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1.
《中国科学院院刊(英文版)》2017,(2)
<正>Cyclophilin A(CypA,encoded by PPIA)is a peptidyl-prolyl cis/trans isomerase(PPIase)that is expressed ubiquitously in all type of cells.CypA is the major cellular target for the immunosuppressive drug cyclosporin A(CsA)and is involved in protein folding,cell signaling,inflammation,and tumorigenesis.Recent work suggests that it also 相似文献
2.
《国家科学评论(英文版)》2014,(4)
<正>CHEMISTRY A novel zirconium catalyst for ethylene(co)polymerization Polyethylene(PE)is the most widely used plastic.Its ingredient(monomer)is ethylene-a rather stable molecule that polymerizes only upon contact with catalysts.Considerable atention has been paid to develop new catalysts for optimizing polymerization activity.Resent 相似文献
3.
《中国科学院研究生院学报》1988,(2)
Vitamin D_2 and vitamin D_3 give a clear polarographic oxidation-wave,respectively,by neopolarography,with a 0.25M solution oflithium perehlorate in ethanol-dimethylformamide(1:1)as the supportingelectrolyte.Peak potentials are both+1.27V(vs.pure Ag plate).Thewave-height is proportional to the concentration in the range from 2.6×10~(-6)M(1μg/ml)to 1.1×10~(-3)M(420μg/ml)for vitamin D_3 and from2.5×10~(-6)M(1μg/ml)to 1.1×10~(-3)M(435μg/ml)for vitamin D_2,respe-ctively.The detection limits are both 1.3×10~(-6)M(0.5μg/ml).Themethod can be satisfactorily applied to the determination of vitamin D_3in injcction.Through various experiments,it is shown that the electrodeprocess of vitamin D at glassy carbon electrode is an irreversible oxida-tion process controlled by diffusion.The value of an is 0.84(α is thetransfer coefficient and n is the number of cleclron in the kineticprocess).n=2.The electrode reaction mechanism has been inferred.Besides,the choices of base solution and of experiment conditions aswell as the stability of vitamin D etc.are also discussed. 相似文献
4.
《中国科学院院刊(英文版)》2014,(3):248-248
<正>Tuberculosis(TB)is a chronic respiratory disease caused by Mycobacterium tuberculosis and is a serious threat to human health.Every year there are 1.3 million new cases of TB worldwide,100,000 of which are multidrug resistant.The TB burden in China is the second highest in the world.The widespread occurrence of multidrug(MDR)and extensively drug-resistant(XDR)tuberculosis is making the treatment of TB more and more problematic.Research on the mechanisms underlying drug resistance,one of the most important,diffi cult and competitive areas of TB research worldwide,has been carried out in the labs of Professors BI Lijun and ZHANG Xian’en at the Institute of Biophysics,CAS.On September 1st,2013,Nature Genetics 相似文献
5.
中国-喜玛拉雅特有属——蓝钟花属的分类修订 总被引:2,自引:0,他引:2
Krishna K. Shrestha 《中国科学院研究生院学报》1997,35(5):396-433
Cyananthus Wallich ex Bentham, the only genus of Campanulaceae with superior ovary, is revised to clarify infrageneric relationships and phylogeny of the genus. Evidence obtained from the comparative gross morphology, anatomy, palynology, and karyomorphology recommends a new infrageneric classification of the genus, recognizing 23 species, belonging to two subgenera, four sections and four subsections. One subgenus(Subgen. Micranthus), one section(Sect. Suffruticulosi) and two subsections(Subsect. Flavi and Subsect. Lichiangenses)are described as new taxa. New combinations at sectional(Sect. Annui) and subsectional(Subsect. Stenolobi) ranks are also proposed. The genus Cyananthus is strictly distributed in the high mountains of China(Xizang, Yunnan and Sichuan), extending to Bhutan, Nepal and India(Kumaon-Garhwal, Assam and Sikkim), with altitudinal ranges from 2500~5300 m. It is observed that 13 species are endemic to SW China and only three species are endemic to the Himalayas(two species in Nepal and one to NW India). It is evident that Cyananthus is one of the most primitive genera of Campanulaceae and within the genus, subgenus Cyananthus(Sect. Stenolobi) is more primitive than the subgenus Micranthus. It is also suggested that SW China(most probably Yunnan) is the center of origin of Cyananthus, considering the occurrence of as many as 20 species of Cyananthus, representing several primitive taxa and many endemic species. 相似文献
6.
《中国科学院院刊(英文版)》2017,(1)
<正>Global warming is driven by the Earth’s energy imbalance(EEI):our planet traps more and more heat due to continuous increasing greenhouse gases.From the energy perspective,the global warming is actually ocean warming,since ocean stores more than 90%of the trapped heat.Therefore,ocean heat content(OHC)change is a fundamental indicator of global warming,and direct measurement of OHC will provide a direct evidence for climate change. 相似文献
7.
<正>Land areas on our planet are facing unprecedented levels of stress.More than70%of the global ice-free land has been affected by human activities,30%of the land is threatened by degradation,biodiversity and other ecosystem services(ESs) are declining,and climate change is altering ecosystem functioning [1].Currently,agriculture is the dominant form of land use,with grazing land comprising27%and cropland 12%(and more than half of the cropland is used to produce animal feed).Agriculture is... 相似文献
8.
Chris D.Jones 《国家科学评论(英文版)》2023,(12):47-48
<正>The basics are clear:climate is changing,it is caused by human activity and it is affecting everyone and everywhere now[1]. The good news is that we know what to do about it—we can stop global temperatures rising further if we stop emitting greenhouse gases. But because some sectors (such as agriculture or aviation)will have ongoing ‘hard-to-abate’ emissions, 相似文献
9.
10.
<正>A current bleeding CMOS mixer with complementary transconductance stage is presented in this paper.The conversion gain of the mixer is increased and the flick noise of the mixer is reduced by inserting the PMOS to form current bleeding circuit in Gilbert mixer.The circuit is designed through SMIC 0.18um CMOS process,the LO frequency is 1.571GHz,RF frequency is 1.575GHz,simulation results show the conversion gain of the mixer is 18.5 dB,SSB NF is about 9.59dB,and third-order input intercept point(IIP3) is-4.6dBm.The mixer consumes 7.8 mA at 1.8 V power supply and the size of the whole layout is 0.73mm×0.68 mm. 相似文献
11.
Deep carbon cycling during subduction revealed by coexisting diamond-methane-magnesite in peridotite
Xiaoxia Wang Yilin Xiao Hans-Peter Schertl Nikolay V.Sobolev Yang-Yang Wang He Sun Deshi Jin Dong-Bo Tan 《国家科学评论(英文版)》2023,(10):15-17
<正>Subduction is an important process for transferring materials from the surface into the deep mantle.During subduction,recycled carbon can be released from the subducting slab to the mantle wedge through various decarbonation processes.Both oxidized(CO2/CO32-) and reduced(CH4) carbon-bearing species have been discovered in(ultra)high-pressure(HP-UHP) subduction zones worldwide [1-3].Diamond is a typical index mineral for UHP metamorphism. 相似文献
12.
From standpoint of floristic division, Sichuan is located in the middle part
of Eastern Asiatic Region (Takhtajan 1978) or is the area where Sino-Himalayan Forest
Subkingdom and Sino-Japan Forest Subkingdom meet (wu 1979). Here exist many so-
called Arcto-Tertiary elements and newly originated species or races. In order to bring
the light the origin and differentiation of Eastern Asiatic elements, cytological investi-
gation on plants of this region are very significant. The materials of the following 5
species were collected on Mt. Emei in Sichuan Province. Voucher specimens are kept in CDBI.
1. Toricellia angulata Oliver var. intermedia (Harms) Hu
PMC meiotic examination revealed n = 12 at diakinesis (Pl. I fig. 9)
Toricellia, consisting of 2 spp., is endemic to Eastern Asiatic Region. Based on
our result along with the report of Toricellia tiliifolia (Wall.) DC. (2n=24) by Kuro-
sawa (1977), we argue that the basic chromosome number of Toricellia is 12. Many
authors, such as Airy-Shaw (1973), Dahlgren (1975, 1977), Takhtajan (1969, 1980),
Thorne (1983), have adopted Hu’s (1934) treatment erecting it as a monotypic family
Toricelliaceae. Its systematic position, whether closer to Cornaceae than to Araliaceae
or vice versa, has been in dispute. Cytologically it seems closer to Araliaceae, as shown
anatomically (Lodriguez 1971), because the basic chromosome number of Cornaceae s.
1. is x=11, 9, 8 (Kurosawa 1977), whereas that of Araliaceae is 12 (Raven 1975).
2. Cardiocrinum giganteum (Wall.) Makino
Somatic chromosome number, 2n=24 was determined from root-tip cells (Ph. I. fig.
8).
Cardiocrinum (Endl.) Lindl., consisting of 3 spp., is endemic to Eastern Asiatic
Region. C. giganteum (Wall.) Makino is distributed from Himalayan region to S. W.
China. The present report is in accord with the number reported by Kurosawa (1966)
who got the material from Darjeeling of India. However the karyotype of the present
plant is slightly different from that given by Kurosawa. In the present material, the
satellites of the 1st. pair of chromosomes and the short arms of llst. pair of chromoso-
mes are visibly longer than those of Kurosawa’s drawing (fig. 1, 2) The plants from
Yunnan, Sichuan and Hubei Provinces, named as C. giganteum var. yunnanense (Leit-
chtlin ex Elwes) Stearn, differ slightly from those of Himalayan region also in outer
morphological characters. The taxon needs both cytological and taxonomical further
studies.
3. Disporum cantoniense (Lour.) Merr.
PMC meiotic examination revealed n=8 at diakinesis (Pl. I. fig. 6)
This species is widely distributed from Himalayan region through Indo-China to
our Taiwan Province and Indonesia. Three cytotypes (2n=14, 16, 30) were reported for
the taxon including its variety, var. parviflorum (Wall) Hara, by various authors (Ha-
segawa 1932, Mehra and Pathamia 1960, Kurosawa 1966, 1971 Mehra and Sachdeva
1976a). Some authors consider D. pullum Salisb. and D. calcaratum D. Don as synonyms
of D. cantoniense. So D. cantoniense may be a species aggregate with different extreme
races. Sen (1973a, b.) reports that the somatic chromosome numbers of D. pullum
and D. calcaratum from Eastern Himalayan region are 14, 16, 28, 30, 32. He also
discovered that chromosome alterations in species of Disporum involve not only the num-
ber but the structure as well. He found that in species of Liliaceae where the reproduc-
tion is mainly vegetative, polysomaty often occurs. In China we have not only D. can-
toniense and D. calcaratum but also D. brachystomon Wang et Tang which is similar
to D. cantoniense var. parviflorum (Wall.) Hara. These taxa need further critical
studies.
4. Paris fargesii Franch.
PMC meiotic examination revealed n=5+2B (Voucher no. 112) or n=5 (Voucher
no. 62) at MI and AI (Pl. I. fig. 1. 4. 5.). This is the first report for the species. A
bridge and a fragment were also observed at AI.
Paris polyphylla Smith is extraordinarily polymorphic species. Hara (1969) re-
gards all chinese extreme forms, such as P. fargesii Franch., P. violacea Lévl., P. pube-
scens (Hand. -Mzt.) Wang et Tang, etc. as infraspecific taxa of P. polyphylla. Need-
less to say, the various races of P. polyphylla Smith in China need further critical stu-
dies and are good material for further study to understand the speciation.
5. Reineckia carnea(Andr.) Kunth
Reineckia is a monotypic genus endemic to Eastern Asiatic Region. In the present
material somatic chromosome number in root-tip cells is determined as 2n=38 (Pl. I. fig.
7). According to the terminology defined by Levan et al., the karyotype formula is
2n=28 m+10 sm. The length of chromosomes varies from 14.28 μ to 5.5 μ. The idiogram
given here (fig. 3) is nearly the same as that presented by Hsu et Li (1984). The same
number has been previously reported by several authors, Noguchi (1936), Satô (1942),
Therman (1956). The karyotype is relatively symmetrical (2B, accorling to the classi-fication of stebbins 1971) in accord with the opinion of Therman (1956). 相似文献
13.
Qixuan Wang Xueling Wang Tao Yang Lu Yang Huihui Liu Yihang Zheng Guixian Jiang Hongchao Liu Chenhui Huang Juan Chen Zhentao Wang Zhaoyan Wang Wei Zhao Jiannan Lin Xuejie Zhang Junbo Shi Kun Han Xingyu Le Yan Ren Yun Li Yingying Hong Wentao Shi Dongqi Cui Minfei Qian Jun Xu Xiaofei Zheng Yunge Gao Chen Li James Lin Zhiwu Huang Hao Wu 《国家科学评论(英文版)》2023,(7):77-80
<正>Noise-induced hearing loss (NIHL) is one of the most common types of hearing loss and contributes to significant morbidity worldwide,as well as being the major cause of age-related hearing loss and tinnitus.The World Health Organization (WHO) estimates that 10%of the world’s population is exposed to sound levels that could potentially cause NIHL[1].It has been widely accepted that NIHL is a multifactorial genetic disorder with estimated heritability of 36%to 40%[2].Ideally,identificatio... 相似文献
14.
15.
《国家科学评论(英文版)》2015,(2)
<正>Astrophysical and cosmological observations show that about 27%of the energy in our universe comes from dark mater(DM).What is DM is an outstanding puzzle in science in the 21st century.he weakly interacting massive particles(WIMPs)have been by far the favored candidate for DM,although they cannot be accommodated in the standard 相似文献
16.
《中国科学院院刊(英文版)》2017,(2)
<正>Rubber(Hevea brasiliensis)is one of the most rapidly expanding cash crops in tropical Asia especially Xishuangbanna.Conserving tropical forest largely depends on the effective management of human-modified landscapes.It is crucial to identify measures to improve biodiversity outcomes in rubberforest mosaics for tropical fauna. 相似文献
17.
《中国科学院院刊(英文版)》2014,(1):27-29
<正>1.Human-cyber-physical ternary computing——a paradigm shift to computing for the masses Over the past five decades,the development of information technology(IT)has mainly focused on highperformance,general purpose and large-scale production,while affordability,usability,reliability,security and customization have not received enough attention.Future information products and services should meet the personalized demand of billions of individual users[1].This trend is called Computing for the masses(or e-People).Traditional computing is dominated by institutional computing in the cyberspace,providing IT value(IT hardware,software,and services)to companies(e-Business),research institutions(e-Science),and government agencies(e-Government).Computing for the masses is different in two aspects:it provides business value to the billions 相似文献
18.
Karel Schulmann Jean Bernard Edel Ondrej Lexa Wenjiao Xiao D.T■ebínová Richard Spikings Urs Schaltegger Arkadiusz Derkowski Marek Szczerba 《国家科学评论(英文版)》2023,(2):9-11
<正>The Central Asian Orogenic Belt constitutes the Kazakhstan and Mongolian oroclinal collages located between the Tarim-North China collage(TNC)to the south and the Siberian craton to the north(Fig.1a) [1].While the oroclinal bending of the western Kazakhstan collage is widely accepted by the paleomagnetic and tectonic community,the oroclinal bending model of the eastern Mongolian collage is disputed[2,3].Despite differences, 相似文献
19.
Restoration forestry (forest rehabilitation) or re-vegetation is one effective measure to solve environmental problems, notably soil erosion. It may be further stimulated by the Clean Development Mechanism for carbon sequestration. However, there is an intensive and on-going debate about the adverse effects arising from afforestation in dryland areas, such as soil drying up which may cause further damage to the success of forest restoration, and the water yield reduction from watershed which may harm the regional development. On other hand, some preliminary studies showed a possibility that these adverse effects may be diminished more or less by properly designing the system structure and spatial distribution of forest/vegetation in a watershed. However, it is urgent to develop an evidence-based and sustainable new forestry policy for harmonizing forest-water interrelation. As a leading country in afforestation, China is beginning to develop a more trans-disciplinary and cross-sectoral forestry policy for harmonizing forestry development with water management. The main points of the changing new forestry policy should include: (1) Establishing a regional development strategy focusing on harmonized forest-water relations; (2) Taking forest-water interactions as an important part of evaluation; (3) Reducing the ’eco-water’ quota of forests through technical advancement; (4) Developing and extending water-adaptive forest management practices; (5) Strengthening forest ecohydrological research and decision support ability. 相似文献
20.
The reproductive feature of the nemalionalean genus Liagora is characterized by
the laterally situated carpogonial branch which is produced by the ordinarily assi-
milative filament. A study of L. farinosa Lamx. has revealed that the carpogonial
branches of this species are not borne on the ordinarily assimilative filaments but
restricted to a kind of short filaments (referring to as “fertile filaments” in the
present article) which are, in turn, initiated by the basal cells of the assimilative
filaments. The carpogonial branches are modified furcations of the fertile filaments.
The fertile filaments may, however, grow and send out assimilative filaments concur-
rently with the maturation of the carpogonial branches. Therefore, the origin of the
carpogonial branches is best shown in their younger developing stages but more or
less obscure in age.
Boergesen, who examined Lamouroux's type, made a detailed study of L. farinosa
from the Canary Islands. The depictions given by Boergesen, Yamada (1938, f. 15),
Tseng (1941, f. 6) and Umezaki (1961, f. lA) concisely illustrated the feature of the
fertile filaments in this species, although all these workers had not envisaged the
taxonomical significance of the peculiar position of the female organs. In our opin-
ion, the differentiation of cortical filaments into assimilative and reproductive as seen
in L. farinosa (even though in a preliminary stage) suggests that the progressive
evolutionary changes have occurred in this species. The unique situation of L. fari-
nosa is, in fact, no parallel in any genus of the, family where female organs are
directly produced (or transformed) by the assimilative filaments.
It thus appears there is no justification for retaining L. farinosa in the genus
Liagora. A new genus, Ganonema Fan et Wang gen. nov. is therefore proposedfor accommodating the species, G. farinosa (Lamx.) Fan et Wang comb. nov. 相似文献