期刊文献+
共找到228篇文章
< 1 2 12 >
每页显示 20 50 100
An early scoring system to predict mechanical ventilation for botulism: a single-center-based study
1
作者 Yaqing An Tuokang Zheng +7 位作者 Yanling Dong Yang Wu Yu Gong Yu Ma Hao Xiao Hengbo Gao Yingping Tian Dongqi Yao 《World Journal of Emergency Medicine》 SCIE CAS CSCD 2024年第5期365-371,共7页
BACKGROUND: Early identification of patients requiring ventilator support will be beneficial for the outcomes of botulism. The present study aimed to establish a new scoring system to predict mechanical ventilation(MV... BACKGROUND: Early identification of patients requiring ventilator support will be beneficial for the outcomes of botulism. The present study aimed to establish a new scoring system to predict mechanical ventilation(MV) for botulism patients.METHODS: A single-center retrospective study was conducted to identify risk factors associated with MV in botulism patients from 2007 to 2022. Univariate analysis and multivariate logistic regression analysis were used to screen out risk factors for constructing a prognostic scoring system. The area under the receiver operating characteristic(ROC) curve was calculated.RESULTS: A total of 153 patients with botulism(66 males and 87 females, with an average age of 43 years) were included. Of these, 49 patients(32.0%) required MV, including 21(13.7%) with invasive ventilation and 28(18.3%) with non-invasive ventilation. Multivariate analysis revealed that botulinum toxin type, pneumonia, incubation period, degree of hypoxia, and severity of muscle involvement were independent risk factors for MV. These risk factors were incorporated into a multivariate logistic regression analysis to establish a prognostic scoring system. Each risk factor was scored by allocating a weight based on its regression coefficient and rounded to whole numbers for practical utilization([botulinum toxin type A: 1], [pneumonia: 2], [incubation period ≤1 day: 2], [hypoxia <90%: 2], [severity of muscle involvement: grade Ⅱ, 3;gradeⅢ, 7;grade IV, 11]). The scoring system achieved an area under the ROC curve of 0.82(95% CI 0.75–0.89, P<0.001). At the optimal threshold of 9, the scoring system achieved a sensitivity of 83.7% and a specificity of 70.2%.CONCLUSION: Our study identified botulinum toxin type, pneumonia, incubation period, degree of hypoxia, and severity of muscle involvement as independent risk factors for MV in botulism patients. A score ≥9 in our scoring system is associated with a higher likelihood of requiring MV in botulism patients. This scoring system needs to be validated externally before it can be applied in clinical settings. 展开更多
关键词 BOTULISM Scoring system Botulinum toxin type incubation period HYPOXIA PNEUMONIA Severity of muscle involvement
下载PDF
Incubation temperature induced developmental plasticity of cold responsive physiological phenotypes in Japanese Quails
2
作者 Yingxin Kou Rongmiao Zhang +3 位作者 Xiaoqian Li Na Zhu Yihang Huang Shuping Zhang 《Avian Research》 SCIE CSCD 2024年第3期385-394,共10页
Embryonic development is a critical period for phenotype formation.Environmental variation during embryonic development can induce changes in postnatal phenotypes of animals.The thyroxine secretion and aerobic metabol... Embryonic development is a critical period for phenotype formation.Environmental variation during embryonic development can induce changes in postnatal phenotypes of animals.The thyroxine secretion and aerobic metabolic activity of small birds are important phenotypes closely related to their winter survival.In the context of climate change,it is necessary to determine whether temperature variation during incubation in birds leads to developmental plasticity of these cold responsive phenotypes.We incubated Japanese Quail(Coturnix japonica)eggs at 36.8℃,37.8℃,and 38.8℃,and raised the chicks to 35-day old at 22℃with same raising conditions,then all the quails were exposed to gradually temperature dropping environment(from 15℃to 0℃).After cold treatment,serum T3 level,resting metabolic rate,skeletal muscle and liver metabolomes of the birds were measured.The serum T3 levels were significantly lower in the 38.8℃group and significantly higher in the 36.8℃group compared to the 37.8℃group.The metabolic rate in the 38.8℃group was significantly lower compared to the 37.8℃group.Compared with the 37.8℃group,metabolites involved in the tricarboxylic acid cycle in the liver were significantly lower in the 38.8℃group,and metabolites related to lipid oxidation metabolism and fatty acid biosynthesis were significantly lower in the skeletal muscles in the 38.8℃group but significantly higher in the 36.8℃group.These results indicate that incubation temperature variation can lead to developmental plasticity in cold responsive physiological phenotypes.Higher incubation temperature may impair the capacity of birds coping with cold challenge. 展开更多
关键词 Cold response Developmental plasticity incubation temperature Metabolic rate Metabolomes Precocial bird THYROXIN
下载PDF
The clutch size,incubation behavior of Reeves’s Pheasant(Syrmaticus reevesii) and their responses to ambient temperature and precipitation
3
作者 Ting Jin Shuai Lu +7 位作者 Yunqi Wang Junqin Hua Zhengxiao Liu Qian Hu Yating Liu Yuze Zhao Jianqiang Li Jiliang Xu 《Avian Research》 SCIE CSCD 2024年第1期72-80,共9页
Weather conditions play a pivotal role in embryo development and parental incubation costs,potentially impacting the clutch size and incubation behavior of birds.Understanding these effects is crucial for bird conserv... Weather conditions play a pivotal role in embryo development and parental incubation costs,potentially impacting the clutch size and incubation behavior of birds.Understanding these effects is crucial for bird conservation.Reeves’ s Pheasant(Syrmaticus reevesii) is a threatened species endemic to China,which is characterized by female-only incubation.However,there is a lack of information regarding the impact of weather conditions on clutch size and incubation behavior in this species.Using satellite tracking,we tracked 27 wild female Reeves’ s Pheasants from 2020 to 2023 in Hubei Province,China.We explored their clutch size and incubation behavior,as well as their responses to ambient temperature and precipitation.Clutch size averaged 7.75 ±1.36,had an association with average ambient temperature and average daily precipitation during the egglaying period,and was potentially linked to female breeding attempts.Throughout the incubation period,females took an average of 0.73 ±0.46 recesses every 24 h,with an average recess duration of 100.80 ±73.37 min and an average nest attendance of 92.98 ±5.27%.They showed a unimodal recess pattern in which nest departures peaked primarily between 13:00 and 16:00.Furthermore,females rarely left nests when daily precipitation was high.Recess duration and nest attendance were influenced by the interaction between daily mean ambient temperature and daily precipitation,as well as day of incubation.Additionally,there was a positive correlation between clutch size and recess duration.These results contribute valuable insights into the lifehistory features of this endangered species. 展开更多
关键词 Ambient temperature Clutch size incubation behavior PRECIPITATION Reeves’s Pheasant
下载PDF
Clinical validation of the early embryo viability assessment system: Analysis for the blastocyst morphology and pregnancy outcomes
4
作者 Vu D Hop An M Cuong +3 位作者 Phi T T Anh Nguyen T L Huong Le Hoang Nguyen V Hanh 《Asian pacific Journal of Reproduction》 CAS 2024年第5期219-227,共9页
Objective:To determine the relationship between the early embryo viability assessment(EEVA)and blastocyst morphological parameters and pregnancy outcomes.Methods:This retrospective cohort study was conducted on 291 in... Objective:To determine the relationship between the early embryo viability assessment(EEVA)and blastocyst morphological parameters and pregnancy outcomes.Methods:This retrospective cohort study was conducted on 291 intracytoplasmic sperm injection cycles including 2522 embryos with indications of prolonging embryo culture to the blastocyst stage in the Genea embryo review incubator,and 511 single vitrified-warmed blastocyst transfer cycles from January 2020 to June 2023.The EEVA system produced an EEVA score from E1(best)to E5(worse)for the potential of blastocyst formation.Blastocyst morphology was evaluated.The association between the EEVA score and each type of blastocyst morphology,implantation rate,clinical pregnancy,and ongoing pregnancy were assessed using generalized estimating equations.Results:The inner cell mass A(ICM A),trophectoderm A(TE A),blastocoele expansion degree of 3,4,5,6,7 rates were higher with lower the EEVA score.The adjusted odd ratio(aOR)(E5 vs E1)was 0.3 for ICM A,0.174 for TE A and 0.210 for BL3,4,5,6,7(all P<0.001),suggesting a significant association between lower EEVA scores and improved embryo quality.The implantation,clinical pregnancy,and ongoing pregnancy rate were also higher with lower the EEVA score.The aOR of E5 vs E1 was 0.245 for implantation,0.185 for clinical pregnancy and 0.200 for ongoing pregnancy rate(P<0.001).Conclusions:There were associations between blastocyst morphology,pregnancy outcome and EEVA scores.The good blastocyst morphology and pregnancy outcomes are higher with lower the EEVA score. 展开更多
关键词 Automated embryo assessment BLASTOCYST Early embryo viability assessment Genea embryo review incubator MORPHOLOGY Pregnancy outcomes Timelapse
下载PDF
The amelioration of degraded larch(Larix olgensis)soil depends on the proportion of Aralia elata litter in larch-A.elata agroforestry systems
5
作者 Pingzhen Gao Jiaojun Zhu +2 位作者 Qiaoling Yan Kai Yang Jinxin Zhang 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第4期1065-1076,共12页
Research has indicated that introducing Aralia elata into larch plantations forms an agroforestry system which could provide economic benefi ts for local farmers and improve degraded soils.However,the impact of litter... Research has indicated that introducing Aralia elata into larch plantations forms an agroforestry system which could provide economic benefi ts for local farmers and improve degraded soils.However,the impact of litter mixtures on soil chemical and microbial properties in this agroforestry system are unclear,which limits effi cient management of the agroforestry system.A 365-d incubation experiment examined the eff ect of litter mixtures of diff erent proportions of larch(L)and A.elata(A)on soil chemical and microbial properties.The results show that levels of mineral N,available P,microbial biomass carbon and nitrogen,cumulative C mineralization,and activities of hydrolases and oxidases increased with an increase of A.elata in the litter mixtures.Concentration of total soil carbon,nitrogen,and phosphorous did not change(except for total nitrogen).Compared with larch litter alone,levels of mineral N,available P,microbial biomass carbon and nitrogen,cumulative C mineralization,and the activities of hydrolases and oxidases increased by 7.6–433.5%.Most chemical and microbial properties were positively correlated with mixed litter proportions and the initial levels of N,P,K,Ca,Mg,Mn,Zn and Cu in the litter,while negatively correlated with the initial concentrations of C,Fe and lignin,C/N and lignin/N ratios.The results indicate that A.elata litter can improve degraded larch soil and the degree depends on the proportion of A.elata litter in the litter mixtures. 展开更多
关键词 Larch-based agroforestry incubation experiment Litter mixtures Litter quality Soil properties
下载PDF
COVID TCL:A Joint Metric Loss Function for Diagnosing COVID-19 Patient in the Early and Incubation Period
6
作者 Rui Wen Jie Zhou +2 位作者 Zhongliang Shen Xiaorui Zhang Sunil Kumar Jha 《Computer Systems Science & Engineering》 SCIE EI 2023年第10期187-204,共18页
Convolution Neural Networks(CNN)can quickly diagnose COVID-19 patients by analyzing computed tomography(CT)images of the lung,thereby effectively preventing the spread of COVID-19.However,the existing CNN-based COVID-... Convolution Neural Networks(CNN)can quickly diagnose COVID-19 patients by analyzing computed tomography(CT)images of the lung,thereby effectively preventing the spread of COVID-19.However,the existing CNN-based COVID-19 diagnosis models do consider the problem that the lung images of COVID-19 patients in the early stage and incubation period are extremely similar to those of the non-COVID-19 population.Which reduces the model’s classification sensitivity,resulting in a higher probability of the model misdiagnosing COVID-19 patients as non-COVID-19 people.To solve the problem,this paper first attempts to apply triplet loss and center loss to the field of COVID-19 image classification,combining softmax loss to design a jointly supervised metric loss function COVID Triplet-Center Loss(COVID-TCL).Triplet loss can increase inter-class discreteness,and center loss can improve intra-class compactness.Therefore,COVID-TCL can help the CNN-based model to extract more discriminative features and strengthen the diagnostic capacity of COVID-19 patients in the early stage and incubation period.Meanwhile,we use the extreme gradient boosting(XGBoost)as a classifier to design a COVID-19 images classification model of CNN-XGBoost architecture,to further improve the CNN-based model’s classification effect and operation efficiency.The experiment shows that the classification accuracy of the model proposed in this paper is 97.41%,and the sensitivity is 97.61%,which is higher than the other 7 reference models.The COVID-TCL can effectively improve the classification sensitivity of the CNN-based model,the CNN-XGBoost architecture can further improve the CNN-based model’s classification effect. 展开更多
关键词 Covid-19 diagnose convolutional neural networks XGBoost COVID triplet-center loss early and incubation COVID-19 patients
下载PDF
Artificial incubation and growth observation for the nestlings of Great Bustard (Otis tarda) 被引量:2
7
作者 田秀华 张佰莲 +1 位作者 刘群秀 何相宝 《Journal of Forestry Research》 SCIE CAS CSCD 2004年第4期301-304,共4页
Growth indicators including weight, body length, wings length, tail length, tarsus, gape, the third toe and head width of 21 nestlings of Great Bustard (Otis tarda) were measured and investigated in Harbin Zoo, Harbin... Growth indicators including weight, body length, wings length, tail length, tarsus, gape, the third toe and head width of 21 nestlings of Great Bustard (Otis tarda) were measured and investigated in Harbin Zoo, Harbin, China during 1999-2002, and methods on successfully fostering nestlings of the bird were also summarized in this article. The results showed: the Great Bustard is a kind of premature bird and its birth weight was 86.31?.56g (N=21); environmental temperature for the neonatal nestlings should be controlled at 36C; the feeding principle having many meals but little food at each for the nestlings should be followed; since six weeks after birth, nestlings of both gender began to show significant difference in body weight, the weight of male was 1.8 times of that of the female after fourteenth week, and by weight and body figure sexual identity could be easily discerned when 3 or 4 months old; There is no significant difference in growth and development of all organs between male and female nestlings and organ growth curves were fit into Logistic equation. 展开更多
关键词 Artificial incubation Great bustard NESTLINGS GROWTH
下载PDF
A VHF PECVD Micro-Crystalline Silicon Bottom Gate TFT with a Thin Incubation Layer 被引量:1
8
作者 李娟 赵淑云 +7 位作者 刘建平 吴春亚 张晓丹 孟志国 赵颖 熊绍珍 张丽珠 张震 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2005年第6期1121-1125,共5页
The incubation layer with amorphous structure between the substrate and crystalline layer may obviously affect the performance for a microcrystalline Si thin film transistor (μc-Si TFT),especially for the bottom gate... The incubation layer with amorphous structure between the substrate and crystalline layer may obviously affect the performance for a microcrystalline Si thin film transistor (μc-Si TFT),especially for the bottom gate TFT(BG-TFT).It is found that decreasing the ratio of SiH 4/(H 2+SiH 4) is an effective way to decrease the incubation layer thickness of μc-Si directly deposited by VHF PECVD without any further thermal or laser treatment.Based on the μc-Si with a thin incubation layer,the BG-TFT with Al/SiN x/μc-Si/n+-μc-Si/Al structure is fabricated.The ratio of on-state current to off-state current is up to 106,the mobility is around 0.7cm2/(V·s),and the threshold voltage is about 5V. 展开更多
关键词 microcrystalline silicon incubation layer silicon concentration bottom gate μc-Si TFT
下载PDF
Hatching and development of maize cyst nematode Heterodera zeae infecting different plant hosts
9
作者 Jiangkuan Cui Haohao Ren +5 位作者 BoWang Fujie Chang Xuehai Zhang Haoguang Meng Shijun Jiang Jihua Tang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第5期1593-1603,共11页
The occurrence, distribution, and rapid molecular detection technology of Heterodera zeae Koshy et al. 1971, have been reported in China. We explored the biological characteristics of H. zeae sampled in Henan Province... The occurrence, distribution, and rapid molecular detection technology of Heterodera zeae Koshy et al. 1971, have been reported in China. We explored the biological characteristics of H. zeae sampled in Henan Province, China to understand its interaction with plants. Cysts and second-stage juveniles(J2s) were identified under an optical and scanning electron microscope, internal transcribed spacer(ITS) phylogenetic tree, and sequence characterized amplified region(SCAR)-PCR analyses. The optimum hatching temperatures of H. zeae were 30°C and 28°C, with cumulative hatching rates of 16.5 and 16.1%, respectively, at 30 days post-hatching(dph). The hatching rate of H. zeae eggs was improved by 20-and 50-time maize soil leachate and root juice, and 10-time root exudates. The hatching rate in 10-time root exudates was the highest(25.9%). The 10-time root exudates of maize and millet produced the highest hatching rate at 30 dph(25.9 and 22.9%, respectively), followed by wheat(19.9%), barley(18.3%), and rice(17.6%). Heterodera zeae developed faster in maize than in other crops. Fourth-stage juveniles(J4s) were detected in maize roots 8 days post-inoculation(dpi) at 28°C but not in other crops. Combined with hatching tests, the Huang–Huai–Hai summer maize region and the south and central-southwest mountainous maize areas are highly suitable for H. zeae in China. This is the first systematically study of the hatching and infection characteristics on different plant hosts of corn cyst nematode H. zeae in temperate regions. This study laid a theoretical foundation for the rapid spread and high environmental adaptability of corn cyst nematode. 展开更多
关键词 crop host resistance Heterodera zeae incubation fluid maize cyst nematode nematode development nematodehatching
下载PDF
Evaluation of the Reproduction Parameters of “Lohmann Brown” Strain Chickens Fed with Cajanus cajan Leaf Meal in the Republic of Congo
10
作者 Richard Missoko Mabeki Alexis Jonas Ognika +2 位作者 Dora Chérita Ekou Nathalie Myreille Ockoyi Parisse Akouango 《Open Journal of Animal Sciences》 2024年第3期234-248,共15页
The objective of this study was to evaluate the reproductive parameters of “Lohmann Brown” strain chickens fed on Cajanus cajan leaves and to assess the viability of the chicks after hatching. 40 hens of the “Lohma... The objective of this study was to evaluate the reproductive parameters of “Lohmann Brown” strain chickens fed on Cajanus cajan leaves and to assess the viability of the chicks after hatching. 40 hens of the “Lohmann Brown” strain fed on Cajanus cajan leaf flour laid 219 eggs divided into four batches depending on the rate of incorporation of Cajanus cajan leaf flour in the rations (0%, 5%, 10% and 15%) were trained and introduced into the incubator. Results: the incubator indicates a hatching temperature of 38˚C to 37.2˚C and relative humidity of 60% to 70%. Hatching performance shows that: The 15% batch recorded the highest fertility rate 86.95% compared to 26.88% of the control batch. The CC 15% batch recorded the highest hatching rate 36.87. The lowest rate (17.18%) was recorded in the control batch (CC 0%). The highest embryonic mortality rate was recorded in the CC 15% batch. The lowest rate in the CC 10% batch. Concerning unfertilized eggs, the highest rate is 72.20% (CC 0%), and the lowest are (12.03%;57.42% and 66.66%) recorded in CC batches. 15%, CC 5% and CC 10% respectively. For the shell mortality rate, the highest is 18.58% recorded in the CC 15% batch. The lowest shell mortality rate is 2.07%, obtained in the control batch (CC 0%);the dust mortality rate was 0% for all chicks. The study seems to indicate that the incorporation of Cajanus cajan leaf meal up to 15% into the reproduction type ration in hens does not cause any harmful effects on the reproduction performance of laying hens. 展开更多
关键词 EGG incubation HATCHING Fertility Mortality VIABILITY
下载PDF
Experimental Study of a Solar Thermal Incubator Using a Phase-Change Material for Off-Grid Use
11
作者 Yéouélé Thio Bati Ernest Boya Bi +1 位作者 Ekoun Paul Magloire Koffi Prosper Gbaha 《Open Journal of Applied Sciences》 2024年第9期2471-2481,共11页
The aim of this study was to provide a simple, easy-to-use incubation system for small-scale rural poultry farmers far from the electricity grid. To this end, a naturally ventilated solar thermal incubator was built a... The aim of this study was to provide a simple, easy-to-use incubation system for small-scale rural poultry farmers far from the electricity grid. To this end, a naturally ventilated solar thermal incubator was built and experimentally tested. A U-shaped evacuated tube collector and a wooden crate holding 50 eggs were used to build the solar thermal incubator. Water was used as the heat transfer fluid, and an EPCM was integrated into the incubation chamber for operation at night or when the sun was hidden. The heat generated by the solar collector and stored in the heat transfer fluid is transported to the incubation chamber by thermosiphon to heat the chamber. Temperature and humidity probes powered by a solar panel were placed at various locations to monitor the thermo-hygrometric efficiency of the incubation system. The incubator, heated by natural convection, proved to function normally, and the incubation chamber was maintained throughout the incubation period within a temperature range of 35.53˚C to 39.53˚C and relative humidity averaging 49.4% to 68.5%. The experiment was carried out by introducing 30 eggs and the results of the experimental study showed that the incubator’s efficiency was 87%. The performance tests gave a fertility rate of 93% and a hatching rate of 93%, i.e. 28 fertile eggs and 26 hatched eggs, respectively. 展开更多
关键词 Solar Incubator Vacuum Tube Collector Encapsulated PCM Poultry Eggs
下载PDF
Effect of Waterlogged and Aerobic Incubation on Enzyme Activities in Paddy Soil 被引量:13
12
作者 WANG Xiao-Chang LU Qin 《Pedosphere》 SCIE CAS CSCD 2006年第4期532-539,共8页
An incubation experiment with soil water content treatments of 0.15 (W1), 0.20 (W2), and 0.40 (W3) g g^-1 soil was carried out for two months to investigate the activities of important enzymes involved in C, N, ... An incubation experiment with soil water content treatments of 0.15 (W1), 0.20 (W2), and 0.40 (W3) g g^-1 soil was carried out for two months to investigate the activities of important enzymes involved in C, N, P, and S cycling in a paddy soil from the Taihu Lake region, China, under waterlogged and aerobic conditions. Compared with air-dried soil, waterlogging resulted in a significant decrease (P ≤ 0.05) of fluorescein diacetate (FDA) and /3-D-glucosidase activities, and this effect was enhanced with increasing waterlogging time. Waterlogging also significantly inhibited (P ≤ 0.05) arylsulfatase as well as alkaline and acid phosphatase activities, but did not decrease the activities with the increase in waterlogging time. Short-term waterlogging did not affect urease activity, but prolonged waterlogging decreased it markedly. In contrast, the aerobic incubation (W1 and W2 treatments) significantly increased (P ≤ 0.05) FDA, alkaline phosphatase, and /3-D-glucosidase activities. With aerobic treatments the activities of FDA and alkaline phosphatase increased with incubation time, whereas /3-D-glucosidase activity decreased. A significant difference (P ≤ 0.05) was usually observed between the W1 and W2 treatments for the activities of FDA as well as alkaline and acid phosphatase; however,/3-D-glucosidase and urease were usually not significant (P ≤ 0.05). No activity differences were observed between waterlogging and aerobic incubation for arylsulfatase and urease. 展开更多
关键词 aerobic incubation enzyme activity paddy soil WATERLOGGING
下载PDF
Formation mechanism of incubation layers in the initial stage of microcrystalline silicon growth by PECVD 被引量:8
13
作者 侯国付 薛俊明 +4 位作者 郭群超 孙建 赵颖 耿新华 李乙钢 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第2期553-557,共5页
The incubation layers in microcrystalline silicon films (μc-Si:H) are studied in detail. The incubation layers in μc- Si:H films are investigated by biracial Raman spectra, and the results indicate that either d... The incubation layers in microcrystalline silicon films (μc-Si:H) are studied in detail. The incubation layers in μc- Si:H films are investigated by biracial Raman spectra, and the results indicate that either decreasing silane concentration (SC) or increasing plasma power can reduce the thickness of incubation layer. The analysis of the in-situ diagnosis by plasma optical emission spectrum (OES) shows that the emission intensities of the SiH*(412 nm) and Hα (656 nm) lines are time-dependent, thus SiH*/Hα ratio is of temporal evolution. The variation of SiH*/Hα ratio can indicate the variation in relative concentration of precursor and atomic hydrogen in the plasma. And the atomic hydrogen plays a crucial role in the formation of μc-Si:H; thus, with the plasma excited, the temporal-evolution SiH*/Hα ratio has a great influence on the formation of an incubation layer in the initial growth stage. The fact that decreasing the SC or increasing the plasma power can decrease the SIH*/Hα ratio is used to explain why the thickness of incubation layer can reduce with decreasing the SC or increasing the plasma power. 展开更多
关键词 microcrystalline silicon incubation layer biracial Raman measurement optical emissionspectrum (OES)
下载PDF
Differences in Incubation Length and Hatchling Morphology among Five Species of Oviparous Phrynocephalus Lizards (Agamidae) from China 被引量:5
14
作者 Zheng WANG Li MA +1 位作者 Min SHAO Xiang JI 《Asian Herpetological Research》 SCIE 2013年第4期225-232,共8页
We incubated eggs of five Phrynocephalus species (P. albolineatus, P. axillaries, P. grumgrzimailoi, P. helioscopus and P. przewalskii) at three constant temperatures (24℃, 28℃ and 32℃) to examine differences i... We incubated eggs of five Phrynocephalus species (P. albolineatus, P. axillaries, P. grumgrzimailoi, P. helioscopus and P. przewalskii) at three constant temperatures (24℃, 28℃ and 32℃) to examine differences in incubation length and hatchling morphology among species and among temperature treatments. We combined data from this study with those reported previously for P. frontalis and P. versicolor to examine whether embryonic stage at laying is a causal factor for interspecific variation in incubation length, and whether the phylogenetic relationship inferred from hatchling morphology is consistent with the relationship based on mitochondrial DNA data. Mean values for incubation length differed among the five species studied herein and, in all these five species, incubation length decreased at a decreasing rate as temperature increased. In none of the five species did hatchling size (snout-vent length and body mass) and other morphological variables differ among the three temperature treatments. The seven oviparous Phrynocephalus lizards found in China differ from each other in hatchling morphology, and embryonic stage at laying is a causal factor of inter- and intra-specific variation in incubation length. The phylogenetic relationship inferred from hatchling morphology is not always consistent with the currently known relationship based on mitochondrial DNA data. Data from this study and those reported previously allow the conclusion that any Phrynocephalus species may have its unique position along the axis defined by hatchling morphology. 展开更多
关键词 AGAMIDAE Phrynocephalus lizards oviparous species egg incubation incubation length hatchling morphology
下载PDF
Effects of Constant versus Fluctuating Incubation Temperatures on Hatching Success, Incubation Length, and Hatchling Morphology in the Chinese Skink (Plestiodon chinensis) 被引量:5
15
作者 Wen SHEN Jianchi PEI +1 位作者 Longhui LIN Xiang JI 《Asian Herpetological Research》 SCIE CSCD 2017年第4期262-268,共7页
We incubated eggs ofPlestiodon chinensis under five constant (24, 26, 28, 30, and 32 ℃) and one fluctuating thermal regimes to examine the effects of constant versus fluctuating incubation temperatures on hatching ... We incubated eggs ofPlestiodon chinensis under five constant (24, 26, 28, 30, and 32 ℃) and one fluctuating thermal regimes to examine the effects of constant versus fluctuating incubation temperatures on hatching success, incubation length, and hatchling morphology. The duration of incubation varied considerably among the six temperature treatments, whereas hatching success did not. The mean incubation length decreased as temperature increased in a nonlinear way, and increased as the thermal variance increased. Incubation temperature affected the body size (linear length and mass) and shape of hatchlings, with eggs incubated at 26, 28, and 30 ℃ producing larger and heavier hatchlings than did those incubated at 24 ℃, 32 ℃, or fluctuating temperatures. Our results showed that exposure of P. chinensis eggs to extreme temperatures for brief periods of time did not increase embryonic mortality and, in the fluctuating-temperature treatment, the thermal variance affected hatchling morphology more evidently than the thermal mean. Our results highlight the importance of the thermal variance in affecting embryonic development and hatchling morphology, and add further evidence that temperatures within the range of 26-30 ℃ are optimal for P. chinensis embryos. 展开更多
关键词 Developmental plasticity egg incubation hatchling phenotype scincid lizard thermal variance thermal mean
下载PDF
Effects of Thermal and Hydric Conditions on Egg Incubation and Hatchling Phenotypes in Two Phrynocephalus Lizards 被引量:5
16
作者 Xiaolong TANG Feng YUE +3 位作者 Ming MA Ningbo WANG Jianzheng HE Qiang CHEN 《Asian Herpetological Research》 SCIE 2012年第3期184-191,共8页
Flexible-shelled eggs of the lizards Phrynocephalus przewalskii and P. versicolor were incubated under different thermal and hydric conditions to elicit the effects of incubation environment on hatching success, embry... Flexible-shelled eggs of the lizards Phrynocephalus przewalskii and P. versicolor were incubated under different thermal and hydric conditions to elicit the effects of incubation environment on hatching success, embryonic development and duration as well as hatchling phenotypes. Embryogenesis of the two species was not sensitive to changes in the hydric environment except P. przewalskii incubated in 30°C group. Temperature significantly altered the duration of embryogenesis, with cooler temperatures leading to a longer incubation period. Hatching success was greater at 26 and 30°C than at 34°C. The hatchlings incubated at 26 and 30°C had longer snout-vent length, larger body mass, and better locomotor performance than those incubated at 34°C. Compared to P. przewalskii, P. versicolor had a shorter incubation period and yielded smaller hatchlings, which then had a higher survival rate in cooler and drier habitats. We conclude that an incubation temperature of 30°C would produce the best balance among developmental rate, hatching success, and post-hatching performance. We speculate that the upper temperature limit for incubation of P. versicolor eggs may be slightly higher than 34°C. 展开更多
关键词 egg incubation hatchling phenotypes post-hatching performance Phrynocephalus przewalskii Phrynocephalus versicolor
下载PDF
Dynamic failure of dry and fully saturated limestone samples based on incubation time concept 被引量:5
17
作者 Yuri V. Petrov Ivan V. Smirnov +3 位作者 Grigory A. Volkov Andrei K. Abramian Anatoliy M. Bragov Stanislav N. Verichev 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2017年第1期125-134,共10页
This paper outlines the results of experimental study of the dynamic rock failure based on the comparison of dry and saturated limestone samples obtained during the dynamic compression and split tests. The tests were ... This paper outlines the results of experimental study of the dynamic rock failure based on the comparison of dry and saturated limestone samples obtained during the dynamic compression and split tests. The tests were performed using the Kolsky method and its modifications for dynamic splitting. The mechanical data(e.g. strength, time and energy characteristics) of this material at high strain rates are obtained. It is shown that these characteristics are sensitive to the strain rate. A unified interpretation of these rate effects, based on the structuraletemporal approach, is hereby presented. It is demonstrated that the temporal dependence of the dynamic compressive and split tensile strengths of dry and saturated limestone samples can be predicted by the incubation time criterion. Previously discovered possibilities to optimize(minimize) the energy input for the failure process is discussed in connection with industrial rock failure processes. It is shown that the optimal energy input value associated with critical load, which is required to initialize failure in the rock media, strongly depends on the incubation time and the impact duration. The optimal load shapes, which minimize the momentum for a single failure impact, are demonstrated. Through this investigation, a possible approach to reduce the specific energy required for rock cutting by means of high-frequency vibrations is also discussed. 展开更多
关键词 Dynamic strength incubation time criterion Split Hopkinson pressure bar(SHPB) test Tensile strength Compressive strength Water-saturated limestone Vibration-assisted rock cutting
下载PDF
Infectivity of Severe Acute Respiratory Syndrome during Its Incubation Period 被引量:2
18
作者 GUANG ZENG SHU-YUN XIE +1 位作者 QIN LI JIAN-MING OU 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2009年第6期502-510,共9页
Objective To evaluate the infectivity of severe acute respiratory syndrome (SARS) during its incubation period by investigating chains of transmission and individuals isolated for medical observation with a view to ... Objective To evaluate the infectivity of severe acute respiratory syndrome (SARS) during its incubation period by investigating chains of transmission and individuals isolated for medical observation with a view to providing scientific evidence for updating protocols of medical isolation. Methods Individuals related with the two SARS chains of transmission in Beijing in 2003 and a group of individuals isolated for medical observation in Haidian district of Beijing during the SARS outbreak were selected as subjects of study. Contactors with SARS patients and those with symptom development following the contacts were investigated via questionnaire. Serum samples were collected from super transmitters and tested for SARS-CoV antibody by neutralization test and enzyme linked immunosorbent assay (ELISA). Results A total of 1 112 contactors were investigated in three surveys. Of them, 669 had a history of close contact with symptomatic SARS patients, 101 developed symptoms with a rate of 15.1%, 363 had a history of close contact with patients in their incubation period, none of whom developed symptoms (0%). Serum samples were collected fi'om 32 highly-exposed individuals, of whom 13 developing SARS symptoms atter contact had serum samples positive for SARS-CoV antibody. Samples collected from the asymptomatic contactors were all negative for SARS-CoV antibody. Conclusion SARS cases are infectious only during their symptomatic period and are non-infectious during the incubation period. Isolation for medical observation should be placed for individuals who are in close contact with symptomatic SARS patients. The results of our study are of decisive significance for the Ministry of Health to the definition of SARS close contactor. 展开更多
关键词 Severe acute respiratory syndrome Chain of transmission incubation period Symptomatic period Infectivity
下载PDF
EffectS of sequence of nylon bags rumen incubation on kinetics of degradation in some commonly used feedstuffs in dairy rations 被引量:2
19
作者 DONG Shuang-zhao Arash Azarfar +3 位作者 ZOU Yang LI Sheng-li WANG Ya-jing CAO Zhi-jun 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2017年第1期162-168,共7页
Nowadays, most available information on the degradative behaviour of feeds in ruminants is based on in situ incubation in the rumen, and it is adopted by many feed evaluation systems currently in use for ruminants. Ho... Nowadays, most available information on the degradative behaviour of feeds in ruminants is based on in situ incubation in the rumen, and it is adopted by many feed evaluation systems currently in use for ruminants. However, the outcome of.this technique might be affected by many factors such as sequence of nylon bags incubation in the rumen. The objective of current study was to investigate effects of sequence of nylon bag incubation on degradative behavior of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) in some feed ingredients commonly used in dairy rations, including alfalfa haylage, corn silage, corn grain and soybean meal. Four multiparous Holstein lactating cows fitted with permanent ruminal cannulas were used. The nylon bags containing feed samples either were placed in the rumen at once and removed at designated time intervals (all in-gradually out method; AG) or were placed in the rumen at designated time points and retrieved at once (gradually in-all out method; GA). Fractional rate of degradation of potentially degradable fraction, lag time and effective rumen degradability (ED) of DM and CP were significantly higher in the AG compared to the GA method (P〈0.05). Fractional rates of DM and CP degradation was higher in alfalfa haylage samples incubated in the rumen using the AG method compared to that using the GA method (0.138 h-1 vs. 0.073 h-1 and 0.002 h-1 vs. 0.1125 h-1, for DM and CP, respectively; P〈0.05). Due to a higher fractional rate of degradation (Kd) of DM and CP, the ED of DM and CP at different fractional passage rates were higher in the AG than those in the GA method (P〈0.05). Potentially degradable fraction and lag time of NDF were higher in the AG method compared to the GA method (P〈0.05). Placing all bags in the rumen at once and removing them at designated time intervals compared with introduction of bags in reverse sequence and removing them all at once led to a lower undegradable fraction (U) of NDF in alfalfa (1.8% vs. 4.0%, respectively; P〈0.05) and corn silage (3.3% vs. 6.7%, respectively; P〈0.05) samples. Potentially degradable fraction of ADF was significantly higher in the AG method compared with the GA method (P〈0.05). Bag incubation sequence had profound effects on kinetics of degradation of DM, CP and NDF in situ in the feed samples studied. The effects were more evident in the forages (especially alfalfa haylage) than in the concentrate ingredientsnamely corn grain and soybean meal..This experiment is the first time to investigate effects of two methods under the same experiment conditions, providing basic data for the determination of ED. 展开更多
关键词 in situ technique sequence of bag incubation FEEDSTUFFS degradative behavior
下载PDF
Sexual Dimorphism, Female Reproductive Characteristics and Egg Incubation in an Oviparous Forest Skink(Sphenomorphus incognitus) from South China 被引量:2
20
作者 Li MA Jianchi PEI +3 位作者 Cuntong ZHOU Yu DU Xiang JI Wen SHEN 《Asian Herpetological Research》 SCIE CSCD 2018年第2期119-128,共10页
We studied sexual dimorphism and female reproduction in an oviparous forest skink (Sphenomorphus incognitus) from South China. We incubated eggs under five thermal regimes (22, 25, 28, 25 ± 3 and 27± 5℃... We studied sexual dimorphism and female reproduction in an oviparous forest skink (Sphenomorphus incognitus) from South China. We incubated eggs under five thermal regimes (22, 25, 28, 25 ± 3 and 27± 5℃) to examine the effects of constant versus fluctuating temperatures on incubation length and hatchling morphology. In our sample the largest male and female were 110 mm and 108 mm snout-vent length (SVL), respectively. Adult males and females did not differ in mean SVL; adult males were larger in head size (both length and width), longer in fore- and hind-limb lengths and shorter in abdomen length than females of the same SVL. Accordingly, we conclude that S. incognitus is a sexually monomorphic species in terms of SVL but shows sexual dimorphism in head size, abdomen length and appendage length. Females laid a single clutch of 3-10 eggs per breeding season from early May to mid- August, with larger females generally laying more (but not always larger) eggs per clutch than did smaller ones. Embryonic stages at laying ranged from Dufaure and Hubert's (1961) stage 31 to 32, with a mean stage of 31.3. The positive relationship between clutch mass and female SVL was not significant. The offspring size-number trade-off does not exist in S, incognitus, as revealed by the fact that egg mass was independent of relative fecundity. Incubation length decreased as temperature increased, and stable temperatures resulted in delayed hatching. Hatchlings incubated under the five thermal regimes did not differ from each other in any examined trait, suggesting that S. incognitus is among oviparous reptilian species where incubation temperature has no role in modifying hatchling morphology as long as eggs are not exposed to extreme temperatures for prolonged periods of time. 展开更多
关键词 EGG hatchling morphology incubation length REPRODUCTION SCINCIDAE sexual dimorphism
下载PDF
上一页 1 2 12 下一页 到第
使用帮助 返回顶部