurfaces enable a few features not attainable in phase-only holography;these include creating artifactfree two-dimensional holographic images,encoding phase and amplitude profiles separately at the object plane,encoding intensity profiles at the metasurface and object planes separately,and controlling the surface textures of three-dimensional holographic objects.
基金funded by Muju Tianma Native Local Industrial Center,Korea
文摘Several studies have demonstrated that the Chinese herb Gastrodia elata Blume can protect against amyloid beta-peptide （Ap）-induced cell death. To investigate the possible therapeutic effects of Gastrodia elata Blume on Alzheimer＇s disease, we established a rat model of AIzheimer＇s disease by injecting A325-35 into bilateral hippocampi. These rats were intragastrically administered 500 or 1 000 mg/kg Gastrodia elata Blume per day for 52 consecutive days. Morris water maze tests showed that Gastrodia elata Blume treatment significantly improved the spatial memory of Alzheimer＇s disease rats. Congo red staining revealed that Gastrodia elata Blume significantly reduced the number of amyloid deposits in the hippocampus of these rats. Western blot analysis showed that choline acetyltransferase expression in the medial septum and hippocampus was significantly increased by the treatment of Gastrodia elata Blume, while EIIman method showed significant decrease in the activity of acetylcholinesterase in all three regions （prefrontal cortex, medial septum and hippocampus）. These findings suggest that long-term administration of Gastrodia elata Blume has therapeutic potential for Alzheimer＇s disease.
基金supported by the Postdoctoral Innovation Talents Support Program(No.BX20180207)the National Nature Science Foundation of China(No.81502722)
文摘Transdermal drug delivery refers to a means of delivering drugs through the surface of the skin for local or systemic treatment. The drug functions after absorption through the skin into the systemic circulation via capillary action at a certain rate. Use of traditional physical and chemical enhancers to improve the transdermal permeation rate by increasing drug solubility, diffusion coefficient, and reservoir effect is not feasible owing to the toxic side effects of the overuse of chemical penetration enhancers. Nanoformulations generally vary in size and range from 10 nm to 100 nm. The smaller particle size leads to increased drug permeability, stability, retention, and targeting, making nano-formulations suitable for transdermal drug delivery. The different applications of nano-formulations(vesicles or nanoparticles and nanoemulsions) have been widely studied. Here, the classification, characteristics, transdermal mechanism, and application of the most popular nano-formulations in transdermal drug delivery system are reviewed.
基金Key item in science and technology of health department of Henan province(20051580058)
文摘目的探讨产前应用皮质激素(ACS)联合产后应用外源性肺表面活性物质(PS)与单一应用防治新生儿呼吸窘迫综合征(RDS)的疗效。方法选取2003年1月-2007年1月本院NICU收治的143例RDS新生儿。随机分为4组:第1组为产前应用ACS联合产后应用PS (n=36);第2组为单一产前应用ACS (n=33);第3组为单一产后应用PS (n=39);第4组为2种治疗措施均未采用(n=35)。对4组患儿的一般资料如性别、胎龄、出生体质量、分娩方式、Apgar评分、产时复苏情况、围生期并发症进行分析,并对不同组间应用鼻导管吸氧、头罩吸氧、持续呼吸道正压(CPAP)、机械通气(MV)等不同氧疗模式的时间,治愈的平均治疗时间及疗效进行比较。结果 4组患儿的一般资料和临床特征相似(Pa>0.05)。第1、2、3、4组采用鼻导管吸氧时间分别为(75.81±15.63)、(130.09±27.32)、(150.67±28.59)、(174.32±25.92) h (P=0.041);头罩吸氧时间分别为(37.16±5.51)、(55.29±11.71)、(62.69±12.39)、(100.75±28.10) h (P=0.047);CPAP时间分别为(24.33±4.41)、(27.44±4.47)、(26.53±3.13)、(56.50±5.50) h (P=0.005);MV时间分别为(56.12±15.65)、(110.19±21.59)、(127.79±26.36)、(156.61±12.92) h (P=0.009);第1组采用MV的几率最低。4组患儿住院天数分别为(15.89±1.29)、(21.61±2.30)、(28.31±3.40)、(32.73±4.57) d(P=0);治愈率分别为63.89%、51.52%、35.90%、20.0%(P=0.005)。结论产前应用ACS联合产后外源性补充PS是治疗RDS的最佳措施,单一产前应用ACS对RDS的疗效优于单一产后应用PS。
基金This research was supported in part by Basic Science Research Program through National Research Foundation of Korea(NRF)funded by the Ministry of Education,Science and Technology(2013R1A1A2012006,2015R1D1A1A01058595)This research was supported in part by the MSIP(Ministry of Science and ICT),Korea,under the ITRC(Information Technology Research Center)support program(IITP-2019-2016-0-00313)supervised by the IITP(Institute for Information and Communications Technology Planning&Evaluation)This work was supported in part by the Brain Korea 21 Plus Program(No.22A20130012814)funded by the National Research Foundation of Korea(NRF).
文摘In the Vehicular Ad-hoc NETworks(VANET),the collection and dissemination of life-threatening traffic event information by vehicles are of utmost importance.However,traditional VANETs face several security issues.We propose a new type of blockchain to resolve critical message dissemination issues in the VANET.We create a local blockchain for real-world event message exchange among vehicles within the boundary of a country,which is a new type of blockchain suitable for the VANET.We present a public blockchain that stores the node trustworthiness and message trustworthiness in a distributed ledger that is appropriate for secure message dissemination.
文摘The cotton aphid, Aphis gossypii Glover, predation rate of convergent lady beetle, Hippodamia convergens Guerin-Meneville, was determined by assigning a single predator randomly to each of four prey density treatments in the laboratory. Prey densities included 25, 50, 100, and 200 aphids per Petri dish arena. Predation response was recorded at 1, 4, 8, 16, 24, and 48 h after assigning predators to their prey treatments. Rate of consumption increased through time, with all 25 aphids consumed during the first 4 h of the experiment. At the highest density, adult lady beetle consumed on average 49, 99, 131, 163, 183, and 200 aphids within 1, 4, 8, 16, 24 and 48 h, respectively. Predators showed a curvilinear feeding response in relation to total available time, indicating that convergent lady beetles have the potential to suppress larger populations of aphids through continuous feeding by regulating their predation efficiency during feeding. The analysis of age-specific mortality in absence of prey revealed that lady beetles could survive for an extended period of time （more than 2 weeks） without prey. The ability of a predator to survive without prey delays or prevents the rebound of pest populations that is a significant factor in natural biological control. A two-year field sampling of 10 cotton arthropod predator species showed that spiders （27%） were the most dominant foliage dwelling predators in the Texas High Plains cotton followed by convergent lady beetles （23.5%）, hooded beetles （13.5%）, minute pirate bugs （11%）, green lacewings （9.5%）, bigeyed bugs （7.5%）, scymnus beetles （3%）, soft-winged flower beetles （2%）, damsel bugs （1.5%）, and assassin bugs （1.5%）. A field cage study showed that one H. convergens adult per plant released at prey density of one aphid per leaf kept the aphid population below economic threshold for the entire growing season.
基金Supported by The Science and Technology Support Project of Sichuan Province,No.2014SZ0002-10
文摘AIM: To review and evaluate the diagnostic dilemma of xanthogranulomatous cholecystitis(XGC) clinically.METHODS: From July 2008 to June 2014, a total of 142 cases of pathologically diagnosed XGC were reviewed at our hospital, among which 42 were misdiagnosed as gallbladder carcinoma(GBC) based on preoperative radiographs and/or intra-operative findings. The clinical characteristics, preoperative imaging, intra-operative findings, frozen section(FS) analysis and surgical procedure data of these patients were collected and analyzed.RESULTS: The most common clinical syndrome in these 42 patients was chronic cholecystitis, followed by acute cholecystitis. Seven(17%) cases presented with mild jaundice without choledocholithiasis. Thirtyfive(83%) cases presented with heterogeneous enhancement within thickened gallbladder walls on imaging, and 29(69%) cases presented with abnormal enhancement in hepatic parenchyma neighboring the gallbladder, which indicated hepatic infiltration. Intra-operatively, adhesions to adjacent organs were observed in 40(95.2%) cases, including the duodenum, colon and stomach. Thirty cases underwent FS analysis and the remainder did not. The accuracy rate of FS was 93%, and that of surgeon's macroscopic diagnosis was 50%. Six cases were misidentified as GBC by surgeon's macroscopic examination and underwent aggressive surgical treatment. No statistical difference was encountered in the incidence of postoperative complications between total cholecystectomy and subtotal cholecystectomy groups(21% vs 20%, P > 0.05).CONCLUSION: Neither clinical manifestations and laboratory tests nor radiological methods provide apractical and effective standard in the differential diagnosis between XGC and GBC.
基金supported by the National Key Research Development Program of China(grant number 2018YFA0606104)National Natural Science Foundation of China(grant numbers 31988102,31911530102,and Chinese Academy of Sciences-Peking University Pioneer Collaboration Team.
文摘Aims Morphological variation of leaves is a key indicator of plant response to climatic change.Leaf size and shape are associated with carbon,water and energy exchange of plants with their environment.However,whether and how leaf size and shape responded to climate change over the past decades remains poorly studied.Moreover,many studies have only explored inter-but not intraspecific variation in leaf size and shape across space and time.Methods We collected>6000 herbarium specimens spanning 98 years(1910–2008)in China for seven representative dicot species and measured their leaf length and width.We explored geographical patterns and temporal trends in leaf size(i.e.leaf length,leaf width and length×width product)and shape(i.e.length/width ratio),and investigated the effects of changes in precipitation and temperature over time and space on the variation in leaf size and shape.Important Findings After accounting for the effects of sampling time,leaf size decreased with latitude for all species combined,but the relationship varied among species.Leaf size and shape were positively correlated with temperature and precipitation across space.After accounting for the effects of sampling locations,leaf size of all species combined increased with time.Leaf size changes over time were mostly positively correlated with precipitation,whereas leaf shape changes were mostly correlated with temperature.Overall,our results indicate significant spatial and temporal intraspecific variation in leaf size and shape in response to climate.Our study also demonstrates that herbarium specimens collected over a considerable period of time provide a good resource to study the impacts of climate change on plant morphological traits.
文摘BACKGROUND:Basic life support(BLS),a key component of the chain of survival decreases the arrest-cardiopulmonary resuscitation interval and increases the rate of hospital discharge.The study aimed to explore the knowledge of and attitude towards basic life support(BLS)among medical/paramedical professionals.METHODS:An observational study was conducted by assessing response to self prepared questionnaire consisting of the demographic information of the medical/paramedical staff,their personnel experience/attitude and knowledge of BLS based on the 2005 BLS Guidelines of European Resuscitation Council.RESULTS:After excluding incomplete questionnaires,the data from 121 responders(27 clinical faculty members,21 dental and basic sciences faculty members,29 house officers and 44 nurses and health assistants)were analyzed.Only 9(7.4%)of the 121 responders answered≥11,53(43%)answered 7-10,and 58(48%)answered<7 of 15 questions correctly.The clinical faculty members,house officers and nurses/HA had a mean score of 7.4±3.15,7.37±2.02 and 6.63±2.16 respectively,while dental/basic sciences faculty members attained a least mean score of 4.52±2.13(P<0.001).Those who had received cardiopulmonary resuscitation(CPR)training within 5 years obtained a highest mean score of 8.62±2.49,whereas those who had the training more than 5 years back or no training obtained a mean score of 5.54±2.38 and 6.1±2.29 respectively(P=0.001).Those who were involved in resuscitation frequently had a higher median score of 8 in comparison to those who were seldom involved or not involved at all(P<0.001).CONCLUSIONS:The average health personnel in our hospital lack adequate knowledge in CPR/BLS.Training and experience can enhance knowledge of CPR of these personnel.Thus standard of CPR/BLS training and assessment are recommended at our hospital.
文摘This study investigated possible effective treatments for cervical pregnancy, a rare form of ectopic pregnancy. The clinical records of 11 cases of ectopic pregnancy admitted to the Third Affiliated Hospital of Sun Yat-sen University from 1998 to 2010 were analyzed. All patients were treated with intermuscular injection of methotrexate （MTX, 50 mg）, and oral mifepristone （25 mg, bid）. All cases were successfully cured by conservative treatments using methotrexate plus mifepristone. Cervical pregnancy is a contributive factor to mutiple abortions and curettages. Methotrexate plus mifepristone, curettage through hysteroscopy and intracervical obturation with gauze are effective treatments of cervical pregnancy without the need for surgical intervention.
